Infrared transmitting-receiving circuit and device

Abstract

The application provides an infrared transmitting and receiving circuit and device, and relates to the field of infrared transmitting and receiving.The circuit comprises a signal processor, an infrared transmitting sub-circuit and an infrared receiving sub-circuit, the infrared transmitting sub-circuit comprises a signal level flip unit, a carrier wave synthesis unit, a signal driving amplification unit and a transmitting unit which are connected in series, one end of a TXD signal transmitted by the signal processor is connected with the input end of the signal level flip unit, and one end of a 38K square wave signal transmitted by the signal processor is connected with the input end of the carrier wave synthesis unit; the infrared receiving sub-circuit comprises a signal receiving control unit and an infrared receiving unit, one end of an RXD signal received by the signal processor is connected with the output end of the signal receiving control unit, and the input end of the signal receiving control unit is connected with the infrared receiving unit.The circuit topology structure is optimized, and the circuit structure of the infrared transmitting and receiving circuit can be effectively simplified.

Description

Technical Field

[0001] The present invention relates to the field of infrared transmission and reception, and in particular to an infrared transmission and reception circuit and device. Background Art

[0002] Infrared transmitter / receiver circuits are widely used in household appliances and industrial control systems. These circuits sense certain substances to switch the circuit on or off. Existing infrared transmitter / receiver circuits come in a wide variety of designs, but most are complex in structure and functionality. They often rely on driver circuits with complex circuit structures to perform infrared transmission and reception. This increases costs and, with increased circuit complexity, increases potential instability, which inadvertently reduces product yield. Furthermore, in devices such as electricity meter readers that require infrared transmitter / receiver circuits, the infrared receiver tubes used in existing infrared transmitter / receiver circuits are at least 9.94 mm tall, hindering the pursuit of thinner overall thickness. Therefore, there is an urgent need to optimize the structure of existing infrared transmitter / receiver circuits to facilitate miniaturization of infrared receiver tubes. Summary of the Invention

[0003] In order to overcome the above problems or at least partially solve the above problems, an embodiment of the present invention provides an infrared transmitting and receiving circuit and device, which can effectively simplify the circuit structure of the infrared transmitting and receiving circuit by optimizing the circuit topology structure, thereby effectively reducing the complexity of the circuit without affecting the working performance of the circuit, thereby further miniaturizing the circuit and improving its portability.

[0004] The embodiment of the present invention is achieved as follows:

[0005] In the first aspect, an embodiment of the present application provides an infrared transmitting and receiving circuit, which includes a signal processor; an infrared transmitting subcircuit, the infrared transmitting subcircuit includes a signal level flipping unit, a carrier synthesis unit, a signal driving amplifying unit and a transmitting unit, the end of the signal processor that sends the TXD signal is connected to the input end of the carrier synthesis unit through the signal level flipping unit, the end of the signal processor that sends the 38K square wave signal is connected to the input end of the carrier synthesis unit, and the output end of the carrier synthesis unit is connected to the transmitting unit after passing through the signal driving amplifying unit; an infrared receiving subcircuit, the infrared receiving subcircuit includes a signal receiving control unit and an infrared receiving unit, the end of the signal processor that receives the RXD signal is connected to the output end of the signal receiving control unit, and the input end of the signal receiving control unit is connected to the infrared receiving unit.

[0006] Based on the first aspect, in some embodiments of the present invention, the above-mentioned signal level flipping unit includes an inverter U3F, the above-mentioned carrier synthesis unit includes a logic chip U1, a resistor R1 and a resistor R2, the above-mentioned signal drive amplification unit includes a resistor R3 and a transistor Q1, and the above-mentioned transmitting unit includes a light-emitting diode LED1 and a resistor R4. The input end of the inverter U3F is connected to the end of the signal processor that sends the TXD signal, the output end of the inverter U3F is connected to pin A of the logic chip U1, pin B of the logic chip U1 is grounded through the resistor R1, pin B of the logic chip U1 is also connected to the end of the signal processor that sends the 38K square wave signal, pin VCC of the logic chip U1 is connected to the external power supply 3.3V, pin C of the logic chip U1 is connected to the external power supply 3.3V through the resistor R2, pin C of the logic chip U1 is also connected to the base of the transistor Q1 through the resistor R3, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the cathode of the light-emitting diode LED1, and the anode of the light-emitting diode LED1 is connected to the external power supply 3.3V through the resistor R4.

[0007] In some embodiments of the present invention, the inverter U3F is a 74HC14.

[0008] In some embodiments of the present invention, the model of the logic chip U1 is SN74HC1G08.

