Pulse width modulation circuit of pulse laser

Abstract

The utility model relates to a pulse width modulation circuit of a pulse laser, which comprises a frequency acquisition circuit, a pulse width acquisition circuit, a singlechip control circuit, a modulation output circuit and a power supply circuit, the frequency acquisition circuit and the pulse width acquisition circuit respectively send acquired frequency signals and pulse width information to the single-chip microcomputer, the single-chip microcomputer outputs corresponding main pulse signals and auxiliary pulse signals according to the pulse width information and the frequency signals, and the main pulse signals and the auxiliary pulse signals are modulated by the modulation circuit and then output required frequency pulse width signals. Parameters of the main pulse and the auxiliary pulse are determined according to collected frequency signals and pulse width information, and signals with various frequencies and various pulse widths are modulated and output according to current requirements through the main pulse and auxiliary pulse combined modulation circuit, so that the reusability of the circuit is greatly improved; the problem that a laser control circuit cannot flexibly change the pulse width according to needs, and consequently the machining precision is low is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of lasers, in particular to a pulse width modulation circuit of a pulse laser. Background Art

[0002] At present, with the improvement of laser processing accuracy, the requirements for laser pulse width modulation are also getting higher and higher. The pulse width of the laser directly affects the transmission and distribution of energy during the processing process. The pulse width is arbitrarily tunable, and the narrower the pulse width, the smaller the heat-affected zone, and the higher the processing accuracy can be obtained. The processing requirements of different materials or different parts may vary greatly, and the energy and time characteristics of the laser pulse need to be flexibly adjusted to meet the diverse processing needs. More sophisticated pulse width modulation means that the energy transfer and action time of each laser pulse can be controlled more accurately, which helps to achieve more complex and sophisticated processing processes.

[0003] However, existing lasers usually use a fixed clock frequency or a preset circuit structure due to their rigid control circuit design, and cannot flexibly change the pulse width as needed. When faced with changing processing requirements, such as: in some cases, shorter pulses may be required to minimize thermal damage, or longer pulses may be required to increase processing speed. In these cases, the fixed pulse width makes it impossible for the laser to provide optimal processing quality or efficiency.

[0004] Therefore, it is necessary to propose a pulse width modulation circuit of a pulse laser, which can adjust the pulse width according to actual needs and improve the processing accuracy. Utility Model Content

[0005] In view of this, it is necessary to provide a pulse width modulation circuit for a pulse laser to solve the technical problem that the laser control circuit in the prior art usually adopts a fixed clock frequency or a preset circuit structure and cannot flexibly change the pulse width as needed, resulting in low processing accuracy.

[0006] In order to achieve the above technical purpose, the utility model adopts the following technical solutions:

[0007] The utility model provides a pulse width modulation circuit of a pulse laser, comprising: a frequency acquisition circuit, a pulse width acquisition circuit, a single-chip control circuit, a modulation output circuit and a power supply circuit; the frequency acquisition circuit, the pulse width acquisition circuit and the modulation output circuit are all connected to the single-chip control circuit, and the power supply circuit is connected to the frequency acquisition circuit, the pulse width acquisition circuit, the single-chip control circuit and the modulation output circuit;

[0008] The frequency acquisition circuit is used to send the acquired frequency signal to the single chip control circuit;

[0009] The pulse width acquisition circuit is used to send the acquired pulse width information to the single chip control circuit;

[0010] The single chip control circuit is used to output the corresponding main pulse information and auxiliary pulse signal according to the frequency signal and pulse width information through the single chip, and transmit the main pulse information and auxiliary pulse signal to the modulation output circuit;

[0011] The modulation output circuit is used to modulate the main pulse and auxiliary pulse signals and output the required frequency pulse width signals;

[0012] The power supply circuit is used to provide a stable operating voltage for a frequency acquisition circuit, a pulse width acquisition circuit, a single chip control circuit and a modulation output circuit.

[0013] Furthermore, the single-chip control circuit includes a pulse recognition module, a pulse width analysis module, and a pulse output module connected to the pulse recognition module and the pulse width analysis module; the pulse recognition module is connected to the frequency acquisition circuit, and the pulse width analysis module is connected to the pulse width acquisition circuit;

[0014] The pulse recognition module is used to recognize whether there is a pulse signal. If a pulse signal is recognized, it is determined that the pulse laser is in a normal working state, and the collected frequency signal is determined as the required frequency; if no pulse signal is recognized, the output signal is stopped;

[0015] The pulse width analysis module is used to analyze the pulse width information and determine the required pulse width;

[0016] The pulse output module is used to output the main pulse and the auxiliary pulse to the modulation output circuit according to the required frequency and the required pulse width.

