Laser apparatus, emission module, lidar, and terminal device

Abstract

A laser apparatus (121), an emission module (120), a lidar (100), and a terminal device, relating to the technical field of lidars. By means of providing laser emitting circuits (1211_1 to 1211_n) and switches (S1, S2, S3) in the laser apparatus (121), lasers (D1_1 to D1_n) in the laser emitting circuits (1211_1 to 1211_n) can be controlled to emit light. Furthermore, when the laser apparatus (121) is in a failure scenario, the switches (S1, S2, S3) can be controlled to cut off paths between a power supply (HV) and first capacitors (C1_1 to C1_n), such that the power supply (HV) is prevented from continuing to charge the first capacitors (C1_1 to C1_n) in the laser emitting circuits (1211_1 to 1211_n), thereby effectively dispersing energy in an internal capacitor (C0) of the power supply (HV) and the first capacitors (C1_1 to C1_n), reducing the light-emitting duration of the lasers (D1_1 to D1_n), and accordingly reducing the risk of the emission power and radiation intensity of laser pulse signals emitted by the lasers (D1_1 to D1_n) exceeding the AEL values required for human eye safety.

Description

A laser device, a transmitting module, a lidar, and a terminal device. Technical Field

[0001] This application relates to the field of lidar technology, and in particular to a laser device, a transmitting module, lidar, and terminal equipment. Background Technology

[0002] LiDAR typically determines the distance to a target by measuring the time of flight (ToF) of light. Its working principle is as follows: a modulated laser pulse signal is emitted by a laser, which is reflected when it hits an object. The reflected laser pulse signal is received by a detector. By measuring the time of flight of the laser pulse signal in the air, the distance from the target object to the detector can be calculated.

[0003] With the rapid development and increasing maturity of intelligent driving technology, automotive LiDAR has received widespread attention and research. Currently, for safety reasons, the emission power and radiation intensity of the laser pulse signal emitted by automotive LiDAR are usually required to be below the Accessible Emission Limit (AEL) value required for human eye safety. Therefore, under normal operating conditions, automotive LiDAR does not pose a threat to human eyes. However, due to certain factors (such as hardware failure, software problems, environmental factors, etc.), the laser in automotive LiDAR may experience failure due to prolonged illumination. In other words, there are still failure scenarios for automotive LiDAR. In these failure scenarios, the risk of the emission power and radiation intensity of the laser pulse signal exceeding the AEL value required for human eye safety increases due to prolonged illumination.

[0004] Summary of the Invention

[0005] This application provides a laser device, a transmitting module, a lidar, and a terminal device to reduce the risk that the emission power and radiation intensity of the laser pulse signal emitted by the laser will exceed the AEL value required for human eye safety in failure scenarios.

[0006] In a first aspect, embodiments of this application provide a laser device, including multiple laser emitting circuits, a second switch, and a third switch. Each laser emitting circuit includes a laser, a first switch, and a first capacitor. The first electrode plate of the first capacitor is connected to a first end of the laser, and the second end of the laser is connected to a first end of the first switch. The second end of the first switch and the second electrode plate of the first capacitor are respectively connected to a ground terminal. The first end of the second switch is connected to a power supply, and the second end of the second switch is connected to the first end of the laser in the multiple laser emitting circuits and the first electrode plate of the first capacitor. The first end of the third switch is connected to the second end of the second switch, and the second end of the third switch is connected to a ground terminal. Thus, by controlling the second switch to be on and the third switch to be off, and then by controlling the first switch, the laser can emit light. Furthermore, by controlling the second switch to be off and the third switch to be on, the path between the power supply and the first capacitor can be cut off, preventing the power supply from continuing to charge the first capacitor through the second switch. This effectively disperses the energy in the capacitor inside the power supply and in the first capacitor, significantly reducing the energy released by the laser during illumination. This reduces the illumination time of the laser, thereby lowering the emission power and radiation intensity of the laser pulse signal emitted by the laser. Consequently, it reduces the risk that the emission power and radiation intensity of the laser pulse signal emitted by the laser will exceed the AEL value required for human eye safety.

[0007] In some embodiments, the second switch further includes a control terminal, which receives a control signal to control the switching on and off between the first and second terminals of the second switch. Thus, the second switch can be configured as a semiconductor switching device having a first terminal, a second terminal, and a control terminal. Exemplarily, the second switch can be implemented using a field-effect transistor (FET), where the control terminal is the gate of the FET, the first terminal is the source of the FET, and the second terminal is the drain of the FET; or, the first terminal is the drain of the FET, and the second terminal is the source of the FET. In some embodiments, since GaN-type FETs can achieve higher electron mobility and better electrical performance, the second switch can be configured as a GaN-type FET.

[0008] In some embodiments, the third switch further includes a control terminal, which receives a control signal to control the switching on and off between the first and second terminals of the third switch. Thus, the third switch can be configured as a semiconductor switching device having a first terminal, a second terminal, and a control terminal. Exemplarily, the third switch can be implemented using a FET, where the control terminal is the gate of the FET, the first terminal is the source of the FET, and the second terminal is the drain of the FET; or, the first terminal is the drain of the FET, and the second terminal is the source of the FET. In some embodiments, since GaN-type FETs can achieve higher electron mobility and better electrical performance, the third switch can be configured as a GaN-type FET.

[0009] In some embodiments, when the illumination duration of the laser in the target laser emitting circuit among multiple laser emitting circuits is greater than or equal to a duration threshold, the control terminal of the second switch controls the first and second terminals of the second switch to disconnect, and the control terminal of the third switch controls the first and second terminals of the third switch to connect. This disconnects the path between the power supply and the first capacitor, preventing the power supply from continuing to charge the first capacitor through the second switch, and effectively dissipates the energy within the power supply's internal capacitor and the first capacitor. This significantly reduces the energy released through laser illumination, thereby reducing the illumination duration of the laser and lowering the emission power and radiation intensity of the emitted laser pulse signal. This, in turn, reduces the risk that the emission power and radiation intensity of the emitted laser pulse signal will exceed the AEL (Advanced Eye Response Level) requirement for human eye safety.

[0010] Under normal operating conditions, when the first switch is open, the first terminal of the first switch is disconnected from the ground terminal. Since the second terminal of the laser is connected to the first terminal of the first switch, the second terminal of the laser is also disconnected from the ground terminal. Therefore, the voltage at the second terminal of the laser can be considered as the high voltage at the positive terminal of the power supply. When the first switch is closed, the first and second terminals of the first switch are connected, making the first terminal of the first switch connected to the ground terminal. Since the second terminal of the laser is connected to the first terminal of the first switch, the second terminal of the laser is connected to the ground terminal. Therefore, the voltage at the second terminal of the laser changes from the high voltage at the positive terminal of the power supply to the low voltage at the ground terminal, thus causing the laser to emit light. However, in the target laser emitting circuit, when the first switch fails due to a short circuit, it is equivalent to the first switch being closed. Therefore, the voltage at both the second terminal of the laser and the first terminal of the first switch changes from high voltage to low voltage, causing the laser to emit light. Based on this, in some embodiments, the laser device may further include a pulse width sampling circuit, which is connected to the first terminal of each first switch. The pulse width sampling circuit detects a pulse width sampling signal of the voltage at the first terminal of each first switch, and the duration of the low voltage at the first terminal of each first switch is used to characterize the laser's illumination duration. Thus, the illumination duration of the laser in the target laser emitting circuit can include the duration of the low voltage at the first terminal of the first switch in the target laser emitting circuit, as detected by the pulse width sampling circuit.

[0011] In some embodiments, a plurality of second capacitors may be included, and the first terminal of a first switch is connected to the pulse width sampling circuit through one of the second capacitors. Thus, the second capacitors can be used to isolate the pulse width sampling circuit from the high voltage at the first terminal of the first switch, reducing the adverse effects of the high voltage at the first terminal of the first switch on the pulse width sampling circuit.

[0012] In some embodiments, the first switch further includes a control terminal, which receives a control signal to control the switching on and off between the first terminal and the second terminal of the first switch. Thus, the first switch can be configured as a semiconductor switching device having a first terminal, a second terminal, and a control terminal. For example, the first switch can be implemented using a FET, where the control terminal is the gate of the FET, the first terminal is the source of the FET, and the second terminal is the drain of the FET; or, the first terminal is the drain of the FET, and the second terminal is the source of the FET. In some embodiments, since GaN-type FETs can achieve higher electron mobility and better electrical performance, the first switch can be configured as a GaN-type FET.

[0013] In some embodiments, to make the on-resistance of the third switch when it is turned on smaller than the equivalent on-resistance when the laser and the first switch are connected in series, the third switch can be of the same FET type as the first switch. For example, both the third switch and the first switch can be set as GaN-type FETs to achieve higher electron mobility and better electrical performance, and also to improve device consistency. Furthermore, the first switch, the second switch, and the third switch can all be set as GaN-type FETs to further improve device consistency.

[0014] In some embodiments, when the illumination duration of the laser in the target laser emitting circuit among the plurality of laser emitting circuits is greater than or equal to a duration threshold, the control terminal of the first switch in the cooperative laser emitting circuit can be controlled to connect the first and second terminals of the first switch. The cooperative laser emitting circuit comprises at least some of the laser emitting circuits other than the target laser emitting circuit. This allows the lasers in the cooperative laser emitting circuit to emit light simultaneously, increasing the energy discharge channels stored in the first capacitor, further reducing the illumination duration of the lasers, further reducing the emission power and radiation intensity of the emitted laser pulse signal, and further reducing the risk that the emission power and radiation intensity of the emitted laser pulse signal exceed the AEL value required for human eye safety.

[0015] In some embodiments, in a failure scenario, if multiple laser emitting circuits are cooperative laser emitting circuits, the first switches in some or all of the cooperative laser emitting circuits can be controlled to be turned on simultaneously, or the first switches in some or all of the cooperative laser emitting circuits can be controlled to be turned on sequentially.

[0016] In some embodiments, under failure scenarios, the duration of the first switch in the collaborative laser emitting circuit being turned on can be made longer than a reference duration. This reference duration is the duration for which the first switch is turned on once when the illumination duration of the laser in each laser emitting circuit is less than a duration threshold. That is, the reference duration is the duration for which the first switch is turned on once under normal operating conditions. This setting allows the energy stored in the first capacitor to be completely released.

[0017] In some embodiments, the collaborative laser emitting circuit can be all laser emitting circuits other than the target laser emitting circuit in a plurality of laser emitting circuits, so as to drive the lasers in the remaining laser emitting circuits other than the target laser emitting circuit to emit light together, further dispersing the energy in the first capacitor.

[0018] In some embodiments, the cooperative laser emitting circuit can be a portion of the laser emitting circuit other than the target laser emitting circuit among multiple laser emitting circuits, so as to drive the lasers in the portion of the laser emitting circuit to emit light together and disperse the energy in the first capacitor.

[0019] In some embodiments, each laser emitting circuit further includes a first resistor, a first end of which is connected to a second end of a second switch, and a second end of which is connected to a first electrode plate of a first capacitor and a first end of a laser. Therefore, the risk of energy from other first capacitors flowing into the laser in the target laser emitting circuit can be reduced by the first resistor, further reducing the illumination time of the laser in the target laser emitting circuit.

[0020] To ensure consistent emission power and radiation intensity of laser pulse signals emitted from different lasers under normal operating conditions, the resistance values ​​of all first resistors can be made identical. Furthermore, maintaining uniformity in the first resistors reduces design complexity and improves device stability. Taking a laser emitting circuit as an example, during the current illumination cycle, when the laser is emitting light, the first capacitor releases energy, causing its voltage to decrease, resulting in a voltage difference between the capacitors. When the laser is not emitting light, the first capacitor is charged through the second switch and the first resistor. The energy of the first capacitor needs to be fully charged to the appropriate level during the laser-off period to ensure the energy requirements for laser illumination in the next cycle. Therefore, the resistance value of the first resistor can be determined based on the illumination cycle.

