CN119044929A

CN119044929A - Emission module, driving control method thereof, photoelectric detection device and electronic equipment

Info

Publication number: CN119044929A
Application number: CN202411083727.0A
Authority: CN
Inventors: 黄诗华; 莫良华; 谷立民; 汪浩; 李佳鹏; 梁乃业; 王小明; 孙庆余; 龙晖
Original assignee: Wuxi Fushi Technology Co ltd
Current assignee: Wuxi Fushi Technology Co ltd
Priority date: 2024-08-07
Filing date: 2024-08-07
Publication date: 2024-11-29

Abstract

The present application provides a transmitting module, which is configured to emit a deflectable and scannable light beam to a preset field of view. The transmitting module includes a light source module, at least one acousto-optic deflection device and a deflection drive module. The light source module is configured to emit a light beam. At least one acousto-optic deflection device is configured to deflect the light beam. 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 light beam by the acousto-optic deflection device by adjusting the frequency of the square wave drive signal. The present application also provides a drive control method of the transmitting module and a photoelectric detection device and an electronic device including the transmitting module.

Description

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

Technical Field

The present application relates to a transmitting module, a driving control method thereof, a photoelectric detection device and related electronic equipment, and more particularly, to a photoelectric detection device.

Background

The ranging function of a lidar is typically based on the Time of Flight (ToF) measurement principle, i.e. by emitting laser pulses to a measurement scene, measuring the Time of Flight of the laser pulses back and forth between the lidar and the target object to calculate the distance equidistance information of the target object. The ToF measurement has the advantages of long sensing distance, high precision, low energy consumption and the like, and is widely applied to the fields of consumer electronics, intelligent driving, AR/VR and the like.

The acousto-optic deflector (Acousto-Optic Deflector, AOD) is a device for adjusting the frequency of incident ultrasonic waves so as to change the emergent direction of incident laser, has higher beam deflection precision and microsecond response speed, can be used for realizing one-dimensional or two-dimensional rapid scanning of laser, and currently, the existing laser radar utilizes the AOD to deflect the beam so as to realize scanning sensing of a video field range.

For commercialized lidar, the key to realizing cost reduction and efficiency improvement is chip formation and integration, and the power consumption of a driving circuit is a bottleneck for limiting the cost. In order to meet the set range-finding requirement, the light beam deflected and emitted by the AOD needs to reach a certain peak light power, and correspondingly, the driving signal of the AOD is required to have a higher peak voltage, so that the process cost of the related driving chip is increased. In addition, the existing AOD is generally driven by adopting a sine wave signal, and because the generation of the sine wave signal needs to pass through more signal shaping devices, the consumption generated in the process can further increase the overall energy consumption of the driving circuit.

Disclosure of Invention

In view of the above, the present application provides a transmitting module, a driving method thereof, a laser radar device and related electronic equipment capable of improving the prior art.

In a first aspect, the present application provides an emission module configured to emit a deflectable-scan light beam toward a predetermined field of view. The transmitting 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, and

And 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 on the light beam by adjusting the frequency of the square wave driving signal.

In some embodiments, the deflection drive module includes a square wave signal generating circuit configured to generate square wave base signals of different frequencies and a power amplifying circuit configured to adjust the power of the square wave base signals to form the square wave drive signal.

In some embodiments, the square wave generating circuit is a fractional frequency division phase-locked loop circuit, which is configured to generate square wave basic signals with different frequencies based on clock signals, the fractional frequency division phase-locked loop circuit includes a crystal oscillator, a frequency-division 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-division phase detector, the frequency-division phase detector controls the charge pump to charge or discharge the loop filter according to the difference between the clock reference signal and a feedback signal in phase and frequency so as to adjust the voltage control signal output by the loop filter to the voltage-controlled oscillator, the voltage-controlled oscillator outputs square wave basic signals with corresponding frequencies according to the voltage control signal, and the square wave basic signals form the feedback signal through the fractional frequency divider and then feed back to the frequency-division phase detector so as to form a feedback control loop.

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

In some embodiments, the emission module includes an acousto-optic deflection device configured to deflect the light beam in a first direction and a liquid crystal polarization grating device configured to deflect the light beam in the first direction and/or a second direction.

In some embodiments, the emission module includes an acousto-optic deflection device configured to deflect the light beam in a first direction and a super-surface device configured to continue to deflect the light beam in the first direction and/or a second direction by a plurality of preset angles.

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

In a second aspect, the present application provides a photodetection device comprising an emission module as described above.

In a third aspect, the application provides an electronic device comprising a photodetection device as described above.

In a fourth aspect, the present application provides a driving control method for an emission module, where the emission module includes a light source module, at least one acousto-optic deflection device, and a deflection driving module, and the method includes the following steps:

the deflection driving 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 driving signal and

The deflection driving module controls the deflection angle of the acousto-optic deflection device to the light beam by adjusting the frequency of the square wave driving signal, so as to realize scanning detection of the video field range.

The application has the beneficial effects that:

Compared with the traditional sine wave driving signal driving acousto-optic deflection device, the square wave driving signal driving acousto-optic deflection device has higher circuit output efficiency and less circuit loss under the condition of meeting the same practical available power, and the square wave driving can also reduce the design difficulty and cost of the driving circuit due to lower peak voltage required to be achieved.

Drawings

The features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

Fig. 1 is a schematic diagram of a functional module of an electronic device according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a functional module of an embodiment of the photodetection device shown in FIG. 1;

FIG. 3 is a schematic view of an optical path of an embodiment of the transmitting module shown in FIG. 2;

FIG. 4 is a schematic structural view of the acousto-optic deflection device shown in FIG. 3;

FIG. 5 is a schematic Fourier decomposition diagram of a square wave drive signal;

FIG. 6 is a functional block diagram of the yaw drive module shown in FIG. 2;

FIG. 7 is a schematic diagram of a functional block diagram of the fractional-N PLL circuit shown in FIG. 6;

FIG. 8 is a schematic diagram of a photoelectric detection device according to an embodiment of the present application as a laser radar for a vehicle;

Fig. 9 is a schematic flow chart illustrating a driving control method of a transmitting module according to an embodiment of the application.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the application. In the description of the present application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or as implicitly indicating the number or order of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present application, unless explicitly specified or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, mechanically connected, electrically connected, or in communication with each other, directly connected, or indirectly connected via an intermediate medium, or may be in communication with each other within two elements or in an interaction relationship between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

The following disclosure provides many different embodiments, or examples, for implementing different structures of the application. In order to simplify the present disclosure, only the components and arrangements of specific examples will be described below. They are, of course, merely examples and are not intended to limit the application. Furthermore, the present application may repeat use of reference numerals and/or letters in the various examples, and is intended to be simplified and clear illustration of the present application, without itself being indicative of the particular relationships between the various embodiments and/or configurations discussed. In addition, the various specific processes and materials provided in the following description of the present application are merely examples of implementation of the technical solutions of the present application, but those of ordinary skill in the art should recognize that the technical solutions of the present application may also be implemented by other processes and/or other materials not described below.

