Transmitting module, driving control method thereof, photoelectric detection device and electronic equipment

Abstract

The application provides a transmitting module configured to emit a deflectable scanning light beam to a preset field of view range. The transmitting module comprises a light source module, at least one acousto-optic deflection device and a deflection driving module. The light source module is configured to emit a light beam. The at least one acousto-optic deflection device is configured to deflect the light beam. The deflection driving module is configured to output a square wave driving signal to drive the acousto-optic deflection device, and control the deflection angle of the acousto-optic deflection device to the light beam by adjusting the frequency of the square wave driving signal. The application also provides a driving control method of the transmitting module, and an optoelectronic detection device and an electronic device comprising the transmitting module.

Description

Technical Field

[0001] This application belongs to the field of photoelectric detection, and in particular relates to a transmitting module and its driving control method, a photoelectric detection device and related electronic equipment. Background Technology

[0002] LiDAR's ranging function is typically based on the Time-of-Flight (ToF) measurement principle. This involves emitting laser pulses into the measurement scene and measuring the time it takes for the laser pulses to travel back and forth between the LiDAR and the target object to calculate distance information. Because ToF measurement offers advantages such as long sensing distance, high accuracy, and low power consumption, it is widely used in consumer electronics, autonomous driving, AR / VR, and other fields.

[0003] An acousto-optic deflector (AOD) is a device that adjusts the frequency of incident ultrasonic waves to change the direction of incident laser emission. It has high beam deflection accuracy and microsecond-level response speed, and can be used to realize one-dimensional or two-dimensional rapid scanning of lasers. Currently, lidar uses AOD to deflect beams to achieve scanning and sensing of the field of view.

[0004] For commercial LiDAR, the key to cost reduction and efficiency improvement lies in chip-based and integrated design. In this case, the power consumption of the drive circuit becomes a bottleneck restricting cost. To meet the set ranging range requirements, the beam deflected by the AOD (Aspect-Oriented Deflector) needs to reach a certain peak optical power, which also requires the AOD's drive signal to have a high peak voltage, thus increasing the manufacturing cost of the related drive chip. Furthermore, existing AODs generally use sinusoidal signals for driving. Since the generation of sinusoidal signals requires numerous signal shaping devices, the energy consumed in this process further increases the overall power consumption of the drive circuit. Summary of the Invention

[0005] In view of this, this application provides a transmitting module and its driving method, a lidar device and related electronic equipment that can improve the problems of the prior art.

[0006] In a first aspect, this application provides a transmitting module configured to emit a deflectable scanning beam into a preset field of view. The transmitting module includes:

[0007] The light source module is configured to emit a beam of light;

[0008] At least one acousto-optic deflecting device is configured to deflect the light beam; and

[0009] The deflection drive module is configured to output a square wave drive signal to drive the acousto-optic deflection device, and to control the deflection angle of the acousto-optic deflection device on the light beam by adjusting the frequency of the square wave drive signal.

[0010] In some embodiments, the deflection drive module includes a square wave signal generation circuit and a power amplifier circuit. The square wave generation circuit is configured to generate square wave fundamental signals of different frequencies, and the power amplifier circuit is configured to adjust the power of the square wave fundamental signals to form the square wave drive signal.

[0011] In some embodiments, the square wave generation circuit is a fractional-frequency-locked loop circuit, used to generate square wave base signals of different frequencies based on a clock signal. The fractional-frequency-locked loop circuit includes a crystal oscillator, a frequency and phase detector, a charge pump, a loop filter, a voltage-controlled oscillator, and a fractional-frequency divider. The crystal oscillator provides a clock reference signal with a preset frequency to the frequency and phase detector. The frequency and phase detector controls the charge pump to charge or discharge the loop filter according to the difference in phase and frequency between the clock reference signal and a feedback signal, thereby adjusting the voltage control signal output by the loop filter to the voltage-controlled oscillator. The voltage-controlled oscillator outputs a square wave base signal of the corresponding frequency according to the voltage control signal. The square wave base signal is fed back to the frequency and phase detector after being divided by the fractional-frequency divider to form the feedback signal, thus forming a feedback control loop.

[0012] In some embodiments, the fractional frequency divider is a fractional frequency divider based on sigma-delta modulation, including a sigma-delta modulator and a high-speed frequency divider. The sigma-delta modulator is configured to modulate a set fractional frequency division value and output a series of integer frequency division values ​​with a fractional average value. The high-speed frequency divider is controlled by the sigma-delta modulator to achieve different division ratios.

[0013] In some embodiments, the emission module includes an acousto-optic deflector and a liquid crystal polarization grating device, wherein the acousto-optic deflector is configured to deflect the light beam along a first direction, and the liquid crystal polarization grating device is configured to deflect the light beam along the first direction and / or a second direction.

[0014] In some embodiments, the emission module includes an acousto-optic deflector and a metasurface device. The acousto-optic deflector is configured to deflect the light beam along a first direction, and the metasurface device is configured to continue deflecting the light beam along the first direction and / or a second direction by a plurality of preset angles.

[0015] In some embodiments, the acousto-optic deflection device uses the beam deflection angle of the beam corresponding to the fundamental frequency component of the square wave driving signal as the actual deflection angle of the beam by the transmitting module.

[0016] Secondly, this application provides a photoelectric detection device, including the emission module as described above.

[0017] Thirdly, this application provides an electronic device including the photoelectric detection device described above.

[0018] Fourthly, this application provides a driving control method for a transmitting module, the transmitting module including a light source module, at least one acousto-optic deflection device, and a deflection driving module, comprising the following steps:

[0019] The deflection drive module uses a square wave drive signal to drive the acousto-optic deflection device to deflect the light beam emitted by the light source module by a preset deflection angle; and

[0020] The deflection drive module controls the deflection angle of the acousto-optic deflection device on the beam by adjusting the frequency of the square wave drive signal, thereby achieving scanning detection of the field of view.

[0021] The beneficial effects of this application are:

[0022] Compared with the traditional sine wave driving signal, the square wave driving signal used in this application to drive the acousto-optic deflection device has higher circuit output efficiency and less circuit loss while meeting the same actual usable power requirements. Moreover, since the required peak voltage is lower, the use of square wave driving can also reduce the design difficulty and cost of the driving circuit. Attached Figure Description

[0023] The features and advantages of the present invention will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0024] Figure 1 This is a schematic diagram of the functional modules of an electronic device provided in an embodiment of this application;

[0025] Figure 2 for Figure 1 A functional module diagram of an embodiment of the photoelectric detection device described herein;

[0026] Figure 3 for Figure 2 A schematic diagram of the optical path of an embodiment of the transmitting module described herein;

[0027] Figure 4 for Figure 3 A schematic diagram of the acousto-optic deflection device described above;

[0028] Figure 5 This is a schematic diagram of the Fourier decomposition of a square wave driving signal.

[0029] Figure 6 for Figure 2 A functional module diagram of the deflection drive module described above;

[0030] Figure 7 for Figure 6 A schematic diagram of the functional modules of the fractional frequency division phase-locked loop circuit described above;

[0031] Figure 8 A schematic diagram of the structure of an optoelectronic detection device provided in an embodiment of this application as an automotive lidar;

[0032] Figure 9 This is a schematic flowchart illustrating the driving control method for a transmitting module provided in an embodiment of this application. Detailed Implementation

[0033] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. In the description of this application, it should be understood that the terms "first" and "second" are used for description only and should not be construed as indicating or implying relative importance or implicitly specifying the number or order of the indicated technical features. Thus, technical features defined with "first" and "second" may explicitly or implicitly include one or more of the stated technical features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0034] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integrated connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0035] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, only specific examples of components and settings are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or reference letters may be repeated in different examples; such repetition is for the purpose of simplifying and clearly describing this application and does not in itself indicate a specific relationship between the various embodiments and / or settings discussed. Moreover, the various specific processes and materials described below are merely examples for implementing the technical solutions of this application; however, those skilled in the art should recognize that the technical solutions of this application can also be implemented using other processes and / or other materials not described below.

