WO2023184857A1

WO2023184857A1 - Laser system and laser driving method

Info

Publication number: WO2023184857A1
Application number: PCT/CN2022/116749
Authority: WO
Inventors: 邹卫华; 谢尚正; 陈东水
Original assignee: 广州童心制物科技有限公司
Priority date: 2022-03-31
Filing date: 2022-09-02
Publication date: 2023-10-05
Also published as: CN116937326A

Abstract

A laser system and a laser driving method. The laser system may comprise: a main control chip (110); a laser emitter (100), wherein the laser emitter (100) has a reference laser power value; a laser driving circuit (120), which is connected to the main control chip (110) and the laser emitter (100), wherein the laser driving circuit (120) is used for adjusting an actual laser power value of the laser emitter (100) according to a PWM signal value, which is transmitted by the main control chip (110); and an optical power measurement apparatus (20), which is used for measuring the actual laser power value of the laser emitter (100), wherein the main control chip (110) is used for adjusting the PWM signal value, according to the relationship between the actual laser power value, which is measured by the optical power measurement apparatus (20), and the reference laser power value, which is outputted by the main control chip, so that the actual laser power value of the laser emitter (100) is equal to the reference laser power value.

Description

Laser system and laser driving method

cross reference

This disclosure claims priority from the Chinese patent application entitled "Laser System and Laser Driving Method" with application number 2022103334329 filed on March 31, 2022. The entire content of this Chinese patent application is incorporated herein by reference.

Technical field

The present disclosure belongs to the field of laser technology, and specifically relates to a laser system and a laser driving method.

Background technique

With the continuous development of laser technology, laser equipment is used in more and more scenes. But currently, the laser transmitters on the market are greatly affected by temperature. When the laser transmitter starts to work, as the temperature gradually rises, the laser power will slowly decrease. Since the laser power of the laser transmitter will continue to change, it is not It is conducive to the subsequent software laser parameter setting and algorithm processing; in addition, there are certain differences in the actual laser power of different laser transmitters. For example, the actual optical power of a typical 5W laser transmitter ranges between 4.5-5.5W. This results in differences in the optical power of different modules, which is not conducive to the setting of optimal parameters for engraving or cutting and the adjustment of software algorithms.

public content

The purpose of this disclosure is to provide a laser system and a laser driving method that can ensure constant laser power output of the laser transmitter, thereby facilitating the setting of software laser parameters and algorithm processing.

The present disclosure provides a laser system including:

Master chip;

A laser transmitter, the laser transmitter has a reference laser power value;

A laser drive circuit connects the main control chip and the laser transmitter, and the laser drive circuit is used to adjust the actual laser power value of the laser transmitter according to the PWM signal value sent by the main control chip;

Optical power detection device, used to detect the actual laser power value of the laser transmitter;

Wherein, the main control chip is used to adjust the PWM signal value output by it according to the relationship between the actual laser power value detected by the optical power detection device and the reference laser power value, so that the laser transmitter The actual laser power value is equal to the reference laser power value.

In an exemplary embodiment of the present disclosure,

The main control chip is used to reduce the PWM signal value output by the optical power detection device when the actual laser power value detected by the optical power detection device is greater than the reference laser power value, so that the actual laser power of the laser transmitter The value is equal to the reference laser power value;

The main control chip is used to increase the PWM signal value output by the optical power detection device when the actual laser power value detected by the optical power detection device is less than the reference laser power value, so that the actual laser power of the laser transmitter The power value is equal to the reference laser power value.

In an exemplary embodiment of the present disclosure,

The optical power detection device includes an optical power attenuation circuit and a photoelectric conversion circuit;

The optical power attenuation circuit is used to obtain the actual laser power value emitted by the laser transmitter and adjust it to an attenuated laser power value according to a fixed ratio, the attenuated laser power value is less than the actual laser power value, and It is also less than the maximum optical power value that the photoelectric conversion circuit can receive;

The photoelectric conversion circuit is used to convert the attenuated laser power value into an actual voltage value;

Wherein, the main control chip is used to reduce the PWM signal value output by the main control chip when the actual voltage value is greater than the reference voltage value, so as to adjust the actual laser power value of the laser transmitter to reduce to the reference laser power. value; also used to increase the PWM signal value output by it when the actual voltage value is less than the reference voltage value, so as to adjust the actual laser power value of the laser transmitter to increase to the reference laser power value. .

In an exemplary embodiment of the present disclosure,

The photoelectric conversion circuit includes:

Photoelectric tube, used to obtain the attenuated laser power value generated by the optical power attenuation circuit, and convert the attenuated laser power value into a current value. The attenuated laser power value is smaller than the maximum light that the photoelectric tube can receive. power value;

A current-to-voltage conversion amplification circuit is used to convert the current value output by the photoelectric tube into a voltage value, and amplify the converted voltage value to generate the actual voltage value.