[0017] Furthermore, the pulse width analysis module also includes a time calculation unit for determining the time delay of the main pulse width relative to the auxiliary pulse width.

[0018] Furthermore, the single chip microcomputer adopts an STM32 or LPC microcontroller.

[0019] Furthermore, the package type of the single chip microcomputer is QFP100.

[0020] Furthermore, the modulation output circuit includes a bidirectional level conversion module U4; the first pin of U4 is connected to a 3.3V power supply, the third pin is connected to the main pulse IO output port of the single-chip microcomputer through a resistor R14, and the main pulse IO output port is also connected to the digital ground; the fourth pin of U4 is connected to one end of a capacitor C11, the other end of the capacitor C11 is connected to one end of a variable resistor RP1, the other end of the variable resistor RP1 is connected to one end of a capacitor C80, and is also connected to the pole of a diode D10; the anode of the diode D10 is connected to a 3.3V voltage through a resistor R70; the other end of the capacitor C80 is connected to the drain of an NMOS tube, the gate of the NMOS is connected to the auxiliary pulse IO output port of the single-chip microcomputer, and the source of the NMOS tube is connected to the digital ground; the second pin of U4 is connected to the digital ground.

[0021] Furthermore, the model adopted by the bidirectional level conversion module U4 is TXB0108.

[0022] Further, the pulse width acquisition circuit includes a level recognition unit;

[0023] The level identification unit is used to identify the currently required operating pulse width through the high and low level combination states of the wiring.

[0024] Furthermore, the cable is a 6-pin FPC cable.

[0025] Furthermore, the external input voltage of the power supply circuit is 24V, and the converted output voltage is two levels of voltage, 5V and 3.3V.

[0026] Compared with the prior art, the beneficial effects of the utility model include: respectively collecting the frequency signal and the required pulse width information of the laser through the frequency acquisition circuit and the pulse width acquisition circuit; the single-chip control circuit accurately adjusts the parameters of the main pulse and the auxiliary pulse according to the real-time processing requirements by receiving the frequency signal and the pulse width information; modulates the main pulse and the auxiliary pulse signal through the modulation output circuit, and outputs the required frequency pulse width signal; the power supply circuit provides a stable working voltage for each module to ensure the accuracy of signal processing and the stability of the system. The utility model can dynamically adjust the pulse width according to different processing tasks, collect the pulse width currently required to be output through the pulse width information, so that the pulse width has arbitrary tunability, greatly improves the reusability of the laser modulation circuit, reduces the laser cost, and solves the problem that the existing laser pulse width is not adjustable. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A structural framework diagram of an embodiment of a pulse width modulation circuit of a pulse laser provided by the utility model;

[0028] Figure 2A circuit structure diagram of an embodiment of a frequency acquisition circuit provided by the utility model;

[0029] Figure 3 A circuit structure diagram of an embodiment of a pulse width acquisition circuit provided by the utility model;

[0030] Figure 4 A circuit structure diagram of an embodiment of a modulation output circuit provided by the utility model;

[0031] Figure 5 A waveform diagram of a main pulse and an auxiliary pulse according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0033] In the description of the present application, “plurality” means two or more than two, unless otherwise clearly and specifically defined.

[0034] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0035] The utility model provides a pulse width modulation circuit for a pulse laser. Figure 1 , Figure 1 The structural framework diagram of the pulse width modulation circuit of the pulse laser provided in this embodiment includes: a frequency acquisition circuit 101, a pulse width acquisition circuit 102, a single-chip control circuit 103, a modulation output circuit 104 and a power supply circuit 105; the frequency acquisition circuit 101, the pulse width acquisition circuit 102, and the modulation output circuit 104 are all connected to the single-chip control circuit 103, and the power supply circuit 105 is connected to the frequency acquisition circuit 101, the pulse width acquisition circuit 102, the single-chip control circuit 103 and the modulation output circuit 104;

[0036] The frequency acquisition circuit 101 is used to send the acquired frequency signal to the single chip control circuit 103;

[0037] The pulse width acquisition circuit 102 is used to send the acquired pulse width information to the single chip control circuit 103;

[0038] The single chip control circuit 103 is used to output the corresponding main pulse information and auxiliary pulse signal according to the frequency signal and pulse width information, and transmit the main pulse information and auxiliary pulse signal to the modulation output circuit 104;

[0039] The modulation output circuit 104 is used to modulate the main pulse and auxiliary pulse signals and output the required frequency pulse width signals;

[0040] The power supply circuit 105 is used to provide a stable operating voltage for the frequency acquisition circuit 101 , the pulse width acquisition circuit 102 , the single chip control circuit 103 and the modulation output circuit 104 .

