Laser emission circuit and laser radar

Abstract

The present application discloses a laser emitting circuit and laser radar, belonging to the field of laser radar. By modifying the structure of the laser emitting circuit, during the energy conversion phase, the energy conversion current from the energy storage element does not pass through the laser diode. The laser diode is in a reverse biased state relative to the energy conversion current. Therefore, the parasitic capacitance of the energy release switch element does not cause the laser diode to emit light prematurely due to the energy conversion charging process, thus preventing the laser diode from emitting light at unexpected times and solving the problem of laser light leakage.

Description

Technical Field

[0001] The present application relates to the field of laser circuits, and in particular to a laser emission circuit and a laser radar. Background Art

[0002] In a laser radar, a laser emitting circuit is used to emit laser light. The working process of the laser emitting circuit is generally divided into three stages: a charging stage, a conversion stage, and an energy release stage. The charging stage includes charging an energy storage element and storing electrical energy in the energy storage element. The conversion stage includes transferring the electrical energy stored in the energy storage element to the conversion element after the charging stage is completed. The energy release stage includes releasing the electrical energy stored in the conversion element after the energy transfer is completed to drive the laser diode to emit laser light. Currently, with the development of laser radar, laser radar needs to complete the charging stage in a shorter time. However, the inventors have found that in the process of reducing the charging time, the original laser emitting circuit will emit laser light prematurely during the conversion stage, resulting in the phenomenon of "laser light leakage", that is, the laser emitting circuit emits light at unexpected times, which affects the measurement performance of the laser radar. Summary of the Invention

[0003] The laser emission circuit and laser radar provided in the embodiments of the present application can solve the problem of laser light leakage caused by the laser emission circuit emitting laser during the energy conversion phase in the related art. The technical solution is as follows:

[0004] In a first aspect, an embodiment of the present application provides a laser emission circuit, comprising:

[0005] a charging circuit connected to the energy discharging circuit, the charging circuit comprising a first energy storage element, configured to charge the first energy storage element using a charging current from a power supply during a charging phase;

[0006] an energy conversion circuit connected to the energy charging circuit and the energy releasing circuit, the energy conversion circuit including a second energy storage element, configured to charge the second energy storage element using an energy conversion current from the first energy storage element during an energy conversion phase; wherein, during the energy conversion phase, the energy conversion current maintains a reverse bias state for the laser diode;

[0007] an energy release circuit connected to the energy conversion circuit, the energy release circuit including the laser diode, and configured to drive the laser diode to emit light using the energy release current from the second energy storage element during the energy release phase;

[0008] Wherein, the energy conversion circuit further includes a bypass diode and a boost rectifier diode; the energy release circuit includes an energy release switch;

[0009] In the reverse bias state, the energy conversion current flows through the boost rectifier diode and the second energy storage element in the circuit loop to the ground, and the energy conversion current flows through the bypass diode and the parasitic capacitance of the energy release switch to the ground; or, in the reverse bias state, the energy conversion current flows through the boost rectifier diode, the bypass diode and the second energy storage element to the ground, and flows through the parasitic capacitance to the ground.

[0010] In a second aspect, an embodiment of the present application provides a laser radar, including the above-mentioned laser emission circuit.

[0011] The beneficial effects of the technical solutions provided by some embodiments of the present application include at least:

[0012] By changing the structure of the laser emission circuit, the energy conversion current from the energy storage element does not pass through the laser diode during the energy conversion stage. The laser diode is in a reverse bias state relative to the energy conversion current. Therefore, the parasitic capacitance of the energy release switch element will not cause the laser diode to emit light prematurely due to the energy conversion charging process, thus avoiding the laser diode from emitting light at unexpected times and solving the problem of laser light leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0014] Figure 1 This is a schematic structural diagram of a laser emission circuit of a related technology provided by an embodiment of the present application;

[0015] Figure 2 is a block diagram of a laser emission circuit provided in an embodiment of the present application;

[0016] Figure 3 This is a schematic diagram of the structure of the laser emission circuit provided in an embodiment of the present application;

[0017] Figure 4 is another structural diagram of the laser emission circuit provided in an embodiment of the present application;

[0018] Figure 5 is another structural diagram of the laser emission circuit provided in an embodiment of the present application;

[0019] Figure 6 is another structural diagram of the laser emission circuit provided in an embodiment of the present application;

[0020] Figure 7 This is another structural diagram of the laser emission circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present application clearer, the embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

[0022] Figure 1 The schematic diagram of the structure of the laser emission circuit in the related art is shown. The working process of the laser emission circuit is divided into three stages: charging stage, energy conversion stage and energy release stage. The three stages are described in detail below.