Further, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of embodiments of the application. It will be appreciated, however, by one skilled in the art that the inventive aspects may be practiced without one or more of the specific details, or with other structures, components, etc. In other instances, well-known structures or operations are not shown or described in detail to avoid obscuring aspects of the application.

Embodiments of the present application provide an emission module configured to emit a deflectable-scan light beam toward a predetermined field of view. The transmitting module comprises:

a light source module configured to emit a light beam;

In some embodiments, the emitting module comprises two acousto-optic deflection devices, namely 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 the light beam along a preset second direction, and the second direction is different from the first direction.

In some embodiments, the emission module includes an acousto-optic deflection device configured to deflect a light beam in a predetermined first direction and an electro-optic deflection device configured to deflect a light beam in a predetermined second direction, the second direction being different from the first direction.

In some embodiments, the first direction and the second direction are perpendicular to each other, the first direction is a horizontal direction, the second direction is a vertical direction, or the first direction is a vertical direction, and the second direction is a horizontal direction.

The embodiment of the application also provides a photoelectric detection device which comprises the emission module of the embodiment.

In some embodiments, the photodetection device further comprises:

A receiving module including a photosensor including a plurality of sensing pixels configured to receive light signals from the field of view range to output respective light sensing signals, the field of view range including a plurality of field of view partitions located at different orientations, and receiving optics configured to transmit light signals from different ones of the field of view partitions to corresponding sensing pixels, and

And the data processing module is configured for analyzing and processing the light sensing signals to obtain corresponding distance information.

The embodiment of the application also provides electronic equipment, which comprises the photoelectric detection device. The electronic equipment realizes corresponding functions according to the distance information obtained by the photoelectric detection device. The electronic equipment is, for example, a mobile phone, an automobile, a robot, an access control/monitoring system, an intelligent door lock, an unmanned vehicle, an unmanned aerial vehicle and the like. The distance information is, for example, proximity information, depth information, distance information, coordinate information, etc. of the object within the field of view. The distance information may be used in the fields of 3D modeling, identity recognition, autopilot, machine vision, monitoring, unmanned aerial vehicle control, augmented Reality (Augmented Reality, AR)/Virtual Reality (VR), instant location and map building (Simultaneous Localizationand Mapping, SLAM), object proximity determination, etc., which is not limited in this application.

The photoelectric detection device can be, for example, a laser radar and can be used for obtaining distance information of objects in the field of view. The laser radar is applied to the fields of intelligent driving vehicles, intelligent driving aircrafts, 3D printing, VR, AR, service robots and the like. Taking an intelligent driving vehicle as an example, a laser radar is arranged in the intelligent driving vehicle, and the laser radar can scan the surrounding environment by rapidly and repeatedly emitting laser beams so as to obtain point cloud data reflecting the morphology, the position and the movement condition of one or more objects in the surrounding environment. Specifically, the lidar emits a laser beam to the surrounding environment, receives an echo beam of the laser beam reflected by each object in the surrounding environment, and determines distance/depth information of each object by calculating a time delay (i.e., time of flight) between the emission time of the laser beam and the return time of the echo beam. Meanwhile, the laser radar can also determine angle information describing the orientation of the view field range of the laser beam, combine the distance/depth information of each object with the angle information of the laser beam, generate a three-dimensional map comprising each object in the scanned surrounding environment, and guide the intelligent driving of the unmanned vehicle by using the three-dimensional map.

Hereinafter, an embodiment of a photodetection device applied to an electronic apparatus will be described in detail with reference to the accompanying drawings.

Fig. 1 is a schematic diagram of a functional module of a photodetection device applied to an electronic device according to an embodiment of the present application. Fig. 2 is a schematic diagram of a functional module of a photodetection device according to an embodiment of the present application.

Referring to fig. 1 and 2, the electronic device 1 comprises a photo detection means 10. The photodetection device 10 can detect the object 2 in a Field Of View range, which can be defined as a stereoscopic space range in which the photodetection device 10 can effectively detect three-dimensional information, and can also be referred to as a Field Of View (FOV) Of the photodetection device 10, to obtain three-dimensional information Of the object 2. Such as, but not limited to, distance information of the object 2, depth information of the surface of the object 2, a combination of distance information of the object 2 and spatial coordinate information of the object 2, etc.

The electronic device 1 may include an application module 20, where the application module 20 is configured to perform a preset operation or implement a corresponding function according to the three-dimensional information detected by the photodetection device 10, for example, but not limited to, whether an object 2 appears in a preset field of view range in front of the electronic device 1 may be determined according to the distance information of the object 2, or the movement of the electronic device 1 may be controlled to avoid an obstacle according to the distance information of the object 2, or 3D modeling, identity recognition, machine vision, etc. may be implemented according to the depth information of the surface of the object 2. That is, the application module 20 may be a collection of software that includes hardware required to perform the operations and implement the functions described above and control coordination of the hardware operations.

The electronic device 1 may further comprise a storage medium 30, which storage medium 30 may provide support for the storage requirements of the electronic device 1 and/or the photo detection means 10 during operation. As shown in fig. 1, in some embodiments, the storage medium 30 may be disposed inside the electronic device 1. As shown in fig. 2, in some embodiments, a storage medium 16 may also be disposed within the photodetector 10. The storage medium 30 includes, but is not limited to, flash Memory (Flash Memory), charged erasable programmable read-only storage medium (ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY, EEPROM), programmable read-only storage medium (Programmable read only Memory, PROM), hard disk, and the like.