[0036] Furthermore, the described features and structures can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced even without one or more of the specific details described, or with other structures, components, etc. In other instances, well-known structures or operations are not shown or described in detail to avoid obscuring the focus of this application.

[0037] Embodiments of this application provide a transmitting module configured to emit a deflectable scanning beam into a preset field of view. The transmitting module includes:

[0038] The light source module is configured to emit a beam of light;

[0039] At least one acousto-optic deflecting device is configured to deflect the light beam; and

[0040] The deflection drive module is configured to output a square wave drive signal to drive the acousto-optic deflection device, and to control the deflection angle of the acousto-optic deflection device on the light beam by adjusting the frequency of the square wave drive signal.

[0041] In some embodiments, the deflection drive module includes a square wave signal generation circuit and a power amplifier circuit. The square wave generation circuit is configured to generate square wave fundamental signals of different frequencies, and the power amplifier circuit is configured to adjust the power of the square wave fundamental signals to form the square wave drive signal.

[0042] In some embodiments, the square wave generation circuit is a fractional-frequency-locked loop circuit, used to generate square wave base signals of different frequencies based on a clock signal. The fractional-frequency-locked loop circuit includes a crystal oscillator, a frequency and phase detector, a charge pump, a loop filter, a voltage-controlled oscillator, and a fractional-frequency divider. The crystal oscillator provides a clock reference signal with a preset frequency to the frequency and phase detector. The frequency and phase detector controls the charge pump to charge or discharge the loop filter according to the difference in phase and frequency between the clock reference signal and a feedback signal, thereby adjusting the voltage control signal output by the loop filter to the voltage-controlled oscillator. The voltage-controlled oscillator outputs a square wave base signal of the corresponding frequency according to the voltage control signal. The square wave base signal is fed back to the frequency and phase detector after being divided by the fractional-frequency divider to form the feedback signal, thus forming a feedback control loop.

[0043] In some embodiments, the fractional frequency divider is a fractional frequency divider based on sigma-delta modulation, including a sigma-delta modulator and a high-speed frequency divider. The sigma-delta modulator is configured to modulate a set fractional frequency division value and output a series of integer frequency division values ​​with a fractional average value. The high-speed frequency divider is controlled by the sigma-delta modulator to achieve different division ratios.

[0044] In some embodiments, the transmitting module includes two acousto-optic deflection devices: a first acousto-optic deflection device and a second acousto-optic deflection device; wherein the first acousto-optic deflection device is configured to deflect the light beam along a preset first direction, and the second acousto-optic deflection device is configured to deflect the light beam along a preset second direction, the second direction being different from the first direction.

[0045] In some embodiments, the transmitting module includes an acousto-optic deflector and an electro-optic deflector. The acousto-optic deflector is configured to deflect the light beam along a preset first direction, and the electro-optic deflector is configured to deflect the light beam along a preset second direction, which is different from the first direction.

[0046] In some embodiments, the emission module includes an acousto-optic deflector and a liquid crystal polarization grating device, wherein the acousto-optic deflector is configured to deflect the light beam along a first direction, and the liquid crystal polarization grating device is configured to deflect the light beam along the first direction and / or a second direction.

[0047] In some embodiments, the emission module includes an acousto-optic deflector and a metasurface device. The acousto-optic deflector is configured to deflect the light beam along a first direction, and the metasurface device is configured to continue deflecting the light beam along the first direction and / or a second direction by a plurality of preset angles.

[0048] In some embodiments, the first direction and the second direction are perpendicular to each other, the first direction is horizontal and the second direction is vertical; or, the first direction is vertical and the second direction is horizontal.

[0049] In some embodiments, the acousto-optic deflection device uses the beam deflection angle of the beam corresponding to the fundamental frequency component of the square wave driving signal as the actual deflection angle of the beam by the transmitting module.

[0050] This application also provides a photoelectric detection device, including the emission module as described in the foregoing embodiments.

[0051] In some embodiments, the photoelectric detection device further includes:

[0052] A receiving module includes a photoelectric sensor and receiving optics. The photoelectric sensor includes multiple sensing pixels, each configured to receive light signals from a field of view and output a corresponding light-sensing signal. The field of view includes multiple field-view sections located at different orientations. The receiving optics are configured to transmit light signals from different field-view sections to corresponding sensing pixels.

[0053] The data processing module is configured to analyze and process the light-sensing signal to obtain the corresponding distance information.

[0054] Embodiments of this application also provide an electronic device including the aforementioned photoelectric detection device. The electronic device performs corresponding functions based on distance information obtained by the photoelectric detection device. Examples of such electronic devices include: mobile phones, automobiles, robots, access control / monitoring systems, smart locks, unmanned vehicles, and drones. The distance information includes, for example, proximity information, depth information, distance information, and coordinate information of objects within the field of view. This distance information can be used, for example, in fields such as 3D modeling, identity recognition, autonomous driving, machine vision, monitoring, drone control, augmented reality (AR) / virtual reality (VR), simultaneous localization and mapping (SLAM), and object proximity detection; this application does not limit its application to these fields.

[0055] The photoelectric detection device can be, for example, a lidar (LiDAR), used to obtain distance information of objects within its field of view. LiDAR is applied in fields such as autonomous vehicles, autonomous aircraft, 3D printing, VR, AR, and service robots. Taking an autonomous vehicle as an example, a lidar is installed in the vehicle. The lidar scans the surrounding environment by rapidly and repeatedly emitting laser beams to obtain point cloud data reflecting the shape, position, and movement of one or more objects in the environment. Specifically, the lidar emits a laser beam into the surrounding environment and receives the echo beams reflected back by various objects in the environment. By calculating the time delay (i.e., flight time) between the emission time of the laser beam and the return time of the echo beams, the distance / depth information of each object is determined. Simultaneously, the lidar can also determine the angular information describing the orientation of the laser beam's field of view. Combining the distance / depth information of each object with the angular information of the laser beam generates a three-dimensional map including all objects in the scanned surrounding environment. This three-dimensional map can guide the autonomous driving of the vehicle.

[0056] Hereinafter, embodiments of photoelectric detection devices applied to electronic devices will be described in detail with reference to the accompanying drawings.

[0057] Figure 1 This is a schematic diagram of the functional modules of the photoelectric detection device provided in this application embodiment applied to electronic devices. Figure 2 This is a schematic diagram of the functional modules of the photoelectric detection device provided in the embodiments of this application.

[0058] Reference Figure 1 and Figure 2 The electronic device 1 includes a photoelectric detection device 10. The photoelectric detection device 10 can detect objects 2 within its field of view to obtain three-dimensional information about the objects 2. The field of view can be defined as the three-dimensional spatial range within which the photoelectric detection device 10 can effectively perform three-dimensional information detection; it can also be referred to as the field of view (FOV) of the photoelectric detection device 10. The three-dimensional information includes, but is not limited to, distance information of the objects 2, depth information of the surface of the objects 2, and a combination of the distance information and the spatial coordinate information of the objects 2, etc.