[0021] For example, each first resistor can be implemented using an actual resistor device, or each first resistor can be implemented using an equivalent resistor device, such as an inductor, circuit trace, or other component with resistive properties.

[0022] In some embodiments, the laser device may include a plurality of third switches, with one of the third switches provided in each laser emitting circuit. Furthermore, in the same laser emitting circuit, the first terminal of the third switch is connected to the first electrode plate of the first capacitor and the second terminal of the laser. Thus, by providing a third switch in each laser emitting circuit, the energy stored in the first capacitor can be discharged directly to ground through the third switch instead of passing through the first resistor, reducing the risk of the energy stored in the first capacitor not being discharged in a timely manner. Moreover, when the third switch is turned on, as much energy as possible is discharged to ground from the first capacitor, thereby minimizing the amount of energy stored in the first capacitor flowing through the laser, further reducing the laser's illumination time and making it easier to meet eye safety requirements in failure scenarios.

[0023] In some embodiments, the laser device may include a third switch to minimize the number of third switches and reduce costs. In other embodiments, the laser device may also include two, three, four or more third switches connected in parallel, so that if one or more third switches fail to open circuit, the remaining third switches can be controlled to perform their functions.

[0024] In some embodiments, the laser device may include a second switch to minimize the number of second switches and reduce costs. In other embodiments, the laser device may also include two, three, four or more second switches connected in parallel, so that if one or more of the second switches fails to open circuit, the remaining second switches can be controlled to perform their functions.

[0025] In some embodiments, a first capacitor is provided in each laser emitting circuit. This first capacitor may consist of one or more capacitors to provide sufficient energy to each laser, ensuring the emission power and radiation intensity of the laser pulse signal emitted by each laser. In other embodiments, some or all laser emitting circuits may share a single first capacitor to reduce the number of first capacitors and lower production costs.

[0026] In practical implementation, the control terminal of the second switch can be directly connected to the control device, allowing the control device to directly control the on / off state of the second switch. However, due to the high voltage output of the power supply, directly controlling the on / off state of the second switch by the control device places high performance requirements on the control device, increasing costs. Using a control device with average performance makes it difficult to control the on / off state of the second switch, affecting the performance of the laser device. Therefore, considering both cost and performance, some embodiments include a fourth switch. The first terminal of the fourth switch is connected to the control terminal of the second switch, and the second terminal of the fourth switch is connected to the ground terminal. Thus, the on / off state of the second switch can be controlled by controlling the on / off state of the fourth switch, balancing the impact of cost and performance. During operation, when the fourth switch is on, the second switch is off. When the fourth switch is off, the circuit between the control terminal and the ground terminal of the second switch is broken, and the second switch is on.

[0027] In some embodiments, the fourth switch further includes a control terminal, which is responsible for receiving control signals to control the connection and disconnection between the first and second terminals of the fourth switch. Thus, the fourth switch can be configured as a semiconductor switching device having a first terminal, a second terminal, and a control terminal. Exemplarily, a control device can be connected to the control terminal of the fourth switch and output a control signal to its control terminal.

[0028] In some embodiments, when the illumination duration of the laser in the target laser emitting circuit among the plurality of laser emitting circuits is greater than or equal to a duration threshold, the control terminal of the fourth switch controls the connection between the first and second terminals of the fourth switch. This allows the control terminal of the second switch to be connected to the ground terminal, and the second switch to be disconnected.

[0029] In some embodiments, both the second and fourth switches may be implemented using FETs.

[0030] In some embodiments, the laser device may further include a second resistor connected between the first terminal of the second switch and its control terminal. Thus, when the fourth switch is open, the control terminal of the second switch is connected to the positive terminal of the power supply via the second resistor, so that the voltage at the positive terminal of the power supply controls the second switch to turn on, thereby eliminating the need for a control device to directly control the opening and closing of the second switch.

[0031] In some embodiments, the laser device may further include a third resistor connected between the control terminal of the second switch and the first terminal of the fourth switch. This allows the control terminal of the second switch to be connected to the first terminal of the fourth switch via the third resistor, reducing the impact of the voltage at the positive terminal of the power supply on the fourth switch.

[0032] In some embodiments, the laser device may further include a fourth resistor connected to the control terminal of the fourth switch, wherein a first end of the fourth resistor is connected to the control terminal of the fourth switch, and a second end of the fourth resistor is connected to the control device. Thus, the control terminal of the fourth switch can receive a high-voltage control signal through the fourth resistor to control the fourth switch to conduct, and the impact of the control signal directly acting on the control terminal of the fourth switch is reduced.

[0033] In some embodiments, the laser device may further include a fifth resistor connected between the control terminal of the fourth switch and the ground terminal. Thus, the control terminal of the fourth switch is grounded through the fifth resistor, and when a high-voltage control signal is not input to the fourth resistor, the fourth switch can be controlled to open by the voltage at the ground terminal.

[0034] In some embodiments, the type of laser may include, but is not limited to: semiconductor laser, gas laser, fiber laser, solid-state laser, dye laser, diode laser, or excimer laser.

[0035] Secondly, embodiments of this application also provide a laser device, which includes multiple laser emitting circuits and a second switch. Each laser emitting circuit includes a laser, a first switch, a first capacitor, and a first resistor. The second terminal of the first resistor is connected to the first electrode plate of the first capacitor and the first terminal of the laser, respectively. The second terminal of the laser is connected to the first terminal of the first switch, and the second terminal of the first switch and the second electrode plate of the first capacitor are respectively connected to a ground terminal. Furthermore, the first terminal of the second switch is connected to a power supply, and the second terminal of the second switch is connected to the first terminal of the first resistor in the multiple laser emitting circuits. Thus, by controlling the second switch to be on, and then controlling the first switch, the laser can emit light. Furthermore, by controlling the second switch to be off, the path between the power supply and the first capacitor can be cut off, preventing the power supply from continuing to charge the first capacitor through the second switch. Furthermore, since each laser emitting circuit has a first resistor, the risk of energy flowing from the first capacitor in the other laser emitting circuits into the laser in the target laser emitting circuit can be reduced. This reduces the illumination time of the laser in the target laser emitting circuit, and consequently reduces the risk that the emission power and radiation intensity of the laser pulse signal emitted by the laser in the target laser emitting circuit will exceed the AEL value required for human eye safety.

[0036] In some embodiments, when the illumination duration of the laser in the target laser emitting circuit of a plurality of laser emitting circuits is greater than or equal to a duration threshold, the control terminal of the second switch controls the first and second terminals of the second switch to disconnect, thereby cutting off the path between the power supply and the first capacitor and preventing the power supply from continuing to charge the first capacitor through the second switch.

[0037] In some embodiments, when the illumination duration of the laser in the target laser emitting circuit among the plurality of laser emitting circuits is greater than or equal to a duration threshold, the control terminal of the first switch in the cooperative laser emitting circuit controls the first terminal and the second terminal of the first switch to conduct. The cooperative laser emitting circuit is at least a portion of the laser emitting circuits other than the target laser emitting circuit among the plurality of laser emitting circuits.

[0038] Furthermore, the remaining structures of the laser devices in the embodiments of the second aspect can be referred to the description of the relevant structures in the embodiments of the first aspect, and will not be repeated here. It is worth mentioning that the various implementations of the embodiments of the second aspect may not depend on the implementation methods in the first aspect, and may be other implementable methods, which are not limited here.

[0039] Thirdly, this application also provides a laser device, which includes a second switch and multiple laser emitting circuits. Each laser emitting circuit includes a laser, a first switch, and a first capacitor. The first electrode plate of the first capacitor is connected to a first end of the laser, and the second end of the laser is connected to a first end of the first switch. The second end of the first switch and the second electrode plate of the first capacitor are respectively connected to a ground terminal. Furthermore, the first end of the second switch is connected to a power supply, and the second end of the second switch is connected to the second end of the laser in the multiple laser emitting circuits and the first electrode plate of the first capacitor. The second switch also includes a control terminal for controlling the connection and disconnection between the first and second ends of the second switch. Based on this, when the illumination duration of the laser in the target laser emitting circuit is greater than or equal to a duration threshold, the control terminal of the second switch controls the connection between the first and second ends of the second switch to be disconnected. Conversely, the control terminal of the first switch in the cooperating laser emitting circuit controls the connection between the first and second ends of the first switch to be connected. The cooperating laser emitting circuit is at least a portion of the laser emitting circuits other than the target laser emitting circuit. Thus, by controlling the second switch to be on and then controlling the first switch, the laser can be made to emit light. Furthermore, by controlling the second switch to disconnect, the path between the power supply and the first capacitor can be cut off, preventing the power supply from continuing to charge the first capacitor through the second switch. Additionally, the laser in the co-emitting laser circuit can be used to emit light simultaneously, increasing the energy release channels in the first capacitor, further reducing the laser's emission time, further reducing the emission power and radiation intensity of the laser pulse signal emitted by the laser, and further reducing the risk that the emission power and radiation intensity of the laser pulse signal emitted by the laser will exceed the AEL value required for human eye safety.

[0040] Furthermore, the remaining structures of the laser devices in the embodiments of the third aspect can be described with reference to the relevant structures in the embodiments of the first or second aspects described above, and will not be repeated here. It is worth mentioning that the various implementations of the embodiments of the third aspect may also be independent of the implementations in the first or third aspects, and may be other implementable methods, which are not limited here.

[0041] Fourthly, embodiments of this application also provide a transmitting module, which may include a laser device. This laser device may be the laser device described in the first aspect or any of the embodiments in the first aspect, or it may be the laser device described in the second aspect or any of the embodiments in the second aspect, or it may be the laser device described in the third aspect or any of the embodiments in the third aspect. Because the laser device in the embodiments of this application can reduce the risk that the emitted power and radiation intensity of the laser pulse signal will exceed the AEL value required for human eye safety in failure scenarios, the laser safety of the transmitting module with this laser device is improved.

[0042] Fifthly, embodiments of this application also provide a lidar, which includes the transmitting module of the fourth aspect or the embodiments of the fourth aspect. Since the transmitting module has the laser device of the embodiments of this application, the laser device of the embodiments of this application can reduce the risk that the emission power and radiation intensity of the laser pulse signal emitted by the laser exceeds the AEL value required for human eye safety in failure scenarios, thereby improving the laser safety of the lidar with the transmitting module.

[0043] Sixthly, embodiments of this application also provide a terminal device, which may include a device body and a lidar as described in the fifth aspect or various embodiments of the fifth aspect, with the lidar mounted on the device body. Because the lidar has the laser device described in the embodiments of this application, the laser device can reduce the risk that the emission power and radiation intensity of the laser pulse signal emitted by the laser exceeds the AEL value required for human eye safety in failure scenarios, thereby improving the laser safety of the terminal device equipped with the lidar. Attached Figure Description

[0044] Figure 1 illustrates an application scenario diagram of a lidar provided in an embodiment of this application;

[0045] Figure 2 illustrates an exemplary internal architecture diagram of a lidar provided in an embodiment of this application;

[0046] Figure 3A illustrates a circuit diagram of a laser device provided in an embodiment of this application;

[0047] Figure 3B illustrates, by way of example, another circuit diagram of the laser device provided in an embodiment of this application;

[0048] Figure 3C illustrates, by way of example, another circuit diagram of the laser device provided in an embodiment of this application;

[0049] Figure 3D exemplarily illustrates another circuit diagram of the laser device provided in an embodiment of this application;

[0050] Figure 4A illustrates a circuit diagram of the laser device in a failure scenario when the second switch S2 and the third switch S3 are not set.