[0023] Charging phase: The gate of switch Q1 is connected to the pulse generator TX_CHG, which sends rectangular pulses to control the on and off of switch Q1. The pulse generator TX_EN sends rectangular pulses to control the on and off of switch Q2. When switch Q1 is on and switch Q2 is off, the laser emission circuit is in the charging phase. The current generated by the power supply VCC forms a loop through inductor L1 and switch Q1, charging inductor L1. Assuming that the on time of switch Q1 is △t (△t is also called the charging time), the current increment in inductor L1 follows the formula: △I = (VCC × △t) / L1 (Formula 1).

[0024] In Formula 1, VCC represents the voltage value of the power supply VCC, and L1 represents the inductance value of the inductor L1.

[0025] The energy of charging follows the formula

[0026] Substituting formula 1 into formula 2, we get According to formula 3, the charging energy W L It is inversely proportional to the inductance value L1 and directly proportional to the square of the on-time Δt of the switch tube Q1. If you want to reduce the on-time of the switch tube Q1 while keeping the charging energy WL unchanged, you need to reduce the inductance value of the inductor L1.

[0027] From Formula 1 and Formula 2, it can be seen that the pulse generator TX_CHG can control the width of the rectangular pulse to control the on-time of the switch tube Q1, that is, to control the charging time of the inductor L1, thereby changing the amount of charging energy and adjusting the laser emission power.

[0028] Energy transfer stage: When the switch tube Q1 is in the off state and the switch tube Q2 is also in the off state, the laser emission circuit is in the energy transfer stage. Because the current of the inductor L1 cannot change suddenly, the inductor L1 stores charging energy. The inductor L1 charges the energy storage element C2 through the boost rectifier diode D1, and the charging energy stored in the inductor L1 is transferred to the energy storage element C2.

[0029] Although the switch tubes Q1 and Q2 are in the off state, there is parasitic capacitance between the drain and source of the two switch tubes. Let the parasitic capacitance between the drain and source of the switch tube Q1 be CQ1-DS, and the parasitic capacitance between the drain and source of the switch tube Q2 be CQ2-DS.

[0030] Then the current increment △I of the inductor L1 will be divided through the following three branches:

[0031] Loop 1: Current forms a loop from inductor L1 through parasitic capacitor CQ1-DS to ground GND. The current in this loop is defined as ICQ1.

[0032] Loop 2: The current flows from the inductor L1 through the boost rectifier diode D1 and the energy storage element C2 to the ground GND to form a loop. The current in this loop is defined as IC2.

[0033] Loop 3: The current flows from L1 through the boost rectifier diode D1, the laser diode LD, CQ2-DS to the ground (GND) to form a loop, and the current is defined as ICQ2.

[0034] Among the above three circuits, only circuit 2 is the main charging circuit, which realizes the energy storage function of the energy storage element C2. Circuit 1 and circuit 3 are both caused by parasitic capacitance.

[0035] Considering that the forward voltage drop of the boost rectifier diode D1 and the laser diode LD is relatively small, the impact on each circuit is small. In order to simplify the calculation, the impact of the voltage drop of the boost rectifier diode D1 and the laser diode LD on the circuit is ignored, and ΔI = IC2 + ICQ1 + ICQ2 (Formula 4) can be obtained.

[0036] Assume that CQ1-DS = CQ2-DS = C2 / N, where N is a number greater than 0, CQ1-DS represents the capacitance of the parasitic capacitance of the switch tube Q1, CQ2-DS represents the capacitance of the parasitic capacitance of the switch tube Q2, and C2 represents the capacitance of the energy storage element C2. Then the current flowing through each circuit is:

[0037]

[0038]

[0039]

[0040] According to loop 3, ICQ2 equals the current ILD of the laser diode LD, i.e., ICQ2 = ILD (Equation 8). Assuming the current threshold for laser diode LD's emission is ILD-TH, if ICQ2 is greater than the current threshold and greater than ILD-TH, the laser diode LD will emit laser light during the energy conversion phase, causing light leakage. In other words, the laser emission circuit emits light at unexpected times, affecting the lidar's measurement performance.