[0059] The electronic device 1 may include an application module 20, which is configured to perform preset operations or implement corresponding functions based on the three-dimensional information detected by the photoelectric detection device 10. For example, but not limited to: determining whether an object 2 appears within a preset field of view in front of the electronic device 1 based on the distance information of the object 2; or controlling the movement of the electronic device 1 to avoid obstacles based on the distance information of the object 2; or realizing 3D modeling, identity recognition, machine vision, etc., based on the depth information of the surface of the object 2. That is, the application module 20 may be a collection of hardware required to perform the above operations and implement the above functions, and software required to control and coordinate the operation of the hardware.

[0060] The electronic device 1 may further include a storage medium 30, which can support the storage needs of the electronic device 1 and / or the photoelectric detection device 10 during operation. Figure 1 As shown, in some embodiments, the storage medium 30 may be disposed inside the electronic device 1. For example... Figure 2 As shown, in some embodiments, a storage medium 16 may also be disposed inside the photoelectric detection device 10. The storage medium 30 includes, but is not limited to, flash memory, electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), hard disk, etc.

[0061] The electronic device 1 may also include a processor 40 to support the data processing needs of the electronic device 1 and / or the photoelectric detection device 10 during operation. For example... Figure 1 As shown, in some embodiments, the processor 40 may be located inside the electronic device 1. For example... Figure 2 As shown, in some embodiments, the processor 17 may also be disposed inside the photoelectric detection device 10. The processor 40 may be, for example, but not limited to, an application processor (AP), a central processing unit (CPU), a micro controller unit (MCU), etc.

[0062] Optionally, in some embodiments, the photoelectric detection device 10 may be, for example, a dToF measurement device for three-dimensional information sensing based on the direct time of flight (dToF) principle. The dToF measurement device can emit a sensing beam within its field of view and receive the sensing beam reflected back from the object 2 within the field of view. The time difference between the emission time and the reception time of the reflected sensing beam is called the flight time t of the sensing beam. The distance information of the object 2 can be obtained by calculating half the distance traveled by the sensing beam within the flight time t. Where c is the speed of light.

[0063] In other embodiments, the photoelectric detection device 10 can also be an iToF measurement device that senses distance information based on the indirect time of flight (iToF) measurement principle. The iToF measurement device obtains the distance information of the object 2 by comparing the phase difference between when the sensing beam is emitted and when it is reflected back and received.

[0064] In other embodiments, the photoelectric detection device 10 can also sense distance information based on the frequency-modulated continuous wave (FMCW) measurement principle. By interfering the returned light and the emitted light, and using frequency mixing detection technology to measure the frequency difference between transmission and reception, the distance to the target object can be calculated from the frequency difference.

[0065] In the embodiments described below, the photoelectric detection device 10 based on the dToF principle is mainly used as an example for illustration.

[0066] In some embodiments, such as Figure 2 As shown, the photoelectric detection device 10 includes a transmitting module 12 and a receiving module 14. The transmitting module 12 is configured to sequentially emit light beams to different directions within the field of view. A portion of these light beams is reflected back by the object 2, and the reflected beam echoes carry distance information about the object 2. A portion of these beam echoes is sensed by the receiving module 14 to obtain the distance information of the object 2. The receiving module 14 is configured to sense light signals from within the field of view and output corresponding photosensitive signals. By analyzing these photosensitive signals, distance information of the object 2 within the field of view can be detected. It is understood that the light signals sensed by the receiving module 14 include both the sensed beam echoes reflected back from the field of view and ambient light from within the field of view.

[0067] like Figure 2As shown, in some embodiments, the transmitting module 12 and the receiving module 14 are arranged side-by-side to form a paraxial light-receiving path. The light-emitting surface of the transmitting module 12 and the light-incident surface of the receiving module 14 both face the same side of the photoelectric detection device 10. The distance between the transmitting module 12 and the receiving module 14 is also called the baseline distance, and its value ranges from, for example, 2 mm to 20 mm. Since the transmitting module 12 and the receiving module 14 are relatively close, although the emission path of the sensing beam from the transmitting module 12 to the object 2 and the return path from the object 2 to the receiving module 14 after reflection are not exactly equal, both are much larger than the distance between the transmitting module 12 and the receiving module 14, and can be considered approximately equal. Therefore, the distance between the object 2 and the photoelectric detection device 10 can be calculated based on the product of half the flight time t of the sensing beam reflected back by the object 2 and the speed of light c. In some other embodiments, the transmitting module and the receiving module may also form a coaxial receiving and transmitting path through a beam splitter (not shown), and this application does not limit this.

[0068] like Figure 2 As shown, in some embodiments, the receiving module 14 includes a photoelectric sensor 140 and a receiving optics 144. The photoelectric sensor 140 may include a single photosensitive pixel 142 or a plurality of photosensitive pixels 142 forming a photosensitive pixel array. One photosensitive pixel 142 may include a single photoelectric conversion device or a plurality of photoelectric conversion devices. The photoelectric conversion device is configured to sense the received light signal and convert it into a corresponding electrical signal as the light-sensing signal output. Optionally, the photoelectric conversion device is, for example, a single photon avalanche diode (SPAD), an avalanche photodiode (APD), a silicon photomultiplier (SiPM) composed of multiple SPADs connected in parallel, and / or other suitable photoelectric conversion elements. For example, in some embodiments, the photoelectric sensor is a SPAD area array chip.

[0069] The field of view of the photoelectric detection device 10 may include multiple field of view partitions located in different directions. The photosensitive pixels 142 of the photoelectric sensor 140 have corresponding field of view partitions within the field of view. The light signal returned from the field of view partition is propagated to the corresponding photosensitive pixel 142 for sensing via the receiving optics 144. That is, the field of view partition corresponding to the photosensitive pixel 142 can be regarded as the spatial range covered by the field of view angle formed by the receiving optics 144 of the photosensitive pixel 142. Thus, when the sensing beam emitted by the transmitting module 12 scans the field of view partition, the sensing beam echo reflected back by the object 2 within the field of view partition is propagated to the corresponding photosensitive pixel 142 for sensing via the receiving optics 144. The light signal returned from the field of view partition includes photons of ambient light from the field of view partition, and when the object 2 is present in the field of view partition, it also includes the sensing beam echo projected onto the partition and reflected back by the object 2.

[0070] The receiving optics 144 is disposed on the light-incident side of the photoelectric sensor 140 and is configured to transmit light signals from different orientations within the field of view to the corresponding photosensitive pixels 142 on the photoelectric sensor 140 for sensing. In some embodiments, the receiving optics 144 may include a receiving lens (not shown). Optionally, the receiving lens may be a single lens or a lens group comprising multiple lenses. In other embodiments, the receiving optics 144 may also include a metasurface device to transmit light beams returning from a specific direction to the corresponding photosensitive pixels 142.

[0071] In some embodiments, the receiving module 14 may further include peripheral circuitry (not shown) consisting of one or more devices such as signal amplifiers and analog-to-digital converters (ADCs), which may be partially or wholly integrated into the photoelectric sensor 140.

[0072] The photoelectric detection device 10 further includes a data processing module 15, used to process and analyze the light-sensing signal generated by the photoelectric conversion device to obtain three-dimensional information of the field of view. For example, the data processing module 15 can process and analyze the light-sensing signal based on time-correlated single photon counting (TCSPC) technology to construct a photon counting histogram; or, based on this, the data processing module 15 can also be configured to process and analyze the photon counting histogram to determine the reception time of the sensing beam echo; or, based on this, the data processing module 15 can also be configured to continuously process and analyze the reception time of the sensing beam echo to obtain corresponding distance information; or, based on this, the data processing module 15 can also be configured to integrate the distance information from different directions within the field of view to form a three-dimensional point cloud map of the field of view.