[0051] Figure 4B illustrates a circuit diagram of a laser device in a failure scenario according to an embodiment of this application.

[0052] Figure 4C illustrates, exemplarily, another circuit diagram of the laser device in a failure scenario according to an embodiment of this application;

[0053] Figure 5A illustrates a schematic diagram of a pulse width sampling circuit in an embodiment of this application.

[0054] Figure 5B is a schematic diagram of the waveform output by the pulse width sampling circuit shown in Figure 5A;

[0055] Figure 6A illustrates, by way of example, another circuit diagram of the laser device provided in an embodiment of this application;

[0056] Figure 6B illustrates, by way of example, another circuit diagram of the laser device provided in an embodiment of this application;

[0057] Figure 7 illustrates, by way of example, another circuit diagram of the laser device provided in an embodiment of this application;

[0058] Figure 8A illustrates, by way of example, another circuit diagram of the laser device provided in an embodiment of this application;

[0059] Figure 8B illustrates another circuit diagram of the laser device in the present application embodiment when it is in a failure scenario;

[0060] Figure 9A illustrates, by way of example, another circuit diagram of the laser device provided in an embodiment of this application;

[0061] Figure 9B illustrates, by way of example, another circuit diagram of the laser device provided in an embodiment of this application;

[0062] Figure 10 illustrates, exemplarily, another circuit diagram of the laser device in the present application embodiment when it is in a failure scenario;

[0063] Figure 11A illustrates, by way of example, another circuit diagram of the laser device provided in an embodiment of this application;

[0064] Figure 11B illustrates, by way of example, another circuit diagram of the laser device provided in an embodiment of this application;

[0065] Figure 12 illustrates another circuit diagram of the laser device in the present application embodiment when it is in a failure scenario. Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The specific operational methods in the method embodiments can also be applied to the device embodiments or system embodiments. It should be noted that in the description of this application, "at least one" refers to one or more, where "multiple" refers to two or more. Therefore, in the embodiments of this application, "multiple" can also be understood as "at least two". "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, the character " / ", unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship. And, words such as "first" and "second" are only used for distinguishing the purpose of description and should not be construed as indicating or implying relative importance or order. In addition, in the embodiments of this application, "connection" refers to electrical connection; the connection between two electrical components can be a direct connection between the two electrical components or an indirect connection through an intermediate medium. For example, A and B can be connected directly, or indirectly through one or more other electrical components, such as A and B being connected. Alternatively, A can be directly connected to C, C can be directly connected to B, and A and B can be connected through C.

[0067] It should be noted that the same reference numerals in the accompanying drawings of this application denote the same or similar structures, and therefore repeated descriptions of them will be omitted. Terms expressing position and direction described in this application are illustrative based on the accompanying drawings, but may be modified as needed, and all modifications are included within the scope of protection of this application. The accompanying drawings of this application are for illustrating relative positional relationships only and do not represent actual scale.

[0068] The lidar in this embodiment can be applied to terminal devices with detection capabilities, and is particularly suitable for terminal devices with laser detection capabilities. The terminal device can be a smart device with laser detection capabilities; for example, smart devices include, but are not limited to, the following:

[0069] Smart home devices include televisions, robot vacuum cleaners, smart lamps, audio systems, smart lighting systems, appliance control systems, home background music systems, home theater systems, intercom systems, and video surveillance systems.

[0070] Intelligent transportation equipment, such as vehicles, ships, drones, trains, freight cars, and trucks.

[0071] Intelligent manufacturing equipment, such as robots, industrial equipment, intelligent logistics, and smart factories.

[0072] Alternatively, the terminal device can also be an electronic device with laser detection capabilities, such as, but not limited to, the following:

[0073] Computer equipment, such as desktop computers, personal computers, servers, etc.

[0074] Portable electronic devices, such as mobile phones, tablets, PDAs, headphones, speakers, wearable devices (such as smartwatches), in-vehicle devices, virtual reality devices, and augmented reality devices. Furthermore, examples of portable electronic devices include, but are not limited to, those equipped with… Alternatively, it could be a portable electronic device with another operating system. Furthermore, the aforementioned portable electronic devices could also be, for example, laptops with touch-sensitive surfaces (such as touch panels).

[0075] In one exemplary application scenario, the lidar in this application embodiment can be applied to a vehicle. Figure 1 illustrates an exemplary application scenario diagram of a lidar provided in this application embodiment. Referring to Figure 1, the vehicle may include a vehicle body 200 and a lidar 100. The lidar 100 is mounted on the vehicle body 200, so the lidar 100 can also be called a vehicle-mounted lidar. In other application scenarios, the lidar is mounted on a ship, so it can be called a shipborne lidar. The lidar is mounted on a machine, so it can be called an airborne lidar, etc. In one possible example, referring to Figure 1, the lidar 100 can be specifically mounted at the front of the vehicle. During vehicle operation, the lidar 100 can emit laser pulse signals. After the laser pulse signals illuminate objects in front of the vehicle (or other areas of the vehicle), they are reflected by the objects to form echo signals. The reflected echo signals can be received by the lidar 100. The lidar 100 detects information about objects in front of the vehicle based on the echo signals, such as the size and distance of the objects, so as to use the object information to realize the vehicle's driving functions, such as including but not limited to autonomous driving or assisted driving.

[0076] The lidar 100 can be one of mechanical lidar, liquid lidar, pure solid-state lidar, or hybrid solid-state lidar (also known as semi-solid-state lidar), or it can be other types of lidar. This application embodiment does not specifically limit it in this regard.

[0077] It is worth mentioning that Figure 1 shows the lidar 100 installed at the front of the vehicle as an example, but it can also be installed at any other location such as the rear, roof, or body of the vehicle.

[0078] Figure 2 illustrates an exemplary internal architecture diagram of a lidar according to an embodiment of this application. Referring to Figure 2, the lidar 100 may include a control device 110, a transmitting module 120, a receiving module 140, and a processing module 150. The transmitting module 120 includes a laser device 121 and a transmitting optical system 122, and the receiving module 140 includes a receiving optical system 141 and a detector 142. It is understood that Figure 2 is only one possible structural example of a lidar, and the lidar structure can be implemented in other ways.

[0079] In the lidar 100, the control device 110 may have signal control capabilities and may be connected to other components in the lidar 100 via a controller area network (CAN) bus or other means, such as including but not limited to the transmitting module 120, the scanning mechanism 130, the receiving module 140, and the processing module 150.

[0080] The laser device 121 may have a laser capable of emitting laser pulse signals, wherein the type of laser may include, but is not limited to: semiconductor laser, gas laser, fiber laser, solid-state laser, dye laser, diode laser or excimer laser.

[0081] The transmitting optical system 122 and the receiving optical system 141 can each refer to a system composed of optical elements, including but not limited to: lenses, filters, polarizers, mirrors, beam splitters, prisms, windows, and diffusers.

[0082] The detector 142 may be of a type including, but not limited to, avalanche photodiode (APD), single photon avalanche diode (SPAD), positive intrinsic-negative (PIN) photodiode, and silicon photomultiplier (SiPM).

[0083] The processing module 150 can have signal processing capabilities and can be connected to the detector 142 via a CAN bus or other means.

[0084] For example, the control device 110 and processing module 150 described above can be integrated into a single semiconductor device or implemented separately in multiple semiconductor devices. Specifically, the semiconductor device can be an integrated circuit chip, such as a general-purpose processor, a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system-on-chip (SoC), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and other integrated chips. The device may include a central processing unit (CPU), a neural network processing unit (NPU), and a graphics processing unit (GPU), and may also include an application processor (AP), a modem processor, an image signal processor (ISP), a video codec, a digital signal processor (DSP), and / or a baseband processor, etc., without being specifically limited.

[0085] Exemplarily, the lidar 100 may further include a scanning mechanism 130. The scanning mechanism 130 may include one or more of a multi-faceted rotating mirror, a tilting mirror, a micro-electro-mechanical system (MEMS) scanning mirror, and a prism. The scanning mechanism 130 can be controlled to scan and traverse the detection area using laser pulse signals. In other embodiments, the scanning mechanism 130 is not a necessary component, and the traversal function achieved by the scanning mechanism 130 can essentially be implemented through the array design within the transmitting module 120 and the receiving module 130, as well as the array control device.

[0086] During the operation of the lidar 100, the control device 110 can control the laser device 121 to emit detection signals (e.g., laser pulse signals) and control the transmitting optical system 122 to transmit the detection signals from the laser device 121. It can also control the scanning mechanism 130 to scan the detection area using the detection signals. When the detection signal is detected by an object in the detection area, it is reflected by the object. The reflected echo signal is received by the receiving optical system 141 and transmitted to the detector 142. The control device 110 controls the detector 142 to convert the optical echo signal into an electrical signal and send it to the processing module 150. Under the control of the control device 110, the processing module 150 analyzes the electrical signal to generate point cloud data. This point cloud data can be used to obtain target information such as the distance, orientation, height, speed, attitude, and even shape of the object. Furthermore, it can be combined with other sensor information from the vehicle to plan autonomous or assisted driving.

[0087] In practical applications, for safety reasons, according to the laser eye safety level certification standard, lidar (especially vehicle-mounted lidar) needs to meet the Class I laser certification standard. Lidar that meets the Class I laser certification standard is designed and structured to ensure that the emitted laser pulse signal's power and radiation intensity are less than the AEL (Advanced Eye Length Eligibility) value required for human eye safety. Therefore, under normal operating conditions, the laser pulse signal emitted by the lidar will not pose a threat to the human eye. However, due to certain factors (e.g., hardware failure, software problems, environmental factors), lidar may malfunction. In lidar failure scenarios, the laser may emit light for an extended period, increasing the risk that the emitted laser pulse signal's power and radiation intensity will exceed the AEL value required for human eye safety. Furthermore, since lidar typically controls the laser pulse signal emission by switching a switch on and off during operation, and to improve the lidar's range accuracy, the laser's driving voltage and capacitance are becoming increasingly larger. In this situation, if the switch fails due to a short circuit, the laser will emit laser pulse signals for an extended period of time, which will further increase the risk that the emitted power and radiation intensity of the laser pulse signals will exceed the AEL value required for human eye safety.

[0088] Therefore, embodiments of this application provide a laser device to reduce the risk that the emission power and radiation intensity of the laser pulse signal emitted by the laser will exceed the AEL value required for human eye safety in a failure scenario.

[0089] The structure and operation of the laser device provided in this application will be described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative of the specific structure of the laser device. In actual implementation, the specific structure of the laser device is not limited to the structure provided in the embodiments of this application, and may also be other structures known to those skilled in the art based on the same concept. No specific limitations are made here.