[0041] For example, in order to meet the comprehensive performance of the lidar, such as increasing the system frequency and realizing dual-transmission and multi-transmission functions, it is required to reduce the charging time △t.

[0042] Under the premise of maintaining the energy WL of inductor L1 and the voltage value of power supply VCC unchanged, according to Formula 3, the inductance value of inductor L1 in the charging circuit needs to be reduced accordingly. Then, according to Formula 1, if the inductance value of inductor L1 is reduced, the charging current △I generated by inductor L1 will increase accordingly. Finally, according to Formulas 7 and 8, when the charging current △I increases, the current flowing through laser diode LD during the energy conversion process will also increase. In this way, the current flowing through laser diode LD may meet the condition ICQ2 = ILD ≥ ILD-TH. At this time, laser diode LD will emit light at an unexpected time, causing "laser leakage" phenomenon.

[0043] Energy release phase: When switch Q1 is off and switch Q2 is on, the laser emission circuit is in the energy release phase. The energy stored in energy storage element C2 forms a loop through laser diode LD, switch Q2, and ground GND, driving laser diode LD to emit laser light, thereby causing laser diode LD to emit laser light at the desired time.

[0044] In order to solve the above technical problems, the present invention provides a laser emission circuit. Figure 2 As shown, the laser emission circuit of the embodiment of the present application includes: a charging circuit 201, an energy conversion circuit 202 and an energy release circuit 203.

[0045] Among them, the charging circuit 201 is connected to the energy conversion circuit 202. The charging circuit 201 includes a first energy storage element, which is used to store electrical energy. The first energy storage element can be a capacitor or an inductor, or can include both a capacitor and an inductor. During the charging stage, the charging circuit 201 uses the charging current from the power supply to charge the first energy storage element.

[0046] Energy conversion circuit 202 is connected to charging circuit 201 and discharging circuit 203. Energy conversion circuit 202 includes a second energy storage element. During the energy conversion phase, energy conversion circuit 202 uses the energy conversion current from the first energy storage element to charge the second energy storage element. During the energy conversion phase, the energy conversion current maintains a reverse bias on the laser diode, preventing the laser diode from emitting light throughout the energy conversion phase. The second energy storage element is used to store electrical energy and can be a capacitor, an inductor, or both.

[0047] The energy release circuit 203 includes the above-mentioned laser diode and is used to drive the laser diode to emit light using the energy release current from the second energy storage element during the energy release phase. The energy release phase is the normal light-emitting time of the laser diode.

[0048] In an embodiment of the present application, by changing the structure of the laser emitting circuit, the energy conversion current from the energy storage element does not pass through the laser diode during the energy conversion stage of the laser emitting circuit, and the laser diode is in a reverse biased state relative to the energy conversion current. Therefore, the parasitic capacitance of the energy release switching element will not cause the laser diode to emit light prematurely due to the energy conversion charging process, thereby avoiding the laser diode from emitting light at unexpected times and solving the problem of laser light leakage.

[0049] In some embodiments of the present application, the number of energy conversion circuits 202 can be one or more, and the number of energy release circuits 203 can also be one or more; when the number of energy conversion circuits 202 is multiple, the number of energy release circuits 203 is also correspondingly multiple, and the energy conversion circuits 202 and the energy release circuits 203 are in a one-to-one mapping relationship; when the number of energy conversion circuits 202 is one, the number of energy release circuits 203 can be multiple, that is, the energy conversion circuits 202 and the energy release circuits 203 are in a one-to-many relationship.

[0050] See also Figure 3 , is a structural diagram of a laser emission circuit provided in an embodiment of the present application.

[0051] In some embodiments of the present application, the charging circuit 201 includes: a power supply VCC, an inductor L1, an energy-discharging switching element Q1, and a decoupling capacitor C1. The first energy storage element is the inductor L1. The power supply VCC may be a DC power supply. The positive electrode of the power supply VCC is grounded via the decoupling capacitor C1, and the negative electrode of the power supply VCC is grounded. The first end of the inductor L1 is connected to the positive electrode of the power supply VCC, the second end of the inductor L1 is connected to the first end of the energy-discharging switching element Q1, and the second end of the inductor L1 is connected to the energy conversion circuit 202. The second end of the energy-discharging switching element Q1 is grounded. The charging switching element Q1 may be a transistor or a MOS transistor, for example, a PNP transistor or an NPN transistor, and the MOS transistor may be an NMOS transistor, a PMOS transistor, or a gallium nitride switch transistor.