[0073] The functional units in the data processing module 15 that implement all or part of the above-mentioned functions can be located within the photoelectric sensor 140. For example, the photoelectric sensor 140 can be configured to analyze and process the light-sensing signal and output histogram data, distance information, and / or a three-dimensional point cloud map. The functional units in the data processing module 15 that implement some of the above-mentioned functions can also be located in other locations besides the photoelectric sensor 140, including but not limited to: on the circuit board of the receiving module 14, on the circuit board of the photoelectric detection device 10, or on the circuit board of the electronic device 1. That is, in some embodiments, the analysis and processing required to obtain distance information and a three-dimensional point cloud map can be completed by functional units located outside the photoelectric sensor 142, and the photoelectric sensor 142 only needs to output histogram data.

[0074] All or part of the functional units of the data processing module 15 can be implemented in hardware, for example, by configuring discrete logic circuits, programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc., such as digital signal processors (DSPs), application-specific integrated circuits (ASICs), image processors (ISPs), programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), or other logic gate circuits that implement logic functions for data signals. All or part of the functional units of the data processing module 15 can also be implemented in software, for example, by firmware embedded in storage media 30, 16 or computer software code stored in storage media 30, 16, and executed by one or more corresponding processors 17, 40 to implement the corresponding functions.

[0075] like Figure 2As shown, in some embodiments, the emitting module 12 includes a light source module 122, a light deflection module 124, and a deflection driving module 126. The light source module 122 is configured to emit a light beam, and the light deflection module 124 deflects the light beam by a preset angle in a time-division multiplexing manner to form a sensing beam within the time-division multiplexing scanning field of view. The light source module 122 includes one or more light-emitting units 1220 (see...). Figure 3 The light-emitting unit 1220 is configured to emit a light beam. The light-emitting unit 1220 can be a vertical-cavity surface-emitting laser (VCSEL), an edge-emitting laser (EEL), a light-emitting diode (LED), a laser diode (LD), a fiber laser, or other similar light-emitting structures. The edge-emitting laser can be a Fabry-Perot (FP) laser, a distributed feedback (DFB) laser, an electro-absorption modulated (EML) laser, etc., and this embodiment does not limit the specific type of laser used.

[0076] In some embodiments, the sensing beam may be, for example, a plurality of laser pulses emitted sequentially. The emitting module 12 is configured to emit a plurality of laser pulses as sensing beams according to a preset time sequence. Specifically, the emitting module 12 emits sensing beam pulses to different directional field-of-view partitions within the field of view according to a preset scanning method for distance detection. For each field-of-view partition, a plurality of sensing beam pulses are emitted according to a corresponding preset time sequence. After emitting a plurality of sensing beam pulses to one field-of-view partition, the distance information of that field-of-view partition can be obtained. This process can be regarded as a partition detection period. By scanning multiple field-of-view partitions one by one, it is regarded as completing a frame detection of the entire field of view, and the distance information of all field-of-view partitions in the entire field of view can be obtained, which can be used to construct a point cloud of a frame of the entire field of view. That is, a frame detection of the field of view includes a plurality of partition detection periods corresponding to the scanning of the field-of-view partitions. In order to make the time-correlated single-photon counting method used in dToF measurement mathematically statistically meaningful, the light source control module 182 controls the corresponding light source module 122 to emit multiple sensing beam pulses according to a preset time sequence within a partition detection period, such as: tens, hundreds, thousands, tens of thousands, or even millions. The emission of one sensing beam pulse corresponds to one sensing period, that is, one partition detection period includes multiple sensing periods.

[0077] Optionally, the sensing beam is, for example, visible light, infrared light or near-infrared light, with a wavelength range of, for example, 390 nm-780 nm, 700 nm-1400 nm, 800 nm-1000 nm, 900 nm-1600 nm, etc.

[0078] The optical deflection module 124 includes at least one acousto-optic deflector (AOD), which is configured to deflect the light beam at multiple different preset deflection angles within a preset deflection angle range according to the applied sound wave frequency. Thus, the deflection angle of the light beam by the acousto-optic deflector can be controlled by adjusting the frequency of the applied sound wave, thereby enabling scanning and sensing of different azimuth field zones within the field of view.

[0079] In some embodiments, the light deflection module 124 includes two acousto-optic deflection devices: a first acousto-optic deflection device and a second acousto-optic deflection device. The first acousto-optic deflection device is configured to deflect the light beam by a plurality of preset angles along a first direction, and the second acousto-optic deflection device is configured to deflect the light beam by a plurality of preset angles along a second direction, wherein the first direction is perpendicular to the second direction, thereby enabling two-dimensional scanning of the field of view by the sensing light beam. Optionally, the first direction is a horizontal direction and the second direction is a vertical direction; or, the first direction is a vertical direction and the second direction is a horizontal direction.

[0080] In some embodiments, the light deflection module 124 includes an acousto-optic deflector and a liquid crystal polarization grating (LCPG). The acousto-optic deflector is configured to deflect the light beam along a first direction by a plurality of preset angles, and the liquid crystal polarization grating is configured to further deflect the light beam along the first direction and / or a second direction by a plurality of preset angles. Optionally, the first direction is a horizontal direction and the second direction is a vertical direction; or, the first direction is a vertical direction and the second direction is a horizontal direction.

[0081] In some embodiments, the optical deflection module 124 includes an acousto-optic deflector and an electro-optic deflector. The acousto-optic deflector is configured to deflect the light beam along a first direction by a plurality of preset angles, and the electro-optic deflector is configured to further deflect the light beam along a second direction by a plurality of preset angles. Optionally, the first direction is a horizontal direction and the second direction is a vertical direction; or, the first direction is a vertical direction and the second direction is a horizontal direction.

[0082] In some embodiments, the optical deflection module 124 includes an acousto-optic deflector and a metasurface device. The acousto-optic deflector is configured to deflect the light beam along a first direction by a plurality of preset angles, and the metasurface device is configured to further deflect the light beam along the first direction and / or a second direction by a plurality of preset angles. The metasurface device achieves the deflection of the light beam by forming a plurality of nanostructures with dimensions smaller than the wavelength of the light beam together to modulate the propagation phase of the light beam. Optionally, the first direction may be perpendicular to the second direction, for example: the first direction is a horizontal direction and the second direction is a vertical direction; or, the first direction is a vertical direction and the second direction is a horizontal direction.

[0083] In some embodiments, the optical deflection module 124 may further include a polarization amplification device, configured to amplify the deflection angle of the light beam after it has been deflected by the acousto-optic deflection device, the liquid crystal polarization grating device, the electro-optic deflection device, and / or the metasurface device by a preset factor along a first direction and / or a second direction. The polarization amplification device may be a single lens or a lens group comprising multiple lenses, such as spherical lenses, cylindrical lenses, and / or metasurface devices.

[0084] like Figure 3 As shown, in some embodiments, the light source module 122 may further include a collimating optics device 1222 for collimating the light beam to meet the collimation requirements of the acousto-optic deflection device 1240 for the incoming light beam. The collimating optics device 1222 may have the same collimation degree for the light beam in different directions or may have different collimation degrees; this application does not limit this.