[0090] Example 1

[0091] Figure 3A illustrates a circuit diagram of a laser device provided in an embodiment of this application. Referring to Figure 3A, the laser device 121 may include multiple laser emitting circuits 1211_1 to 1211_n, a second switch S2, and a third switch S3. The laser emitting circuit 1211_1 includes a laser D1_1, a first switch S1_1, and a first capacitor C1_1. The first electrode plate of the first capacitor C1_1 is connected to the first end of the laser D1_1, and the second end of the laser D1_1 is connected to the first end of the first switch S1_1. The second end of the first switch S1_1 and the second electrode plate of the first capacitor C1_1 are respectively connected to the ground terminal GND. ...The laser emitting circuit 1211_n includes a laser D1_n, a first switch S1_n, and a first capacitor C1_n. The first electrode plate of the first capacitor C1_n is connected to the first end of the laser D1_n, and the second end of the laser D1_n is connected to the first end of the first switch S1_n. The second end of the first switch S1_n and the second electrode plate of the first capacitor C1_n are respectively connected to the ground terminal GND. Furthermore, the first end of the second switch S2 is connected to the power supply HV, and the second end of the second switch S2 is connected to the first end of the lasers D1_1 to D1_n in each laser emitting circuit 1211_1 to 1211_n, as well as the first electrode plate of the first capacitors C1_1 to C1_n. The first end of the third switch S3 is connected to the second end of the second switch S2, the first end of the lasers D1_1 to D1_n in each laser emitting circuit 1211_1 to 1211_n, and the first electrode plate of the first capacitors C1_1 to C1_n. The second end of the third switch S3 is connected to the ground terminal GND.

[0092] The operation of the laser device in the embodiments of this application will be described below with reference to the schematic diagrams shown in Figures 4A and 4B. Figure 4A exemplarily shows a circuit diagram of the laser device in a failure scenario when the second switch S2 and the third switch S3 are not set, and Figure 4B exemplarily shows a circuit diagram of the laser device in a failure scenario according to an embodiment of this application.

[0093] As shown in Figure 4A, when the laser device is not equipped with the second switch S2 and the third switch S3, the power supply HV outputs the high voltage required to drive lasers D1_1 to D1_n, charging the first capacitors C1_1 to C1_n. Then, the first switches S1_1 to S1_n can be sequentially turned on according to the requirements of the lidar, controlling the lasers D1_1 to D1_n to emit light sequentially. Taking the laser emitting circuit 1211_1 as an example, under normal operating conditions, the first switch S1_1 is on, and the first capacitor C1_1 provides energy for laser D1_1 to emit light for a short time, enabling laser D1_1 to emit laser pulse signals. When the first switch S1_1 is off, laser D1_1 does not emit light, and the power supply HV charges the first capacitors C1_1 to C1_n, thus achieving dynamic balance. If the first switch S1_1 fails due to a short circuit, the energy stored in capacitor C0 inside the power supply HV, as well as the energy stored in the first capacitors C1_1 to C1_n, will be released through laser D1_1. This will cause laser D1_1 to be in a state of continuous illumination, which may not only easily lead to overheating and damage to laser D1_1, but also cause the emission power and radiation intensity of the laser pulse signal emitted by laser D1_1 to exceed the AEL value required for human eye safety, thus posing a risk to human eye safety.

[0094] As the illumination duration of the laser pulse signal emitted by laser D1_1 continuously increases over time, the laser device in this embodiment can compare the illumination duration of the laser pulse signal emitted by laser D1_1 with a duration threshold to obtain the relationship between the illumination duration of laser D1_1 and the duration threshold. Based on this relationship, it can identify whether laser D1_1 is in a long-term illumination state, thereby identifying whether the first switch S1_1 has a short-circuit failure. Referring to Figure 4B, the laser device in this embodiment, by setting a second switch S2 and a third switch S3, indicates that when the illumination duration of laser D1_1 is greater than or equal to the duration threshold, it means that laser D1_1 is in a long-term illumination state, and the first switch S1_1 has a short-circuit failure. A control signal EN1 is output to control the second switch S2 to open, and a control signal EN2 is output to control the third switch S3 to turn on. Since the second switch S2 is open, the path between the power supply HV and the first capacitors C1_1 to C1_n can be cut off, preventing the power supply HV from continuing to charge the first capacitors C1_1 to C1_n through the second switch S2. Furthermore, since the third switch S3 is turned on, the capacitor C0 inside the power supply HV and the first electrode plates of the first capacitors C1_1 to C1_n can be grounded. Because the equivalent resistance of the third switch S3 is smaller than that of the laser D1_1 and the first switch S1_1, most of the energy in the capacitor C0 inside the power supply HV and the first electrode plates of the first capacitors C1_1 to C1_n can be discharged to ground through the third switch S3. This effectively disperses the energy in the capacitors C0 and C1_1 to C1_n inside the power supply HV, thus reducing the energy released by the laser D1_1 through the illumination of the power supply HV. This reduces the illumination time of the laser D1_1, thereby reducing the emission power and radiation intensity of the laser pulse signal emitted by the laser D1_1. In turn, it reduces the risk that the emission power and radiation intensity of the laser pulse signal emitted by the laser D1_1 will exceed the AEL value required for human eye safety.

[0095] It is worth mentioning that "laser D1_1 illumination" refers to the laser pulse signal emitted by laser D1_1, and "laser D1_1 illumination duration" refers to the duration during which laser D1_1 continuously outputs laser pulse signals. The illumination durations of other lasers can be deduced similarly and will not be elaborated upon here. Furthermore, the directions indicated by the dashed arrows in Figures 4A and 4B represent the energy release paths of capacitor C0 and the first capacitors C1_1 to C1_n within the power supply HV, respectively.

[0096] In some embodiments, when the duration of the laser pulse signal emitted by laser D1_1 is greater than or equal to a duration threshold, the third switch S3 can be controlled to turn on earlier than the second switch S2, so as to turn on the third switch S3 more quickly and preferentially discharge the energy in capacitor C0 and the first capacitors C1_1 to C1_n inside the power supply HV to ground. In other embodiments, the third switch S3 and the second switch S2 can be controlled to turn on simultaneously, or the third switch S3 can turn on later than the second switch S2.

[0097] It is understandable that the above explanation uses laser emitting circuit 1211_1 as the target laser emitting circuit as an example. In specific implementations, under failure scenarios, there may be one or more target laser emitting circuits. When there are multiple target laser emitting circuits, the working process of the laser device can refer to the working process when laser emitting circuit 1211_1 is the target laser emitting circuit, and the details will not be elaborated here.

[0098] Furthermore, the duration threshold can be t0 + Δt, where t0 represents the duration of a single laser beam under normal operating conditions, and Δt is a margin, for example, a value greater than zero, to identify abnormal laser beam patterns. For instance, under normal operating conditions, if the duration of a single laser beam is 8 ns, then t0 is 8 ns, and Δt can be set to 8 ns, with a duration threshold of 16 ns. Of course, Δt can also be set according to the needs of the actual application scenario, and is not limited here.

[0099] Referring again to Figure 3A, in the laser device of this embodiment, under normal operating conditions, i.e., when the illumination duration of each laser D1_1 to D1_n is less than a duration threshold, the second switch S2 can be turned on and the third switch S3 can be turned off. The power supply HV outputs the high voltage required to drive the lasers D1_1 to D1_n, charging the first capacitors C1_1 to C1_n. Then, according to the requirements of the lidar, the first switches S1_1 to S1_n can be turned on sequentially to control the lasers D1_1 to D1_n to illuminate sequentially. In other embodiments, some or all of the first switches S1_1 to S1_n can also be turned on simultaneously, allowing some or all of the lasers D1_1 to D1_n to illuminate simultaneously.

[0100] It is worth mentioning that the structure and connection method of the remaining laser emitting circuits can be deduced from the foregoing description and will not be repeated here. Furthermore, n is an integer greater than 1; for example, n can be 2, 3, 4, 5, 6, etc., and is not limited here. In the embodiments of this application, a first capacitor is provided in each laser emitting circuit. This first capacitor can be composed of one or more capacitors to provide sufficient energy to each laser, ensuring the emission power and radiation intensity of the laser pulse signal emitted by each laser. In other embodiments, some or all laser emitting circuits can share a single first capacitor to reduce the number of first capacitors and lower production costs.

[0101] In some embodiments, the control terminals of the first switches S1_1 to S1_n, the second switch S2, and the third switch S3 can be connected to a control device to output control signals to the control terminals of these switches, thereby controlling the on / off state of these switches. For example, outputting high-voltage control signals to the control terminals of the first switches S1_1 to S1_n, the second switch S2, and the third switch S3 can control the first switches S1_1 to S1_n, the second switch S2, and the third switch S3 to be turned on. Outputting low-voltage control signals to the control terminals of the first switches S1_1 to S1_n, the second switch S2, and the third switch S3 can control the first switches S1_1 to S1_n, the second switch S2, and the third switch S3 to be turned off.

[0102] In specific implementation, the same laser emitting circuit can be integrated into a single semiconductor device, or the components of the same laser emitting circuit can be distributed on a circuit board (e.g., a printed circuit board, PCB) and implemented separately. The specific implementation method can be determined according to the needs of the actual application scenario, and this application does not limit it.

[0103] In this application, there are various ways to determine the relationship between the illumination duration and the duration threshold of the laser pulse signal emitted by the laser. These methods are illustrated below.

[0104] First implementation method:

[0105] Taking the laser emitting circuit 1211_1 as an example, under normal operating conditions, the first terminal of the first switch S1_1 is open-circuited with the ground terminal GND. Since the second terminal of the laser D1_1 is connected to the first terminal of the first switch S1_1, the second terminal of the laser D1_1 is also open-circuited with the ground terminal GND. Therefore, the voltage at the second terminal of the laser D1_1 can be considered as the high voltage of the positive terminal of the power supply HV, that is, the voltage at the second terminal of the laser D1_1 is high relative to the ground terminal GND. When the first switch S1_1 is turned on, the first and second terminals of the first switch S1_1 are connected, making the first and second terminals of the first switch S1_1 connected. Since the second terminal of the laser D1_1 is connected to the first terminal of the first switch S1_1, the second terminal of the laser D1_1 is connected with the ground terminal GND. Therefore, the voltage at the second terminal of the laser D1_1 changes from the high voltage of the positive terminal of the power supply HV to the low voltage of the ground terminal GND, thereby enabling the laser D1_1 to emit light. However, when the first switch S1_1 fails to short-circuit, it is equivalent to the first switch S1_1 being turned on. The voltage at the second terminal of laser D1_1 and the first terminal of the first switch S1_1 will change from high to low, and laser D1_1 will emit light. Based on this, in this embodiment, the duration of the low voltage at the first terminal of the first switch S1_1 can be used to characterize the illumination duration of laser D1_1. The duration of the low voltage at the first terminal of the first switch S1_1 can refer to the duration during which the voltage at the first terminal of the first switch S1_1 remains in a low voltage state. The illumination duration of other lasers can be deduced similarly, and will not be elaborated upon here.

[0106] To detect the duration for which the voltage at the first terminal of each first switch S1_1 to S1_n is low, refer to Figure 3B, which exemplarily shows another circuit diagram of the laser device provided in this application embodiment. The laser device 121 may also include a pulse width sampling circuit 1212 and multiple second capacitors C2_1 to C2_n. The first terminal of the first switch S1_1 is connected to the first terminal of the second capacitor C2_1, and the second terminal of the second capacitor C2_1 is connected to the pulse width sampling circuit 1212. ...The first terminal of the first switch S1_n is connected to the first terminal of the second capacitor C2_n, and the second terminal of the second capacitor C2_n is connected to the pulse width sampling circuit 1212. Based on this, the pulse width sampling circuit 1212 can detect the pulse width sampling signal of the voltage at the first terminal of each first switch S1_1 to S1_n. The pulse width sampling signal may include analog voltage signals when the voltage at the first terminal of the first switches S1_1 to S1_n is low and high. Subsequently, the control device 110 may further include a filter and an analog-to-digital converter (ADC). The pulse width sampling circuit 1212 may also input the detected pulse width sampling signal into the filter to perform pulse width shaping on these pulse width sampling signals. Afterwards, the pulse width sampling signal can be obtained in the form of a digital voltage signal through analog-to-digital conversion by the ADC. The duration of the low voltage at the first terminal of the first switch S1_1 in the digital voltage signal pulse width sampling signal is the illumination duration of laser D1_1. The illumination durations of the remaining lasers D1_2 to D1_n can be deduced similarly. Subsequently, the control device 110 compares the duration of the low voltage at the first terminals of the first switches S1_1 to S1_n in the pulse width sampling signal in the form of a digital voltage signal with a duration threshold. When the duration of the low voltage at the first terminals of one or more of the first switches S1_1 to S1_n is greater than or equal to the duration threshold, it indicates that the illumination duration of one or more of the lasers D1_1 to D1_n is greater than or equal to the duration threshold. In this case, the second switch S2 is turned off and the third switch S3 is turned on. When the duration of the low voltage at the first terminals of the first switches S1_1 to S1_n is less than the duration threshold, it indicates that the illumination duration of the lasers D1_1 to D1_n is less than the duration threshold. In this case, the second switch S2 is turned on and the third switch S3 is turned off, and the lasers D1_1 to D1_n are illuminated sequentially, thus operating under normal working conditions.