In an exemplary embodiment of the present disclosure,

The current-to-voltage conversion amplifier circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, an operational amplifier chip, a filter circuit and a voltage follower circuit; wherein,

Both ends of the first resistor are connected to the first node and the second node respectively, the first node is connected to the first pole of the photoelectric tube, the second pole of the photoelectric tube is connected to the power supply end, and the The second node is connected to the ground;

The positive terminal of the operational amplifier chip is connected to the first node through the second resistor, and the negative terminal of the operational amplifier chip is connected to the second node through the third resistor;

One end of the fourth resistor is connected to the negative terminal of the operational amplifier chip, and the other end is connected to the output terminal of the operational amplifier chip;

The positive terminal of the voltage following circuit is connected to the output terminal of the operational amplifier chip through the filter circuit, the negative terminal of the voltage following circuit is connected to the output terminal of the voltage following circuit, and the output of the voltage following circuit The terminal is connected to the main control chip, and the two power terminals of the voltage following circuit are connected to the power supply terminal and the ground terminal respectively.

In an exemplary embodiment of the present disclosure,

The filter circuit includes a filter resistor and a filter capacitor,

The two ends of the filter resistor are respectively connected to the output terminal of the operational amplifier chip and the positive terminal of the voltage follower circuit;

The two poles of the filter capacitor are respectively connected to the positive terminal and the ground terminal of the voltage following circuit.

In an exemplary embodiment of the present disclosure,

There are multiple optical power detection devices and they are distributed in a matrix at multiple locations; wherein each of the optical power detection devices is connected in parallel to the digital-to-analog converter of the main control chip.

In an exemplary embodiment of the present disclosure,

The laser system also includes a delay protection circuit, the input end of the delay protection circuit is connected to the output voltage end of the laser drive circuit, and the output end of the delay protection circuit is connected to the PWM signal of the laser drive circuit. Receiver connection; where,

The delay protection circuit is used to detect the output voltage of the laser drive circuit and output a first level signal when the output voltage reaches the target voltage threshold. The PWM signal receiving end of the laser drive circuit is connected to the delay When the first level signal output by the protection circuit is capable of receiving the PWM signal sent by the main control chip;

The delay protection circuit is also used to output a second level signal when the output voltage does not reach the target voltage threshold. The PWM signal receiving end of the laser driving circuit outputs a second level signal when the delay protection circuit outputs a second level signal. The signal is received when the signal is 0.

In an exemplary embodiment of the present disclosure,

It also includes a level conversion circuit connected between the PWM signal output end of the main control chip and the PWM signal receiving end of the laser driving circuit.

A second aspect of the present disclosure provides a laser driving method for use in a laser system, wherein the laser system includes a laser transmitter, a laser driving circuit and an optical power detection device, the laser transmitter has a reference laser power value, wherein , the laser driving method includes:

Obtain the actual laser power value of the laser transmitter detected by the optical power detection device;

According to the relationship between the actual laser power value detected by the optical power detection device and the reference laser power value, the corresponding PWM signal value is input to the laser driving circuit, and the laser driving circuit can be based on the PWM signal value. The current value input to the laser emitter is adjusted so that the actual laser power value of the laser emitter is equal to the reference laser power value.

This disclosed solution has the following beneficial effects:

The disclosed laser system sets up an optical power detection device to detect the actual laser power value of the laser transmitter, and transmits the detection result to the main control chip. The main control chip can detect the actual laser power value based on the optical power detection device. The relationship between the laser power value and the reference laser power value adjusts the PWM signal value output by it so that the actual laser power value of the laser transmitter is equal to the reference laser power value. That is to say, a feedback system is formed through the optical power detection device and the main control chip. , This design can enable the laser transmitter to always maintain the output reference laser power value and ensure the constant output of the laser power of the laser transmitter, thereby facilitating the setting of software laser parameters and algorithm processing.

Additional features and advantages of the disclosure will be apparent from the following detailed description, or, in part, may be learned by practice of the disclosure.

It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and do not limit the present disclosure.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

FIG. 1 shows a structural block diagram of a laser system according to an embodiment of the present disclosure.

FIG. 2 shows a circuit schematic diagram of a photoelectric conversion circuit according to an embodiment of the present disclosure.

FIG. 3 shows a structural block diagram of a laser system according to another embodiment of the present disclosure.

FIG. 4 shows a schematic circuit diagram of a laser driving device according to an embodiment of the present disclosure.

FIG. 5 shows a schematic flowchart of a laser driving method according to an embodiment of the present disclosure.

Detailed ways

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concepts of the example embodiments. To those skilled in the art.

Furthermore, the described features, structures or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. may be adopted. In other instances, well-known methods, apparatus, implementations, or operations have not been shown or described in detail to avoid obscuring aspects of the present disclosure.