[0085] like Figure 3 As shown, in some embodiments, the light source module 122 may further include a beam-shrinking optics device 1223, which can be used to narrow the cross-sectional size of the light beam, that is, the size of the light beam in a cross-section perpendicular to the beam propagation direction. The beam-shrinking optics device 1223 can be disposed in the optical path before the light beam enters the acousto-optic deflector 1240, and is configured to first reduce the light beam emitted by the light source module 122 to a preset size before transmitting it to the acousto-optic deflector 1240. Since the incident area of ​​the acousto-optic deflector 1240 that can effectively receive the light beam has a certain size, in order to improve the utilization rate of the light beam incident on the acousto-optic deflector 1240, it is necessary to modulate the light beam to a size matching the incident area before transmitting it to the acousto-optic deflector 1240. It should be understood that in other embodiments, if the size of the light beam emitted by the light source module 122 already meets the size requirements of the incident acousto-optic deflector 1240, the beam-shrinking optics device 1223 may also be omitted.

[0086] like Figure 3As shown, in some embodiments, the light source module 122 may further include a linear polarizer 1221. The linear polarizer 1221 is disposed in the optical path before the light beam enters the acousto-optic deflector 124 and is configured to convert the light beam into linearly polarized light with a preset polarization state before entering the acousto-optic deflector 124. It should be understood that in other embodiments, if other optical elements can convert the light beam into linearly polarized light with a preset deflection state before it is transmitted to the acousto-optic deflector 124, the linear polarizer 1221 may be omitted.

[0087] like Figure 3 As shown, the beam-shrinking optical device 1223 is disposed between the light source module and the linear polarizer 1221. It should be understood that in other embodiments, the arrangement order of the beam-shrinking optical device 1223 and the linear polarizer in the optical path can be interchanged, as long as both are disposed in the optical path before the light beam enters the acousto-optic deflector 1240. This application does not impose specific limitations on this.

[0088] like Figure 4 As shown, in some embodiments, the acousto-optic deflection device 1240 includes an acousto-optic interaction medium 1241 and a sound wave generator 1242. The acousto-optic interaction medium 1241 has a preset light-incident surface 1244, a light-exit surface 1246, and a sound wave incident surface 1248. The sound wave generator 1242 is disposed on the sound wave incident surface 1248 and configured to generate sound waves propagating in a preset direction within the acousto-optic interaction medium 1241. The light beam emitted by the light source module 122 enters the acousto-optic interaction medium 1241 from the light-incident surface 1244 at a preset incident angle. Under the action of the sound waves, the acousto-optic interaction medium 1241 deflects the propagation direction of the light beam, and the deflected light beam exits from the light-exit surface 1246.

[0089] The incident angle can be defined as the angle between the incident direction of the light beam and the normal direction of the incident surface 1244. In some embodiments, the material of the acousto-optic interaction medium 1241 is tellurium dioxide (TeO2), the incident angle ranges from 2 to 10 degrees, and there is a preset off-axis angle θ between the propagation direction of the sound wave in the tellurium dioxide crystal and the lattice direction [1,1,0] of the tellurium dioxide crystal. α (Not shown in the image).

[0090] In some embodiments, the acoustic wave generator 1242 can be a piezoelectric transducer, which generates ultrasonic waves that propagate into the acousto-optic interaction medium 1241 to deflect the propagation direction of the light beam passing through the acousto-optic interaction medium 1241 at a preset incident angle.

[0091] It should be understood that the propagation of sound waves within the acousto-optic interaction medium 1241 causes a change in the refractive index of the medium. By appropriately configuring parameters, anomalous Bragg diffraction can be achieved in the acousto-optic interaction medium 1241 under the influence of sound waves. The propagation direction of the resulting diffracted beam is deflected relative to the propagation direction of the incident beam, and the deflection angle α is related to the frequency f of the sound wave by the following formula:

[0092]

[0093] Where, θ d Let θ be the exit angle of the diffracted beam, and θ represent the propagation direction of the diffracted beam. i Let be the incident angle of the incident beam, represent the propagation direction of the incident beam, λ be the wavelength of the incident beam and the diffracted beam, n represent the refractive index of the acousto-optic interaction medium 1241, and V be the off-axis angle θ. α The relevant function value is denoted as V = V(θ). a The parameters configured above include the wavelength, polarization state, incident angle, and propagation direction of the incident beam, as well as the frequency and propagation direction of the sound wave. Therefore, by changing the frequency of the sound wave applied to the acousto-optic interaction medium 1241, the deflection angle of the beam passing through the medium can be controlled. When the frequency of the sound wave changes by Δf, the deflection angle of the beam changes accordingly, i.e., the scanning angle is...

[0094] It should be noted that the deflection angle α and scanning angle Δα mentioned above refer to the angle inside the acousto-optic interaction medium 1241. In actual applications, the angle outside the acousto-optic interaction medium 1241 is used. According to the law of refraction, the angle outside the acousto-optic interaction medium 1241 needs to be multiplied by the corresponding refractive index factor. Furthermore, since sound wave propagation takes time, when the sound wave frequency just begins to change from f1 to f2, the sound wave frequency in the acousto-optic interaction medium 1241, which is immediately adjacent to the sound wave generator 1242, switches from f1 to f2, and the beam deflection angle changes from α1 to α2. The sound wave frequency and beam deflection angle in the remaining parts of the acousto-optic interaction medium 1241 have not yet changed. If the sound wave propagates through the entire area traversed by the beam within the acousto-optic interaction medium 1241, i.e., the width of the acousto-optic interaction medium 1241, the time required is called the sound wave transit time. After the transit time, the sound wave frequency in the entire acousto-optic interaction medium 1241 changes from f1 to f2, and the beam deflection angle completely changes to α2. Therefore, when adjusting the sound wave frequency to change the beam deflection angle, the deflection time τ required for the beam to complete one deflection can be considered equal to the sound wave transit time. The calculation of the deflection time τ satisfies the following relationship:

[0095]

[0096] Where W is the aperture of the incident aperture of the light beam on the acousto-optic interaction medium 1241, that is, the width of the light beam incident on the acousto-optic interaction medium 1241, which is usually equal to the width of the acousto-optic interaction medium 1241, and V is the angle θ with respect to the off-axis. α The relevant function value is denoted as V = V(θ). a ).

[0097] In the acousto-optic interaction medium 1241, the wave vectors of the diffracted beam, the incident beam, and the sound wave need to satisfy the momentum matching condition in order to form a stable and coherent diffracted beam within the acousto-optic interaction medium 1241. The incident angle of the beam that produces anomalous Bragg diffraction changes with the frequency of the sound wave. However, in practical applications, the incident angle of the beam in the acousto-optic interaction medium 1241 remains constant. As the frequency of the sound wave changes, the momentum matching condition no longer holds. The further the beam deviates from the momentum matching condition, the greater the decrease in diffraction efficiency. The range of sound wave frequencies that can effectively complete anomalous Bragg diffraction is called the Bragg bandwidth. In some embodiments, the wavelength of the sensing beam is 905 nm, the material of the acousto-optic interaction medium 1241 is tellurium dioxide crystal, and the Bragg bandwidth of the corresponding acousto-optic deflection device 124 is approximately 30 MHz, the scanning angle is approximately 40 milliradians (mrad), or approximately 2.3 degrees, the deflection time τ required to complete one beam deflection is approximately 10 microseconds (μs), the frequency change accuracy of the acoustic wave is approximately 30 kHz, and the corresponding scanning angle change accuracy is approximately 0.04 mrad. Achieving acousto-optic deflection within the tellurium dioxide crystal using anomalous Bragg diffraction requires the incident beam to have a right-handed e-ray component. Optionally, if the incident beam is linearly polarized e-ray, the diffracted beam emitted after acousto-optic deflection is linearly polarized o-ray; if the incident beam is right-handed circularly polarized, the diffracted beam emitted after acousto-optic deflection is left-handed circularly polarized. The utilization rate of the outgoing diffracted beam is determined by the ellipticity of the intrinsic mode right-handed e-beam of the incident beam, which in turn is determined by the wavelength of the incident light, the incident angle, and the material properties of the acousto-optic interaction medium 1241.