[0052] In some embodiments of the present application, the energy release circuit 203 includes an energy release switch element Q2 and a laser diode LD. The anode of the laser diode LD is connected to the energy transfer circuit 202, the cathode of the laser diode LD is connected to the first terminal of the energy release switch element Q2, and the second terminal of the energy release switch element Q2 is grounded. The energy release switch element Q2 can be a transistor or a MOS transistor. For example, the transistor can be a PNP transistor or an NPN transistor, and the MOS transistor can be an NMOS transistor, a PMOS transistor, or a gallium nitride switch transistor.

[0053] Optionally, the energy release circuit 203 further includes: a dynamic compensation capacitor C3, which is connected between the first terminal and the second terminal of the energy release switch element.

[0054] In some embodiments of the present application, the energy conversion circuit 202 includes: a capacitor C2 and a bypass diode D2, and the second energy storage element is the capacitor C2; wherein the first end of the capacitor C2 is connected to the first end of the inductor L1, and the second end of the capacitor C2 is grounded; the anode of the bypass diode D2 is connected to the second end of the inductor L1, and the cathode of the bypass diode D2 is connected to the first end of the energy release switch element Q2.

[0055] Optionally, the energy conversion circuit 202 further includes a boost rectifier diode D1, wherein the anode of the boost rectifier diode D1 is connected to the second end of the inductor L1, and the cathode of the boost rectifier diode D1 is connected to the first end of the capacitor C2. The boost rectifier diode D1 has a unidirectional conduction function, which prevents the capacitor C2 from reversely discharging during the energy conversion and release phases, thereby preventing the capacitor C2 from causing a backflow of electrical energy in the capacitor C2 and causing electrical energy leakage in the capacitor C2. It is understood that the boost rectifier diode D1 may be a Schottky diode.

[0056] The following describes the working process of the laser emission circuit by taking the example that both the charging switch element Q1 and the releasing switch element Q2 are MOS tubes.

[0057] 1. Charging stage.

[0058] Pulse generator TX_CHG sends rectangular pulses to the gate of MOS transistor Q1, turning it on and turning off MOS transistor Q2. Power supply VCC charges inductor L1. Decoupling capacitor C1, connected between the positive and negative terminals of power supply VCC, prevents parasitic oscillations caused by the positive feedback path formed by power supply VCC.

[0059] 2. Energy conversion stage.

[0060] After charging is complete, the pulse generator TX_CHG stops sending rectangular pulses to the MOS transistor Q1, and the MOS transistor Q1 is in the off state. At this time, the MOS transistor Q2 is still in the off state. Because the current of the inductor L1 cannot change suddenly, the inductor L1 will continue to generate the energy conversion current of ΔI, which is divided into two paths. One path passes through the boost rectifier diode D1 and the capacitor C2 to the ground to form a loop. In this loop, the charging current charges the energy storage element C2. Due to the action of the bypass diode D2, the laser diode LD is in a reverse biased state, so the laser diode LD will not emit light. The other path of the charging current passes through the bypass diode D2 and the parasitic capacitance CQ2-DS of the MOS transistor Q2 (not shown in the figure) to the ground to form another loop. In this loop, the charging current does not pass through the laser diode LD, so the laser diode LD will not emit light.

[0061] Obviously, neither of the above two energy conversion currents will flow through the laser diode LD, so it will not emit light at unexpected times, solving the problem of laser light leakage.

[0062] 3. Energy release stage.

[0063] Pulse generator TX_EN sends a rectangular pulse to the gate of MOS transistor Q2, turning it on and turning off MOS transistor Q1. The electrical energy stored in capacitor C2 flows through the laser diode LD, the drain and source of MOS transistor Q2, and then to ground, forming a discharge circuit that drives the laser diode LD to complete laser emission. Furthermore, dynamic compensation capacitor C3 also forms its own discharge circuit through the drain and source of MOS transistor Q2, releasing the stored energy during the conversion process and preparing for the next laser emission cycle.

[0064] See also Figure 4 , is a structural diagram of a laser emission circuit provided in an embodiment of the present application.