The present disclosure will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted here that the technical features involved in the various embodiments of the present disclosure described below can be combined with each other as long as they do not conflict with each other. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present disclosure and are not to be construed as limitations of the present disclosure.

The present disclosure provides a laser system, which can be applied in the field of desktop-level laser equipment. As shown in FIG. 1 , this laser system may include a laser driving device 10 and an optical power detection device 20 .

Referring to FIG. 1 , the laser driving device 10 may include a laser emitter 100 , a main control chip 110 and a laser driving circuit 120 . The laser transmitter 100 may have a reference laser power value;

The laser driving circuit 120 can connect the main control chip 110 and the laser emitter 100 . Specifically, the main control chip 110 may have a PWM signal output terminal, and the PWM signal output terminal may be used to output a PWM signal. For example, the main control chip 110 can be an MCU (Microcontroller Unit).

The laser driving circuit 120 may have a PWM signal receiving end and a driving end. The PWM signal receiving end of the laser driving circuit 120 is connected to the PWM signal output end of the main control chip 110. The driving end of the laser driving circuit 120 is connected to the laser transmitter 100.

The laser driving circuit 120 is used to adjust the actual laser power value of the laser transmitter 100 according to the PWM (pulse width modulation) signal value sent by the main control chip 110 . The optical power detection device 20 can be used to detect the actual laser power value of the laser transmitter 100; and the main control chip 110 is used to adjust its operation according to the relationship between the actual laser power value detected by the optical power detection device 20 and the reference laser power value. The output PWM signal value is such that the actual laser power value of the laser transmitter 100 is equal to the reference laser power value.

The laser system of the present disclosure detects the actual laser power value of the laser transmitter 100 by setting up the optical power detection device 20, and transmits the detection result to the main control chip 110. The main control chip 110 can detect according to the optical power detection device 20 The relationship between the actual laser power value and the reference laser power value adjusts the PWM signal value output by it, so that the actual laser power value of the laser transmitter 100 is equal to the reference laser power value, that is, through the optical power detection device 20 Forming a feedback system with the main control chip 110, this design can enable the laser transmitter 100 to always maintain the output reference laser power value, ensuring a constant laser power output of the laser transmitter 100, thus facilitating the setting of software laser parameters and algorithm processing.

In addition, by arranging the optical power detection device 20 to detect the actual laser power value of the laser transmitter 100, it can also be used to assist in determining the dirtiness of the optical lens, thereby prompting the user to clean the lens.

It should be understood that the actual laser power value of the laser transmitter 100 mentioned in this embodiment is equal to the reference laser power value can be understood to mean that within the allowable error range, the actual laser power value is basically equal to the reference laser power value, or it can be understood as The absolute difference between the actual laser power value of the laser transmitter 100 and the reference laser power value is within the error range, thereby achieving a constant laser power output of the laser transmitter 100 .

Specifically, the main control chip 110 is used to reduce the PWM signal value output by the optical power detection device 20 when the actual laser power value detected by the optical power detection device 20 is greater than the reference laser power value, so that the actual laser power value of the laser transmitter 100 is equal to Baseline laser power value. And the main control chip 110 is used to increase the PWM signal value output by the optical power detection device 20 when the actual laser power value detected by the optical power detection device 20 is less than the reference laser power value, so that the actual laser power value of the laser transmitter 100 is equal to the reference value. Laser power value.

As shown in FIG. 1 , the optical power detection device 20 includes an optical power attenuation circuit 210 and a photoelectric conversion circuit 220 .

The optical power attenuation circuit 210 is used to obtain the actual laser power value emitted by the laser transmitter 100 and adjust it to an attenuated laser power value according to a fixed ratio. This attenuated laser power value is less than the actual laser power value and is also less than the photoelectric conversion circuit 220 The maximum optical power value that can be received. The photoelectric conversion circuit 220 is used to convert the attenuated laser power value into an actual voltage value.

Among them, the main control chip 110 is used to reduce the PWM signal value output by it when the actual voltage value is greater than the reference voltage value, so as to adjust the actual laser power value of the laser transmitter 100 to reduce to the reference laser power value; it is also used to When the actual voltage value is less than the reference voltage value, the PWM signal value output by it is increased to adjust the actual laser power value of the laser transmitter 100 to increase to the reference laser power value.

In the embodiment of the present disclosure, by setting the optical power attenuation circuit 210, the output power of the laser transmitter 100 can first be attenuated to a limit range that the photoelectric conversion circuit 220 can accept, for example, the power can be attenuated from 5W to 10mW. This can The photoelectric conversion circuit 220 provides protection.

For example, as shown in FIGS. 1 and 2 , the photoelectric conversion circuit 220 may include a photoelectric tube D6 and a current-to-voltage conversion amplification circuit.