[0098] like Figure 2As shown, the transmitting module 12 further includes a deflection driving module 126. The deflection driving module 126 includes a driving circuit for driving the active optical deflection device within the optical deflection module 124. The active optical deflection device is, for example, the acousto-optic deflection device, a liquid crystal polarization grating device, and / or an electro-optic deflection device. Specifically, for the acousto-optic deflection device, the deflection driving module 126 is configured to output a square wave driving signal with a preset frequency to drive the acoustic wave generator 1242 to emit an acoustic wave signal of the corresponding frequency, and to control the deflection angle of the beam deflected by the acousto-optic interaction medium 1241 by adjusting the frequency of the acoustic wave emitted by the acoustic wave generator 1242.

[0099] See Figure 5 As shown, the periodic square wave driving signal is decomposed using the Fourier transform formula:

[0100]

[0101] The period of the square wave is 2L. The square wave driving signal can be decomposed into a series of discrete sinusoidal signals with frequencies f, 3f, 5f, 7f, etc., where f is called the fundamental frequency and the other frequencies are harmonic frequencies. The term n=1 in the above formula corresponds to the fundamental frequency sinusoidal component of the square wave, which corresponds to the thin red line in the figure. That is to say, when a square wave signal drives an acousto-optic deflector, sound waves corresponding to the above multiple harmonic frequencies are actually generated simultaneously in the acousto-optic interaction medium, so that the diffracted light is deflected to multiple directions corresponding to these frequencies simultaneously. In some traditional applications of acousto-optic deflectors, such as their use as discrete optical scanning devices in coaxial optical path microscopes in biological or medical research, in order to avoid optical crosstalk caused by harmonic frequencies deflecting the beam to multiple directions, the input driving signal is usually required to be a sine wave. In scenarios where the acousto-optic deflector is used as the optical scanning device of a lidar, since the transmitting and receiving optical paths are not coaxial, the diffracted beam generated by the ultrasonic harmonic frequency is far away from the field of view area used by the photosensitive pixel of the receiving module. Therefore, when the acousto-optic deflector 1240 is driven by a square wave driving signal, the diffracted beam formed by the acousto-optic deflector 1240 based on the harmonic frequency component of the square wave driving signal will not interfere with the receiving module 14. The deflection angle of this part of the diffracted beam will not be used as the deflection angle of the sensing beam that has actual effect on the transmitting module 12. Instead, the beam deflection angle of the acousto-optic deflector 1240 based on the fundamental frequency component of the square wave driving signal is used as the actual deflection angle of the beam by the transmitting module 12.

[0102] Based on this, using a square wave drive signal has additional advantages compared to a traditional sine wave drive signal:

[0103] See Figure 5Taking a square wave drive signal f(x) with alternating positive and negative peak voltages of Vm = 1V as an example, according to the Fourier decomposition transform formula mentioned above, the fundamental frequency sinusoidal component of the square wave drive signal with n = 1 corresponds to the thin red line in the figure. The peak voltage of this fundamental frequency sinusoidal component is 4 / π, approximately 1.27V, which exceeds the peak voltage of the square wave drive signal. If a square wave drive signal and a sinusoidal drive signal with the same peak voltage of 1V are applied to the same load, the power of the fundamental frequency sinusoidal component of the square wave drive signal is (4 / π) of the power when the sine wave is used as the direct drive signal. 2 = 1.62 times. That is, under the same peak voltage, the power of the fundamental frequency sine wave component of the square wave is 162% of the power of the sine wave drive signal at the same frequency. It can be seen that using a square wave as the drive signal of the acousto-optic deflection device can achieve the required power with a lower voltage, which is beneficial to reducing the manufacturing cost of related drive circuits.

[0104] In a driving circuit, to achieve a tunable periodic signal, a phase-locked loop (PLL) circuit is first used to convert a fixed-frequency clock signal into a square wave signal with the required frequency period. To further generate a sine wave signal, digital technology, such as a Direct Digital Synthesizer (DDS), is needed to adjust the input low-voltage square wave signal into a sine wave signal, which is then amplified by a power amplifier to obtain the required high-voltage sine wave. During this process, both the DDS and the power amplifier consume some input power. However, if a square wave signal is generated, a DDS is unnecessary; the power amplifier can directly amplify the peak voltage of the square wave. Therefore, the energy consumption required to obtain a square wave driving signal is inherently less than that required to obtain a sine wave driving signal. Moreover, as mentioned earlier, since waveform adjustment is not required, the circuit for obtaining a square wave driving signal is simpler and has lower design and manufacturing costs than the circuit for obtaining a sine wave driving signal.

[0105] The efficiency of an acousto-optic deflector is related to the ultrasonic power. Taking tellurium dioxide as the acousto-optic interaction medium, the required ultrasonic power is approximately 1W, with a standard load of 50 ohms as an example. If a sine wave drive is used, the output power is P = (Vm). 2 / (2·50ohm)=1W, solving for the peak voltage of the required sinusoidal drive signal, we get Vm=10V. If a square wave drive signal is used, its fundamental frequency sinusoidal component has a power of 1W, which can be obtained from the formula P=(Vm) 2 ·(4 / π) 2 / (2·50ohm)=1W, solving for the peak voltage of the required square wave drive signal yields Vm=7.85V. Here (4 / π) 2The coefficient is the proportionality coefficient between the power of the fundamental frequency sinusoidal component of the square wave drive signal and the power of a sinusoidal drive signal with the same peak voltage. Based on the peak voltage Vm = 7.85V of the square wave drive signal, its power P = Vm·Vm / (R) is calculated, yielding a total power of 1.23W. Therefore, the power of the fundamental frequency sinusoidal component accounts for 1 / 1.23 = 81% of the total power of the square wave drive signal.

[0106] Calculate the power consumption and efficiency of the circuit corresponding to a 1W sinusoidal drive signal and a 1.23W square wave drive signal based on the typical parameters of the drive circuit. The input power P0 of the circuit is the sum of the power loss and the output power, denoted as P0 = P1 + P2 + P3, where P1 is the power loss in the DDS, P2 is the power loss in the power amplifier, and P3 is the output power. The output efficiency η of the circuit can be expressed as η = P3 / P0.

[0107] For a sinusoidal drive signal, taking typical values ​​for a DDS circuit, with input voltage V1 = 1.2V and input current I1 = 400mA, we can obtain P1 = V1·I1 = 0.48W. The power loss in the power amplifier is the equivalent DC loss P2 = V2·I2, where the typical value of I2 is approximately 30mA. V2 is positively correlated with the peak voltage Vm, expressed as V2 = ΔV + 2·Vm, where ΔV is approximately 2V, representing the necessary voltage margin in the circuit design. Therefore, we can obtain P2 = 0.66W. With a sinusoidal drive signal, the circuit's output efficiency η = P3 / P0 = P3 / P1 + P2 + P3 = 1 / (1 + 0.48 + 0.66) = 47%.

[0108] For a square wave drive signal, without DDS, P1 = 0, P2 = 0.53W, the output efficiency of the circuit η = P3 / P0 = P3 / P1 + P2 + P3 = 1.23 / 0.53 + 1.23 = 70%.