The electronic device 1 may also comprise a processor 40 for providing support for data processing requirements of the electronic device 1 and/or the photo detection means 10 during operation. As shown in fig. 1, in some embodiments, the processor 40 may be disposed internal to the electronic device 1. As shown in fig. 2, in some embodiments, the processor 17 may also be disposed within the photodetection device 10. Such as, but not limited to, an application processor (Application Processor, AP), a central processor (Central Processing Unit, CPU), a microcontroller (Micro Controller Unit, MCU), etc.

Alternatively, in some embodiments, the photodetection device 10 may be, for example, a dToF measurement device that performs three-dimensional information sensing based on the direct time of Flight (DIRECT TIME of Flight, dToF) principle. The dToF measuring device can emit a sensing light beam in the field of view and receive the sensing light beam reflected by the object 2 in the field of view, the time difference between the emitting time and the receiving time of the reflected sensing light beam is called as the flight time t of the sensing light beam, and the distance information of the object 2 can be obtained by calculating half the distance of the sensing light beam in the flight time tWherein c is the speed of light.

In other embodiments, the photodetector 10 may also be a iToF measurement device that senses distance information based on an indirect time-of-Flight (INDIRECT TIME of Flight, iToF) measurement principle. The iToF measuring device obtains distance information of the object 2 by comparing the phase difference of the sensing beam as it is transmitted with that of the sensing beam as it is received back after reflection.

In other embodiments, the photodetection device 10 may also perform distance information sensing based on a frequency modulated continuous wave (Frequency Modulated Continuous Wave, FMCW) measurement principle, by interfering the return light with the emitted light, measuring the frequency difference between the transmission and reception by using a mixed frequency detection technique, and converting the distance of the target object by using the frequency difference.

In the following embodiments of the present application, the photodetection device 10 will be mainly described based on dToF principle.

In some embodiments, as shown in fig. 2, the photodetection device 10 includes a transmitting module 12 and a receiving module 14. The transmitting module 12 is configured to sequentially transmit light beams to different directions within the angle of view, wherein part of the light beams are reflected by the object 2 and returned, and the reflected light beam echoes carry the distance information of the object 2, and a part of the light beam echoes are sensed by the receiving module 14 to acquire the distance information of the object 2. The receiving module 14 is configured to sense the light signal from the view angle range and output a corresponding light sensing signal, and by analyzing the light sensing signal, the distance information of the object 2 in the view angle range can be detected. It will be appreciated that the optical signal sensed by the receiving module 14 includes the sensing beam echo reflected from the field angle range, as well as the ambient light from the field angle range.

As shown in fig. 2, in some embodiments, the transmitting module 12 and the receiving module 14 are disposed side by side and adjacent to each other to form a paraxial transceiving optical path, the light emitting surface of the transmitting module 12 and the light incident surface of the receiving module 14 face the same side of the photodetection device 10, and the distance between the transmitting module 12 and the receiving module 14 is also referred to as a baseline distance, and the value range is, for example, 2 millimeters (mm) to 20mm. Because the transmitting module 12 and the receiving module 14 are relatively close to each other, the transmitting path of the sensing beam from the transmitting module 12 to the object 2 and the returning path from the object 2 to the receiving module 14 after reflection are not completely equal, but are far greater than the distance between the transmitting module 12 and the receiving module 14, which can be regarded as approximately equal. Thereby, the distance between the object 2 and the photo detection means 10 can be calculated from the product of half the time of flight t of the sensing beam reflected back by the object 2 and the speed of light c. In other embodiments, the transmitting module and the receiving module may also form a coaxial transceiving optical path through an optical splitter (not shown), which is not limited in the present application.

As shown in fig. 2, in some embodiments, the receiving module 14 includes a photosensor 140 and receiving optics 144. The photosensor 140 may include a single photosensitive pixel 142 or include a plurality of photosensitive pixels 142 to form a photosensitive pixel array. One of the photosensitive pixels 142 may include a single photoelectric conversion device or include a plurality of photoelectric conversion devices. The photoelectric conversion device is configured to sense a received optical signal and convert the received optical signal into a corresponding electrical signal to be output as the photo-sensing signal. Optionally, the photoelectric conversion device is, for example, a single photon avalanche diode (Single Photon Avalanche Diode, SPAD), an avalanche photodiode (AVALANCHE PHOTON DIODE, APD), a silicon photomultiplier (Silicon Photomultiplier, siPM) provided in parallel by a plurality of SPADs, and/or other suitable photoelectric conversion elements. For example, in some embodiments, the photosensor is a SPAD planar array chip.

The field of view range of the photodetection device 10 may include a plurality of field of view partitions respectively located at different orientations, the photosensitive pixels 142 of the photosensor 140 have corresponding field of view partitions in the field of view range, and the optical signals returned from the field of view partitions propagate to the corresponding photosensitive pixels 142 via the receiving optics 144 for sensing. That is, the field of view corresponding to the photosensitive pixel 142 can be regarded as a 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 emitting module 12 scans the field of view, the sensing beam echoes reflected by the object 2 in the field of view propagate through the receiving optics 144 to the corresponding photosensitive pixels 142 for sensing. The optical signal returned from the field of view partition comprises photons of ambient light from the field of view partition, and when an object 2 is present in the field of view partition, also comprises a sensing beam echo projected to the partition and reflected back by the object 2.

The receiving optics 144 are disposed on the light entrance side of the photosensor 140 and are configured to transmit light signals from different azimuth field of view divisions in the field of view angle range to corresponding photosensitive pixels 142 on the photosensor 140 for sensing, respectively. In some embodiments, the receiving optics 144 may include a receiving lens (not shown). Alternatively, the receiving lens may be one lens or a lens group including a plurality of lenses. In other embodiments, the receiving optics 144 may also include a super-surface device that transmits the returned light beam from a particular direction to the corresponding photosensitive pixel 142.