Among them, the photoelectric tube D6 can be used to obtain the attenuated laser power value generated by the optical power attenuation circuit 210 and convert the attenuated laser power value into a current value. The attenuated laser power value is smaller than the maximum optical power value that the photoelectric tube D6 can receive. The current-to-voltage conversion amplifier circuit can be used to convert the current value output by the photoelectric tube D6 into a voltage value, and amplify the converted voltage value to generate an actual voltage value. By amplifying the voltage value, it is convenient for the main control chip 110 to perform Follow-up operations.

Specifically, as shown in Figure 2, the current-to-voltage conversion amplification circuit includes a first resistor R12, a second resistor R9, a third resistor R10, a fourth resistor R11, an operational amplifier chip U3A, a filter circuit and a voltage follower chip U3B.

Both ends of the first resistor R12 are connected to the first node M2 and the second node M3 respectively. The first node M2 is connected to the first pole of the photoelectric tube D6, and the second pole of the photoelectric tube D6 is connected to the power supply terminal VCC. For example, , the voltage of the power supply terminal VCC here can be 3.3V, but is not limited to this, depending on the specific situation, the second node M3 is connected to the ground terminal DGND.

The positive terminal of the operational amplifier chip U3A is connected to the first node M2 through the second resistor R9, and the negative terminal of the operational amplifier chip U3A is connected to the second node M3 through the third resistor R10.

One end of the fourth resistor R11 is connected to the negative terminal of the operational amplifier chip U3A, and the other end is connected to the output terminal of the operational amplifier chip U3A.

The positive terminal of the voltage following chip U3B is connected to the output terminal of the operational amplifier chip U3A through the filter circuit, the negative terminal of the voltage following chip U3B is connected to the output terminal of the voltage following chip U3B, and the output terminal of the voltage following chip U3B is connected to the main control chip 110 , specifically, it can be connected to the digital-to-analog converter MCU-ADC of the main control chip 110 . And the two power supply terminals of the voltage following chip U3B are respectively connected to the power supply terminal VCC and the ground terminal GND.

Optionally, the filter circuit includes a filter resistor R8 and a filter capacitor C6. The two ends of the filter resistor R8 are respectively connected to the output end of the operational amplifier chip U3A and the positive end of the voltage follower chip U3B; the two ends of the filter capacitor C6 are respectively connected to the voltage follower chip. The positive terminal of U3B is connected to the ground terminal DGND.

Based on the aforementioned current-to-voltage conversion amplifier circuit, when the actual optical power value emitted by the laser transmitter 100 becomes larger, that is, when the light intensity becomes larger, the voltage difference across the first resistor R12 becomes larger, and the operational amplifier chip U3A will The difference signal is amplified, and after passing through the RC filter circuit composed of filter resistor R8 and filter capacitor C6, enters the voltage follower chip U3B, and finally enters the main control chip 110. The main control chip 110 collects the voltage signal through the digital-to-analog converter ADC.

In the embodiment of the present disclosure, the photoelectric tube D6 detects changes in light intensity and converts them into changes in current; the current-voltage conversion amplification circuit converts the change value of the current into a voltage value, that is, performs I-V conversion; and finally amplifies the voltage signal. For processing, the main control chip 110 collects the voltage signal through the digital-to-analog converter ADC, adjusts the change of the PWM signal value according to the operation result, and finally controls the value of the optical power.

Specifically, when the actual laser power value output by the laser transmitter 100 deviates more from the reference laser power value, the ADC value of the digital-to-analog converter will be greater. After judgment, the main control chip 110 will reduce the PWM signal value, thereby making the driving current smaller. , so that the actual laser power value output by the laser transmitter 100 is equal to or closer to the reference optical power value; when the actual laser power value output by the laser transmitter 100 deviates from the reference laser power value by a smaller amount, at this time, the ADC value of the digital-to-analog converter becomes smaller. is small, after the main control chip 110 determines, it increases the PWM signal value, thereby increasing the driving current, so that the actual laser power value output by the laser transmitter 100 is equal to or closer to the reference optical power value; thus forming feedback, which can ensure that the laser The actual laser power value output by the transmitter 100 is stable within a certain limit or range, realizing automatic adjustment; facilitating software algorithm processing, engraving and cutting parameter setting.

Among them, multiple optical power detection devices 20 mentioned above can be provided and distributed in multiple positions in a matrix, so that changes in the actual laser power value of the laser transmitter 100 can be judged more accurately; wherein, each optical power detection device The device 20 is connected in parallel to the digital-to-analog converter of the main control chip 110 .

In an embodiment of the present disclosure, as shown in Figure 3, the laser driving device 10 may further include a delay protection circuit 130, and the laser driving circuit 120 may also have an output voltage terminal.