[0041] The pulse width modulation circuit of a pulse laser provided by the embodiment of the utility model collects the laser pulse frequency and the required pulse width information through the frequency acquisition circuit and the pulse width acquisition circuit respectively; the single-chip control circuit accurately adjusts the parameters of the main pulse and the auxiliary pulse according to the real-time processing requirements by receiving the frequency signal and the pulse width information; the main pulse and the auxiliary pulse signal are modulated by the modulation output circuit, and the required frequency pulse width signal is output; the power supply circuit provides a stable working voltage for each module to ensure the accuracy of signal processing and the stability of the system. The utility model can dynamically adjust the pulse width according to different processing tasks, collect the pulse width currently required to be output through the pulse width information, so that the pulse width has arbitrary tunability, greatly improves the reusability of the laser modulation circuit, reduces the laser cost, and solves the problem that the existing laser pulse width is not adjustable.

[0042] like Figure 2 As shown, the frequency acquisition circuit collects the pulse signal CLK from the laser and transmits it to the IO port of the single-chip microcomputer through the resistor R49. If the single-chip microcomputer recognizes that there is a pulse signal, it determines that the pulse laser is in a normal working state, and then calculates and analyzes the frequency to determine the current required pulse frequency. The calculation and analysis of the frequency adopts the common methods of the prior art, such as: using a counter to measure the time interval between two consecutive pulses, calculating the frequency by measuring the time interval, and so on.

[0043] As a preferred embodiment, the pulse width acquisition circuit includes a level recognition unit;

[0044] The level identification unit is used to identify the currently required operating pulse width through the high and low level combination states of the wiring.

[0045] As a preferred embodiment, the flat cable is a 6-pin FPC flat cable.

[0046] In some embodiments, in order to save space and provide good electrical performance such as low resistance, such as Figure 3As shown, the 6-pin cable in the pulse width acquisition circuit uses an FFC / FPC connector. Due to their flat and flexible characteristics, the FFC / FPC connector and the flexible cable socket can effectively save the internal space of the device, and are particularly suitable for designs with limited space or requiring a compact layout. The flexible cable socket is a 1.MM-6PIN bottom-connected drawer-type specification, which is suitable for compact space design and can effectively utilize the internal space of the device. The bottom drawer design makes it easier to insert and remove cables or harnesses, which can be completed by sliding or lightly pressing, which can simplify maintenance and replacement work.

[0047] Specifically, the current required pulse width identified by the high and low level of the 6-pin wiring combination of the pulse width acquisition circuit is shown in Table 1. This identification method is a common means of determining the required pulse width duration by identifying the high and low levels of the pins.

[0048] Table 1 Pulse Width Table

[0049] 6pin pin (1-4) Pulse width ns 0x0000 20 0x0001 60 0x0010 100 0x0011 200 0x0100 500

[0050] The single-chip control circuit includes a pulse recognition module, a pulse width analysis module, and a pulse output module connected to the pulse recognition module and the pulse width analysis module; the pulse recognition module is connected to the frequency acquisition circuit, and the pulse width analysis module is connected to the pulse width acquisition circuit;

[0051] The pulse recognition module is used to recognize whether there is a pulse signal. If a pulse signal is recognized, it is determined that the pulse laser is in a normal working state, and the collected frequency signal is determined as the required frequency; if no pulse signal is recognized, the output signal is stopped;

[0052] The pulse width analysis module is used to analyze the pulse width information and determine the required pulse width;

[0053] The pulse output module is used to output the main pulse and the auxiliary pulse to the modulation output circuit according to the required frequency and the required pulse width.

[0054] It should be noted that the above-mentioned pulse recognition module, pulse width analysis module and pulse output module are all divided inside the single-chip microcomputer. The pulse recognition module in the single-chip microcomputer confirms that the laser pulse width modulation circuit is working normally only when it collects the frequency pulse signal of the laser; otherwise, it is determined that the laser pulse width modulation circuit has no output. The pulse width that needs to be output is collected through the pulse width information, and the pulse width analysis module analyzes the pulse width information. The pulse width is arbitrarily tunable, which greatly improves the reusability of the laser modulation circuit, reduces the laser cost, and solves the problem that the existing laser pulse width is not adjustable.