In some embodiments, the receiving module 14 may further include a peripheral circuit (not shown) formed by one or more of a signal amplifier, an Analog-to-Digital Converter (ADC), and the like, and the peripheral circuit may be partially or fully integrated in the photosensor 140.

The photodetection device 10 further includes a data processing module 15 for processing and analyzing the light sensing signal generated by the photoelectric conversion device to obtain three-dimensional information of the field of view range. For example, the data processing module 15 may process and analyze the light sensing signal based on a Time-dependent single photon counting (Time-Correlated Single PhotonCounting, TCSPC) technique to construct a photon counting histogram, or the data processing module 15 may be further configured to process and analyze the photon counting histogram to determine a reception moment of the sensing beam echo, or the data processing module 15 may be further configured to sequentially process and analyze the reception moment of the sensing beam echo to obtain corresponding distance information, or the data processing module 15 may be further configured to integrate the distance information of different directions within the field of view to form a three-dimensional point cloud map of the field of view.

Functional units of the data processing module 15 that implement all or some of the above functions may be disposed within the photosensor 140, for example, the photosensor 140 may be configured to analyze the light sensing signal to correspondingly output histogram data, distance information, and/or a three-dimensional point cloud. The functional units of the data processing module 15 that perform a part of the functions described above may also be disposed at other locations than the photoelectric sensor 140, including, but not limited to, on the circuit board of the receiving module 14, the circuit board of the photoelectric detection device 10, or the circuit board of the electronic apparatus 1. That is, in some embodiments, the analysis and processing required to obtain distance information and three-dimensional point cloud images may be accomplished by functional units disposed beyond the photosensor 142, which photosensor 142 need only output histogram data.

All or some of the functional units of the data processing module 15 may implement the corresponding functions in hardware, for example, by configuring discrete logic circuits, programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. of a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an image processor (ISP), a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or other logic gate circuit that implements logic functions on data signals. All or some of the functional units of the data processing module 15 may also implement the respective functions in a software manner, for example by firmware solidified in the storage medium 30, 16 or computer software code stored in the storage medium 30, 16 and executed by the corresponding one or more processors 17, 40 to implement the respective functions.

As shown in fig. 2, in some embodiments, the emission module 12 includes a light source module 122, a light deflection module 124, and a deflection drive 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 predetermined angle to form a sensing light beam of a time-division scan field of view range. The light source module 122 includes one or more light emitting units 1220 (see fig. 3), and the light emitting units 1220 are configured to emit light beams. The light emitting unit 1220 may be a light emitting structure in the form of a vertical cavity Surface emitting Laser (VERTICAL CAVITY Surface EMITTING LASER, abbreviated as VCSEL, or may be translated into a vertical cavity Surface emitting Laser), a side emitting Laser (EDGE EMITTING LASER, EEL), a light emitting Diode (LIGHT EMITTING Diode, LED), a Laser Diode (LD), a fiber Laser, or the like. The edge emitting laser may be a Fabry Perot (FP) laser, a distributed feedback (Distribute Feedback, DFB) laser, an Electro-absorption modulated laser (Electro-absorption Modulated, EML), or the like, which is not limited in the embodiment of the present application.

In some embodiments, the sensing beam may be, for example, a plurality of laser pulses that are sequentially emitted. The emission module 12 is configured to emit a plurality of laser pulses as sensing beams according to a preset time sequence. Specifically, the transmitting module 12 transmits the sensing beam pulses to the field of view subareas in different directions within the field of view according to a preset scanning mode in a time sharing manner to perform distance detection, and transmits a plurality of sensing beam pulses to each field of view subarea according to a corresponding preset time sequence, so that the distance information of the field of view subarea can be correspondingly obtained after the transmission of the plurality of sensing beam pulses to one field of view subarea is completed. That is, one frame detection of the video field range includes a plurality of partition detection periods corresponding to the field-of-view partition scanning. In order to make dToF the time-dependent single photon counting method used for measurement have a mathematical statistical significance, the light source control module 182 controls the corresponding light source module 122 to emit a plurality of sensing light beam pulses in a predetermined time sequence within one partitioned detection period, for example, tens, hundreds, thousands, tens of thousands, or even millions, and the emission of one sensing light beam pulse corresponds to one sensing period, that is, one partitioned detection period includes a plurality of sensing periods.

Alternatively, the sensing beam is, for example, visible light, infrared light, or near infrared light, with wavelengths ranging, for example, from 390 nanometers (nm) to 780 nm, from 700 nm to 1400 nm, from 800 nm to 1000 nm, from 900nm to 1600nm, and so forth.

The optical deflection module 124 includes at least one acousto-optic deflection device (Acousto-OpticDeflector, AOD) configured to deflect the optical beam through a plurality of different preset deflection angles within a preset deflection angle range depending on the applied acoustic wave frequency. Therefore, the deflection angle of the acousto-optic deflection device to the light beam can be controlled by adjusting the frequency of the applied sound wave, so that scanning sensing of different azimuth view fields in the view field range can be realized.

In some embodiments, the optical 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, so that the two-dimensional scanning of the sensing light beam on the video field range can be realized. Optionally, the first direction is a horizontal direction, the second direction is a vertical direction, or the first direction is a vertical direction, and the second direction is a horizontal direction.

In some embodiments, the optical deflection module 124 includes an acousto-optic deflection device configured to deflect the light beam in a first direction by a plurality of preset angles and a liquid crystal polarization grating device (Liquid Crystal Polarization Grating, LCPG) configured to continue to deflect the light beam in the first direction and/or a second direction by a plurality of preset angles. Optionally, the first direction is a horizontal direction, the second direction is a vertical direction, or the first direction is a vertical direction, and the second direction is a horizontal direction.

In some embodiments, the optical deflection module 124 includes an acousto-optic deflection device configured to deflect the light beam in a first direction by a plurality of preset angles and an electro-optic deflection device configured to continue to deflect the light beam in a second direction by a plurality of preset angles. Optionally, the first direction is a horizontal direction, the second direction is a vertical direction, or the first direction is a vertical direction, and the second direction is a horizontal direction.

