CN117215137A

CN117215137A - Emission module, photoelectric detection device and electronic equipment

Info

Publication number: CN117215137A
Application number: CN202311138840.XA
Authority: CN
Inventors: 莫良华; 谷立民; 李佳鹏; 吕晨晋; 汪浩; 刘德胜; 陈艺章
Original assignee: Shenzhen Fushi Technology Co Ltd
Current assignee: Shenzhen Fushi Technology Co Ltd
Priority date: 2022-09-02
Filing date: 2023-09-02
Publication date: 2023-12-12
Also published as: CN117214869A; CN117214863A

Abstract

The application provides an emission module which comprises a light source module, a light beam deflection module and a control circuit. The beam deflection module comprises a first liquid crystal polarization grating sheet, a liquid crystal half wave plate and a liquid crystal polarization grating sheet combination which are arranged in a cascading way, wherein the first liquid crystal polarization grating sheet divides unpolarized light into left-handed circularly polarized light and right-handed circularly polarized light, and the liquid crystal half wave plate and the liquid crystal polarization grating sheet combination which are arranged in the cascading way deflect the left-handed circularly polarized light and the right-handed circularly polarized light respectively by two preset deflection angles which are symmetrically distributed. The control circuit correspondingly adjusts different voltage configurations applied to the liquid crystal half wave plate and the liquid crystal polarization grating plate which are arranged in a cascading way at a plurality of moments respectively so as to correspondingly deflect the left-handed circularly polarized light and the right-handed circularly polarized light by different preset deflection angles. The beam deflection module deflects a plurality of preset deflection angles of the beam to form an arithmetic array according to preset first angle intervals, and the first deflection angle range is larger than or equal to the first angle intervals. The application also provides a photoelectric detection device and electronic equipment.

Description

Emission module, photoelectric detection device and electronic equipment

The present application claims the national priority of the prior application for 2022, 9 and 2, with application number 202211069041.7, entitled transmitting module, photo-detecting device and electronic device, the entire contents of which are incorporated herein by reference.

Technical Field

The application belongs to the field of photoelectric detection, and particularly relates to an emission module, a photoelectric detection device and electronic equipment.

Background

A Time of Flight (ToF) measurement principle calculates three-dimensional information such as a distance of an object from a Time of Flight of detected light reflected by the object in a measurement scene. 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 detection device for ranging by using the ToF measurement principle has a limited field angle, and a larger detection range needs to be obtained by continuously changing the detection direction and scanning. At present, one of the ways of changing the detection direction is realized by adopting a mechanical structure to rotate the detection device, however, the way often needs a plurality of groups of discrete devices, the debugging and assembly complexity of an optical path is high, the complicated mechanical structure is easy to damage and misalign, and the appearance of terminal equipment using the device is influenced due to larger size. Another way to change the detection direction is a mixed solid solution, mainly using a vibration component to drive the optical structure to change the detection direction. Although the cost and size of the hybrid solid state solution are significantly reduced relative to the mechanical rotation solution, the reliability of the system is still low due to the fragile vibrating components, limiting the application scenarios of the detection device.

Disclosure of Invention

In view of the above, the present application provides a transmitting module, a photoelectric detection device, an electronic apparatus and a three-dimensional information detection method capable of improving the prior art.

In a first aspect, the present application provides an emission module configured to emit a sensing beam into a detection range to perform three-dimensional information detection on an object in the detection range, including:

a light source module configured to emit unpolarized light and deflect the emitted unpolarized light within a first deflection angle range;

the light beam deflection module comprises a first liquid crystal polarization grating sheet, a liquid crystal half wave plate and a liquid crystal polarization grating sheet combination, wherein the first liquid crystal polarization grating sheet and the liquid crystal half wave plate and the liquid crystal polarization grating sheet combination are sequentially arranged along the light propagation direction, the first liquid crystal polarization grating sheet is configured to split unpolarized light emitted by the light source module into left-handed circularly polarized light and right-handed circularly polarized light, and the liquid crystal half wave plate and the liquid crystal polarization grating sheet combination are configured to respectively deflect the split left-handed circularly polarized light and right-handed circularly polarized light by two preset deflection angles which are symmetrically distributed; a kind of electronic device with high-pressure air-conditioning system

A control circuit configured to correspondingly adjust different voltage configurations applied to the cascade-arranged liquid crystal half wave plate and liquid crystal polarization grating plate at a plurality of times respectively to correspondingly deflect the left-handed circularly polarized light and the right-handed circularly polarized light at the plurality of times by different preset deflection angles to form sensing light beams with different emergent directions in a second deflection angle range;

The beam deflection module deflects a plurality of preset deflection angles of a beam to form an arithmetic array according to preset first angle intervals, and the first deflection angle range is larger than or equal to the first angle intervals.

In a second aspect, the present application provides a photodetection device configured to perform distance detection of an object located within a preset detection range. The photoelectric detection device comprises a receiving module, a processing circuit and the transmitting module. The receiving module is configured to sense the light signals from the detection range and output corresponding light sensing signals, and the processing circuit is configured to analyze and process the light sensing signals to obtain three-dimensional information of the object in the detection range.

In a third aspect, the present application provides an electronic device, including an application module and a photodetection device as described above. The application module is configured to realize corresponding functions according to the detection result of the photoelectric detection device.

The application has the beneficial effects that:

compared with the deflection of the sensing light beam realized by a mechanical rotation scheme and a mixed solid state scheme, the application realizes the quasi-continuous deflection of the sensing light beam in the second deflection angle range psi by the pure solid state light source module and the light beam deflection module, does not need to rely on rotation and vibration of components, and has the beneficial effects of better reliability and compact size.

Drawings

The features and advantages of the present application 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 diagram of a statistical histogram obtained by the processing circuit shown in FIG. 2;

FIG. 4 is a schematic diagram of the structure of the transmitting module shown in FIG. 2;

FIG. 5 is a schematic view of the light source module shown in FIG. 4;

FIG. 6 is a schematic view of the divergence angle of the light beam emitted from the light source module shown in FIG. 4;

FIG. 7 is a schematic view of a structure of a different embodiment of the light source shown in FIG. 5;

FIGS. 8-9 are schematic diagrams illustrating the structure of the light source module according to various embodiments of the light source module shown in FIG. 4;

fig. 10 is a schematic diagram of the structure of the LCPG unit in the beam deflection module of fig. 4;

FIGS. 11-12 are schematic illustrations of beam deflection when LCPG slices having different grating vector directions in the LCPG cell of FIG. 10 are cascaded;

FIG. 13 is a schematic diagram of a binary cascaded LCPG cell according to one embodiment of the present application;

FIG. 14 is a schematic diagram showing the relationship between the voltage control and the deflection angle of the binary cascaded LCPG cells shown in FIG. 13;

Fig. 15 is a schematic diagram of a binary-like cascaded LCPG sheet according to an embodiment of the present application;

FIG. 16 is a schematic diagram of voltage control versus deflection angle for the binary-like cascaded LCPG slices depicted in FIG. 15;

FIG. 17 is a schematic diagram of a three-valued cascaded LCPG cell according to one embodiment of the present application;

FIG. 18 is a schematic diagram illustrating the voltage control and deflection angle relationship of the three-valued cascaded LCPG cells shown in FIG. 17;

fig. 19 is a schematic diagram of a binary cascaded passive LCPG unit according to an embodiment of the present application;

FIG. 20 is a schematic diagram showing the relationship between the voltage control and the deflection angle of the binary cascaded passive LCPG cell shown in FIG. 19;

fig. 21 is a schematic diagram of a beam deflection module including two LCPG cell groups having different scan directions according to an embodiment of the present application;

fig. 22 is a schematic structural diagram of an embodiment of the light source module and the beam deflection module of the emission module shown in fig. 2.