[0065] In some embodiments of the present application, the charging circuit 201 includes: a power supply VCC, an inductor L1, a decoupling capacitor C1 and a charging switch element Q1, wherein the inductor L1 is a first energy storage element. The connection relationship between the various elements in the charging circuit 201 can be referred to Figure 3 As shown, I will not repeat it this time.

[0066] In some embodiments of the present application, the energy release circuit 203 includes an energy release switch element Q2 and a laser diode LD. The energy release switch element Q1 can be a transistor or a MOS transistor. For example, the transistor can be a PNP transistor or an NPN transistor, and the MOS transistor can be an NMOS transistor, a PMOS transistor, or a gallium nitride switch transistor.

[0067] The cathode of the laser diode LD is connected to the energy conversion circuit 202 , and the anode of the laser diode LD is grounded. The first end of the energy release switch element Q2 is connected to the energy conversion circuit 202 , and the second end of the energy release switch element Q2 is connected to the anode of the laser diode LD.

[0068] Optionally, the energy release circuit 203 further includes: a dynamic compensation capacitor C3, which is connected between the first terminal and the second terminal of the energy release switch element.

[0069] In some embodiments of the present application, the energy conversion circuit 202 includes: a capacitor C2 and a bypass diode D2, where the capacitor C2 is a second energy storage element; the first end of the capacitor C2 is connected to the second end of the inductor L1, and the second end of the capacitor C2 is connected to the cathode of the laser diode LD; the anode of the bypass diode D2 is connected to the cathode of the laser diode LD, and the cathode of the bypass diode D2 is grounded.

[0070] Furthermore, the energy conversion circuit 202 also includes a boost rectifier diode D1, wherein the anode of the boost rectifier diode D1 is connected to the second end of the inductor L1, and the cathode of the boost rectifier diode D1 is connected to the first end of the capacitor C2. The boost rectifier diode D1 has a unidirectional conduction function, which prevents the capacitor C2 from reversely discharging during the energy conversion and release phases, thereby preventing the backflow of electrical energy in the capacitor C2 and causing the electrical energy in the capacitor C2 to leak. The boost rectifier diode D1 can be a Schottky diode.

[0071] Figure 4 The charging switch element Q1 and the releasing switch element Q2 can be MOS tubes. The working process of the laser emission circuit is described below:

[0072] 1. Charging stage.

[0073] The process of the charging phase can be referred to Figure 3 The description of the mid-charging stage will not be repeated here.

[0074] 2. Energy conversion stage.

[0075] After charging is complete, the pulse generator TX_CHG stops sending rectangular pulses to the MOS transistor Q1, and the MOS transistor Q1 is in the off state. At this time, the MOS transistor Q2 is still in the off state. Because the current in the inductor L1 cannot change suddenly, the inductor L1 will continue to generate the conversion current of ΔI. After passing through the boost rectifier diode D1, it is divided into two paths. One path passes through the capacitor C2 and the bypass diode D2 to the ground to form a loop. In this loop, the charging current charges the capacitor C2. Due to the action of the bypass diode D2, the laser diode LD is in a reverse biased state, so the laser diode LD will not emit light. The other path of the charging current passes through the parasitic capacitor CQ2-DS (not shown) of the MOS transistor Q2 to the ground to form another loop. In this loop, the charging current does not pass through the laser diode LD, so the laser diode LD will not emit light.

[0076] Obviously, neither of the above two energy conversion currents will flow through the laser diode LD, so it will not emit light at unexpected times, solving the problem of laser light leakage.

[0077] 3. Energy release stage.

[0078] Pulse generator TX_EN sends a rectangular pulse to the gate of MOS transistor Q2, turning it on. At this point, MOS transistor Q1 is off. The electrical energy stored in capacitor C2 forms a discharge circuit through MOS transistor Q2, laser diode LD, and ground, driving laser diode LD to complete laser emission. Furthermore, dynamic compensation capacitor C3 also forms its own discharge circuit through the drain and source of MOS transistor Q2, releasing the stored energy during the conversion process and preparing for the next laser emission cycle.

[0079] See also Figure 5 , which is a result schematic diagram of a laser emission circuit provided in an embodiment of the present application.

[0080] In some embodiments of the present application, the charging circuit 201 includes a power supply VCC, an inductor L1, a decoupling capacitor C1, and a charging switch element Q1; the inductor L1 is a first energy storage element, and the connection relationship between the various elements in the charging circuit 201 can be referred to. Figure 3 The description is not repeated here.