In some embodiments, the optical deflection module 124 includes an acousto-optic deflection device configured to deflect the light beam in a first direction by a plurality of preset angles and a super-surface device configured to continue to deflect the light beam in the first direction and/or a second direction by a plurality of preset angles. The super-surface device modulates the propagation phase of the light beam together by forming a plurality of nanostructures of a size smaller than the wavelength of the light beam to effect deflection of the light beam. Alternatively, the first direction may be perpendicular to the second direction, e.g., 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.

In some embodiments, the optical deflection module 124 may further include a deflection device configured to amplify the deflected light beam by the acousto-optic deflection device, the liquid crystal polarization grating device, the electro-optic deflection device, and/or the super surface device by a preset multiple along the deflection angle of the first direction and/or the second direction. The spreading device may be a single lens or a lens group comprising a plurality of lenses, such as spherical lenses, cylindrical lenses, and/or super surface devices, etc.

As shown in fig. 3, in some embodiments, the light source module 122 may further include collimating optics 1222 for collimating the light beam to meet the collimation requirements of the incoming light beam by the acousto-optic deflection device 1240. The collimating optics 1222 may have the same collimation degree or different collimation degrees for the light beams in different directions, which is not limited by the present application.

As shown in fig. 3, in some embodiments, the light source module 122 may further include beam shrinking optics 1223 that may be used to narrow the cross-sectional dimension of the light beam, i.e., the dimension of the light beam in a cross-section perpendicular to the direction of light beam propagation. The beam shrinking optics 1223 may be disposed in the optical path before the light beam enters the acousto-optic deflection device 1240, and configured to shrink the light beam emitted by the light source module 122 to a preset size before transmitting the light beam to the acousto-optic deflection device 1240. Since the incident area of the acousto-optic deflection device 1240 capable of effectively receiving the light beam has a certain size, in order to improve the utilization of the light beam incident on the acousto-optic deflection device 1240, it is necessary to modulate the light beam to a size matching the incident area before it is transmitted to the acousto-optic deflection device 124. It should be understood that in other embodiments, the beam shrinking optics 1223 may be omitted if the size of the light beam emitted by the light source module 122 meets the size requirement of the incident acousto-optic deflection device 124.

As shown in fig. 3, 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 of the light beam before entering the acousto-optic deflector 124, and is configured to convert the light beam into linearly polarized light having a predetermined polarization state before entering the acousto-optic deflector 124. It should be appreciated that in other embodiments, the linear polarizer 1221 may be omitted if other optical elements may convert the light beam to linearly polarized light in a predetermined deflection state prior to transmission to the acousto-optic deflection device 124.

As shown in fig. 3, the beam reduction optics 1223 are 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 optics 1223 and the linear polarizer on the optical path may be interchanged, so long as both are disposed in the optical path before the light beam enters the acousto-optic deflection device 1240, which is not particularly limited by the present application.

As shown in fig. 4, in some embodiments, the acousto-optic deflection device 1240 includes an acousto-optic interaction medium 1241 and an acoustic wave generator 1242. The acousto-optic interaction medium 1241 has a predetermined light incident surface 1244, a predetermined light emergent surface 1246 and a predetermined 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 predetermined direction in 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 along a preset incident angle, the acousto-optic interaction medium 1241 deflects the propagation direction of the light beam under the action of the sound wave, and the deflected light beam is emitted from the light emergent surface 1246.

The incident angle may be defined as an angle between an incident direction of the light beam and a normal direction of the light incident surface 1244. In some embodiments, the material of the acousto-optic interaction medium 1241 is tellurium dioxide (TeO ₂), the range of the incident angle is 2-10 degrees, and the preset off-axis angle θ _α exists between the propagation direction of the sound wave in the tellurium dioxide crystal and the lattice direction [1, 0] of the tellurium dioxide crystal (not shown).

In some embodiments, the acoustic wave generator 1242 may be a piezoelectric transducer that generates ultrasonic waves to 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 angle of incidence.

It should be understood that, the propagation of the acoustic wave in the acousto-optic interaction medium 1241 may cause the refractive index inside the acousto-optic interaction medium 1241 to change, by reasonably configuring parameters, the incident beam may cause abnormal bragg diffraction in the acousto-optic interaction medium 1241 under the action of the acoustic wave, the propagation direction of the formed diffracted beam may deflect compared with the propagation direction of the incident beam, and the deflection angle α may be related to the frequency f of the acoustic wave by the following formula:

Wherein θ _d is the exit angle of the diffracted beam, representing the propagation direction of the diffracted beam, θ _i is the incident angle of the incident beam, representing the propagation direction of the incident beam, λ is the wavelengths of the incident beam and the diffracted beam, n is the refractive index of the acousto-optic interaction medium 1241, V is the function value associated with the off-axis angle θ _α, denoted as v=v (θ _a), and the above reasonably configured parameters include the wavelength, polarization state, incident angle, propagation direction, frequency of the acoustic wave, propagation direction, and the like of the incident beam. Thus, by varying the frequency of the sound wave applied to the acousto-optic interaction medium 1241, the deflection angle of the light beam passing through the acousto-optic interaction medium 1241 can be controlled, and when the frequency of the sound wave is changed to Δf, the deflection angle of the light beam is correspondingly changed, i.e. the scan angle is

The deflection angle α and the scan angle Δα refer to angles inside the acousto-optic interaction medium 1241, and in practical applications, angles outside the acousto-optic interaction medium 1241 are used, and it is known from the law of refraction that the angles outside the acousto-optic interaction medium 1241 need to be multiplied by corresponding refractive index factors. Furthermore, since the time required for the acoustic wave to propagate is required, when the frequency of the acoustic wave is just changed from f1 to f2, the acousto-optic interaction medium 1241 is changed from f1 to f2 only in the part next to the acoustic wave generator 1242, the deflection angle of the light beam is changed from α1 to α2, and the deflection time τ required for the light beam to complete one deflection is considered to be equal to the transit time of the acoustic wave when the deflection angle of the light beam is changed by adjusting the acoustic wave frequency, if the acoustic wave propagates through the entire region where the light beam passes in the acousto-optic interaction medium 1241, that is, the width of the acousto-optic interaction medium 1241, the required time is called the transit time, the acoustic wave frequency in the entire acousto-optic interaction medium 1241 is changed from f1 to f2 after the transit time, and the deflection angle of the light beam is completely changed to α2, and therefore the deflection time τ required for the light beam to complete one deflection can be considered to be equal to the transit time of the acoustic wave when the deflection angle is adjusted:

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 is also generally equal to the width of the acousto-optic interaction medium 1241, and V is a function value related to the off-axis angle θ _α, denoted as v=v (θ _a).