[0009] In some embodiments of the present invention, the signal receiving control unit includes a logic chip U4A, and the infrared receiving unit includes an infrared receiving head U2 and a capacitor C1. Pin VCC of the infrared receiving head U2 is connected to an external 3.3V power supply, and pin VCC of the infrared receiving head U2 is also grounded via capacitor C1. Pin OUT of the infrared receiving head U2 is connected to an input of the logic chip U4A, and an output of the logic chip U4A is connected to a terminal of the signal processor that receives an RXD signal. The communication enable terminal of the logic chip U4A is connected to the signal processor.

[0010] In some embodiments of the present invention, the model of the logic chip U4A is 74HC125.

[0011] In some embodiments of the present invention, the model of the infrared receiving head U2 is TSOP34138.

[0012] In a second aspect, an embodiment of the present application provides an infrared transmitting and receiving device, which includes a housing and a circuit board provided with any one of the infrared transmitting and receiving circuits in the first aspect, wherein the circuit board is arranged in the housing.

[0013] Based on the second aspect, in some embodiments of the present invention, a connection structure electrically connected to the circuit board is provided on the outer wall of the housing, and the connection structure is used to electrically connect to a mainboard of an external meter reader.

[0014] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0015] First, an embodiment of the present invention provides an infrared transmitting and receiving circuit. In the infrared transmitting portion of the circuit, a signal processor flips the level of a TXD signal to be transmitted through a level flipping unit, and then the signal is passed to a carrier synthesizer unit, where it is modulated with a 38K square wave signal provided by the signal processor. Specifically, the carrier synthesizer unit superimposes the 38K square wave signal onto the flipped TXD signal. The output signal of the carrier synthesizer unit is then amplified by a signal drive amplifier unit, and then converted into an infrared signal by a transmitting unit for transmission. In the infrared receiving portion of the circuit, the infrared receiving unit demodulates the received infrared signal and outputs it to a signal receiving control unit for control processing. This controls whether the received infrared signal can be transmitted to the signal processor through the signal receiving control unit, thereby preventing unwanted signals from entering the signal processor. Only when data transmission is required does the signal receiving control unit open the corresponding signal transmission channel, allowing communication data (the demodulated received infrared signal) to be transmitted to the processor end (signal processor).

[0016] That is, by optimizing the circuit topology, the circuit structure of the infrared transmitting and receiving circuit can be effectively simplified, which makes it possible to effectively reduce the complexity of the circuit without affecting the working performance of the circuit, thereby further miniaturizing the circuit and improving its portability.

[0017] Secondly, an embodiment of the present invention provides an infrared transmitting and receiving device, which is made into an infrared transmitting and receiving device by encapsulating a circuit board provided with an infrared transmitting and receiving circuit into a housing, and can be conveniently and quickly used by users. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is a structural diagram of the infrared generating portion of an infrared transmitting and receiving circuit according to an embodiment of the present invention;

[0020] Figure 2Structure diagram of an infrared receiving part of an infrared transmitting and receiving circuit according to an embodiment of the present application;

[0021] Figure 3 Circuit diagram of an infrared transmitting sub-circuit of an infrared transmitting and receiving circuit according to an embodiment of the present application;

[0022] Figure 4 Circuit diagram of an infrared receiving sub-circuit of an infrared transmitting and receiving circuit according to an embodiment of the present application.

[0023] Figure: 1, signal processor; 2, infrared transmitting sub-circuit; 21, signal level flip unit; 22, carrier wave synthesis unit; 23, signal drive amplification unit; 24, transmitting unit; 3, infrared receiving sub-circuit; 31, signal receiving control unit; 32, infrared receiving unit. DETAILED DESCRIPTION

[0024] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0026] EMBODIMENTS

[0027] Some embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the case of no conflict, each of the following embodiments and each feature in the embodiments can be combined with each other.

[0028] Please refer to Figure 1-2An embodiment of the present invention provides an infrared transmitting and receiving circuit, which includes a signal processor 1, an infrared transmitting subcircuit 2, and an infrared receiving subcircuit 3. The infrared transmitting subcircuit 2 includes a signal level inversion unit 21, a carrier synthesis unit 22, a signal driving and amplifying unit 23, and a transmitting unit 24. The end of the signal processor 1 that transmits the TXD signal is connected to the input end of the carrier synthesis unit 22 through the signal level inversion unit 21. The end of the signal processor 1 that transmits the 38K square wave signal is connected to the input end of the carrier synthesis unit 22. The output end of the carrier synthesis unit 22 is connected to the transmitting unit 24 after passing through the signal driving and amplifying unit 23. The infrared receiving subcircuit 3 includes a signal receiving control unit 31 and an infrared receiving unit 32. The end of the signal processor 1 that receives the RXD signal is connected to the output end of the signal receiving control unit 31, and the input end of the signal receiving control unit 31 is connected to the infrared receiving unit 32.