[0109] Based on this, the comparison of various functional parameters when using sine wave drive signals and square wave drive signals can be summarized in the following table:

[0110]

[0111]

[0112] Therefore, under the condition of meeting the same actual available power, the acousto-optic deflection device driven by the square wave driving signal in this application has higher circuit output efficiency and less circuit loss than the acousto-optic deflection device driven by the traditional sine wave driving signal. Moreover, since the required peak voltage is lower, it also has lower circuit design difficulty and cost.

[0113] like Figure 6As shown, in some embodiments, the deflection drive module 126 includes a square wave generation circuit 127 and a power amplifier circuit 128. The square wave generation circuit 127 is configured to generate a square wave fundamental signal with different frequencies. The power amplifier circuit 128 is configured to adjust the power of the square wave fundamental signal to form the square wave drive signal.

[0114] like Figure 7 As shown, in some embodiments, the square wave generation circuit 127 is a fractional-frequency-locked loop circuit used to generate square wave base signals of different frequencies based on a clock signal. The fractional-frequency-locked loop circuit 127 includes a crystal oscillator (OSC) 1271, a phase-frequency detector (PFD) 1272, a charge pump (CP) 1273, a loop filter (LPF) 1274, a voltage-controlled oscillator (VCO) 1275, and a fractional-frequency divider 1276. The crystal oscillator 1271 provides a clock reference signal with a preset frequency to the phase-frequency detector 1272. The phase-frequency detector 1272 controls the charge pump 1273 to charge or discharge the loop filter 1274 based on the phase and frequency differences between the clock reference signal and a feedback signal, thereby adjusting the voltage control signal output by the loop filter 1274 to the voltage-controlled oscillator. The voltage-controlled oscillator 1275 outputs a square wave base signal of the corresponding frequency based on the voltage control signal. The square wave fundamental signal, after being divided by the fractional frequency divider 1276 to form the feedback signal, is fed back to the frequency and phase detector 1274 to form a feedback control loop. Assume the frequency of the output square wave fundamental signal is F. out The frequency of the feedback signal obtained after the fractional frequency divider 1276 divides the square wave fundamental signal is F. in =F out ·β, i.e., F out = (1 / β)·F in β is the feedback coefficient of the fractional frequency divider 1276. Through continuous iterative feedback adjustment, the frequency F of the feedback signal can be adjusted. in F that is infinitely close to the clock reference signal ref The frequency, then the frequency F of the output square wave fundamental signal at this time. out = (1 / β)·F ref The frequency F of the square wave fundamental signal output by the fractional frequency divider 1276 can be adjusted by changing the feedback coefficient β of the fractional frequency divider 1276. out Size.

[0115] like Figure 7As shown, in some embodiments, the fractional frequency divider 1276 can be a fractional frequency divider based on sigma-delta (∑-Δ) modulation, including a sigma-delta modulator 1278 and a high-speed frequency divider 1277. The sigma-delta modulator 1278 is configured to modulate a set fractional frequency division value, outputting a series of integer frequency division values ​​with a fractional average. The high-speed frequency divider 1277 is controlled by the sigma-delta modulator 1278 to achieve different division ratios. Thus, the fractional frequency division value jointly set by the sigma-delta modulator 1278 and the high-speed frequency divider 1277 is quantized into continuously changing integer frequency division values, such that their average value equals the set fractional frequency division value.

[0116] The deflection drive module 184 controls the acousto-optic deflector 124 to deflect the light beam at multiple preset deflection angles within a corresponding deflection angle range via a square wave drive signal. Since the frequency of the square wave drive signal is the same as the frequency of the sound wave output by the sound generator, the acousto-optic deflection drive module 184 can control the deflection angle of the light beam by the acousto-optic deflector 124 by adjusting the frequency of the output square wave drive signal. The deflection time τ required for the acousto-optic deflector 124 to change the light beam deflection angle once is approximately 10 microseconds. For each light beam deflection angle, the transmitting module 12 needs to emit multiple sensing beam pulses to detect distance information in the direction illuminated by that deflection angle. The number of sensing beam pulses that the transmitting module 12 needs to emit along different beam deflection angles can be the same or different. For example, the number of sensing beam pulses emitted along the direction can be set according to the maximum distance detection value that the photoelectric detection device 10 needs to satisfy in the irradiation direction of each beam deflection angle. The number of sensing time periods included in the partition detection time period corresponding to the beam deflection angle corresponds to the number of sensing beam pulses that need to be emitted at that beam deflection angle.

[0117] During detection, the acousto-optic deflection drive module 184 controls the acousto-optic deflection device 124 to deflect the light beam with a preset deflection accuracy within the corresponding deflection angle range. For each preset deflection angle of the light beam, the light source module 122 emits multiple sensing beam pulses according to a preset time sequence. The photosensitive pixel 142, corresponding to the field of view partition pointed to by each preset deflection angle, senses the light signal returned from the direction of illumination of the current deflection angle of the light beam, thereby performing distance detection in the direction corresponding to the deflection angle of the light beam. The data processing module analyzes and processes the light sensing signal output by the photosensitive pixel 142 to obtain the corresponding distance information.

[0118] like Figure 8As shown, in some embodiments, the photoelectric detection device 10 is, for example, a lidar, and the electronic device 1 is, for example, a car. The lidar can be installed in multiple different locations on the car to detect the distance information of objects within the car's surrounding area and thereby achieve driving control.

[0119] This application also provides a driving control method for a transmitting module, the transmitting module including a light source module, at least one acousto-optic deflection device, and a deflection driving module. The transmitting module is a transmitting module of a photoelectric detection device, such as a lidar. The driving control method flow is as follows: Figure 9 As shown, it includes the following steps:

[0120] S101: The deflection drive module drives the acousto-optic deflection device to deflect the light beam emitted by the light source module by a preset deflection angle through a square wave drive signal.

[0121] In this step, the deflection drive module provides a square wave base signal through a fractional frequency division phase-locked loop circuit, and adjusts the power of the square wave base signal through a power amplifier circuit to form the square wave drive signal.

[0122] For a detailed implementation of the fractional frequency division phase-locked loop circuit, please refer to the aforementioned... Figure 7 The relevant descriptions will not be repeated here.

[0123] The light beam used for scanning detection by the photoelectric detection device is a beam deflected by an acousto-optic deflector based on the fundamental sinusoidal component of the square wave driving signal. Light beams deflected by the acousto-optic deflector based on other harmonic frequencies of the square wave driving signal are not used for scanning detection. Therefore, the beam deflection angle of the photoelectric detection device is related to the fundamental frequency of the square wave driving signal.

[0124] S102: The deflection drive module controls the deflection angle of the acousto-optic deflection device on the beam by adjusting the frequency of the square wave drive signal, thereby realizing the scanning detection of the field of view.

[0125] In this step, the acousto-optic deflection device includes an acousto-optic interaction medium and a sound wave generator. The square wave driving signal output by the deflection driving module drives the sound wave generator to emit sound waves of a corresponding frequency. The beam deflection angle of the photoelectric detection device is proportional to the frequency of the sound wave, and thus proportional to the frequency of the square wave driving signal. Therefore, the deflection driving module can proportionally control the deflection angle of the beam by the acousto-optic deflection device by adjusting the frequency of the square wave driving signal.

[0126] It should be noted that the technical solution to be protected by this application may satisfy only one of the above embodiments or simultaneously satisfy multiple of the above embodiments. In other words, embodiments composed of one or more of the above embodiments also fall within the protection scope of this application.