[0107] In some embodiments, one or a combination of the pulse width sampling circuit, the filter, and the ADC can be integrated with the control device in a single semiconductor device, or they can be distributed across multiple semiconductor devices and implemented separately. The specific implementation can be determined according to the needs of the actual application scenario, and this application does not limit it.

[0108] It is worth mentioning that when the first switches S1_1 to S1_n are open, the voltage at their first terminals is usually high. In this embodiment, by setting second capacitors C2_1 to C2_n, the pulse width sampling circuit 1212 is isolated from the high voltage at the first terminals of the first switches S1_1 to S1_n, thereby reducing the adverse effect of the high voltage at the first terminals of the first switches S1_1 to S1_n on the pulse width sampling circuit. In other embodiments, if the high voltage at the first terminals of the first switches S1_1 to S1_n has a small impact on the pulse width sampling circuit, the second capacitors C2_1 to C2_n can be omitted, and the first terminals of the first switches S1_1 to S1_n can be directly connected to the pulse width sampling circuit to reduce the number of components and reduce production costs.

[0109] In some embodiments, referring to FIG5A, FIG5A exemplarily illustrates a circuit diagram of a pulse width sampling circuit in an embodiment of the present application. The pulse width sampling circuit 1212 may include: a plurality of sixth resistors R6_1 to R6_n, a seventh resistor R7, a first diode D2, a second diode D3, and an inverter U1. The first end of the sixth resistor R6_1 is connected to the second end of the second capacitor C2_1, ... the first end of the sixth resistor R6_n is connected to the second end of the second capacitor C2_n, and the second ends of the sixth resistors R6_1 to R6_n are all connected to the first end of the seventh resistor R7. The second end of the seventh resistor R7 is connected to the sampling power supply. The cathode of the first diode D2 is connected to the sampling power supply, and the anode of the first diode D2, the cathode of the second diode D3, the input terminal of the inverter U1, and the first end of the seventh resistor R7 are connected. The output terminal of the inverter U1 is connected to the control device 110. During operation, refer to Figure 5B, which is a waveform diagram of the pulse width sampling circuit output shown in Figure 5A. Ota represents the waveform of the pulse width sampling signal output by the pulse width sampling circuit under normal operating conditions, and Otb represents the waveform of the pulse width sampling signal output by the pulse width sampling circuit under failure conditions.

[0110] For example, referring to Figures 5A and 5B, taking a sampling power supply voltage of 3.3V and a high voltage of 30V at the first terminals of the first switches S1_1 to S1_n as an example, under normal operating conditions, referring to the waveform shown in Ota, the first switches S1_1 to S1_n are sequentially turned on. When the first switches S1_1 to S1_n are turned off, the voltage at the first terminals of the second capacitors C2_1 to C2_n is 30V, and the voltage at the second terminals of the second capacitors C2_1 to C2_n is 3.3V. Taking the laser emitting circuit 1211_1 as an example, when the first switch S1_1 is turned on, the voltage at the first terminal of the second capacitor C2_1 drops from 30V to 0V. Since the voltage difference between the two terminals of the second capacitor C2_1 cannot change abruptly, the voltage at the second terminal of the second capacitor C2_1 becomes -26.7V. Considering the 3.3V sampling power supply becomes -26.7V after passing through resistor R7 (seventh resistor) and R6_1 (sixth resistor), the voltage at the second terminal of resistor R7 can be calculated according to the resistor voltage divider mechanism (assuming the resistance values ​​of resistor R7 and R6_1 are the same, then the voltage at the second terminal of resistor R7 is -11.7V). If the voltage at the second terminal of resistor R7 is less than 0V, then diode D3 conducts. Assuming diode D3 is an ideal diode with no conduction voltage drop, the voltage at the second terminal of resistor R7 is pulled down to 0V. This achieves the high level of 3.3V at the input of inverter U1 when switch S1_1 is open, and the output voltage of inverter U1 is low. Conversely, when switch S1_1 is on, the input voltage of inverter U1 is 0V, and the output voltage of inverter U1 is high. Furthermore, since the first switches S1_1 to S1_n are not simultaneously turned on, if the first switches S1_1 to S1_n are turned on sequentially, then the high level Aa appearing sequentially in the waveform shown in Ota can represent the waveform when the first switches S1_1 to S1_n are turned on, and the low level Ab can represent the waveform when the first switches S1_1 to S1_n are turned off. Based on the waveform shown in Ota, the duration t0 of the high level Aa represents the illumination duration of the lasers D1_1 to D1_n, and the control device 110 can determine that the illumination duration of the lasers D1_1 to D1_n is less than the duration threshold.

[0111] In a failure scenario, taking the laser emitting circuit 1211_1 as an example, if the first switch S1_1 fails due to a short circuit, the first switch S1_1 remains on, causing the voltage at the first terminal of the second capacitor C2_1 to remain at 0V. This results in the voltage at the input terminal of the inverter U1 remaining at 0V, and consequently, the voltage at the output terminal of the inverter U1 remaining at a high level. Referring to the waveform shown in Otb, the high level Ac can represent the waveform when the first switch S1_1 is short-circuited. Based on the waveform shown in Otb, the duration of the high level Ac represents the illumination duration of the laser D1_1. The control device 110 can determine that the illumination duration of the laser D1_1 is greater than or equal to the duration threshold.

[0112] It is understood that the above embodiments are merely illustrative examples of the specific structure of the pulse width sampling circuit. In specific implementation, the specific structure of the pulse width sampling circuit is not limited to the structure provided in the embodiments of this application, and may also be other structures known to those skilled in the art based on the same concept. No specific limitations are made here.

[0113] The second implementation method is to set up an optical sensor such as a photodetector in the lidar. The optical sensor can directly detect the illumination duration of the lasers D1_1 to D1_n. The optical sensor and the control device 110 can transmit data through wired or wireless communication to send the detected illumination duration of the lasers D1_1 to D1_n to the control device 110. The control device 110 can compare the illumination duration of the lasers D1_1 to D1_n with the duration threshold. Based on the comparison result, the second switch S2 and the third switch S3 can be controlled accordingly.

[0114] In some embodiments of this application, in a failure scenario, i.e. when the illumination duration of the laser in the target laser emitting circuit among multiple laser emitting circuits is greater than or equal to the duration threshold, all laser emitting circuits other than the target laser emitting circuit among the multiple laser emitting circuits can be used as cooperative laser emitting circuits. This not only controls the second switch S2 to be open and the third switch S3 to be open, but also drives the control terminal of the first switch in the cooperative laser emitting circuit to control the conduction between the first terminal and the second terminal of the first switch, further generating a path for dispersing the energy stored in the first capacitor, further increasing the speed of discharging the energy stored in the first capacitor, thereby further reducing the illumination duration of the laser in the target laser emitting circuit. The following example uses laser emitting circuit 1211_1 as the target laser emitting circuit and laser emitting circuits 1211_2 to 1211_n as the cooperative laser emitting circuits. Referring to Figure 4C, which exemplarily illustrates another circuit diagram of the laser device in this application embodiment under a failure scenario, when the illumination duration of laser D1_1 is greater than or equal to the duration threshold, not only is the second switch S2 turned off and the third switch S3 turned on, but the first switches S1_2 to S1_n are also turned on. Lasers D1_2 to D1_n illuminate together, and the illumination path of lasers D1_2 to D1_n releases part of the energy stored in the first capacitors C1_2 to C1_n. This allows the energy stored in the first capacitors C1_2 to C1_n to not only be discharged through the third switch S3, but also consumed by driving lasers D1_2 to D1_n to illuminate, further increasing the speed of energy discharge from the first capacitors C1_2 to C1_n, thereby further reducing the illumination duration of laser D1_1. In addition, under normal circumstances, the illumination area of ​​one laser in a vehicle-mounted lidar is generally larger than the area that the human eye can receive. Therefore, when laser D1_1 is malfunctioning and the laser pulse signal emitted by laser D1_1 enters the human eye, the laser pulse signals emitted by lasers D1_2 to D1_n will not enter the human eye. Thus, even if lasers D1_2 to D1_n are illuminating, more laser energy will not enter the human eye, which can also reduce the safety risk to the human eye.

[0115] In some embodiments, under failure scenarios, taking the laser emitting circuits 1211_2 to 1211_n as a cooperative laser emitting circuit as an example, some or all of the first switches S1_2 to S1_n can be controlled to be turned on simultaneously, or the first switches S1_2 to S1_n can be controlled to be turned on sequentially.

[0116] In some embodiments, under failure scenarios, taking laser emitting circuits 1211_2 to 1211_n as a cooperative laser emitting circuit as an example, the conduction duration of the first switches S1_2 to S1_n can be made greater than the conduction reference duration. This reference duration is the duration for which the first switches S1_1 to S1_n conduct once when the illumination duration of the laser in each laser emitting circuit 1211_1 to 1211_n is less than a duration threshold. That is, the conduction reference duration is the duration for which the first switches S1_1 to S1_n conduct once under normal operating conditions. This setting allows the energy stored in the first capacitors C1_2 to C1_n to be completely released. In other embodiments, under failure scenarios, the conduction duration of the first switches S1_2 to S1_n can also be less than or equal to the conduction reference duration.

[0117] In other embodiments, taking laser emitting circuit 1211_1 as the target laser emitting circuit as an example, some of the laser emitting circuits 1211_2 to 1211_n can also be used as cooperative laser emitting circuits. In a failure scenario, the first switch in this part of the laser emitting circuit is turned on, and the first switches in the remaining parts of the laser emitting circuits 1211_2 to 1211_n are turned off. Alternatively, in a failure scenario, the first switches in the laser emitting circuits 1211_2 to 1211_n can be directly turned off.

[0118] Referring again to Figures 3A and 3B, the first terminal of the second switch S2 is connected to the positive terminal of the power supply HV, and the negative terminal of the power supply HV is connected to the ground terminal GND. Therefore, when the second switch S2 is on, the power supply HV can charge the first capacitors C1_2 to C1_n; when the second switch S2 is off, the power supply HV cannot charge the first capacitors C1_2 to C1_n. Exemplarily, the laser device may include one second switch S2 to minimize the number of second switches S2 and reduce costs. In other embodiments, the laser device may also include two, three, four, or more second switches S2 connected in parallel, so that if one or more second switches S2 experience an open-circuit failure, the remaining second switches S2 can be controlled to maintain their function.