[0081] In some embodiments of the present application, the energy release circuit 203 includes a laser diode LD and an energy release switch element Q2. The anode of the laser diode LD is connected to the energy transfer circuit 202, the cathode of the laser diode LD is connected to the first terminal of the energy release switch element Q2, and the second terminal of the energy release switch element Q2 is grounded. The energy release switch element Q1 can be a transistor or a MOS transistor. For example, the transistor can be a PNP transistor or an NPN transistor, and the MOS transistor can be an NMOS transistor, a PMOS transistor, or a gallium nitride switch transistor.

[0082] Optionally, the energy release circuit 203 further includes: a dynamic compensation capacitor C3, which is connected between the first terminal and the second terminal of the energy release switch element.

[0083] In some embodiments of the present application, the energy conversion circuit 202 includes a capacitor C2 and a bypass diode D2, where the capacitor C2 is a second energy storage element, the first end of the capacitor C2 is connected to the anode of the laser diode LD, and the cathode of the capacitor C2 is grounded; the cathode of the bypass diode D2 is connected to the anode of the laser diode LD, and the anode of the bypass diode D2 is connected to the cathode of the laser diode LD.

[0084] Optionally, the energy conversion circuit 202 further includes a boost rectifier diode D1, wherein the anode of the boost rectifier diode D1 is connected to the second end of the inductor L1, and the cathode of the boost rectifier diode D1 is connected to the cathode of the laser diode LD. The boost rectifier diode D1 has a unidirectional conduction function, which prevents the capacitor C2 from reversely discharging during the energy conversion and release phases, thereby preventing the backflow of electrical energy in the capacitor C2 and causing leakage of electrical energy in the capacitor C2. The boost rectifier diode D1 can be a Schottky diode.

[0085] Figure 5 The charging switch element Q1 and the releasing switch element Q2 can be MOS tubes. The working process of the laser emission circuit includes:

[0086] 1. Charging stage.

[0087] The process of the charging phase can be referred to Figure 3 The description of the mid-charging stage will not be repeated here.

[0088] 2. Energy conversion stage.

[0089] After charging is complete, the pulse generator TX_CHG stops sending rectangular pulses to the MOS transistor Q1, and the MOS transistor Q1 is in the off state. At this time, the MOS transistor Q2 is still in the off state. Because the current in the inductor L1 cannot change suddenly, the inductor L1 will continue to generate the conversion current of ΔI. After passing through the boost rectifier diode D1, it is divided into two paths. One path passes through the bypass diode D2 and the capacitor C2 to the ground to form a loop. In this loop, the charging current charges the capacitor C2. Due to the action of the bypass diode D2, the laser diode LD is in a reverse biased state, so the laser diode LD will not emit light. The other path of the charging current passes through the parasitic capacitor CQ2-DS (not shown) of the MOS transistor Q2 to the ground to form another loop. In this loop, the charging current does not pass through the laser diode LD, so the laser diode LD will not emit light.

[0090] Obviously, neither of the above two energy conversion currents will flow through the laser diode LD, so it will not emit light at unexpected times, solving the problem of laser light leakage.

[0091] 3. Energy release stage.

[0092] Pulse generator TX_EN sends a rectangular pulse to the gate of MOS transistor Q2, turning it on and turning off MOS transistor Q1. The electrical energy stored in capacitor C2 passes through laser diode LD, MOS transistor Q2, and ground, forming a release (discharge) circuit that drives laser diode LD to complete laser emission. Furthermore, dynamic compensation capacitor C3 also forms its own discharge circuit through the drain and source of MOS transistor Q2, releasing the stored energy during the conversion process and preparing for the next laser emission cycle.

[0093] See also Figure 6 , is a structural diagram of a laser emission circuit provided in an embodiment of the present application.

[0094] In some embodiments of the present application, there is one energy conversion circuit 202 and multiple energy release circuits 203, i.e., there is a one-to-many relationship between the energy conversion circuit 202 and the energy release circuit 203, and the multiple energy release circuits 203 are connected in parallel. There are multiple bypass diodes D2 in the energy conversion circuit 202, and the number of bypass diodes D2 is equal to the number of energy release circuits 203, i.e., each energy release circuit 203 is provided with a bypass diode D2. In some embodiments, multiple energy release circuits 203 can also share a bypass diode D2. Figure 6 In the figure, one energy conversion circuit 202 corresponds to three energy release circuits 203 for illustration.