The delay protection circuit 130 may have an input terminal and an output terminal. The input terminal of the delay protection circuit 130 is connected to the output voltage terminal of the laser drive circuit 120 . The output terminal of the delay protection circuit 130 is connected to the PWM signal of the laser drive circuit 120 . The receiving end is connected, and the delay protection circuit 130 is used to adjust the receiving state of the PWM signal receiving end of the laser driving circuit 120 according to the output voltage of the laser driving circuit 120 .

In the embodiment of the present disclosure, by providing a delay protection circuit 130 in the laser driving device 10, the delay protection circuit 130 can adjust the PWM (Pulse Width Modulation) signal receiving end of the laser driving circuit 120 according to the output voltage of the laser driving circuit 120. receiving state. Specifically, when the delay protection circuit 130 determines that the output voltage of the laser driving circuit 120 reaches a stable voltage threshold, the output terminal of the delay protection circuit 130 can output a level signal corresponding to the stable state. At this time, the laser The drive circuit 120 can normally receive the PWM signal sent by the main control chip 110, and adjust the laser power value of the laser transmitter 100 according to the PWM signal value sent by the main control chip 110; the delay protection circuit 130 determines the output voltage of the laser drive circuit 120 When the stable voltage threshold is not reached, the output terminal of the delay protection circuit 130 can output a level signal corresponding to the unstable state. At this time, no matter how the PWM signal sent by the main control chip 110 changes, the PWM signal of the laser driving circuit 120 The input signal at the output end is 0, so that the laser transmitter 100 does not emit laser light, thus protecting the entire laser driving device 10 and improving or preventing abnormal light emission, thereby improving the situation of laser damage.

The laser driving device 10 will be described in detail below.

As shown in FIG. 3 and FIG. 4 , the delay protection circuit 130 may include a delay protection chip U2 and an isolation diode D5. The input terminal Vth of the delay protection chip U2 is connected to the output voltage terminal Vcc of the laser drive circuit 120. The delay protection The output terminal Vout of the chip U2 is connected to the cathode of the isolation diode D5, the ground terminal Gnd of the delay protection chip U2 is connected to the ground, and the anode of the isolation diode D5 is connected to the PWM signal receiving terminal Vpwm of the laser drive circuit 120.

Specifically, the output terminal Vout of the delay protection chip U2 is used to output a first level signal when the output voltage of the laser driving circuit 120 is greater than the set input voltage of the delay protection chip U2. For example, this first level signal The signal can be a high-level signal, so that the PWM signal receiving end Vpwm of the laser driving circuit 120 can receive the PWM signal sent by the main control chip 110 (ie: MCU-PWM in Figure 4). That is to say, in the laser driving circuit When the output voltage of the output voltage terminal Vcc of 120 is greater than the set input voltage of the input terminal Vth of the delay protection chip U2, the delay protection chip U2 determines that the output voltage of the laser drive circuit 120 reaches a stable voltage threshold. At this time, the entire laser driver The device 10 is in a normal state, and the laser driving circuit 120 can normally receive the PWM signal sent by the main control chip 110, and adjust the operating current of the laser transmitter 100 according to the PWM signal value sent by the main control chip 110, thereby adjusting the output of the laser transmitter 100. Laser power value.

The output terminal Vout of the delay protection chip U2 is used to output a second level signal when the output voltage of the laser driving circuit 120 is less than the set input voltage of the delay protection chip U2. For example, the second level signal can be Low level signal, so that the PWM signal receiving terminal Vpvm of the laser driving circuit 120 receives a signal of 0, that is, when the output voltage of the output voltage terminal Vcc of the laser driving circuit 120 is less than the set input voltage of the delay protection chip U2 , the delay protection chip U2 determines that the output voltage of the laser drive circuit 120 has not reached the stable voltage threshold. At this time, the entire laser drive device 10 is in an abnormal state. No matter how the PWM signal sent by the main control chip 110 changes, the PWM of the laser drive circuit 120 The signal input to the signal receiving terminal Vpwm is 0, so that the laser transmitter 100 does not emit laser light, thereby protecting the entire laser driving device 10 and improving or preventing abnormal light emission, thereby improving the situation of laser damage.

It should be noted that this embodiment does not limit the specific model of the delay protection chip U2, as long as it can realize the above functions.

In addition, as shown in FIG. 3 and FIG. 4 , the embodiment of the present disclosure can isolate the MCU-PWM signal by arranging an isolation diode D5 in the delay protection circuit 130 to prevent it from affecting the operation of the delay protection chip U2.

In an embodiment of the present disclosure, as shown in FIG. 3 and FIG. 4 , the laser driving circuit 120 may include a switching MOS transistor Q1, a laser driving chip U1, a first pull-up resistor R5, current sensing resistors R1 and R2, a first overshoot resistor Protection resistor R3, freewheeling diode D2, energy storage inductor L.