[0119] The laser device may include a third switch S3 to minimize the number of third switches S3 and reduce costs. In other embodiments, the laser device may also include two, three, four or more third switches S3 connected in parallel, so that if one or more third switches S3 fail to open circuit, the remaining third switches S3 can be controlled to perform their functions.

[0120] In this application embodiment, the specific structure of the first switch to the third switch S3 can have various implementations. The structure of the first switch to the third switch S3 is illustrated below.

[0121] In some embodiments, the first switches S1_2 to S1_n further include a control terminal, which is responsible for receiving control signals to control the conduction and disconnection between the first and second ends of the first switches S1_2 to S1_n. Thus, the first switches S1_2 to S1_n can be configured as semiconductor switching devices having a first end, a second end, and a control terminal. For example, referring to FIG3C, which exemplarily shows another circuit diagram of a laser device provided in an embodiment of this application, the first switches S1_2 to S1_n can be implemented using field-effect transistors (FETs). In this case, the control terminal of the first switches S1_2 to S1_n is the gate of the FET, the first end is the source of the FET, and the second end is the drain of the FET; or, the first end is the drain of the FET, and the second end is the source of the FET. In some embodiments, since GaN-type FETs can achieve higher electron mobility and better electrical performance, the first switches S1_2 to S1_n can be configured as GaN-type FETs. In other embodiments, the first switches S1_2 to S1_n may also be configured as other types of FETs, which are not limited here.

[0122] In some embodiments, the second switch S2 further includes a control terminal, which receives a control signal to control the connection and disconnection between the first and second terminals of the second switch S2. Thus, the second switch S2 can be configured as a semiconductor switching device having a first terminal, a second terminal, and a control terminal. Furthermore, when the illumination duration of the laser in the target laser emitting circuit is greater than or equal to a duration threshold, a corresponding control signal can be output to the control terminal of the second switch S2 to control the disconnection between the first and second terminals of the second switch S2. For example, referring to FIG3C, the second switch S2 can be implemented using a FET, where the control terminal of the second switch S2 is the gate of the FET, the first terminal is the source of the FET, and the second terminal is the drain of the FET; or, the first terminal is the drain of the FET, and the second terminal is the source of the FET. In some embodiments, since GaN-type FETs can achieve higher electron mobility and better electrical performance, the second switch S2 can be configured as a GaN-type FET. In other embodiments, the second switch S2 can also be configured as other types of FETs, which are not limited here.

[0123] In some embodiments, the third switch S3 further includes a control terminal, which receives a control signal to control the conduction and disconnection between the first and second terminals of the third switch S3. Thus, the third switch S3 can be configured as a semiconductor switching device having a first terminal, a second terminal, and a control terminal. Furthermore, when the illumination duration of the laser in the target laser emitting circuit is greater than or equal to a duration threshold, a corresponding control signal can be output to the control terminal of the third switch S3 to control the conduction between the first and second terminals of the third switch S3. For example, referring to FIG3C, the third switch S3 can be implemented using a FET, in which case the control terminal of the third switch S3 is the gate of the FET, the first terminal is the source of the FET, and the second terminal is the drain of the FET; or, the first terminal is the drain of the FET, and the second terminal is the source of the FET. In some embodiments, since GaN-type FETs can achieve higher electron mobility and better electrical performance, the third switch S3 can be configured as a GaN-type FET. In other embodiments, the third switch S3 can also be configured as other types of FETs, which are not limited here.

[0124] Furthermore, to make the on-resistance of the third switch S3 when it is turned on smaller than the equivalent on-resistance when the laser and the first switch are connected in series, the third switch S3 can be of the same FET type as the first switches S1_1 to S1_n. For example, the third switch S3 and the first switches S1_1 to S1_n can all be set as GaN-type FETs to achieve higher electron mobility and better electrical performance, and also to improve device consistency. Further, the first switches S1_1 to S1_n, the second switch S2, and the third switch S3 can all be set as GaN-type FETs to improve device consistency.

[0125] In some embodiments, the power supply HV can be a power source capable of outputting DC voltage. Exemplarily, the power supply HV may include a voltage conversion circuit that receives a lower input voltage Vin, boosts and converts Vin to output the high voltage required to drive lasers D1_1 to D1_n. Thus, under normal operating conditions, the high voltage output by the voltage conversion circuit charges the first capacitors C1_1 to C1_n via the second switch S2. Exemplarily, the voltage conversion circuit can be integrated into the lidar system as part of it. Alternatively, the voltage conversion circuit can be mounted on the main body of the terminal device, supplying power to the lidar via wiring, thus spatially separating it from the lidar.

[0126] In some examples, the input voltage Vin can be a DC voltage, in which case the voltage conversion circuit can be configured as a direct current-to-direct current (DC-DC) voltage conversion circuit. For example, referring to FIG3D, which exemplarily illustrates another circuit diagram of the laser device provided in an embodiment of this application, the voltage conversion circuit can be configured as a boost circuit. The boost circuit may include an inductor L0, a diode D0, a capacitor C0, and a switch S0. Exemplarily, the switch S0 can also be formed using a FET. Of course, the voltage conversion circuit can also be configured as other circuits capable of implementing the boost function, and this application does not limit it in this regard.

[0127] In other examples, the input voltage Vin can also be an AC voltage, in which case the voltage conversion circuit can be set as an alternating current-direct current (AC-DC) voltage conversion circuit.

[0128] Example 2

[0129] Figure 6A illustrates another circuit diagram of the laser device provided in an embodiment of this application. Referring to Figure 6A, this embodiment is a modification of the implementation in Embodiment 1. The differences between this embodiment and Embodiment 1 will be described below, while the similarities will not be repeated here.

[0130] In practical implementation, the control terminal of the second switch S2 can be directly connected to the control device 110, and the control device 110 can directly control the on / off state of the second switch S2. However, since the output voltage of the power supply HV is relatively high, if the control device 110 directly controls the on / off state of the second switch S2, the performance requirements of the control device 110 will be high, leading to increased costs. If a control device 110 with general performance is used, it will be difficult to control the on / off state of the second switch S2, affecting the performance of the laser device. Therefore, considering both cost and performance, in this embodiment, referring to FIG6A, a fourth switch S4 can also be provided in the laser device 121. The first terminal of the fourth switch S4 is connected to the control terminal of the second switch S2, and the second terminal of the fourth switch S4 is connected to the ground terminal GND. Thus, the on / off state of the second switch S2 can be controlled by controlling the on / off state of the fourth switch S4, balancing the impact of cost and performance. During operation, when the fourth switch S4 is on, the second switch S2 is off. When the fourth switch S4 is off, the control terminal of the second switch S2 is disconnected from the ground terminal GND, and the second switch S2 is on.

[0131] In some embodiments, the fourth switch S4 further includes a control terminal, which is responsible for receiving control signals to control the connection and disconnection between the first and second terminals of the fourth switch S4. Thus, the fourth switch S4 can be configured as a semiconductor switching device having a first terminal, a second terminal, and a control terminal. Exemplarily, the control device 110 can be connected to the control terminal of the fourth switch S4 and output control signals to its control terminal.

[0132] For example, referring to FIG6B, which exemplarily illustrates another circuit diagram of the laser device provided in an embodiment of this application, the fourth switch S4 can also be implemented using a FET. In this case, the control terminal of the fourth switch S4 is the gate of the FET, the first terminal is the source of the FET, and the second terminal is the drain of the FET; or, the first terminal is the drain of the FET, and the second terminal is the source of the FET. In some embodiments, since GaN-type FETs can achieve higher electron mobility and better electrical performance, the fourth switch S4 can be set as a GaN-type FET. In other embodiments, the fourth switch S4 can also be set as other types of FETs, which are not limited here.

[0133] In some embodiments, when both the second switch S2 and the fourth switch S4 are implemented using FETs, referring to FIG6B, the laser device 121 may further include a second resistor R2 connected between the first terminal and the control terminal of the second switch S2. Thus, when the fourth switch S4 is open, the control terminal of the second switch S2 is connected to the positive terminal of the power supply HV through the second resistor R2, so that the voltage at the positive terminal of the power supply HV controls the second switch S2 to turn on, thereby eliminating the need for the control device 110 to directly control the on and off of the second switch S2.

[0134] Referring to Figure 6B, the laser device 121 may further include a third resistor R3 connected between the control terminal of the second switch S2 and the first terminal of the fourth switch S4. This allows the control terminal of the second switch S2 to be connected to the first terminal of the fourth switch S4 via the third resistor R3, reducing the influence of the voltage at the positive terminal of the power supply HV on the fourth switch S4.

[0135] Referring to Figure 6B, the laser device 121 may further include a fourth resistor R4 connected to the control terminal of the fourth switch S4, wherein the first end of the fourth resistor R4 is connected to the control terminal of the fourth switch S4, and the second end of the fourth resistor R4 is connected to the control device. Thus, the control terminal of the fourth switch S4 can receive the high-voltage control signal EN3 through the fourth resistor R4 to control the fourth switch S4 to conduct, and reduce the impact of the control signal directly acting on the control terminal of the fourth switch S4.

[0136] Referring to Figure 6B, the laser device 121 may further include a fifth resistor R5 connected between the control terminal of the fourth switch S4 and the ground terminal GND. Thus, the control terminal of the fourth switch S4 is grounded through the fifth resistor R5, and when the high-voltage control signal EN3 is not input to the fourth resistor R4, the fourth switch S4 can be opened by the voltage at the ground terminal GND.

[0137] The working process of the laser device in this application embodiment will be described below using the structure of the laser device shown in Figure 6B as an example.

[0138] During the operation of the lidar, under normal working conditions, that is, the illumination time of each laser D1_1 to D1_n is less than the duration threshold, no voltage signal is applied to the second end of the fourth resistor R4, and the control end of the fourth switch S4 is grounded through the fifth resistor R5, so that the first and second ends of the fourth switch S4 are disconnected. Then, the high voltage of the positive end of the power supply HV is applied to the control end of the second switch S2 through the second resistor R2, and the second switch S2 is turned on.

[0139] During the operation of the lidar, in a failure scenario, i.e., the illumination duration of one or more of the lasers D1_1 to D1_n is greater than or equal to the duration threshold, a high voltage control signal EN3 is applied to the second terminal of the fourth resistor R4, controlling the conduction between the first and second terminals of the fourth switch S4. Then, the control terminal of the second switch S2 is connected to the ground terminal GND, and the second switch S2 is disconnected.

[0140] Furthermore, the remaining working principle of the laser device shown in Figure 6B can be referred to Embodiment 1, and will not be elaborated here.

[0141] Example 3

[0142] Figure 7 illustrates another circuit diagram of the laser device provided in this application embodiment. Referring to Figure 7, this embodiment modifies the implementation method in Embodiment 2. The similarities are not repeated here, but the differences are: each laser emitting circuit is further provided with a first resistor. The first resistor reduces the risk of energy from other first capacitors flowing into the laser in the target laser emitting circuit, thereby further reducing the illumination time of the laser in the target laser emitting circuit.

[0143] For example, referring to Figure 7, the laser emitting circuit 1211_1 is provided with a first resistor R1_1, and the first end of the first resistor R1_1 is connected to the second end of the second switch S2. The second end of the first resistor R1_1 is connected to the first electrode plate of the first capacitor C1_1 and the first end of the laser D1_1. ... The laser emitting circuit 1211_n may also be provided with a first resistor R1_n, the first end of which is connected to the second end of the second switch S2, and the second end of which is connected to the first electrode plate of the first capacitor C1_n and the first end of the laser D1_n. Other laser emitting circuits can be deduced similarly, and will not be described in detail here.