[0095] in, Figure 6 The connection relationship and working principle of each component in the charging circuit 201, the energy conversion circuit 202 and the energy release circuit 203 can be referred to Figure 3 As shown, no further details are given here.

[0096] See also Figure 7 , is a structural diagram of a laser emission circuit provided in an embodiment of the present application.

[0097] In some embodiments of the present application, there are multiple energy conversion circuits 202 and energy release circuits 203, and the number of energy conversion circuits 202 and energy release circuits 203 is equal, that is, there is a one-to-one relationship between the energy conversion circuits 202 and the energy release circuits 203. One energy conversion circuit 202 and one energy release circuit 203 constitute a circuit unit, and the circuit units are connected in parallel. Figure 7 The laser emission circuit includes three circuit units, each of which includes an energy conversion circuit 202 and an energy release circuit 203.

[0098] in, Figure 7The connection relationship and working principle of each component in the charging circuit 201, the energy conversion circuit 202 and the energy release circuit 203 can be referred to Figure 3 As shown, no further details are given here.

[0099] It should be noted that in Figures 3 to 7 In this embodiment, decoupling capacitor C1 is connected in parallel between the positive and negative terminals of power supply VCC to prevent parasitic oscillations caused by the positive feedback path formed by power supply VCC. Decoupling prevents current fluctuations in the power supply circuit caused by changes in current between the preceding and following circuits from affecting normal circuit operation. In other words, the decoupling circuit effectively eliminates parasitic coupling between circuits.

[0100] It should be noted that in Figures 3 to 7 In the embodiment, the charging switch element Q1 or the releasing switch element Q2 is a transistor, the collector of the transistor is the first end of the charging switch element Q1 or the releasing switch element Q2, the emitter of the transistor is the second end, the base of the transistor is the enable end, and the base of the transistor is connected to the output end of the first pulse generator; the first pulse generator controls the crystal to be in the on state by outputting a high level, and controls the transistor to be in the off state by outputting a low level.

[0101] It should be noted that in Figures 3 to 7 In the embodiment, the charging switch element Q1 or the releasing switch element Q2 can be a transistor, the emitter of the transistor is the first end of the charging switch element Q1 or the releasing switch element Q2, the collector of the transistor is the second end of the charging switch element Q1 or the releasing switch element Q2, and the base of the transistor is the enable end, which is connected to the output end of the first pulse generator. The first pulse generator controls the crystal to be in the off state by outputting a high level, and controls the transistor to be in the on state by outputting a low level.

[0102] It should be noted that in Figures 3 to 7 In the embodiment, the charging switch element Q1 or the releasing switch element Q2 is a MOS transistor. The drain of the MOS transistor is a first terminal, the gallium nitride switch transistor is a second terminal, and the gate of the gallium nitride switch transistor is an enable terminal connected to the output terminal of the first pulse generator. The first pulse generator is used to control the conduction time of the MOS transistor.

[0103] It should be noted that the charging switch element Q1 or the discharging switch element Q2 can be a MOS transistor, wherein the source of the MOS transistor is a first terminal, the drain of the MOS transistor is a second terminal, and the gate of the MOS transistor is an enable terminal connected to the output terminal of the first pulse generator. The first pulse generator is used to control the conduction time of the MOS transistor.

[0104] It should be noted that in Figures 3 to 7In the embodiment, the dynamic compensation capacitor C3 can suppress the current resonance caused by the parasitic parameters of the discharge circuit of the capacitor C2, and supplement the dynamic impedance when the energy release switch element Q2 is turned on. Optionally, the capacitance value of the dynamic compensation capacitor C3 is less than the capacitance value of the capacitor C2. Optionally, the capacitor C2 can be composed of a plurality of capacitors in parallel to reduce the ESR (Equivalent Series Resistance) of the capacitor C2. It is understandable that the capacitance values ​​of the plurality of capacitors can be equal or unequal. Preferably, the capacitance values ​​of the plurality of capacitors in parallel are equal, and the ESR consistency of the capacitors with equal capacitance values ​​in parallel is better, and the discharge of each parallel capacitor is more equal, which can better improve the efficiency of the energy storage element.