FIG. 23 is a schematic view of the beam expansion module of FIG. 4 in the form of a cylindrical concave lens;

FIG. 24 is a side light path view of the cylindrical concave lens depicted in FIG. 23;

FIG. 25 is a schematic view of the beam expansion module of FIG. 4 in the form of a cylindrical convex lens;

FIG. 26 is a side view of the cylindrical convex lens of FIG. 25;

FIG. 27 is a timing diagram of signals when the photo-detection device according to an embodiment of the present application detects;

fig. 28 is a schematic diagram of a photoelectric detection device as an automotive laser radar according to an embodiment of the present application.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

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, it should be noted that, 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; can be mechanically connected, electrically connected or communicated with each other; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements or interaction relationship between the 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 sensing beam into a detection range to perform three-dimensional information detection on an object within the detection range, including:

Optionally, in some embodiments, the light source module includes a plurality of light sources and a projection lens, the plurality of light sources are disposed on a focal plane of the projection lens, the light beams emitted by the light sources are emitted along corresponding preset emission directions after passing through the projection lens to form the light beams emitted by the light source module, the preset emission directions emitted by the light sources after passing through the projection lens have a corresponding relationship with positions of the light sources on the focal plane of the projection lens, and the light source module lightens the light sources at different positions on the focal plane of the projection lens by addressing to form the light beams deflected between different preset emission directions within the first deflection angle range.

Optionally, in some embodiments, the light source module includes a light source configured to emit a light beam and an optical deflection device configured to deflect the light beam emitted by the light source in a preset emission direction within the first deflection angle range, and the optical deflection device may be a liquid crystal on silicon phased array or an acousto-optic deflection crystal.

Optionally, in some embodiments, the light source module and the beam deflection module deflect the passing beam along a first scanning direction, and the emission module further includes a beam expansion module configured to expand a divergence angle of the passing beam along a preset second scanning direction, where the second scanning direction and the first scanning direction are perpendicular to each other or form a preset included angle.

Optionally, in some embodiments, the beam expansion module includes a beam expansion lens, where the beam expansion lens includes a light incident surface and a light emitting surface sequentially disposed along a zero-order beam emission direction, the zero-order beam is a beam located at an intermediate angular position in a corresponding deflection angle range of the beam deflection module, and at least one of the light incident surface and the light emitting surface is an optical surface curved along the second scanning direction, so as to expand a divergence angle of the beam transmitted through the beam expansion lens along the second scanning direction.

Optionally, in some embodiments, the beam expanding lens is a cylindrical concave lens, and the optical surface is a concave curved surface concave toward the zero order beam emission direction; or alternatively

The beam expanding lens is a cylindrical convex lens, and the optical surface is a convex curved surface protruding out from the direction of emitting the zero-order light beam.

Optionally, in some embodiments, the beam deflection module further comprises a temperature control unit configured to control the temperature of the liquid crystal deflection grating sheet within a preset temperature range.

Optionally, in some embodiments, the combination of the liquid crystal half wave plate and the liquid crystal polarization grating plate disposed in cascade includes a plurality of liquid crystal polarization grating units sequentially disposed along an outgoing direction of the light beam, each liquid crystal polarization grating unit includes a liquid crystal half wave plate and a liquid crystal polarization grating plate, the deflection angle of the passing light beam is gradually increased in a way of being in a natural number of two in order of being sequentially arranged along the outgoing direction of the light beam, and the value of the natural number is the serial number of the liquid crystal polarization grating plate minus one.

Optionally, in some embodiments, the combination of the liquid crystal half wave plate and the liquid crystal polarization grating plate disposed in cascade includes a plurality of liquid crystal polarization grating units disposed in sequence along an outgoing direction of the light beam, each liquid crystal polarization grating unit includes a liquid crystal half wave plate and a liquid crystal polarization grating plate, the deflection angle of the passing light beam is gradually increased in a natural number of three in a sequential order along the outgoing direction of the light beam, and the value of the natural number is the serial number of the liquid crystal polarization grating plate minus one.

Optionally, in some embodiments, the combination of the liquid crystal half wave plate and the liquid crystal polarization grating plate that are disposed in cascade includes one liquid crystal half wave plate and a plurality of liquid crystal polarization grating plates that are disposed in sequence along an outgoing direction of the light beam, a deflection angle of the liquid crystal polarization grating plate to the light beam increases gradually according to a sequence that is disposed in sequence along the outgoing direction of the light beam, a difference between deflection angles of one liquid crystal polarization grating plate and an adjacent previous liquid crystal polarization grating plate to the light beam increases gradually according to a natural number of two in sequence that is disposed in sequence along the outgoing direction of the light beam, and a value of the natural number is a sequence number of the liquid crystal polarization grating plate minus one.

Alternatively, in some embodiments, the liquid crystal polarization grating is an active liquid crystal polarization grating provided with electrodes capable of being applied with a saturation voltage, the active liquid crystal polarization grating not deflecting the passing light beam when the saturation voltage is applied, the active liquid crystal polarization grating deflecting the passing light beam when the voltage is not applied.

Alternatively, in some embodiments, the liquid crystal polarization grating is a passive liquid crystal polarization grating that is not provided with electrodes and cannot be applied with a voltage, the passive liquid crystal polarization grating deflecting the passing light beam.

The embodiment of the application also provides a photoelectric detection device which comprises the transmitting module, a receiving module and a processing circuit. The receiving module is configured to sense the light signals from the detection range and output corresponding light sensing signals, and the processing circuit is configured to analyze and process the light sensing signals to obtain three-dimensional information of the object in the detection range.

The embodiment of the application also provides electronic equipment, which comprises the photoelectric detection device. The electronic equipment realizes corresponding functions according to the three-dimensional information obtained by the photoelectric detection device. The electronic device is, for example: cell phones, automobiles, robots, access control/monitoring systems, intelligent door locks, unmanned aerial vehicles, etc. The three-dimensional information is, for example: proximity information, depth information, distance information, coordinate information, and the like of an object within the detection range. The three-dimensional information may be used in fields such as 3D modeling, face recognition, automatic driving, machine vision, monitoring, unmanned aerial vehicle control, augmented Reality (Augmented Reality, AR)/Virtual Reality (VR), instant positioning and map construction (Simultaneous Localization and 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 three-dimensional information of an object in a detection range. 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 for describing the pointing direction of the emitted laser beam in the detection range, 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 intelligent driving of the transport means 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 within a detection range to obtain three-dimensional information of the object 2, where the detection range may be defined as a three-dimensional space range in which the photodetection device 10 can effectively detect three-dimensional information, and may also be referred to as a viewing angle of the photodetection device 10. Such as, but not limited to, one or more of proximity information of the object 2, depth information of the surface of the object 2, distance information of the object 2, and spatial coordinate information of the object 2.