The diffracted beam in the acousto-optic interaction medium 1241, the incident beam and the wave vector of the acoustic wave need to satisfy the momentum matching condition to form a stable coherent diffracted beam in the acousto-optic interaction medium 1241, the incident angle of the beam generating abnormal bragg diffraction will change along with the change of the acoustic wave frequency, however, in practical application, the incident angle of the beam of the acousto-optic interaction medium 1241 remains unchanged, the momentum matching condition is no longer satisfied along with the change of the acoustic wave frequency, the farther the momentum matching condition is deviated, the more the diffraction efficiency is reduced, and the acoustic wave frequency range capable of effectively completing abnormal bragg diffraction is called as the bragg bandwidth. In some embodiments, the wavelength of the sensing beam is 905nm, the material of the acousto-optic interaction medium 1241 is tellurium dioxide crystal, the bragg bandwidth of the corresponding acousto-optic deflection device 124 is about 30 megahertz (MHz), the scanning angle is about 40 milliradians (mrad), that is, about 2.3 degrees, the deflection time τ required for completing one beam deflection is about 10 microseconds (μs), the accuracy of the change of the acoustic wave frequency is about 30 kilohertz (KHz), and the accuracy of the change of the corresponding scanning angle is about 0.04mrad. The realization of acousto-optic deflection in tellurium dioxide crystal by utilizing anomalous Bragg diffraction requires that the incident light beam has a right-handed e light component, alternatively, if the incident light beam is linear polarized e light, the diffracted light beam emitted after acousto-optic deflection is linear polarized o light, and if the incident light beam is right-handed circularly polarized light, the diffracted light beam emitted after acousto-optic deflection is left-handed circularly polarized light. The utilization of the outgoing diffracted beam is determined by the ellipticity of the eigenmode dextrorotatory e-light of the incident beam, which is determined by the wavelength of the incident light, the angle of incidence and the material properties of the acousto-optic interaction medium 1241.

As shown in fig. 2, the transmit module 12 further includes a yaw drive module 126. The deflection driving module 126 includes driving circuits for driving active optical deflection devices, such as the acousto-optic deflection device, the liquid crystal polarization grating device, and/or the electro-optic deflection device, etc., within the optical deflection module 124. Wherein, for an acousto-optic deflection device, the deflection driving module 18 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 with a corresponding frequency, and to control the deflection angle of the light beam deflected by the acousto-optic interaction medium 1241 by adjusting the frequency of the acoustic wave emitted by the acoustic wave generator 1242.

Referring to fig. 5, the periodic square wave driving signal is decomposed by a fourier decomposition transformation formula:

Wherein the period length of square wave is 2L. The square wave drive signal can be decomposed into a series of summations of sine wave signals of discrete frequencies f, 3f, 5f, 7f, etc., f being referred to as the fundamental frequency, the remaining frequencies being harmonic frequencies, the term n=1 in the above equation corresponding to the fundamental sine wave component of the square wave and to the red thin line in the figure. That is, when the acousto-optic deflection device is driven by the square wave signal, the acoustic waves corresponding to the harmonic frequencies are generated in the acousto-optic interaction medium at the same time, so that the diffracted light is deflected to a plurality of directions corresponding to the frequencies at the same time. In some conventional applications of acousto-optic deflection devices, such as in biological or medical research as optical scanning discrete devices of coaxial optical path microscopes, it is often desirable to input a drive signal that is sinusoidal in order to avoid optical crosstalk caused by deflecting the beam in multiple directions at harmonic frequencies. In the case of the acousto-optic deflection device as the optical scanner of the laser radar, since the transmitting and receiving optical paths are not coaxial, the diffracted beam generated by the harmonic frequency of the ultrasonic wave is far away from the field of view zone for which the photosensitive pixel of the receiving module is working, so that in the case of driving the acousto-optic deflection device 1240 by using the square wave driving signal, the diffracted beam formed by the acousto-optic deflection device 1240 based on the harmonic frequency component of the square wave driving signal to deflect the beam correspondingly will not interfere with the receiving module 14, the deflection angle of the diffracted beam will not be used as the deflection angle of the sensing beam of the transmitting module 12 with practical utility, and the beam deflection angle of the deflected beam corresponding to the fundamental frequency component of the square wave driving signal by the acousto-optic deflection device 1240 is used as the practical deflection angle of the transmitting module 12 to the beam.

On this basis, the use of square wave drive signals has the additional advantage over conventional sine wave drive signals:

Referring to fig. 5, taking the square wave driving signal f (x) with the peak voltage vm=1v and alternating positive and negative as an example, as can be seen from the above fourier decomposition transformation formula, the fundamental frequency sine wave component of the square wave driving signal with n=1 corresponds to the red thin line in the figure, and the peak voltage of the fundamental frequency sine wave component is 4/pi, about 1.27V, and exceeds the peak voltage of the square wave driving signal. If a square wave drive signal and a sine wave drive signal with peak voltages of 1V are applied to the same load, the power of the fundamental frequency sine wave component of the square wave drive signal is (4/pi) ² =1.62 times the power when the sine wave is used as a direct drive signal. That is, at the same peak voltage, the power of the fundamental sine wave component of the square wave is 162% of the power of the sine wave drive signal at the same frequency. Therefore, the square wave is adopted as the driving signal of the acousto-optic deflection device, so that the required power can be realized by using lower voltage, and the process cost of the related driving circuit is reduced.