[0055] As a preferred embodiment, the pulse width analysis module further includes a time calculation unit for determining the time delay of the main pulse width relative to the auxiliary pulse width.

[0056] The main pulse width and the auxiliary pulse width produce a time difference through delay, resulting in the phenomenon that the high level of the pulse width overlaps each other. By adjusting the delay, the main pulse width and the auxiliary pulse width can achieve the requirement of adjusting the final output pulse width.

[0057] The relevant time delay method adopts the common method of the prior art, such as the method described in the patented nanosecond pulse laser light source structure with tunable pulse width and power with publication number CN209217423U, etc.

[0058] Specifically, as shown in Table 2, after the single-chip control circuit receives the frequency signal and pulse width information, it outputs the main pulse signal and auxiliary pulse signal corresponding to the received frequency according to the pulse width information to the modulation output circuit for processing. In order to save hardware costs, the pulse width of the auxiliary pulse is usually fixed at 220ns. For a signal with a sampling pulse width of 500ns, it is only necessary to output the main pulse width, and there is no need to output the auxiliary pulse width; if the sampling pulse width is 20 or 60ns, the main pulse width of 190ns is delayed by 90ns and 30ns respectively relative to the auxiliary pulse width of 220ns.

[0059] Table 2 Main pulse and auxiliary pulse signal output

[0060]

[0061] As a preferred embodiment, the single-chip microcomputer adopts an ARM Cortex-M3 microcontroller, and the package type is QFP100. QFP (Quad Flat Package) refers to a quad flat package, and the number 100 indicates that the package has 100 pins. Therefore, QFP100 can be used to package integrated circuits of various different architectures. QFP100 is generally suitable for medium-density applications. Unlike larger packages (such as BGA), which require more complex PCB design and manufacturing technology, it has low cost and can be flexibly adapted to various application scenarios. It also has obvious advantages in terms of high integration, good heat dissipation, easy manufacturing and welding.

[0062] like Figure 4As shown in the figure, as a preferred embodiment, the modulation output circuit includes a bidirectional level conversion module U4; the first pin of U4 is connected to a 3.3V DC power supply through an inductor LB1, the third pin is connected to the main pulse IO output port of the single-chip computer through a resistor R14, and the main pulse IO output port is also connected to the digital ground; the fourth pin of U4 is connected to one end of a capacitor C11, the other end of the capacitor C11 is connected to the adjustment end of a variable resistor RP1, the fixed end of the variable resistor RP1 is connected to one end of a capacitor C80, and is also connected to the gate of an NMOS tube U30. The gate of the NMOS tube U30 is also connected to the cathode of the diode D10; the anode of the diode D10 is connected to the 3.3V DC power supply through the resistor R70; the other end of the capacitor C80 is connected to the drain of the NMOS tube U80, the gate of the NMOS tube U80 is connected to the auxiliary pulse IO output port of the single-chip microcomputer, and the source of the NMOS tube U80 is connected to the digital ground; the second pin of U4 is connected to the digital ground, the fifth pin is connected to the DC power supply VCC through the resistor R11 and the inductor LB2, and the sixth pin is connected to VCC through the inductor LB2.

[0063] Among them, the U30 is a high-speed MOS tube, and the model used by U4 is TXB0108.

[0064] As a specific example, Figure 5 As shown, Figure 5 The waveform diagram of the main pulse and auxiliary pulse is shown. Figure 5 The main pulse is represented by blue. The main pulse input Figure 4 U4 in yellow auxiliary pulse input Figure 4 The U80 in the circuit is finally input into the U30 high-speed MOS tube. The main pulse width and the auxiliary pulse width produce a time difference through delay, resulting in the phenomenon that the high level of the pulse width overlaps each other. By adjusting the delay, the main pulse width and the auxiliary pulse width can achieve the requirement of adjusting the final output pulse width.

[0065] As a preferred embodiment, the external input voltage of the power supply circuit is 24V, and the converted output voltage is two levels of voltage: 5V and 3.3V.

[0066] The power supply circuit converts the external input 24V power supply into voltages of different levels to meet the working needs of the entire circuit.