Specifically, as shown in FIG. 4 , the switching MOS transistor Q1 may have a first terminal S, a second terminal D and a control terminal G. The first terminal S of the switching MOS transistor Q1 is connected to the ground DGND. The laser driver chip U1 can have the aforementioned PWM signal receiving terminal Vpwm, driving terminal DRV and output voltage terminal Vcc, and also has an input voltage terminal Vin, a ground terminal Vss and a chip select terminal CS. The input voltage terminal Vin of the laser driver chip U1 is connected to the power supply terminal VCC. For example, the voltage provided by the power supply terminal VCC in the embodiment of the present disclosure may be 12V, but is not limited thereto. The ground terminal Vss of the laser driver chip U1 is connected to the ground DGND.

In the embodiment of the present disclosure, the switching MOS transistor Q1 plays a switching role, and the driving terminal DRV of the laser driver chip U1 adjusts the change of the output current by adjusting the switching frequency and duration of the switching MOS transistor Q1, thereby adjusting the emission of the laser transmitter 100 laser power value.

For example, the switching MOS transistor Q1 in the embodiment of the present disclosure may be of NMOS type, but is not limited thereto, and may also be of PMOS type.

As shown in Figure 4, the two ends of the first pull-up resistor R5 are respectively connected to the PWM signal receiving terminal Vpwm and the output voltage terminal Vcc of the laser driver chip U1.

As shown in Figure 3 and Figure 4, two current sensing resistors can be set and set in parallel, corresponding to the labels of R1 and R2 in Figure 4 respectively. Specifically, the two ends of the current sensing resistors R1 and R2 are respectively connected to the input voltage terminal Vin and the chip selection terminal CS of the laser driver chip U1, and one end of the current sensing resistors R1 and R2 is connected to the chip selection terminal CS of the laser transmitter 100. Positive connection.

In this embodiment, the current sensing resistors R1 and R2 are used to set the maximum output current of the laser driver chip U1. The specific value depends on the specific situation and will not be described in detail here.

As shown in Figure 4, the two ends of the first overshoot protection resistor R3 are respectively connected to the drive terminal DRV of the laser driver chip U1 and the control terminal G of the switching MOS transistor Q1 for overshoot protection.

As shown in Figure 4, the cathode and anode of the freewheeling conduction diode D2 are respectively connected to the input voltage terminal Vin of the laser driver chip U1 and the second terminal D of the switching MOS transistor Q1. The freewheeling conduction diode D2 plays a freewheeling role. It is ensured that when the switch MOS tube Q1 is turned off, the current has a complete conduction loop.

As shown in FIG. 3 and FIG. 4 , the two ends of the energy storage inductor L are respectively connected to the second end D of the switching MOS transistor Q1 and the negative electrode of the laser transmitter 100 .

In the embodiment of the present disclosure, the energy storage inductor L plays an energy storage role. When the switching MOS transistor Q1 is turned off, since the inductor current cannot change suddenly, the continuity of the current on the laser transmitter 100 can be ensured.

The laser transmitter 100 may include a plurality of laser diodes connected in series, such as the two shown in Figure 4, corresponding to the labels D3 and D4 respectively. The cathode of the laser diode D4 is connected to the energy storage inductor L, and the anode of the laser diode D4 is connected to the laser. The cathode of the diode D3 is connected, and the anode of the laser diode D3 is connected to one end of the current sensing resistors R1 and R2 connected to the chip select terminal CS.

For example, the rated laser power value of the laser diode can be 5W, 10W or 20W, but is not limited to this, and can also be other values, depending on the specific situation.

In an exemplary embodiment of the present disclosure, the laser driving circuit 120 further includes a filter circuit to perform a filtering function.

Specifically, three filter circuits may be provided, namely a first filter circuit, a second filter circuit and a third filter circuit.

Among them, as shown in Figure 3 and Figure 4, one end of the first filter circuit is connected to the input voltage terminal Vin of the laser driver chip U1, and the other end is connected to the ground DGND. One end of the second filter circuit is connected to the output voltage terminal Vcc of the laser driver chip U1, and the other end is connected to the ground DGND. One end of the third filter circuit is connected to one end of the current sensing resistors R1 and R2 connected to the chip selection terminal CS, and the other end is connected to the end of the energy storage inductor L connected to the negative electrode of the laser transmitter 100 .

Further, as shown in Figure 4, the first filter circuit may include two filter capacitors C3 and C4 arranged in parallel, the second filter circuit may include two filter capacitors C1 and C2 arranged in parallel, and the second filter circuit may include a filter capacitor C3 and C4 arranged in parallel. Capacitor C5.

In one embodiment of the present disclosure, as shown in FIG. 3 and FIG. 4 , the laser driving device 10 further includes a level conversion circuit 140 connected to the PWM signal output end of the main control chip 110 and the PWM signal receiving end of the laser driving circuit 120 By setting the level conversion circuit 140 between the terminals Vpwm, the compatibility of the entire laser driving device 10 can be improved, and it can be compatible with more types of laser driving chips.