[0144] To ensure consistent emission power and radiation intensity of the laser pulse signals emitted by lasers D1_1 to D1_n under normal operating conditions, the resistance values ​​of the first resistors R1_1 to R1_n can be made identical. Furthermore, maintaining uniformity in the first resistors reduces the complexity of resistor design and improves device stability. Taking laser emitting circuit 1211_1 as an example, during the current illumination cycle, when laser D1_1 is emitting light, the first capacitor C1_1 releases energy, causing its voltage to decrease, resulting in a voltage difference between capacitor C0 and the first capacitor C1_1. When laser D1_1 is not emitting light, capacitor C0 charges the first capacitor C1_1 through the second switch S2 and the first resistor R1_1. The energy in the first capacitor C1_1 needs to be fully charged to the appropriate level during the time laser D1_1 is not emitting light to ensure the energy requirements of laser D1_1 in the next illumination cycle. Therefore, the resistance values ​​of the first resistors R1_1 to R1_n can be determined according to the illumination cycle.

[0145] For example, each of the first resistors R1_1 to R1_n can be implemented using actual resistor devices, or each of the first resistors R1_1 to R1_n can also be implemented using equivalent resistor devices, such as inductors, circuit traces, or other components with resistive properties.

[0146] As shown in Figure 4A, if the first switch S1_1 fails due to a short circuit, not only will the energy stored in the first capacitor C1_1 be released through the laser D1_1, but the energy stored in the first capacitors C1_2 to C1_n will also be released through the laser D1_1. To further reduce the energy released through the laser D1_1 by the first capacitors C1_2 to C1_n, as shown in Figure 7, in this embodiment, a first resistor R1_1 is provided in the laser emitting circuit 1211_1. Taking the laser emitting circuit 1211_n as an example, the energy stored in the first capacitor C1_n needs to pass through the first resistor R1_n and the first resistor R1_1 to flow into the laser D1_1. However, the equivalent resistance of the first resistors R1_n and R1_1 is much greater than the equivalent resistance when the laser D1_n and the first switch S1_n are connected in series. Therefore, the energy stored in the first capacitor C1_n will preferentially use the path with the lower equivalent resistance for discharge. For example, as shown in Figure 4B, the energy stored in the first capacitor C1_n can be preferentially discharged by turning on the third switch S3. As shown in Figure 4C, the energy stored in the first capacitor C1_n can be preferentially discharged by turning on both the third switch S3 and the first switch S1_n. This reduces the risk of energy stored in the first capacitor C1_n flowing back into the first capacitor C1_1. The remaining laser emitting circuits can be deduced similarly and will not be elaborated here. Furthermore, the remaining operating principles of the laser device shown in Figure 7 can be referred to Embodiment 1, and will not be elaborated here.

[0147] Example 4

[0148] Figure 8A exemplarily illustrates another circuit diagram of the laser device provided in an embodiment of this application. Referring to Figure 8A, this embodiment modifies the implementation method in Embodiment 3. The similarities are not repeated here, but the differences are as follows: the laser device 121 includes a plurality of third switches S3_1 to S3_n. A third switch S3_1 is provided in the laser emitting circuit 1211_1. The first end of the third switch S3_1 is connected to the first electrode plate of the first capacitor C1_1, the second end of the laser D1_1, and the second end of the first resistor R1_1. ... A third switch S3_n is provided in the laser emitting circuit 1211_n. The first end of the third switch S3_n is connected to the first electrode plate of the first capacitor C1_n, the second end of the laser D1_n, and the second end of the first resistor R1_n.

[0149] Taking the laser emitting circuit 1211_1 as an example, as shown in Figure 7, when a third switch S3 is set in the laser device, the energy stored in the first capacitor C1_1 needs to pass through the first resistor R1_1 to be discharged to ground through the third switch S3. However, the on-state equivalent resistance of the first resistor R1_1 is much greater than the on-state equivalent resistance when the laser D1_1 and the first switch S1_1 are connected in series. As a result, most of the energy stored in the first capacitor C1_1 is discharged through the light-emitting path of the laser D1_1 and the first switch S1_1. Therefore, in this embodiment of the application, referring to Figure 8B, which exemplarily illustrates another circuit diagram of the laser device in this embodiment under a failure scenario, the laser device 121 in this embodiment, by setting a third switch S3_1 in the laser emitting circuit 1211_1, when the third switch S3_1 is turned on, the energy stored in the first capacitor C1_1 no longer needs to pass through the first resistor R1_1, but is directly discharged to ground through the third switch S3_1, reducing the risk that the energy stored in the first capacitor C1_1 cannot be discharged in time. Furthermore, when the third switch S3_1 is turned on, it can also allow as much energy stored in the first capacitor C1_1 as possible to be discharged to ground, thereby minimizing the amount of energy stored in the first capacitor C1_1 flowing through the laser D1_1, further reducing the illumination time of the laser D1_1, and making it easier to meet the eye safety requirements under failure scenarios. The remaining laser emitting circuits can be deduced similarly, and will not be elaborated here. In addition, the remaining working principles of the laser device shown in Figure 8A can be referred to Embodiment 1, and will not be elaborated here.

[0150] In some embodiments, since the cost of sampling separation devices is high, but the cost increase from using integrated devices is not significant, the first switch and its driver can be integrated together, thereby achieving faster and more precise control. Furthermore, the same laser emitting circuit can be integrated into a single semiconductor device. In other embodiments, the components of the same laser emitting circuit can be implemented separately on a circuit board.

[0151] Example 5

[0152] Figure 9A exemplarily illustrates another circuit diagram of the laser device provided in an embodiment of this application. Referring to Figure 9A, this embodiment modifies the implementation method in Embodiment 1. The similarities are not repeated here, but the differences are as follows: the laser device 121 may include a second switch S2 and multiple laser emitting circuits 1211_1 to 1211_n. The laser emitting circuit 1211_1 may include a laser D1_1, a first switch S1_1, a first capacitor C1_1, and a first resistor R1_1. The second end of the first resistor R1_1 is connected to the first electrode plate of the first capacitor C1_1 and the first end of the laser D1_1, respectively. The second end of the laser D1_1 is connected to the first end of the first switch S1_1. The second end of the first switch S1_1 and the second electrode plate of the first capacitor C1_1 are respectively connected to the ground terminal GND. ...The laser emitting circuit 1211_n may include a laser D1_n, a first switch S1_n, a first capacitor C1_n, and a first resistor R1_n. The second terminal of the first resistor R1_n is connected to the first electrode plate of the first capacitor C1_n and the first terminal of the laser D1_n. The second terminal of the laser D1_n is connected to the first terminal of the first switch S1_n. The second terminal of the first switch S1_n and the second electrode plate of the first capacitor C1_n are both connected to the ground terminal GND. Furthermore, the first terminal of the second switch S2 is connected to the power supply HV, and the second terminal of the second switch S2 is connected to the first terminals of the first resistors R1_1 to R1_n in the plurality of laser emitting circuits 1211_1 to 1211_n.

[0153] In a failure scenario, taking laser emitting circuit 1211_1 as the target laser emitting circuit and laser emitting circuits 1211_2 to 1211_n as the cooperative laser emitting circuits as an example, and referring to Figure 10, which exemplarily shows another circuit diagram of the laser device in the failure scenario of the embodiment of this application, the laser device 121 in the embodiment of this application, by setting the second switch S2, when the illumination duration of laser D1_1 is greater than or equal to the duration threshold, the control signal EN1 controls the second switch S2 to open, which can cut off the path between the power supply HV and the first capacitors C1_1 to C1_n, and can prevent the power supply HV from continuing to charge the first capacitors C1_1 to C1_n through the second switch S2. Furthermore, the first switches S1_2 to S1_n are also controlled to be turned on. Since the laser device 121 is equipped with first resistors R1_1 to R1_n, taking the laser emitting circuit 1211_n as an example, if the energy stored in the first capacitor C1_n wants to flow into the laser D1_1, it needs to pass through the first resistor R1_n and the first resistor R1_1. However, the conduction equivalent resistance of the first resistor R1_n and the first resistor R1_1 is much greater than the conduction equivalent resistance when the laser D1_n and the first switch S1_n are connected in series. Therefore, the energy stored in the first capacitor C1_n will preferentially be discharged through the light-emitting path of the laser D1_n and the first switch S1_n. Based on this, by controlling the first switches S1_2 to S1_n in the laser emitting circuits 1211_2 to 1211_n to be turned on, the lasers D1_2 to D1_n emit light together. The light emission path of the lasers D1_2 to D1_n will release the energy stored in the first capacitors C1_2 to C1_n, reducing the risk of the energy stored in the first capacitors C1_2 to C1_n flowing into the laser D1_1. This can reduce the light emission time of the laser D1_1, thereby reducing the emission power and radiation intensity of the laser pulse signal emitted by the laser D1_1. In turn, it can reduce the risk that the emission power and radiation intensity of the laser pulse signal emitted by the laser D1_1 will exceed the AEL value required for human eye safety.

[0154] It is worth mentioning that the direction indicated by the dashed arrow in Figure 10 represents the energy release path in the first capacitors C1_1 to C1_n.

[0155] Furthermore, under normal circumstances, the illumination area of ​​one laser in a vehicle-mounted LiDAR is generally larger than the area that the human eye can receive. Therefore, when laser D1_1 is malfunctioning and the laser pulse signal emitted by laser D1_1 enters the human eye, the laser pulse signals emitted by lasers D1_2 to D1_n will not enter the human eye. Thus, even if lasers D1_2 to D1_n are illuminating, no more laser energy will enter the human eye. This effectively reduces the laser energy entering the human eye in failure scenarios, thereby reducing the safety risks to the human eye.

[0156] Under normal operating conditions, where the illumination duration of each laser D1_1 to D1_n is less than a duration threshold, the second switch S2 can be turned on. The power supply HV outputs the high voltage required to drive the lasers, charging the first capacitors C1_1 to C1_n. Then, the first switches S1_1 to S1_n can be turned on sequentially according to the requirements of the lidar, controlling the lasers D1_1 to D1_n to illuminate sequentially. In other embodiments, some or all of the first switches S1_1 to S1_n can be turned on simultaneously, allowing some or all of the lasers D1_1 to D1_n to illuminate simultaneously.

[0157] It is understood that the implementation methods of the first switches S1_1 to S1_n and the second switch S2 in the embodiments of this application, as well as the remaining implementation methods of the cooperative laser emission circuit, can refer to the description in Embodiment 1, and will not be repeated here. The implementation methods of the first resistors R1_1 to R1_n in the embodiments of this application can refer to the description in Embodiment 3, and will not be repeated here.

[0158] In this embodiment, the implementation method for determining the relationship between the illumination duration and the duration threshold of the laser pulse signal emitted by the laser can also refer to the description of Embodiment 1. Based on this, in some embodiments, referring to FIG9B, FIG9B exemplarily shows another circuit diagram of the laser device provided in the embodiment of this application. The laser device in the embodiment of this application can also be provided with a pulse width sampling circuit 1212 and multiple second capacitors C2_1 to C2_n. The specific implementation method and working process can refer to the description in Embodiment 1, and will not be repeated here.

[0159] In specific implementation, referring to Figure 9B, the laser device in this embodiment may also be provided with a fourth switch S4 connected between the control terminal of the second switch S2 and the ground terminal GND. The specific implementation and operation process can be referred to the description in Embodiment 2, and will not be repeated here. Furthermore, the laser device in this embodiment may also be provided with a second resistor R2 to a fifth resistor R5. The specific implementation and operation process can also be referred to the description in Embodiment 2, and will not be repeated here.