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 a detection result of the photodetection device 10, for example, but not limited to: whether the object 2 appears in a detection range preset in front of the electronic equipment 1 can be judged according to the proximity information of the object 2; or, the movement of the electronic equipment 1 can be controlled to avoid the obstacle according to the distance information of the object 2; alternatively, 3D modeling, face recognition, machine vision, etc. may be implemented based on depth information of the surface of the object 2. The electronic device 1 may further comprise a storage medium 30, which storage medium 30 may provide support for the storage requirements of the photo detection means 10 during operation.

Alternatively, in some embodiments, the photodetection device 10 may be, for example, a dtofmeasurement device that performs three-dimensional information sensing based on the direct time of flight (direct Time of Flight, dtofl) principle. The dtoff measuring device 10 can emit a sensing beam within a detection range and receive the sensing beam reflected by the object 2 within the detection range, the time difference between the emission time and the receiving time of the reflected sensing beam is called as the time of flight t of the sensing beam, and three-dimensional information of the object 2 can be obtained by calculating half the distance that the sensing beam has travelled within the time of flight tWherein c is the speed of light.

Alternatively, in other embodiments, the photodetection device 10 may be an iToF measurement device 10 that performs three-dimensional information sensing based on an indirect time-of-flight (indirect Time of Flight, iToF) measurement principle. The iToF measuring device 10 obtains three-dimensional information of the object 2 by comparing the phase difference of the sensing beam when emitted and when received back by reflection.

In the following embodiments of the present application, the photodetection device 10 is mainly described as a dtif measuring device.

Optionally, as shown in fig. 2, the photodetection device 10 includes a transmitting module 12, a receiving module 14, and a processing circuit 15. The transmitting module 12 is configured to transmit a sensing beam to the detection range to detect three-dimensional information of the object 2 within the detection range, wherein a part of the sensing beam is reflected by the object 2 and returns, and the reflected sensing beam carries the three-dimensional information of the object 2, and a part of the reflected sensing beam can be sensed by the receiving module 14 to obtain the three-dimensional information of the object 2. The receiving module 14 is configured to sense the optical signal from the detection range and output a corresponding optical sensing signal, and by analyzing the optical sensing signal, three-dimensional information detection of the object 2 in the detection range can be realized. It is understood that the optical signal sensed by the receiving module 14 may be a photon, for example, a photon including a sensing beam reflected by the object 2 in the detection range and a photon of ambient light in the detection range. The processing circuit 15 is configured to analyze and process the photo-sensing signal to obtain a time instant at which the sensing beam is sensed by the receiving module 14, and to obtain three-dimensional information of the object 2 based on a time difference between an emission time instant and a reflected back sensed time instant of the sensing beam.

The processing circuit 15 may be provided on the photo detection means 10. Alternatively, in other embodiments, all or part of the functional units of the processing circuit 15 may be provided on the electronic device 1.

Alternatively, the sensing beam may be a laser pulse having a preset frequency. The emission module 12 is configured to periodically emit the laser pulse as a sensing beam at a preset frequency within a detection frame.

Alternatively, the sensing beam is, for example, visible, infrared or near infrared light, and the wavelength range is, for example, 390 nanometers (nm) -780nm, 700nm-1400nm, 800nm-1000nm.

Referring to fig. 2 and fig. 3 together, fig. 3 is a schematic diagram of a statistical histogram obtained by the processing circuit 15 shown in fig. 2. Optionally, in some embodiments, the processing circuit 15 may include a timing unit 152, a statistics unit 154, a time-of-flight acquisition unit 156, and a three-dimensional information acquisition unit 158.

The timing unit 152 is configured to determine a time of receipt of the optical signal sensed by the receiving module 14. The photoelectric detection device 10 sends out a plurality of sensing beams through the transmitting module 12 in the detection process, the timing unit 152 starts timing from each time of transmitting the sensing beam by the transmitting module 12 to record the receiving time of the optical signal sensed by the receiving module 14 between two adjacent times of transmitting the sensing beam, during which the receiving module 14 outputs a corresponding optical sensing signal each time when receiving one optical signal, and the timing unit 152 records the receiving time of the sensed optical signal according to the optical sensing signal output by the receiving module 14 and counts in the time bin corresponding to the receiving time. The time bin is the minimum time unit Δt for the timing unit 152 to record the time of the generation of the photo-sensing signal, and can reflect the accuracy of time recording of the photo-sensing signal by the timing unit 152, and the finer the time bin, the higher the accuracy of recording time. Alternatively, the timing unit 152 may implement a timing function through a Time-to-Digital Converter, TDC) 1522. The TDC1522 may be connected to the corresponding photosensitive pixel 142 and configured to record a receiving time of the sensed light signal according to the light sensing signal generated by the corresponding photosensitive pixel 142. Optionally, in some embodiments, the timing unit 152 may include a count memory 1524, where the count memory 1524 has a count memory space allocated according to a time bin, and the TDC1522 adds one to the count memory space of the corresponding time bin every time the receiving time of the optical signal is recorded.

The statistics unit 154 is configured to count the optical signal counts accumulated in each time bin, so as to obtain a statistical histogram capable of reflecting the distribution of the reception times of the plurality of optical signals sensed by the reception module 14. The abscissa of the statistical histogram represents the time stamp of each corresponding time bin, and the ordinate of the statistical histogram represents the accumulated light signal count value in each corresponding time bin. Optionally, the statistics unit 154 may include a histogram circuit 1544, the histogram circuit 1544 being configured to count the light signal counts within each time bin to generate a statistical histogram. It should be understood that the statistics unit 154 performs a statistical analysis on the counts of the optical signals corresponding to the accumulated sensing beams emitted multiple times in one detection frame, so that the counts have a mathematical statistical significance, and the number of emissions of the sensing beams in one detection frame may be up to several thousands, tens of thousands, hundreds of thousands, or even millions.

During the sensing process, a large number of photons of ambient light are also sensed by the receiving module 14 to generate corresponding counts of the optical signals. The probability that photons of these ambient light are sensed leaving counts within each time bin tends to be the same, constituting Noise floors (Noise levels) within the detection range, which are measured at relatively high average levels in scenes of higher ambient light intensity and relatively low average levels in scenes of lower ambient light. On the basis, the sensing light beam reflected from the object 2 is sensed and the corresponding generated optical signal count is superposed on the noise back, so that the optical signal count in the time bin corresponding to the sensing time of the sensing light beam is obviously higher than the optical signal count of other time bins, and further a protruding signal peak is formed. It will be appreciated that the count value of the signal peak may be affected by factors such as the optical power of the sensing beam, the reflectivity of the object 2, the detection range of the photodetection device 10, and the like, and the width of the signal peak may be affected by factors such as the pulse width of the emitted sensing beam, the time jitter of the photoelectric conversion element of the receiving module 14 and the TDC1522, and the like. Thus, the time-of-flight acquisition unit 156 can obtain the time-of-flight of the relevant sensing beam reflected by the object 2 from the time difference between the time stamp t1 of the time bin corresponding to the peak value of the signal peak and the emission time t0 (not shown) of the relevant sensing beam generating the signal peak. The three-dimensional information acquisition unit 158 may be configured to obtain three-dimensional information between the object 2 reflecting the sensing light beam and the photodetection device 10 from the time of flight of the sensing light beam determined by the statistical histogram, for example: the distance between the object 2 and said photo detection means 10 in the detection range.