In order to realize a frequency-tunable periodic signal in a driving circuit, a phase-locked loop circuit is required to convert a clock signal with a fixed frequency into a square wave signal with a required frequency period, if a sine wave signal is required to be continuously generated, a digital technology, such as a Direct digital frequency synthesizer (Direct DigitalSynthesizer, DDS), is required to adjust an input low-voltage square wave signal into a sine wave signal, and then a high-voltage sine wave with required power is obtained through a power amplifier, and in the process, the DDS and the power amplifier consume part of input electric energy. If the square wave signal is generated, the power amplifier directly amplifies the peak voltage of the square wave without DDS. It follows that the energy consumption required to obtain a square wave drive signal is itself less than the energy consumption required to obtain a sine wave drive signal. Moreover, as previously described, the circuit for obtaining a square wave drive signal is simpler than the circuit for obtaining a sine wave drive signal, and is less costly to design and manufacture, since no waveform adjustment is required.

The working efficiency of the acousto-optic deflection device is related to ultrasonic power, tellurium dioxide is taken as an acousto-optic interaction medium, the required ultrasonic power is about 1W, standard load is 50 ohms (ohm) for example, if sine wave driving is adopted, and the peak voltage of a required sine wave driving signal is calculated to be vm=10V according to the fact that the output power is P= (Vm) ²/(2.50ohm) =1W. If a square wave drive signal is used, the peak voltage of the required square wave drive signal is calculated as vm=7.85V from the equation p= (Vm) ²·(4/π)²/(2·50 ohm) =1w, with a power of 1W as the fundamental frequency sine wave component. The coefficient of (4/pi) ² here is the proportionality of the fundamental sine wave component power of a square wave drive signal to the sine wave drive signal power of the same peak voltage. The power p=vm·vm/(R) of the square wave drive signal is calculated from the peak voltage vm=7.85V, and the total power of the square wave drive signal at this time is calculated to be 1.23W. Thus, the proportion of the power of the fundamental sine wave component to the total power of the square wave drive signal is 1/1.23=81%.

And calculating circuit power consumption and efficiency corresponding to the sine wave driving signal with the output power of 1W and the square wave driving signal with the output power of 1.23W according to typical parameters of the driving circuit. The input power P0 of the circuit is the sum of the loss power and the output power, denoted p0=p1+p2+p3, where P1 is the power lost in DDS, P2 is the power lost in the power amplifier, and P3 is the output power. The output efficiency η of the circuit may be expressed as η=p3/p0.

For the sine wave driving signal, taking a typical value of DDS circuit, the input voltage v1=1.2v, the input current i1=400 mA, p1=v1·i1=0.48W can be obtained. The power lost in the power amplifier is equivalent dc loss p2=v2·i2, where typical values of I2 are about 30ma, V2 is positively correlated with peak voltage Vm, expressed as v2=Δv+2·vm, where Δv is about 2V, which is a necessary voltage margin in circuit design. Thus, p2=0.66W can be obtained. In the case of using a sine wave drive signal, the output efficiency η=p3/p0=p3/p1+p2+p3=1/1+0.48+0.66=47% of the circuit

For square wave drive signals, 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%.

Accordingly, the comparison of the various functional parameters when using sine wave drive signals and square wave drive signals can be summarized in the following table:

Therefore, under the condition of meeting the same practical available power, the acousto-optic deflection device driven by the square wave driving signal has higher circuit output efficiency and less circuit loss compared with the traditional sine wave driving signal driving acousto-optic deflection device, and has lower circuit design difficulty and cost due to lower peak voltage required to be achieved.

As shown in fig. 6, in some embodiments, the deflection drive module 126 includes a square wave generation circuit 127 and a power amplification circuit 128. The square wave generation circuit 127 is configured to generate square wave base signals having different frequencies. The power amplification circuit 128 is configured to adjust the power of the square wave base signal to form the square wave drive signal.

As shown in fig. 7, in some embodiments, the square wave generating circuit 127 is a fractional frequency phase locked loop circuit for generating square wave base signals of different frequencies based on a clock signal. The fractional-n pll 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 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 according to the difference between the clock reference signal and a feedback signal in phase and frequency, so as to adjust the voltage control signal output by the loop filter 1274 to the voltage controlled oscillator 1275, and the voltage controlled oscillator 1275 outputs a square wave basic signal with a corresponding frequency according to the voltage control signal. The square wave base signal is fed back to the phase frequency detector 1274 after being passed through the fractional divider 1276 to form the feedback signal, so as to form a feedback control loop. Assuming that the frequency of the square wave basic signal outputted is F _out, the frequency of the feedback signal obtained by dividing the square wave basic signal by the fractional divider 1276 is F _in＝F_out ·β, that is, F _out＝(1/β)·F_in, β is the feedback coefficient of the fractional divider 1276, and after continuous iterative feedback adjustment, the frequency F _in of the feedback signal is infinitely close to the frequency F _ref of the clock reference signal, the frequency F _out＝(1/β)·F_ref of the square wave basic signal outputted at this time can be adjusted by changing the feedback coefficient β of the fractional divider 1276, so that the frequency F _out of the square wave basic signal outputted by the fractional divider pll circuit 127 can be adjusted.

As shown in fig. 7, in some embodiments, the fractional divider 1276 may be a sigma-delta modulation based fractional divider, including a sigma-delta modulator 1278 and a high-speed divider 1277. Wherein sigma-delta modulator 1278 is configured to modulate a set fractional divider value and output a series of integer divider values averaged over a fractional value. High speed divider 1277 is controlled by sigma-delta modulator 1278 to achieve different division ratios. Thus, the fractional division value commonly set by the sigma-delta modulator 1278 and the high-speed divider 1277 is quantized to an integer division value that varies continuously so that the average value thereof is equal to the set fractional division value.

The deflection driving module 184 controls the acousto-optic deflection device 124 to deflect the light beam by a plurality of preset deflection angles within the corresponding deflection angle range through the square wave driving signal. Since the frequency of the square wave driving signal is the frequency of the sound wave output by the sound wave generator, the acousto-optic deflection driving module 184 can control the deflection angle of the acousto-optic deflection device 124 to the light beam by adjusting the frequency of the square wave driving signal. The deflection time τ required by the acousto-optic deflection device 124 to change the primary beam deflection angle is approximately 10 microseconds. For each beam deflection angle, the transmitting module 12 needs to transmit a plurality of sensing beam pulses to detect distance information in the direction illuminated by the beam deflection angle. The number of the sensing beam pulses to be emitted by the emitting module 12 along different beam deflection angles may be the same or different, for example, the number of the sensing beam pulses to be emitted along the direction may be set according to the distance detection furthest value to be satisfied by the photoelectric detection device 10 in the direction irradiated by each beam deflection angle, where the number of sensing periods included in the partition detection period corresponding to the beam deflection angle corresponds to the number of the sensing beam pulses to be emitted on the beam deflection angle.