Specifically, as shown in FIG. 3 and FIG. 4 , the level conversion circuit 140 also includes a current limiting protection resistor R6, a second pull-up resistor R4, a second overshoot protection resistor R7, a first triode Q3 and a second triode. Diode Q2. Among them, the base b of the first transistor Q3 is connected to the PWM signal output terminal of the main control chip 110 through the second overshoot protection resistor R7, and the collector c of the first transistor Q3 is connected to the PWM signal output terminal of the main control chip 110 through the second pull-up resistor R4. The power supply terminal is connected, and the emitter e of the first transistor Q3 is connected to the ground DGND.

The base b of the second transistor Q2 is connected to the collector of the first transistor Q3 through the current limiting protection resistor R6, and the collector c of the second transistor Q2 is connected to the PWM signal receiving terminal Vpwm of the laser driver chip U1. , the emitter e of the second transistor Q2 is connected to ground DGND.

For example, the first transistor Q3 and the second transistor Q2 in the embodiment of the present disclosure may be of NPN type, but are not limited thereto, and may also be of PNP type, depending on the specific circumstances.

Based on the above content, when the voltage output by the output voltage terminal Vcc of the laser driver chip U1 is greater than the set input voltage of the input terminal Vth of the delay protection chip U2, the output terminal Vout of the delay protection chip U2 outputs a high level. At this time The laser driver chip U1 normally receives the MCU_PWM signal and adjusts the laser power; when MCU_PWM is high level, the PWM signal receiving end Vpwm of the laser driver chip U1 is a high level signal; when MCU_PWM is low level, the PWM signal of the laser driver chip U1 The signal receiving end Vpwm is a low-level signal; thereby realizing the normal high and low changes of PWM, at this time the entire circuit works normally and adjusts the optical power of the output laser.

When the laser driver chip U1 is abnormal or malfunctions, that is, when the voltage output by the output voltage terminal Vcc of the laser driver chip U1 is less than the set input voltage of the input terminal Vth of the delay protection chip U2, the output terminal of the delay protection chip U2 Vout is low level. At this time, the PWM signal receiving end Vpwm of the laser driver chip U1 is pulled low and cannot receive the MCU_PWM signal; the entire system is protected to prevent abnormal laser output.

Embodiments of the present disclosure also provide a laser driving method for use in a laser system. For this laser system, reference may be made to the content described in any of the foregoing embodiments, which will not be described in detail here. As shown in Figure 5, the laser driving method includes:

S1. Obtain the actual laser power value of the laser transmitter 100 detected by the optical power detection device;

S2. According to the relationship between the actual laser power value detected by the optical power detection device and the reference laser power value, the corresponding PWM signal value is input to the laser driving circuit. The laser driving circuit can adjust the input to the laser transmitter 100 according to the PWM signal value. The current value is such that the actual laser power value of the laser transmitter 100 is equal to the reference laser power value.

It should be understood that this laser driving method is implemented by the main control chip 110 in the aforementioned laser system. Furthermore, the terms “first”, “second”, “third”, etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Thus, features defined as "first," "second," "third," etc. may explicitly or implicitly include one or more of these features. In the description of the present disclosure, "plurality" means two or more than two, unless otherwise expressly and specifically limited.

In this disclosure, unless otherwise explicitly stated and limited, the terms "installation", "connection", "connection", "fixing" and other terms should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. , or integrated; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interaction between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

In the description of this specification, reference to the terms "some embodiments," "exemplarily," etc. means that a particular feature, structure, material or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present disclosure or in the example. In this specification, the schematic expressions of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art may combine and combine different embodiments or examples and features of different embodiments or examples described in this specification unless they are inconsistent with each other.

Although the embodiments of the present disclosure have been shown and described above, it can be understood that the above-mentioned embodiments are illustrative and should not be construed as limitations of the present disclosure. Those of ordinary skill in the art can make modifications to the above-mentioned embodiments within the scope of the present disclosure. The embodiments are subject to changes, modifications, substitutions and modifications, so any changes or modifications made in accordance with the claims and description of the present disclosure shall be within the scope of the patent of the present disclosure.