It should be understood that the transmitting module 12 and the receiving module 14 are disposed adjacent to each other side by side, the light emitting surface of the transmitting module 12 and the light entering surface of the receiving module 14 face the same side of the photodetecting device 10, and the distance between the transmitting module 12 and the receiving module 14 may be, 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.

As shown in fig. 2 and 4, in some embodiments, the emission module 12 includes a light source module 122 and a beam deflection module 124. The light source module 122 is configured to emit a light beam and deflect the emitted light beam within a preset first deflection angle range phi. The beam deflection module 124 is configured to deflect the light beams emitted by the light source module 122 at a plurality of moments by corresponding different preset deflection angles to form sensing light beams with a plurality of different emission directions. The plurality of preset deflection angles of the beam deflection module 124 form an arithmetic series according to a preset angle interval, the angle interval can be regarded as an angle tolerance of the arithmetic series, and the first deflection angle range phi is greater than or equal to the angle interval.

Referring to fig. 5 and 6 together, the light source module 122 includes a plurality of light sources 121 and an optical deflection device 123, the light sources 121 are configured to emit light beams, and the optical deflection device 123 is configured to change the emission direction of the light beams emitted from the light sources 121 with a preset deflection accuracy within the first deflection angle range Φ.

Optionally, in some embodiments, the optical deflecting device 123 is a projection lens, the plurality of light sources 121 are disposed on a focal plane of the projection lens 123, and the light beams emitted by the light sources 121 are emitted in corresponding preset directions after passing through the projection lens 123 to form the light beams emitted by the light source module 122. The preset emitting direction of the light beam emitted by the light source 121 after passing through the projection lens 123 corresponds to the position of the light source 121 on the focal plane of the projection lens 123. Thereby, the light source module 122 can illuminate the light sources 121 at different positions on the focal plane of the projection lens 123 by addressing to correspond to the light beams deflected between different preset emission directions formed within the first deflection angle range phi. It should be understood that, for convenience of illustration, only the light beam from the light source 121 passing through the optical center of the projection lens 123 is shown in fig. 5.

In some embodiments, as shown in fig. 7, each light source 121 may include one or more light emitting units 120, and the one or more light emitting units 120 as the same light source 121 emit light at the same time, and the emitted light beam is the light beam emitted by the light source 121. Alternatively, the light emitting unit 120 may be a light emitting structure in the form of a vertical cavity surface emitting Laser (Vertical Cavity Surface Emitting Laser, VCSEL for short), a vertical cavity surface emitting Laser (VCSEL for short), an edge 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.

Alternatively, if the light emitting holes of each light emitting unit 120A size of a ₀ The light emitting units 120 on the light source 121 are sequentially arranged along a preset direction on the focal plane of the projection lens 123, and the distance between the corresponding edges of the light emitting holes of two adjacent light emitting units 120 is p ₀ Each light source 121 includes n light emitting units 120, and the size a= (n-1) ·p of each light source 121 ₀ +a ₀ I.e., the distance between the edges of the two light emitting units 120 facing away from each other, which are furthest from each other in the light source 121; and the distance d=n·p between the centers of two adjacent light sources 121 ₀ . The beam deflection accuracy of the light source module 122 within the first deflection angle range phi, that is, the minimum angle at which the emission direction of the emitted light beam can be changed, can be defined as the angle difference between the preset emission directions of the corresponding emitted light beams of two adjacent light sources 121, if the focal length of the projection lens 123 is f, the deflection accuracy of the light beam emitted by the light source module 122Beam divergence angle of single light source 121 deflected by projection lens 123>The first deflection range phi of the light beam emitted from the light source module 122 is determined by the deflection accuracy of the light beam and the number of groups of the light source 121. Since the plurality of light emitting units 120 of the light source module 122 have the same size and are arranged at equal intervals in the above embodiment, the deflection accuracy of the preset emitting direction of the light beam emitted by the light source module 122 within the first deflection angle range phi can be calculated. Taking the light emitting unit 120 as a VCSEL for example, the size a=0.20 mm, d=0.21 mm of each light source 121, and the deflection accuracy δ and the divergence angle α of the deflected light beam are determined by the focal length f of the projection lens 123. For example, when the deflection accuracy δ=0.29° =5 mrad is required, the focal length f=42 mm of the projection lens 123, and the beam divergence angle α=0.27° of the beam emitted from the light source 121 deflected by the projection lens 123. If the first deflection range is required to reach 4 ° (±2°), the light source module 122 is required to be provided with 20 light sources 121. It can be seen that VCSEL arrays with a common semiconductor substrate are used as The light emitting unit 120 can greatly shorten the center-to-center distance between two adjacent light sources 121, so that the focal length of the projection lens 123 required by the light sources 121 under the same deflection precision is shorter, and the structure of the light source module 122 is more compact.

It should be understood that, in other embodiments, the plurality of light emitting units 120 of the light source module 122 may be arranged in a preset pattern with unequal intervals, and the correspondence between the arrangement positions of the light sources 121 and the preset emitting directions of the emitted light beams is determined by design and calibration. However, the present application is not particularly limited thereto, and the light source module 122 may be enabled to change the position of the illuminated light source 121 by addressing to correspondingly deflect the preset emission direction of the emitted light beam.

Alternatively, in some embodiments, if the divergence angle of the light beam emitted from the light emitting unit 120 is too large, the directivity of the light beam deflected by the projection lens 123 may be reduced, and it may be necessary to reduce the beam diameter before the light beam enters the projection lens 123. Thus, the light source module 122 may further include a condensing lens 125, and the condensing lens 125 is configured to condense the light beam to reduce a divergence angle of the light beam emitted from the light source 121.

As shown in fig. 8, the converging lens 125 may be a microlens array disposed between the light source 121 and the projection lens 123, the microlens array including a plurality of microlens units. Alternatively, the microlens unit may be provided corresponding to the light emitting unit 120, for example: one microlens unit corresponds to one light emitting unit 120 or one microlens unit corresponds to two or more light emitting units 120. Alternatively, the microlens unit may be disposed corresponding to the light source 121, for example: one microlens unit corresponds to one light source 121 or one microlens unit corresponds to two or more light sources 121, which is not particularly limited in the present application.

As shown in fig. 9, in other embodiments, the converging lens 125 may be a cylindrical lens, and the cylindrical lens 125 is disposed behind the projection lens 123 in the emission direction of the light beam. That is, the cylindrical lens 125 is disposed on an optical path of the projection lens 123 on a side facing away from the light source 121, and the cylindrical lens 125 is located between the projection lens 123 and the beam deflection module 124, or the projection lens 123 is located between the light source 121 and the converging lens 125. The converging lens 125 is configured to converge the light beam emitted from the projection lens 123 to form the light beam emitted from the light source module 122, so as to improve the directivity of the light beam emitted from the light source module 122.

Alternatively, in other embodiments, the optical deflecting device 123 may be a liquid crystal on silicon phased array (LCOS-OPAs) or an acousto-optic deflecting crystal, which is not specifically limited in the present application, so long as the optical deflecting device 123 can deflect the light beam emitted from the light source 121 within the first deflection angle range Φ with a preset deflection accuracy δ.