[0160] Example 6

[0161] Figure 11A exemplarily illustrates another circuit diagram of the laser device provided in an embodiment of this application. Referring to Figure 11A, this embodiment modifies the implementation method in Embodiment 5, and the similarities are not repeated here. The difference is that the first resistors R1_1 to R1_n are not provided in the laser emitting circuits 1211_1 to 1211_n. That is, the laser emitting circuit 1211_1 includes a laser D1_1, a first switch S1_1, and a first capacitor C1_1, ... the laser emitting circuit 1211_n may include a laser D1_n, a first switch S1_n, and a first capacitor C1_n. The connection relationship between the laser emitting circuits 1211_1 to 1211_n and the second switch S2 is as described in Embodiment 1, and will not be repeated here.

[0162] In a failure scenario, taking laser emitting circuit 1211_1 as the target laser emitting circuit and laser emitting circuits 1211_2 to 1211_n as the cooperative laser emitting circuits as an example, and referring to Figure 12, which exemplarily shows another circuit diagram of the laser device in the failure scenario of the embodiment of this application, the laser device in the embodiment of this application, by setting the second switch S2, when the illumination duration of laser D1_1 is greater than or equal to the duration threshold, controls the second switch S2 to open, which can cut off the path between the power supply HV and the first capacitors C1_1 to C1_n, and can prevent the power supply HV from continuing to charge the first capacitors C1_1 to C1_n through the second switch S2. Furthermore, the first switches S1_2 to S1_n are also controlled to be turned on. Taking the laser emitting circuit 1211_n as an example, if the energy stored in the first capacitor C1_n wants to flow into the laser D1_1, it needs to pass through the trace between the first capacitor C1_n and the laser D1_1. However, the equivalent resistance of the trace between the first capacitor C1_n and the laser D1_1, as well as the equivalent resistance of the laser D1_1 and the first switch S1_1, is greater than the equivalent resistance of the laser D1_n and the first switch S1_n when they are connected in series. Therefore, the energy stored in the first capacitor C1_n will preferentially be discharged through the light-emitting path of the laser D1_n and the first switch S1_n. Based on this, by controlling the first switches S1_2 to S1_n in the laser emitting circuits 1211_2 to 1211_n to be turned on, the lasers D1_2 to D1_n emit light together. The light emission path of the lasers D1_2 to D1_n will release the energy stored in the first capacitors C1_2 to C1_n, reducing the risk of the energy stored in the first capacitors C1_2 to C1_n flowing into the laser D1_1. This can reduce the light emission time of the laser D1_1, thereby reducing the emission power and radiation intensity of the laser pulse signal emitted by the laser D1_1. In turn, it can reduce the risk that the emission power and radiation intensity of the laser pulse signal emitted by the laser D1_1 will exceed the AEL value required for human eye safety.

[0163] It is worth mentioning that the direction pointed to by the dashed arrow in Figure 12 represents the energy release path in the first capacitors C1_1 to C1_n.

[0164] Furthermore, under normal circumstances, the illumination area of ​​one laser in a vehicle-mounted LiDAR is generally larger than the area that the human eye can receive. Therefore, when laser D1_1 is malfunctioning and the laser pulse signal emitted by laser D1_1 enters the human eye, the laser pulse signals emitted by lasers D1_2 to D1_n will not enter the human eye. Thus, even if lasers D1_2 to D1_n are illuminating, no more laser energy will enter the human eye. This effectively reduces the laser energy entering the human eye in failure scenarios, thereby reducing the safety risks to the human eye.

[0165] The working process of the laser device in this application embodiment under normal working conditions can be referred to the description in Embodiment 5, and will not be repeated here.

[0166] It is understood that the implementation of the first switch S1_1 to S1_n and the second switch S2 in the embodiments of this application, as well as the other implementations of the cooperative laser emission circuit, can refer to the description in Embodiment 1, and will not be repeated here.

[0167] In this embodiment, the implementation method for determining the relationship between the illumination duration and the duration threshold of the laser pulse signal emitted by the laser can also refer to the description of Embodiment 1. Based on this, in some embodiments, referring to FIG11B, FIG11B exemplarily shows another circuit diagram of the laser device provided in the embodiment of this application. The laser device in the embodiment of this application can also be provided with a pulse width sampling circuit 1212 and multiple second capacitors C2_1 to C2_n. The specific implementation method and working process can refer to the description in Embodiment 1, and will not be repeated here.

[0168] In specific implementation, referring to FIG11B, the laser device in this embodiment may also be provided with a fourth switch S4 connected between the control terminal of the second switch S2 and the ground terminal GND. The specific implementation and operation process can be referred to the description in Embodiment 2, and will not be repeated here. Furthermore, the laser device in this embodiment may also be provided with a second resistor R2 to a fifth resistor R5. The specific implementation and operation process can also be referred to the description in Embodiment 2, and will not be repeated here.

[0169] The above content is only a specific implementation of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application.

Claims

1. A laser device, characterized by, include: Multiple laser emitting circuits are provided, each laser emitting circuit including a laser, a first switch and a first capacitor, the first electrode plate of the first capacitor is connected to the first end of the laser, the second end of the laser is connected to the first end of the first switch, and the second end of the first switch and the second electrode plate of the first capacitor are respectively connected to a ground terminal. The second switch has a first end connected to the power supply and a second end connected to the first end of the laser in the plurality of laser emitting circuits and the first electrode plate of the first capacitor. The third switch has its first end connected to the second end of the second switch, and its second end connected to the grounding terminal.

2. The laser device of claim 1, wherein The second switch also includes a control terminal, which is used to control the connection and disconnection between the first terminal and the second terminal of the second switch.

3. The laser device of claim 1 or 2, wherein The third switch also includes a control terminal, which is used to control the connection and disconnection between the first terminal and the second terminal of the third switch.

4. The laser device of claim 2 or 3, wherein When the illumination duration of the laser in the target laser emitting circuit of the plurality of laser emitting circuits is greater than or equal to the duration threshold, the control terminal of the second switch controls the first and second terminals of the second switch to disconnect, and the control terminal of the third switch controls the first and second terminals of the third switch to conduct.

5. The laser device of any one of claims 1-4, wherein, Each of the laser emitting circuits further includes a first resistor, the first end of which is connected to the second end of the second switch, and the second end of which is connected to the first electrode plate of the first capacitor and the first end of the laser, respectively.

6. The laser device of claim 5, wherein, The laser device includes a plurality of the third switches, and one of the third switches is provided in each of the plurality of third switches in the laser emitting circuit; In the same laser emitting circuit, the first terminal of the third switch is connected to the first electrode plate of the first capacitor and the second terminal of the laser.

7. The laser device of any one of claims 1-5, wherein, The laser device includes one of the third switches.

8. A laser device, characterized by include: Multiple laser emitting circuits are provided, each laser emitting circuit including a laser, a first switch, a first capacitor and a first resistor. The second end of the first resistor is connected to the first electrode plate of the first capacitor and the first end of the laser. The second end of the laser is connected to the first end of the first switch. The second end of the first switch and the second electrode plate of the first capacitor are connected to the ground terminal. The second switch has its first end connected to the power supply and its second end connected to the first end of the first resistor in the plurality of laser emitting circuits.

9. The laser device as claimed in claim 8, characterized in that, The second switch also includes a control terminal, which is used to control the connection and disconnection between the first terminal and the second terminal of the second switch.

10. The laser device as claimed in claim 9, characterized in that, When the illumination duration of the laser in the target laser emitting circuit among the plurality of laser emitting circuits is greater than or equal to the duration threshold, the control terminal of the second switch controls the first terminal and the second terminal of the second switch to disconnect.

11. The laser device according to any one of claims 5-10, characterized in that, The resistance values ​​of each of the first resistors are the same.

12. The laser device according to any one of claims 1-11, characterized in that, The first switch also includes a control terminal, which is used to control the connection and disconnection between the first terminal and the second terminal of the first switch.

13. The laser device as claimed in claim 12, characterized in that, When the illumination duration of the laser in the target laser emitting circuit among the plurality of laser emitting circuits is greater than or equal to the duration threshold, the control terminal of the first switch in the cooperative laser emitting circuit controls the first terminal and the second terminal of the first switch to conduct. The cooperative laser emitting circuit is at least a portion of the laser emitting circuits other than the target laser emitting circuit among the plurality of laser emitting circuits.

14. A laser device, characterized in that, include: Multiple laser emitting circuits are provided, each laser emitting circuit including a laser, a first switch and a first capacitor, the first electrode plate of the first capacitor is connected to the first end of the laser, the second end of the laser is connected to the first end of the first switch, and the second end of the first switch and the second electrode plate of the first capacitor are respectively connected to the ground terminal. The second switch has a first terminal connected to a power supply, and a second terminal connected to the second terminal of the laser in the plurality of laser emitting circuits and the first electrode plate of the first capacitor. The second switch also includes a control terminal, which is used to control the connection and disconnection between the first terminal and the second terminal of the second switch. When the illumination duration of the laser in the target laser emitting circuit among the plurality of laser emitting circuits is greater than or equal to the duration threshold, the control terminal of the second switch controls the first terminal and the second terminal of the second switch to disconnect, and the control terminal of the first switch in the cooperative laser emitting circuit controls the first terminal and the second terminal of the first switch to conduct, wherein the cooperative laser emitting circuit is at least a portion of the laser emitting circuits other than the target laser emitting circuit among the plurality of laser emitting circuits.

15. The laser device as claimed in claim 13 or 14, characterized in that, The coordinated laser emitting circuit refers to all laser emitting circuits other than the target laser emitting circuit among the plurality of laser emitting circuits.

16. The laser device as claimed in claim 13, 14 or 15, characterized in that, The duration of the first switch in the coordinated laser emission circuit is longer than the reference duration of conduction; The conduction reference duration is the duration during which the first switch is turned on once when the illumination duration of the laser in each laser emitting circuit is less than the duration threshold.

17. The laser device according to any one of claims 2-16, characterized in that, It also includes a fourth switch, the first end of which is connected to the control terminal of the second switch, and the second end of which is connected to the grounding terminal.

18. The laser device as claimed in claim 17, characterized in that, The fourth switch also includes a control terminal, which is used to control the connection and disconnection between the first terminal and the second terminal of the fourth switch.

19. The laser device as claimed in claim 18, characterized in that, When the illumination duration of the laser in the target laser emitting circuit among the plurality of laser emitting circuits is greater than or equal to the duration threshold, the control terminal of the fourth switch controls the first and second terminals of the fourth switch to conduct.

20. The laser device as claimed in claim 18 or 19, characterized in that, Also includes: A second resistor connected between the first terminal and the control terminal of the second switch; or, A third resistor connected between the control terminal of the second switch and the first terminal of the fourth switch; or... The fourth resistor is connected to the control terminal of the fourth switch; or, A fifth resistor is connected between the control terminal of the fourth switch and the ground terminal.

21. The laser device as claimed in claim 4, 10, 13, 14 or 19, characterized in that, It also includes a pulse width sampling circuit, which is connected to the first terminal of each of the first switches; The illumination duration of the laser in the target laser emitting circuit includes: The pulse width sampling circuit detects the duration of the low voltage at the first terminal of the first switch in the target laser emitting circuit. long.

22. The laser device as claimed in claim 21, characterized in that, It also includes a plurality of second capacitors, and a first terminal of the first switch is connected to the pulse width sampling circuit through one of the plurality of second capacitors.

23. A transmitting module, characterized in that, Includes the laser device as described in any one of claims 1-22.

24. A lidar, characterized in that, Includes the launch module as described in claim 23.

25. A terminal device, characterized in that, It includes a device body and a lidar as described in claim 24, wherein the lidar is mounted on the device body.

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