[0067] The utility model provides a pulse width modulation circuit of a pulse laser. The single chip control circuit determines that the laser pulse width modulation circuit works normally only when the frequency pulse signal is collected; otherwise, it is determined that the laser pulse width modulation circuit has no output. The pulse width currently required to be output is collected through pulse width information, and the pulse width has arbitrary tunability, which greatly improves the reusability of the laser modulation circuit, reduces the laser cost, and solves the problem that the existing laser pulse width cannot be adjusted.

[0068] The above is only a preferred specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention.

Claims

1. A pulse width modulation circuit for a pulse laser, characterized in that: include: Frequency acquisition circuit, pulse width acquisition circuit, single chip control circuit, modulation output circuit and power supply circuit; The frequency acquisition circuit, pulse width acquisition circuit, and modulation output circuit are all connected to the single-chip control circuit, and the power supply circuit is connected to the frequency acquisition circuit, pulse width acquisition circuit, single-chip control circuit, and modulation output circuit; The frequency acquisition circuit is used to send the acquired frequency signal to the single chip control circuit; The pulse width acquisition circuit is used to send the acquired pulse width information to the single chip control circuit; The single chip control circuit is used to output the corresponding main pulse information and auxiliary pulse signal according to the frequency signal and pulse width information through the single chip, and transmit the main pulse information and auxiliary pulse signal to the modulation output circuit; The modulation output circuit is used to modulate the main pulse and auxiliary pulse signals and output the required frequency pulse width signals; The power supply circuit is used to provide a stable operating voltage for the frequency acquisition circuit, the pulse width acquisition circuit, the single chip control circuit and the modulation output circuit.

2. The pulse width modulation circuit of the pulse laser according to claim 1, characterized in that: The single-chip control circuit includes a pulse recognition module, a pulse width analysis module, and a pulse output module connected to the pulse recognition module and the pulse width analysis module; the pulse recognition module is connected to the frequency acquisition circuit, and the pulse width analysis module is connected to the pulse width acquisition circuit; The pulse recognition module is used to recognize whether there is a pulse signal. If a pulse signal is recognized, it is determined that the pulse laser is in a normal working state, and the collected frequency signal is determined as the required frequency; if no pulse signal is recognized, the output signal is stopped; The pulse width analysis module is used to analyze the pulse width information and determine the required pulse width; The pulse output module is used to output the main pulse and the auxiliary pulse to the modulation output circuit according to the required frequency and the required pulse width.

3. The pulse width modulation circuit of the pulse laser according to claim 2, characterized in that: The pulse width analysis module also includes a time calculation unit for determining the time delay of the main pulse width relative to the auxiliary pulse width.

4. The pulse width modulation circuit of the pulse laser according to claim 1, characterized in that: The single chip microcomputer adopts STM32 or LPC microcontroller.

5. The pulse width modulation circuit of the pulse laser according to claim 1, characterized in that: The package type of the single chip microcomputer is QFP100.

6. The pulse width modulation circuit of the pulse laser according to claim 1, characterized in that: The modulation output circuit includes a bidirectional level conversion module U4; the first pin of U4 is connected to a 3.3V power supply, the third pin is connected to the main pulse IO output port of the single-chip microcomputer through a resistor R14, and the main pulse IO output port is also connected to the digital ground; the fourth pin of U4 is connected to one end of a capacitor C11, the other end of the capacitor C11 is connected to one end of a variable resistor RP1, the other end of the variable resistor RP1 is connected to one end of a capacitor C80, and is also connected to the pole of a diode D10; the anode of the diode D10 is connected to a 3.3V voltage through a resistor R70; the other end of the capacitor C80 is connected to the drain of an NMOS tube, the gate of the NMOS is connected to the auxiliary pulse IO output port of the single-chip microcomputer, and the source of the NMOS tube is connected to the digital ground; the second pin of U4 is connected to the digital ground.

7. The pulse width modulation circuit of the pulse laser according to claim 6, characterized in that: The model used by the bidirectional level conversion module U4 is TXB0108.

8. The pulse width modulation circuit of the pulse laser according to claim 1, characterized in that: The pulse width acquisition circuit includes a level recognition unit; The level identification unit is used to identify the currently required operating pulse width through the high and low level combination states of the wiring.

9. The pulse width modulation circuit of the pulse laser according to claim 8, characterized in that: The cable is a 6-pin FPC cable.

10. The pulse width modulation circuit of a pulse laser according to claim 1, characterized in that: The external input voltage of the power supply circuit is 24V, and the converted output voltage is two levels of voltage: 5V and 3.3V.

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