As shown in fig. 10, the beam deflection module 124 includes at least one liquid crystal polarization grating (Liquid Crystal Polarization Grating, LCPG) sheet 127. The LCPG sheet 127 is configured to diffract light beams incident in different polarization states to deflection angles corresponding to the different diffraction orders, respectively. The beam deflection module 124 correspondingly controls the angle of deflection of the LCPG sheet 127 through which the light beam is deflected by changing the diffraction state of the LCPG sheet 127 and/or the polarization state of the light beam when it is incident on the LCPG sheet 127. Alternatively, the beam deflection module 124 may correspondingly change the diffraction state of the LCPG sheet 127 for the passing beam by applying a voltage to change the orientation of the liquid crystals in the LCPG sheet. For example, when the incident light beam is circularly polarized light and the phase retardation of the LCPG sheet 127 is an odd multiple of pi, the diffracted light beam formed after passing through the LCPG sheet 127 may be switched between deflection angles corresponding to three diffraction orders of zero order, positive order, and negative order of the grating by setting the polarization state of the incident light beam and the phase retardation of the LCPG sheet 127, each of which is determined by the period of the LCPG sheet 127.

Alternatively, the polarization state of the light beam incident on the LCPG sheet 127 may be controlled by providing a liquid crystal half-wave plate 128. Specifically, for example: one right circularly polarized light beam is changed into left circularly polarized light after passing through the liquid crystal half wave plate 128 without voltage, is diffracted to the positive first order after passing through the LCPG piece 127, and is changed into right circularly polarized light; applying a saturation voltage to the lc half-wave plate 128 so that the polarization state of the light beam passing through the lc half-wave plate 128 is not changed, and the right circularly polarized light is still right circularly polarized light after passing through the lc half-wave plate 128, and is diffracted to a negative first order after passing through the LCPG plate 127 and is changed into left circularly polarized light; upon application of a saturation voltage to the LCPG sheet 127, the light beam will be diffracted to the zero order, i.e., the propagation direction and polarization of the light beam will not be changed after passing through the LCPG sheet 127. Therefore, by adjusting the liquid crystal half-wave plate 128 to change the polarization state when the light beam is incident on the LCPG sheet 127 and by applying a voltage across the LCPG sheet 127 to change the diffraction state of the LCPG sheet 127, the light beam passing through the LCPG sheet 127 can be correspondingly deflected to deflection angles corresponding to the three diffraction orders of zero order, positive order, and negative order. Thus, in some embodiments, the beam deflection module 124 may include an LCPG unit 129, with one LCPG unit 129 including one liquid crystal half wave plate 128 and one LCPG plate 127 to achieve three discrete deflection angles. The angle of deflection of the individual LCPG sheets 127 may be determined by the grating equation:

Wherein lambda is the incident wavelength, lambda is the grating period, m=1, 0, -1, θ _in ,θ _out The incidence angle and the emergence angle of the light beam are indicated, respectively.

Since the incident light beam is circularly polarized, the diffracted light beam passing through the LCPG sheet 127 is also circularly polarized, and the LCPG cells 129 can be used in a plurality of cascade connections, and by combining and cascading a plurality of LCPG cells 129 with different grating periods and controlling voltages applied to the liquid crystal half wave plate 128 and the LCPG sheet 127, the deflection angle range of the light beam and the deflection angle number of the light beam can be increased.

The effect of the grating vector direction of the LCPG sheet 127 on beam deflection may also be considered when cascading multiple LCPG cells 129, with the direction of deflection of the same polarization by the LCPG sheet 127 having different grating vector directions being different. For example: the LCPG sheet 127 having a first grating vector direction deflects incident left-handed circularly polarized light by a deflection angle corresponding to a positive one of the diffraction orders, while the LCPG sheet 127 having a second grating vector direction opposite to the first grating vector direction deflects incident left-handed circularly polarized light by a deflection angle corresponding to a negative one of the diffraction orders. Therefore, a cascade connection manner for deflecting light beams in different directions can be obtained by collocating the grating vector directions of the LCPG sheets 127, as shown in fig. 11, if the grating vector directions of two LCPG sheets 127 are the same, when a circularly polarized light beam passes through the two LCPG sheets 127, the polarization state of the passing light beam will be changed by the LCPG sheets 127, and the deflection direction of the passing light beam by the latter LCPG sheet will be opposite to the deflection direction of the light beam by the former LCPG sheet 127, and the total deflection angle of the light beam after passing through the two LCPG sheets 127 is the difference value of the respective deflection angles of the two LCPG sheets 127. As shown in fig. 12, if the grating vector directions of the two LCPG sheets 127 are opposite, when circularly polarized light passes through the two LCPG sheets 127, the direction of deflection of the light beam by the latter LCPG sheet 127 is the same as the direction of deflection of the light beam by the former LCPG sheet 127, and the total deflection angle of the light beam after passing through the two LCPG sheets 127 is the sum of the respective deflection angles of the two LCPG sheets 127. Thus, when multiple LCPG sheets 127 are cascaded, multiple different deflection angles for the light beam can also be obtained by setting the grating vector directions of the individual LCPG sheets 127 therein, so that there is greater flexibility in controlling the deflection angle for the light beam in a manner in which the multiple LCPG sheets 127 are cascaded. It should be appreciated that the grating vector direction of the LCPG sheet 127 depends on the alignment direction of the liquid crystal molecules in the LCPG sheet 127.

Alternatively, as shown in fig. 13, in some embodiments, the plurality of liquid crystal half-wave plates 128 and the LCPG plates 127 of the beam deflection module 124 may be in a binary cascade manner. The beam deflection module 124 includes a plurality of LCPG units 129 sequentially disposed along the emission direction of the beam, each LCPG unit 129 includes a liquid crystal half-wave plate 128 and an LCPG plate 127, the deflection angle of the LCPG plate 127 to the beam increases progressively in a manner of a natural number of two in order sequentially arranged along the emission direction of the beam, and the value of the natural number is the serial number of the located LCPG unit 129 minus one. Correspondingly, the beam deflection module 124 deflects the passing beam by a factor of two less the number of the LCPG cells 129, where the minimum deflection angle of the passing beam by the LCPG sheet 127 is a factor of two.

Specifically, if the beam deflection module 124 includes M LCPG units 129, each LCPG unit 129 includes a liquid crystal half-wave plate 128 and an LCPG plate 127. The M LCPG units 129 are sequentially arranged along the outgoing direction of the light beam and sequentially increment the deflection angle of the passing light beam in a natural order of two in the sequential arrangement order. That is, the first LCPG unit 129 closest to the light source module 122 has the smallest deflection angle to the passing light beam, and the last LCPG unit 129 farthest from the light source module 122 has the largest deflection angle to the passing light beam, assuming that the deflection angle of the first LCPG unit 129 to the passing light beam is r, the deflection angles of the M LCPG units 129 sequentially arranged in the outgoing direction of the light beam to the passing light beam are ±r, ±2r, ±4r, …, ±2, respectively, in order ^M-1 r. Correspondingly, the entire beam deflection module 124 including the M LCPG units 129 may deflect the passing beam by an angle of 0, ±r, ±2r, ±3r …, ± (2) ^M -1) r, it can be seen that the beam deflection module 124 is capable of providing a beam deflection angle that is a multiple of the minimum deflection angle r of the passing beam by a single LCPG unit 129, the multiple being a natural number, the maximum of which is two, minus one to the power M, M being the number of LCPG units 129 comprised by the beam deflection module 124. The angular interval between adjacent levels of deflection is r, that is, the angular interval between the preset deflection angles of the passing beam is distributed in an equi-differential array by the beam deflection module 124, and the angular interval can be regarded as an angular tolerance of the equi-differential array, and the deflection accuracy of the passing beam is r. Thus, the second deflection angle range ψ of the passing light beam and the total number Ω of different deflection angles that can be provided based on the beam deflection module 124 cascade of binary LCPG units 129 are expressed as:

Ψ＝(2 ^M -1)r (2)

Ω＝(2 ^M+1 -1) (3)

where r is the minimum deflection angle of the passing beam among the M LCPG units 129, and M is the total number of LCPG units 129 in the beam deflection module 124.