[0029] In the above embodiment, for the infrared transmission portion of the circuit, signal processor 1 flips the level of the TXD signal to be transmitted through the level flipping unit. The signal then passes to carrier synthesis unit 22, where it is modulated with the 38K square wave signal provided by signal processor 1. In other words, carrier synthesis unit 22 superimposes the 38K square wave signal onto the flipped TXD signal. The output signal of carrier synthesis unit 22 is then amplified by signal driver amplifier unit 23, before being converted into an infrared signal by transmission unit 24 and transmitted.

[0030] For the infrared receiving part of the circuit, the infrared receiving unit 32 demodulates the received infrared signal and outputs it to the signal receiving control unit 31 for control processing, thereby controlling whether the received infrared signal can be transmitted to the signal processor 1 through the signal receiving control unit 31, thereby avoiding some unnecessary signals from entering the signal processor 1. Only when data needs to be transmitted, the signal receiving control unit 31 opens the corresponding signal transmission channel, and the communication data (the demodulated received infrared signal) can be transmitted to the processor end (signal processor 1).

[0031] That is to say, the technical solution provided by the above embodiment can effectively simplify the circuit structure of the infrared sending and receiving circuit by optimizing the circuit topology structure, so as to effectively reduce the complexity of the circuit without affecting the working performance of the circuit, thereby further miniaturizing the circuit and improving its portability.

[0032] Please refer to Figure 3In some embodiments of the present application, the signal level inversion unit 21 comprises an inverter U3F, the carrier wave synthesis unit 22 comprises a logic chip U1, a resistor R1 and a resistor R2, the signal drive amplification unit 23 comprises a resistor R3 and a transistor Q1, and the transmitting unit 24 comprises a light emitting diode LED1 and a resistor R4. The input end of the inverter U3F is connected to one end of the TXD signal transmitted by the signal processor 1, the output end of the inverter U3F is connected to the pin A of the logic chip U1, the pin B of the logic chip U1 is grounded through the resistor R1, the pin B of the logic chip U1 is also connected to one end of the 38K square wave signal transmitted by the signal processor 1, the pin VCC of the logic chip U1 is connected to an external power supply 3.3V, the pin C of the logic chip U1 is connected to the external power supply 3.3V through the resistor R2, the pin C of the logic chip U1 is also connected to the base of the transistor Q1 through the resistor R3, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the cathode of the light emitting diode LED1, and the anode of the light emitting diode LED1 is connected to the external power supply 3.3V through the resistor R4.

[0033] In the above embodiment, the inverter U3F can perform level inversion after receiving the TXD signal transmitted by the signal processor 1, i.e., changing signal 0 to signal 1 and signal 1 to signal 0. In addition, by modulating the level-inverted signal with the 38K square wave signal, the anti-interference ability of the infrared ray can be improved to avoid interference from atmospheric infrared rays. The resistor R2 is a pull-up resistor, which can improve the output ability of the logic chip U1.

[0034] For example, the model of the inverter U3F is 74HC14, which has low power consumption and high speed, and can convert a slowly changing input signal into a clear and non-jitter output signal. In addition, the model of the logic chip U1 is SN74HC1G08, which has the advantages of a wide working VCC range of 2V to 5.5V, low propagation delay allowing fast switching, and higher operating speed, and can optimize the signal transmission in the circuit.

[0035] For example, the model of the inverter U3F is 74HC14, which has low power consumption and high speed, and can convert a slowly changing input signal into a clear and non-jitter output signal. In addition, the model of the logic chip U1 is SN74HC1G08, which has the advantages of a wide working VCC range of 2V to 5.5V, low propagation delay allowing fast switching, and higher operating speed, and can optimize the signal transmission in the circuit. Figure 4 In some embodiments of the present application, the signal receiving control unit 31 comprises a logic chip U4A, and the infrared receiving unit 32 comprises an infrared receiving head U2 and a capacitor C1. The pin VCC of the infrared receiving head U2 is connected to an external power supply 3.3V, the pin VCC of the infrared receiving head U2 is also grounded through the capacitor C1, the pin OUT of the infrared receiving head U2 is connected to the input end of the logic chip U4A, the output end of the logic chip U4A is connected to one end of the RXD signal received by the signal processor 1, and the communication enable end of the logic chip U4A is connected to the signal processor 1.

[0036] In the above embodiment, pin 1 of the logic chip U4A is a communication enable pin that controls whether signals can be transmitted to the signal processor 1 through the logic chip U4A. Communication control can prevent unwanted signals from entering the signal processor 1. Only when data transmission is required does the signal receiving control unit 31 control the enable pin of the logic chip U4A to be turned on, allowing communication data to be transmitted to the signal processor 1. Capacitor C1 is a bypass capacitor for the infrared receiver U2, which provides a stable supply voltage to the infrared receiver U2.