[0127] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with the said embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0128] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A launch module, comprising: The emission module is configured to emit a deflectable scanning light beam to a preset field of view, and the emission module comprises: a light source module configured to emit a light beam; at least one acousto-optic deflection device configured to deflect the light beam, the acousto-optic deflection device comprising an acousto-optic interaction medium and an acoustic wave generator, the acousto-optic interaction medium having a preset light entrance surface, a light exit surface, and an acoustic wave incidence surface, and the acoustic wave generator being arranged on the acoustic wave incidence surface and configured to generate an acoustic wave propagating in a preset direction in the acousto-optic interaction medium; and a deflection driving module configured to output a square wave driving signal with a preset frequency to drive the acoustic wave generator to emit an acoustic wave signal with a corresponding frequency, and to control the deflection angle of the light beam deflected by the acousto-optic interaction medium by adjusting the frequency of the acoustic wave emitted by the acoustic wave generator. The acousto-optic deflection device corresponds to the deflection angle of the deflected light beam as the actual deflection angle of the light beam by the emission module based on the fundamental component of the square wave driving signal.

2. The launch module of claim 1, wherein, The deflection driving module comprises a square wave generation circuit and a power amplifier circuit, the square wave generation circuit is configured to generate square wave base signals with different frequencies, and the power amplifier circuit is configured to adjust the power of the square wave base signals to form the square wave driving signal.

3. The launch module of claim 2, wherein, The square wave generation circuit is a fractional-N phase-locked loop circuit for generating square wave base signals with different frequencies based on a clock signal, the fractional-N phase-locked loop circuit comprises a crystal oscillator, a frequency and phase discriminator, a charge pump, a loop filter, a voltage-controlled oscillator, and a fractional divider, the crystal oscillator provides a clock reference signal with a preset frequency to the frequency and phase discriminator, the frequency and phase discriminator controls the charge pump to charge or discharge the loop filter to adjust the voltage control signal output from the loop filter to the voltage-controlled oscillator according to the difference in phase and frequency between the clock reference signal and a feedback signal, the voltage-controlled oscillator outputs a square wave base signal with a corresponding frequency according to the voltage control signal, and the square wave base signal is fed back to the frequency and phase discriminator after passing through the fractional divider to form the feedback signal to constitute a feedback control loop.

4. The launch module of claim 3, wherein the at least one of the plurality of optical fibers is a single mode optical fiber. The fractional divider is a fractional divider based on sigma-delta modulation, comprising a sigma-delta modulator and a high-speed frequency divider, the sigma-delta modulator is configured to modulate a set fractional division value and output a series of integer division values with an average value of a fractional value, and the high-speed frequency divider is controlled by the sigma-delta modulator to achieve different division ratios.

5. The launch module of claim 1, wherein, The emission module comprises an acousto-optic deflection device and a liquid crystal polarization grating device, the acousto-optic deflection device is configured to deflect the light beam in a first direction, and the liquid crystal polarization grating device is configured to deflect the light beam in the first direction and / or a second direction.

6. The launch module of claim 1, wherein, The emission module comprises an acousto-optic deflection device and a metasurface device, the acousto-optic deflection device is configured to deflect the light beam in a first direction, and the metasurface device is configured to continue to deflect the light beam in the first direction and / or a second direction by a plurality of preset angles.

7. The launch module of claim 1, wherein, The emission module comprises two acousto-optic deflection devices: a first acousto-optic deflection device and a second acousto-optic deflection device; wherein the first acousto-optic deflection device is configured to deflect a light beam along a preset first direction, and the second acousto-optic deflection device is configured to deflect a light beam along a preset second direction, the second direction being different from the first direction.

8. The launch module of claim 1, wherein, The emission module comprises an acousto-optic deflection device and an electro-optic deflection device, the acousto-optic deflection device being configured to deflect a light beam along a preset first direction, and the electro-optic deflection device being configured to deflect a light beam along a preset second direction, the second direction being different from the first direction.

9. The launch module of any of claims 5-8, wherein, The first direction and the second direction are arranged perpendicular to each other, the first direction being a horizontal direction, and the second direction being a vertical direction; or, the first direction being a vertical direction, and the second direction being a horizontal direction.

10. A photodetector device, comprising: The emission module comprises the emission module according to any one of claims 1-9.

11. The photodetector device of claim 10, wherein, The photoelectric detection device further comprises: a receiving module comprising a photoelectric sensor and a receiving optical device, the photoelectric sensor comprising a plurality of sensing pixels configured to receive light signals from the field of view range to output corresponding light sensing signals, the field of view range comprising a plurality of field of view sub-zones located at different orientations, and the receiving optical device being configured to transmit light signals from different field of view sub-zones to corresponding sensing pixels; and a data processing module configured to analyze and process the light sensing signals to obtain corresponding distance information.

12. An electronic device, comprising: The photoelectric detection device comprises the photoelectric detection device according to claim 10 or 11.

13. A drive control method of a transmission module, characterized by, The emission module comprises a light source module, at least one acousto-optic deflection device, and a deflection driving module, the acousto-optic deflection device comprising an acousto-optic interaction medium and an acoustic wave generator, the acousto-optic interaction medium having a preset light entrance surface, a light exit surface, and an acoustic wave incidence surface, the acoustic wave generator being arranged on the acoustic wave incidence surface and configured to generate acoustic waves propagating along a preset direction in the acousto-optic interaction medium, and the driving control method comprising the following steps: The deflection driving module drives the acoustic wave generator to emit acoustic wave signals of a corresponding frequency through a square wave driving signal having a preset frequency; and The deflection driving module adjusts the frequency of the acoustic waves emitted by the acoustic wave generator to control the deflection angle of the light beam deflected by the acousto-optic interaction medium, thereby realizing scanning detection of the field of view range; wherein the acousto-optic deflection device corresponds to the light beam deflection angle of the deflected light beam based on the fundamental component of the square wave driving signal as the actual deflection angle of the light beam by the emission module. The emission module comprises the emission module according to any one of claims 1-9. The photoelectric detection device further comprises: a receiving module comprising a photoelectric sensor and a receiving optical device, the photoelectric sensor comprising a plurality of sensing pixels configured to receive light signals from the field of view range to output corresponding light sensing signals, the field of view range comprising a plurality of field of view sub-zones located at different orientations, and the receiving optical device being configured to transmit light signals from different field of view sub-zones to corresponding sensing pixels; and a data processing module configured to analyze and process the light sensing signals to obtain corresponding distance information. The photoelectric detection device comprises the photoelectric detection device according to claim 10 or 11. The emission module comprises a light source module, at least one acousto-optic deflection device, and a deflection driving module, the acousto-optic deflection device comprising an acousto-optic interaction medium and an acoustic wave generator, the acousto-optic interaction medium having a preset light entrance surface, a light exit surface, and an acoustic wave incidence surface, the acoustic wave generator being arranged on the acoustic wave incidence surface and configured to generate acoustic waves propagating along a preset direction in the acousto-optic interaction medium, and the driving control method comprising the following steps: The deflection driving module drives the acoustic wave generator to emit acoustic wave signals of a corresponding frequency through a square wave driving signal having a preset frequency; and The deflection driving module adjusts the frequency of the acoustic waves emitted by the acoustic wave generator to control the deflection angle of the light beam deflected by the acousto-optic interaction medium, thereby realizing scanning detection of the field of view range; wherein the acousto-optic deflection device corresponds to the light beam deflection angle of the deflected light beam based on the fundamental component of the square wave driving signal as the actual deflection angle of the light beam by the emission module.

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