In use, the change in polarization of the passing light beam by the liquid crystal half-wave plate 128 may be controlled by applying a voltage to the liquid crystal half-wave plate 128 in the LCPG unit 129. For example, the liquid crystal half wave plate 128 to which the saturation voltage is applied does not change the polarization state of the passing light beam, and the liquid crystal half wave plate 128 to which the voltage is not applied changes the polarization state of the passing light beam, such as: the left circularly polarized light is changed into right circularly polarized light. In addition, the diffraction state of the passing beam may also be controlled by applying a voltage to the LCPG sheet 127 in the LCPG unit 129. For example, the LCPG sheet 127 to which the saturation voltage is applied does not act on the passing light beam, that is, the traveling direction of the light beam after passing through the LCPG sheet 127 to which the saturation voltage is applied does not change, corresponding to zero-order diffraction of the passing light beam by the LCPG sheet 127. The LCPG sheet 127, to which no voltage is applied, deflects the passing light beam by a predetermined deflection angle, the direction of deflection being related to the polarization state of the light beam at the time of incidence and the direction of the grating vector of the LCPG sheet 127. Since the grating vector direction of the same LCPG sheet 127 remains unchanged, that is, for the same LCPG unit 129, different polarization states of the light beam when it enters the LCPG sheet 127 can be selected by controlling the voltage applied to the liquid crystal half-wave plate 128, and the passing light beam is further deflected by a preset deflection angle in different directions symmetrically distributed compared with the incident direction, which corresponds to the positive-order diffraction and the negative-order diffraction of the passing light beam by the LCPG sheet 127, respectively.

Fig. 14 is a schematic diagram showing the relationship between the voltage control of the binary cascaded LCPG unit 129 and the deflection angle of the passing light beam, and the hatched area in fig. 14 indicates that the saturation voltage is applied to the corresponding lc half-wave plate 128 and LCPG plate 127, and the lc half-wave plate 128 and LCPG plate 127 do not act on the passing light beam. The white area indicates that the voltages applied to the lc half-wave plate 128 and the LCPG plate 127 are turned off, the corresponding lc half-wave plate 128 will change the polarization state of the passing light beam, and the corresponding LCPG plate 127 will deflect the passing light beam. The beam deflection module 124 is exemplarily shown in fig. 14 to include 5 LCPG cells 129 in binary cascade, each LCPG cell 129 including a liquid crystal half-wave plate 128 and an LCPG plate 127, denoted in turn as: liquid crystal half-wave plate I and LCPG plate I, liquid crystal half-wave plate II and LCPG plate II, liquid crystal half-wave plate III and LCPG plate III, liquid crystal half-wave plate IV and LCPG plate IV, and liquid crystal half-wave plate V and LCPG plate V, and LCPG plates I-V have the same grating vector direction. Wherein, the deflection angle of the LCPG piece I-V to the light beam sequentially increases gradually in a way of a natural number of two, the natural number is the serial number of the LCPG unit 129 where the natural number is located minus one, and the serial numbers are r, 2r, 4r, 8r and 16r sequentially. Referring to fig. 13 and 14 together, the light beam incident in the horizontal direction is 0 degrees, the light beam is deflected to the left as a positive angle, and deflected to the right as a negative angle to establish a reference system, if the light beam needs to maintain the 0 degree direction through the light beam deflection module 124, a saturation voltage is applied to all the liquid crystal half wave plates I-V and the LCPG plates I-V of the LCPG unit 129 so as not to change the direction of the passing light beam; if the beam passes through the beam deflection module 124 to be deflected +r, the voltage of the LCPG plate I is turned off to deflect the beam +r and a saturation voltage is applied to the subsequent liquid crystal half-wave plates II-V and LCPG plates II-V to maintain the angle of beam deflection +r; if the light beam needs to be deflected by +3r through the light beam deflection module 124, the voltage of the LCPG sheet I is turned off to deflect the light beam by +3r, and since the polarization state of the light beam is changed while the light beam is deflected through the LCPG sheet I, the polarization state of the light beam passing through the liquid crystal half-wave plate II needs to be restored to the polarization state when the light beam enters the light beam deflection module 124 by turning off the saturation voltage applied to the liquid crystal half-wave plate II, and the light beam deflected by +2r is deflected by turning off the saturation voltage applied to the LCPG sheet II to obtain a deflection angle of +3r, and simultaneously, the saturation voltage is applied to the subsequent liquid crystal half-wave plate III-V and the LCPG sheet III-V to maintain the angle of light beam deflection of +3r. Similarly, the beam deflection module 124 may deflect the passing beam by other preset deflection angles by applying a voltage as shown in fig. 14.

It should be understood that the beam deflection module 124 shown in fig. 13 and 14 may also deflect the passing light beams by angles of-r to-7 r, which may require changing the polarization state of the light beam as it is incident on the beam deflection module 124 or by changing the voltage applied to the lc half wave plate 128 to correspondingly adjust the polarization state of the light beam as it passes through each of the non-voltage applied LCPG plates 127.

It should be appreciated that depending on the diffraction characteristics of the LCPG sheet 127, the polarization state of the light beam at incidence may be left-circularly polarized light or right-circularly polarized light, depending on the grating vector direction of the LCPG sheet 127 and the predefined deflection direction. The circularly polarized light may be generated by linearly polarized light or non-polarized light, and if the light beam emitted from the light source module 122 is linearly polarized light, the circularly polarized light may be changed into circularly polarized light by a quarter wave plate; if the light emitted from the light source module 122 is unpolarized or partially polarized, it may be first changed into linearly polarized light by a polarizer and then into circularly polarized light by a quarter wave plate. Thus, the light source module 122 may further include a polarizing device (not shown) to adjust the polarization state of the light beam emitted from the light source 121 to corresponding circularly polarized light.

Alternatively, as shown in fig. 15, in some embodiments, the lc half-wave plate 128 and the plurality of LCPG sheets 127 of the beam-deflecting module 124 may be in a binary-like cascade. The beam deflection module 124 includes a liquid crystal half-wave plate 128 and a plurality of LCPG plates 127 sequentially arranged along the light beam emitting direction, the deflection angles of the LCPG plates 127 to the light beam gradually increase in order sequentially arranged along the light beam emitting direction, the difference between the deflection angles of one LCPG plate 127 and the adjacent previous LCPG plate 127 to the light beam increases in order sequentially in natural number of two according to the order sequentially arranged along the light path, and the value of the natural number is the sequence number of the LCPG plate 127 minus one. Correspondingly, the deflection angle of the beam deflection module 124 for the passing beam is a multiple of the minimum deflection angle of the LCPG sheet 127 for the passing beam, and the multiple is reduced by one to the power of two on the sequence number of the LCPG sheet 127.