Claims

A laser system, including:

Master chip;

A laser transmitter, the laser transmitter has a reference laser power value;

A laser drive circuit connects the main control chip and the laser transmitter, and the laser drive circuit is used to adjust the actual laser power value of the laser transmitter according to the PWM signal value sent by the main control chip;

Optical power detection device, used to detect the actual laser power value of the laser transmitter;

Wherein, the main control chip is used to adjust the PWM signal value output by it according to the relationship between the actual laser power value detected by the optical power detection device and the reference laser power value, so that the laser transmitter The actual laser power value is equal to the reference laser power value.
The laser system of claim 1, wherein

The main control chip is used to reduce the PWM signal value output by the optical power detection device when the actual laser power value detected by the optical power detection device is greater than the reference laser power value, so that the actual laser power of the laser transmitter The value is equal to the reference laser power value;

The main control chip is used to increase the PWM signal value output by the optical power detection device when the actual laser power value detected by the optical power detection device is less than the reference laser power value, so that the actual laser power of the laser transmitter The power value is equal to the reference laser power value.
The laser system according to claim 2, wherein the optical power detection device includes an optical power attenuation circuit and a photoelectric conversion circuit;

The optical power attenuation circuit is used to obtain the actual laser power value emitted by the laser transmitter and adjust it to an attenuated laser power value in a fixed proportion, the attenuated laser power value is less than the actual laser power value, and It is also less than the maximum optical power value that the photoelectric conversion circuit can receive;

The photoelectric conversion circuit is used to convert the attenuated laser power value into an actual voltage value;

Wherein, the main control chip is used to reduce the PWM signal value output by the main control chip when the actual voltage value is greater than the reference voltage value, so as to adjust the actual laser power value of the laser transmitter to reduce to the reference laser power. value; also used to increase the PWM signal value output by it when the actual voltage value is less than the reference voltage value, so as to adjust the actual laser power value of the laser transmitter to increase to the reference laser power value. .
The laser system of claim 3, wherein the photoelectric conversion circuit includes:

Photoelectric tube, used to obtain the attenuated laser power value generated by the optical power attenuation circuit, and convert the attenuated laser power value into a current value. The attenuated laser power value is smaller than the maximum light that the photoelectric tube can receive. power value;

A current-to-voltage conversion amplification circuit is used to convert the current value output by the photoelectric tube into a voltage value, and amplify the converted voltage value to generate the actual voltage value.
The laser system according to claim 4, wherein the current-to-voltage conversion amplifier circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, an operational amplifier chip, a filter circuit and a voltage follower circuit; wherein,

Both ends of the first resistor are connected to the first node and the second node respectively, the first node is connected to the first pole of the photoelectric tube, the second pole of the photoelectric tube is connected to the power supply end, and the The second node is connected to the ground;

The positive terminal of the operational amplifier chip is connected to the first node through the second resistor, and the negative terminal of the operational amplifier chip is connected to the second node through the third resistor;

One end of the fourth resistor is connected to the negative terminal of the operational amplifier chip, and the other end is connected to the output terminal of the operational amplifier chip;

The positive terminal of the voltage following circuit is connected to the output terminal of the operational amplifier chip through the filter circuit, the negative terminal of the voltage following circuit is connected to the output terminal of the voltage following circuit, and the output of the voltage following circuit The terminal is connected to the main control chip, and the two power terminals of the voltage following circuit are connected to the power supply terminal and the ground terminal respectively.
The laser system according to claim 5, wherein the filter circuit includes a filter resistor and a filter capacitor,

The two ends of the filter resistor are respectively connected to the output end of the operational amplifier chip and the positive end of the voltage follower circuit;

The two poles of the filter capacitor are respectively connected to the positive terminal and the ground terminal of the voltage following circuit.
The laser system according to claim 2, wherein a plurality of said optical power detection devices are provided and distributed in a matrix at multiple positions; wherein each said optical power detection device is connected in parallel to the digital signal of the main control chip. analog converter.
The laser system according to claim 1, wherein the laser system further includes a delay protection circuit, the input end of the delay protection circuit is connected to the output voltage end of the laser drive circuit, the delay protection circuit The output end is connected to the PWM signal receiving end of the laser driving circuit; wherein,

The delay protection circuit is used to detect the output voltage of the laser drive circuit and output a first level signal when the output voltage reaches the target voltage threshold. The PWM signal receiving end of the laser drive circuit is connected to the delay When the first level signal output by the protection circuit is capable of receiving the PWM signal sent by the main control chip;

The delay protection circuit is also used to output a second level signal when the output voltage does not reach the target voltage threshold. The PWM signal receiving end of the laser driving circuit outputs a second level signal when the delay protection circuit outputs a second level signal. The signal is received when the signal is 0.
The laser system according to claim 1, further comprising a level conversion circuit connected between the PWM signal output end of the main control chip and the PWM signal receiving end of the laser driving circuit.
A laser driving method for a laser system, wherein the laser system includes a laser transmitter, a laser driving circuit and an optical power detection device, the laser transmitter has a reference laser power value, wherein the laser driving method includes :

Obtain the actual laser power value of the laser transmitter detected by the optical power detection device;

According to the relationship between the actual laser power value detected by the optical power detection device and the reference laser power value, the corresponding PWM signal value is input to the laser driving circuit, and the laser driving circuit can be based on the PWM signal value. The current value input to the laser emitter is adjusted so that the actual laser power value of the laser emitter is equal to the reference laser power value.