[0037] For example, the logic chip U4A is a 74HC125, which is a 4-way buffer / line driver with three-state outputs, and the output is controlled by an enable input (IR_CON). A high level on IR_CON causes the output to be in a high-impedance state. The output has a built-in clamping diode, so that the input interface can be connected to a voltage exceeding VCC using a current-limiting resistor. That is, the signal receiving control unit 31 can be designed using the logic chip U4A with a model of 74HC125, which is simple and practical. The infrared receiving head U2 is a TSOP34138, which takes advantage of its small footprint to facilitate the miniaturization of the overall circuit design. An embodiment of the present invention also provides an infrared transmitting and receiving device, which includes a housing and a circuit board provided with the above-mentioned infrared transmitting and receiving circuit, and the circuit board is provided in the housing. By encapsulating the circuit board provided with the infrared transmitting and receiving circuit in the housing, it is made into an infrared transmitting and receiving device, which can be conveniently and quickly used by the user.

[0038] In some embodiments of the present invention, a connection structure electrically connected to the circuit board is provided on the outer wall of the housing. This connection structure is used to electrically connect to the mainboard of an external meter reader. This connection structure facilitates connection of the infrared transmitter / receiver to the mainboard of the meter reader, thereby facilitating connection of the infrared transmitter / receiver to any location in the meter reader, thereby facilitating miniaturization of the meter reader.

[0039] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

[0040] It will be apparent to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above and that the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present application is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. An infrared transmitting and receiving circuit, characterized in that: include: signal processor; An infrared transmitting subcircuit, the infrared transmitting subcircuit comprising a signal level flip unit, a carrier synthesis unit, a signal drive amplification unit, and a transmitting unit, wherein one end of the signal processor that transmits a TXD signal is connected to the input end of the carrier synthesis unit via the signal level flip unit, one end of the signal processor that transmits a 38K square wave signal is connected to the input end of the carrier synthesis unit, and the output end of the carrier synthesis unit is connected to the transmitting unit via the signal drive amplification unit; An infrared receiving subcircuit, the infrared receiving subcircuit comprising a signal receiving control unit and an infrared receiving unit, wherein one end of the signal processor receiving the RXD signal is connected to the output end of the signal receiving control unit, and the input end of the signal receiving control unit is connected to the infrared receiving unit; The signal level flip unit includes an inverter U3F, the carrier synthesis unit includes a logic chip U1, a resistor R1 and a resistor R2, the signal drive amplification unit includes a resistor R3 and a transistor Q1, and the transmitting unit includes a light-emitting diode LED1 and a resistor R4; The input end of the inverter U3F is connected to the end of the signal processor that sends the TXD signal, the output end of the inverter U3F is connected to pin A of the logic chip U1, pin B of the logic chip U1 is grounded through the resistor R1, pin B of the logic chip U1 is also connected to the end of the signal processor that sends a 38K square wave signal, pin VCC of the logic chip U1 is connected to an external power supply 3.3V, pin C of the logic chip U1 is connected to an external power supply 3.3V through the resistor R2, pin C of the logic chip U1 is also connected to the base of the transistor Q1 through the resistor R3, the emitter of the transistor Q1 is grounded, the collector of the transistor Q1 is connected to the cathode of the light-emitting diode LED1, and the anode of the light-emitting diode LED1 is connected to the external power supply 3.3V through the resistor R4; The signal receiving control unit includes a logic chip U4A, and the infrared receiving unit includes an infrared receiving head U2 and a capacitor C1; The pin VCC of the infrared receiving head U2 is connected to the external power supply 3.3V, and the pin VCC of the infrared receiving head U2 is also grounded through the capacitor C1. The pin OUT of the infrared receiving head U2 is connected to the input end of the logic chip U4A, and the output end of the logic chip U4A is connected to the end of the signal processor that receives the RXD signal. The communication enable end of the logic chip U4A is connected to the signal processor.

2. The infrared transmitting and receiving circuit according to claim 1, characterized in that: The model of the inverter U3F is 74HC14.

3. The infrared transmitting and receiving circuit according to claim 1, characterized in that: The model of the logic chip U1 is SN74HC1G08.

4. The infrared transmitting and receiving circuit according to claim 3, characterized in that: The model of the logic chip U4A is 74HC125.

5. The infrared transmitting and receiving circuit according to claim 3, characterized in that: The model of the infrared receiving head U2 is TSOP34138.

6. An infrared transmitting and receiving device, characterized in that: It comprises a shell and a circuit board provided with an infrared transmitting and receiving circuit according to any one of claims 1 to 5, wherein the circuit board is arranged in the shell.

7. An infrared transmitting and receiving device according to claim 6, characterized in that: A connection structure electrically connected to the circuit board is provided on the outer wall of the shell, and the connection structure is used to be electrically connected to a mainboard of an external meter reading machine.

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