Specifically, the beam-deflecting module 124, which is a binary-like cascade, includes a liquid crystal half-wave plate 128 and M LCPG plates 127. The liquid crystal half-wave plate 128 is arranged in front of the M LCPG sheets 127 along the emitting direction of the light beam, and the M LCPG sheets 127 are sequentially arranged along the emitting direction of the light beam and gradually increase the deflection angle of the passing light beam according to the sequential arrangement order. That is, the first LCPG piece 127 closest to the light source module 122 has the smallest deflection angle to the passing light beam, and the last LCPG piece 127 farthest from the light source module 122 has the largest deflection angle to the passing light beam, assuming that The deflection angle of the first LCPG sheet 127 to the passing beam is r, and the deflection angles of the M LCPG sheets 127 to the passing beam, which are sequentially arranged along the outgoing direction of the beam, are respectively: r, 3r, 7r, …, ± (2) ^M -1) r. The difference between the deflection angles of one of the LCPG sheets 127 and the adjacent preceding LCPG sheet 127 to the light beam is in the order of sequentially arranging along the outgoing direction of the light beam: + -2 ¹ r,±2 ² r,±2 ³ r,…,±2 ^M-1 r, i.e., a natural number of two, is incremented in steps, the natural number having the value of the sequence number of the LCPG sheet 127 minus one. Correspondingly, the entire beam deflection module 124 including the M LCPG sheets 127 may deflect the passing beam by an angle of 0, ±r, ±2r, ±3r …, ± (2) ^M -1) r, it can be seen that the beam deflection module 124 is capable of providing a beam deflection angle that is a multiple of the minimum deflection angle r of the passing beam by a single LCPG sheet 127, the multiple being a natural number, the maximum of the natural number being two, reduced by one to the power M, and M being the number of LCPG sheets 127 included in the beam deflection module 124. The angle interval between the preset deflection angles of the adjacent stages is r, that is, the beam deflection module 124 forms an arithmetic progression for the angle interval between the preset deflection angles of the passing beam, and the deflection accuracy of the passing beam is r, where the angle interval r can be regarded as the angular tolerance of the arithmetic progression. Thus, the second deflection angle range ψ of the passing light beam and the total number Ω of different deflection angles that can be provided based on the beam deflection module 124 cascade of the binary-like LCPG sheets 127 are expressed as:

Ψ＝(2 ^M -1) r (4)

Ω＝(2 ^M+1 -1) (5)

Where r is the minimum deflection angle of the passing light beam in the M LCPG sheets 127, and M is the total number of the LCPG sheets 127 in the light beam deflection module 124.

In use, the polarization state of a light beam incident on the LCPG sheet 127 may be changed by applying a voltage to the liquid crystal half-wave plate 128 in front of the LCPG sheet 127. For example, the liquid crystal half wave plate 128 to which the saturation voltage is applied does not change the polarization state of the passing light beam, and the liquid crystal half wave plate 128 to which the voltage is not applied changes the polarization state of the passing light beam, such as: the left circularly polarized light is changed into right circularly polarized light. In addition, the diffraction state of the passing beam can also be controlled by applying a voltage to the LCPG sheet 127. For example, the LCPG sheet 127 to which the saturation voltage is applied does not act on the passing light beam, that is, the traveling direction of the light beam after passing through the LCPG sheet 127 to which the saturation voltage is applied does not change, corresponding to zero-order diffraction of the passing light beam by the LCPG sheet 127. The LCPG sheet 127, to which no voltage is applied, deflects the passing light beam by a predetermined deflection angle, the direction of deflection being related to the polarization state of the light beam at the time of incidence and the direction of the grating vector of the LCPG sheet 127. Since the grating vector direction of the same LCPG sheet 127 remains unchanged, different polarization states of the light beam incident on the LCPG sheet 127 can be selected by controlling the voltage applied to the liquid crystal half-wave plate 128, and the passing light beam is further deflected by a preset deflection angle in different directions symmetrically distributed compared with the incident direction, which correspond to the positive-order diffraction and the negative-order diffraction of the passing light beam by the LCPG sheet 127, respectively.

Fig. 16 is a schematic diagram showing the relationship between the voltage control of the liquid crystal half-wave plate 128 and the LCPG sheet 127, which are connected in a binary-like manner, and the deflection angle of the passing light beam, and the hatched area in fig. 16 shows that the saturation voltage is applied to the corresponding liquid crystal half-wave plate 128 and LCPG sheet 127, and the liquid crystal half-wave plate 128 and LCPG sheet 127 do not act on the passing light beam. The white area indicates that the voltages applied to the lc half-wave plate 128 and the LCPG plate 127 are turned off, the corresponding lc half-wave plate 128 will change the polarization state of the passing light beam, and the corresponding LCPG plate 127 will deflect the passing light beam. The beam deflection module 124 is exemplarily shown in fig. 16 to include 1 liquid crystal half-wave plate 128 and 5 LCPG plates 127 in a binary-like cascade, and is denoted by the following in order along the outgoing direction of the optical path: the liquid crystal half wave plate I and LCPGI-V have the same grating vector direction. The deflection angles of the LCPGI-V to the light beams are gradually increased in sequence, and the deflection angles are respectively r, 3r, 7r, 15r and 31r. Referring to fig. 15 and 16 together, the light beam incident in the horizontal direction is 0 degrees, the light beam is deflected to the left as a positive angle, and deflected to the right as a negative angle to establish a reference system, if the light beam needs to maintain the 0 degree direction through the light beam deflection module 124, a saturation voltage is applied to the liquid crystal half-wave plate I and all the LCPG plates I-V so as not to change the direction of the light beam passing through; if the beam passes through the beam deflection module 124 requiring deflection +r, the voltage of the LCPG piece I is turned off to deflect the beam +r and a saturation voltage is applied to the subsequent LCPG piece II-V to maintain the angle of beam deflection +r; if the beam passes through the beam deflection module 124 to be deflected by +2r, the voltage applied to the lc half-wave plate I is turned off to change the polarization state of the incident beam, and the voltage applied to the LCPG plate I is turned off to deflect the beam whose polarization state is changed by the lc half-wave plate I by-r. Since the polarization state of the light beam is changed while passing through the LCPG sheet I, the voltage applied to the LCPG sheet II is turned off, so that it deflects the passing light beam by +3r on the basis of the previous-r angle to obtain a total of +2r deflection angle, while a saturation voltage is applied to the subsequent LCPG sheet III-V to maintain the angle of beam deflection +2r. Similarly, the beam deflection module 124 may deflect the passing beam by other preset deflection angles by applying a voltage as shown in fig. 16.

It should be understood that the beam deflection module 124 shown in fig. 15 and 16 may also deflect the passing light beams by angles of-r to-7 r, which may require changing the polarization state of the light beam when it is incident on the beam deflection module 124 or by changing the voltage applied to the liquid crystal half wave plate 128 to correspondingly adjust the polarization state of the light beam when it passes through each of the non-voltage applied LCPG plates 127.

Compared to the binary cascade LCPG cell 129, the liquid crystal half-wave plate 128 and the LCPG plate 127 adopting the binary cascade can set the desired beam deflection angle by deflecting the angle difference of the beams in different directions, thereby reducing the number of liquid crystal half-wave plates 128 required and having higher beam transmittance.