In detection, the acousto-optic deflection driving module 184 controls the acousto-optic deflection device 124 to deflect the light beam with a preset deflection accuracy within a corresponding deflection angle range. The light source module 122 emits a plurality of sensing beam pulses according to a preset time sequence corresponding to each preset deflection angle of the light beam, and the photosensitive pixels 142 corresponding to the field of view zone to which each preset deflection angle is directed sense the light signal returned from the direction irradiated by the current deflection angle of the light beam to perform distance detection of the direction corresponding to the deflection angle of the light beam. The data processing module obtains corresponding distance information according to analysis and processing of the light sensing signals output by the photosensitive pixels 142.

As shown in fig. 8, in some embodiments, the photodetection device 10 is, for example, a lidar, and the electronic device 1 is, for example, an automobile. The laser radar can be arranged at a plurality of different positions on the automobile to detect the distance information of objects in the peripheral range of the automobile and realize driving control according to the distance information.

The embodiment of the application also provides a driving control method of the emission module, which comprises 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, for example, a laser radar. The flow of the driving control method is shown in fig. 9, and comprises the following steps:

S101, a deflection driving module drives the acousto-optic deflection device to deflect a light beam emitted by a light source module by a preset deflection angle through a square wave driving signal;

In this step, the deflection driving module provides a square wave basic signal through a fractional frequency phase-locked loop circuit, and adjusts the power of the square wave basic signal through a power amplifying circuit to form the square wave driving signal.

The detailed implementation of the fractional-n pll circuit can be seen from the foregoing description related to fig. 7, and will not be repeated here.

The photoelectric detection device is used for scanning and detecting light beams deflected by the acousto-optic deflection device based on fundamental frequency sine wave components of square wave driving signals. The beam deflected by the acousto-optic deflection device based on the other harmonic frequencies of the square wave drive signal is not used for scanning detection. Whereby the beam deflection angle of the photo detection means is related to the fundamental frequency of the square wave drive signal.

S102, the deflection driving module controls the deflection angle of the acousto-optic deflection device to the light beam by adjusting the frequency of the square wave driving signal so as to realize scanning detection of the video field range.

In the step, the acousto-optic deflection device comprises an acousto-optic interaction medium and an acoustic wave generator, the square wave driving signal output by the deflection driving module drives the acoustic wave generator to emit acoustic waves with corresponding frequencies, and the beam deflection angle of the photoelectric detection device is in direct proportion to the frequency of the acoustic waves and then in direct proportion to the frequency of the square wave driving signal. Therefore, the deflection driving module can correspondingly control the deflection angle of the acousto-optic deflection device to the light beam by adjusting the frequency of the square wave driving signal.

It should be noted that, the technical solution to be protected by the present application may only satisfy one of the embodiments described above or simultaneously satisfy the embodiments described above, that is, the embodiment formed by combining one or more embodiments described above also belongs to the protection scope of the present application.

In the description of the present specification, reference to the terms "one embodiment," "certain embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the application.

Claims

1. A transmitting module, characterized in that it is configured to transmit a deflectable scanning light beam to a preset field of view, the transmitting module comprising:

A light source module is configured to emit a light beam;

at least one acousto-optic deflection device configured to deflect the light beam; and

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

2. The transmitting module as described in claim 1 is characterized in that the deflection drive module includes a square wave signal generating circuit and a power amplifying circuit, the square wave generating circuit is configured to generate square wave basic signals of different frequencies, and the power amplifying circuit is configured to adjust the power of the square wave basic signal to form the square wave driving signal.

3. The transmitting module as described in claim 2 is characterized in that the square wave generating circuit is a fractional frequency phase-locked loop circuit, which is used to generate square wave basic signals of different frequencies based on a clock signal, and the fractional frequency phase-locked loop circuit includes a crystal oscillator, a frequency 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 detector, and the frequency 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 to adjust the voltage control signal output by the loop filter to the voltage-controlled oscillator. The voltage-controlled oscillator outputs a square wave basic signal of a corresponding frequency according to the voltage control signal, and the square wave basic signal is fed back to the frequency detector after passing through the fractional frequency divider to form the feedback signal to form a feedback control loop.

4. The transmitting module as described in claim 3 is characterized in that the fractional divider is a fractional divider based on sigma-delta modulation, including a sigma-delta modulator and a high-speed divider, the sigma-delta modulator is configured to modulate the set fractional division value and output a series of integer division values whose average value is a fractional value, and the high-speed divider is controlled by the sigma-delta modulator to achieve different division ratios.

5. The transmitting module as described in claim 1 is characterized in that the transmitting module includes an acousto-optic deflection device and a liquid crystal polarization grating device, the acousto-optic deflection device 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 the second direction.

6. The transmitting module as described in claim 1 is characterized in that the transmitting module includes an acousto-optic deflection device and a metasurface device, the acousto-optic deflection device is configured to deflect the light beam along a first direction, and the metasurface device is configured to continue to deflect the light beam along the first direction and/or the second direction by multiple preset angles.

7. The transmitting module as described in claim 1 is characterized in that the acousto-optic deflection device uses the beam deflection angle of the deflected light beam corresponding to the fundamental frequency component of the square wave driving signal as the actual deflection angle of the light beam by the transmitting module.

8. A photoelectric detection device, characterized in that it comprises the emission module as described in any one of claims 1-7.

9. An electronic device, comprising the photoelectric detection device according to claim 8.

10. A driving control method for a transmitting module, characterized in that the transmitting module includes a light source module, at least one acousto-optic deflection device and a deflection driving module, comprising the following steps:

The deflection driving module drives the acousto-optic deflection device to deflect the light beam emitted by the light source module to a preset deflection angle through a square wave driving signal; and

The deflection driving module controls the deflection angle of the light beam by the acousto-optic deflection device by adjusting the frequency of the square wave driving signal, thereby realizing scanning detection of the field of view.