[0105] It is understandable that in Figures 3 to 7 In the embodiment of the present invention, the grounding connection mode of each component in the laser emission circuit (for example, the bypass diode D2, the laser diode LD and the energy release switch element) can be changed to be connected to the negative pole of the power supply, which can also achieve Figures 3 to 7 The same function as the laser emission circuit in .

[0106] An embodiment of the present application also provides a laser radar, including the above-mentioned laser emission circuit.

[0107] Specifically, the aforementioned laser emitting circuit can be used in a laser radar. In addition to the laser emitting circuit, the laser radar may also include specific structures such as a power supply, processing equipment, optical receiving equipment, a rotating body, a base, a housing, and a human-computer interaction device. It is understood that the laser radar can be a single-channel laser radar including a single laser emitting circuit, or a multi-channel laser radar including multiple laser emitting circuits and corresponding control systems. The specific number of channels can be determined based on actual needs.

[0108] The above-mentioned laser radar changes the structure of the laser emission circuit so that during the energy conversion stage, the energy conversion current from the energy storage element does not pass through the laser diode. The laser diode is in a reverse biased state relative to the energy conversion current. Therefore, the parasitic capacitance of the energy release switch element will not cause the laser diode to emit light prematurely due to the energy conversion charging process, thereby avoiding the laser diode from emitting light at unexpected times and solving the problem of laser leakage.

[0109] Those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing related hardware through a computer program. The program can be stored in a computer-readable storage medium, and when executed, the program can include the processes in the above-described method embodiments. The storage medium can be a magnetic disk, an optical disk, a read-only memory, or a random access memory.

[0110] The above disclosure is only a preferred embodiment of the present application, and certainly cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. A laser emitting circuit, characterized in that: include: a charging circuit connected to the energy discharging circuit, the charging circuit comprising a first energy storage element, configured to charge the first energy storage element using a charging current from a power supply during a charging phase; an energy conversion circuit connected to the energy charging circuit and the energy releasing circuit, the energy conversion circuit including a second energy storage element, configured to charge the second energy storage element using an energy conversion current from the first energy storage element during an energy conversion phase; wherein, during the energy conversion phase, the energy conversion current maintains a reverse bias state for the laser diode; an energy release circuit connected to the energy conversion circuit, the energy release circuit including the laser diode, and configured to drive the laser diode to emit light using the energy release current from the second energy storage element during the energy release phase; Wherein, the energy conversion circuit further includes a bypass diode and a boost rectifier diode; the energy release circuit includes an energy release switch; In the reverse bias state, the energy conversion current flows through the boost rectifier diode and the second energy storage element in the circuit loop to the ground, and the energy conversion current flows through the bypass diode and the parasitic capacitance of the energy release switch to the ground; or, in the reverse bias state, the energy conversion current flows through the boost rectifier diode, the bypass diode and the second energy storage element to the ground, and flows through the parasitic capacitance to the ground.

2. The circuit according to claim 1, wherein: The charging circuit includes: a power supply, a decoupling capacitor, an inductor, and a charging switch element; the first energy storage element is an inductor, and the charging switch element is provided with a first end, an enable end, and a second end; In which, the negative pole of the power supply is grounded; the positive pole of the power supply is grounded through the decoupling capacitor, and the positive pole of the power supply is connected to the first end of the first energy storage element, the second end of the first energy storage element is connected to the first end of the charging switch element, and the second end of the second energy storage element is connected to the energy conversion circuit, and the second end of the charging switch element is grounded.

3. The circuit according to claim 1, wherein: The number of the energy conversion circuits is one or more, and the number of the energy release circuits is one or more.

4. The circuit according to claim 2, characterized in that The charging switch element is a transistor or a metal oxide semiconductor (MOS) tube.

5. The circuit according to claim 1, wherein: The energy release switch element is a transistor or a metal oxide semiconductor (MOS) tube.

6. The circuit according to claim 5, characterized in that The energy release circuit further includes a dynamic compensation capacitor connected between the first end and the second end of the energy release switch element.

7. The circuit according to claim 6, characterized in that The capacitance value of the dynamic compensation capacitor is smaller than the capacitance value of the energy storage element.

8. The laser emitting circuit according to claim 1, wherein: The second energy storage element is composed of a plurality of capacitors connected in parallel.

9. A laser radar, characterized in that: include: The laser emitting circuit according to any one of claims 1 to 8.

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