Alternatively, as shown in fig. 17, in some embodiments, the lc half-wave plate 128 and the LCPG plate 127 of the beam-deflecting module 124 may be cascaded in three values. The beam deflection module 124 includes a plurality of LCPG units 129 sequentially disposed along the light beam emitting direction, each LCPG unit 129 includes a liquid crystal half-wave plate 128 and an LCPG plate 127, the deflection angle of the LCPG plate 127 to the light beam increases progressively in a third natural number in order of sequentially arranging along the light beam emitting direction, and the value of the natural number is the serial number of the located LCPG unit 129 minus one. Correspondingly, the beam deflection module 124 deflects the passing beam by a factor of half the minimum deflection angle of the passing beam by the LCPG sheet 127 therein, which factor is reduced by one to the order of three for the LCPG unit 129.

Specifically, if the beam deflection module 124 includes M LCPG units 129, each LCPG unit 129 includes a liquid crystal half-wave plate 128 and an LCPG plate 127. The M LCPG units 129 are sequentially arranged along the outgoing direction of the light beam and sequentially increment the deflection angle of the passing light beam in the order of sequentially arranged in a natural order of three. That is, the first LCPG unit 129 closest to the light source module 122 has the smallest deflection angle to the passing light beam, and the last LCPG unit 129 farthest from the light source module 122 has the largest deflection angle to the passing light beam, and assuming that the deflection angle of the first LCPG unit 129 to the passing light beam is r, the deflection angles of the M LCPG units 129 sequentially arranged in the outgoing direction of the light beam to the passing light beam are ±r, ±3r, ±9r, …, ±3, respectively ^M-1 r. Correspondingly, the entire beam deflection module 124 including the M LCPG cells 129 may deflect the passing beam by an angle of It can be seen that the beam deflection module 124 can provide a beam deflection angle that is a multiple of half the minimum deflection angle r of the passing beam by a single LCPG unit 129, the multiple being a natural number, the maximum of the natural number being three divided by one to the power M, M being the number of LCPG units 129 included in the beam deflection module 124. The angular interval between the preset deflection angles of the adjacent orders is r, that is, the beam deflection module 124 is distributed in an arithmetic progression for the angular intervals between the preset deflection angles of the passing beam, and the deflection accuracy of the passing beam is r, and the angular intervals can be regarded as the angular tolerance of the arithmetic progression. Thus, the beam bias based on the cascade of three-valued LCPG cells 129 The conversion module 124 expresses the relationship between the second deflection angle range ψ of the passing light beam and the total number Ω of different deflection angles that can be provided as follows:

Ω＝3 ^M (7)

In use, the change in polarization of the passing light beam by the liquid crystal half-wave plate 128 may be controlled by applying a voltage to the liquid crystal half-wave plate 128 in the LCPG unit 129. For example, the liquid crystal half wave plate 128 to which the saturation voltage is applied does not change the polarization state of the passing light beam, and the liquid crystal half wave plate 128 to which the voltage is not applied changes the polarization state of the passing light beam, such as: the left circularly polarized light is changed into right circularly polarized light. In addition, the diffraction state of the passing beam may also be controlled by applying a voltage to the LCPG sheet 127 in the LCPG unit 129. For example, the LCPG sheet 127 to which the saturation voltage is applied does not act on the passing light beam, that is, the traveling direction of the light beam after passing through the LCPG sheet 127 to which the saturation voltage is applied does not change, corresponding to zero-order diffraction of the passing light beam by the LCPG sheet 127. The LCPG sheet 127 to which no voltage is applied deflects the passing light beam by a predetermined deflection angle, the direction of deflection being related to the polarization state of the light beam at the time of incidence and the direction of the grating vector of the LCPG sheet 127. Since the grating vector direction of the same LCPG sheet 127 remains unchanged, that is, for the same LCPG unit 129, different polarization states of the light beam when it enters the LCPG sheet 127 can be selected by controlling the voltage applied to the liquid crystal half-wave plate 128, and the passing light beam is further deflected by a preset deflection angle in different directions symmetrically distributed compared with the incident direction, which corresponds to the positive-order diffraction and the negative-order diffraction of the passing light beam by the LCPG sheet 127, respectively.

Fig. 18 is a schematic diagram showing the relationship between the voltage control of the three-valued cascade-connected LCPG unit 129 and the deflection angle of the passing light beam, and the hatched area in fig. 18 indicates that the saturation voltage is applied to the corresponding lc half-wave plate 128 and LCPG plate 127, and the lc half-wave plate 128 and LCPG plate 127 do not act on the passing light beam. The white area indicates that the voltages applied to the lc half-wave plate 128 and the LCPG plate 127 are turned off, the corresponding lc half-wave plate 128 will change the polarization state of the passing light beam, and the corresponding LCPG plate 127 will deflect the passing light beam. The beam deflection module 124 is exemplarily shown in fig. 18 to include 4 LCPG units 129 in a three-valued cascade, and each LCPG unit 129 includes a liquid crystal half-wave plate 128 and an LCPG plate 127, which are sequentially labeled as: liquid crystal half-wave plate I and LCPG plate I, liquid crystal half-wave plate II and LCPG plate II, liquid crystal half-wave plate III and LCPG plate III, and liquid crystal half-wave plate IV and LCPG plate IV, and LCPG plates I-IV have the same grating vector direction. Wherein, the deflection angles of the LCPG sheets I-IV to the light beams sequentially increase gradually in a way of three natural numbers, the natural numbers are the serial numbers of the LCPG units 129 where the natural numbers are reduced by one, and the serial numbers are r, 3r, 9r and 27r. Referring to fig. 17 and 18 together, the light beam incident in the horizontal direction is 0 degrees, the light beam is deflected to the left as a positive angle, and deflected to the right as a negative angle to establish a reference system, if the light beam needs to maintain the 0 degree direction through the light beam deflection module 124, a saturation voltage is applied to the liquid crystal half-wave plates I-IV and the LCPG plates I-IV of all the LCPG units 129 so as not to change the direction of the passing light beam; if the beam passes through the beam deflection module 124 to be deflected +r, the voltage of the LCPG plate I is turned off to deflect the beam +r and a saturation voltage is applied to the subsequent liquid crystal half-wave plates II-IV and LCPG plates II-IV to maintain the angle of beam deflection +r; if the light beam needs to deflect +2r through the beam deflection module 124, the voltages of the liquid crystal half-wave plate I and the LCPG plate I are turned off, the incident light beam is deflected-r angle through the LCPG plate I after passing through the liquid crystal half-wave plate I, and is also deflected-r angle through the LCPG plate I after passing through the liquid crystal half-wave plate II with the saturation voltage applied thereto, and then the incident polarization state is kept unchanged after passing through the liquid crystal half-wave plate II with the saturation voltage applied thereto, so as to deflect +3r angle from-r angle when passing through the LCPG plate II with the turned off voltage, thereby obtaining +2r angle deflection, and simultaneously, the saturation voltage is applied to the subsequent liquid crystal half-wave plates III-IV and LCPG plates III-IV to maintain the beam deflection +2r angle. Similarly, the beam deflection module 124 may deflect the passing beam by other preset deflection angles by applying a voltage as shown in fig. 18.

It should be appreciated that the beam-deflecting module 124 shown in fig. 17 and 18 may also deflect the passing light beams by angles-r to-14 r, which may require changing the polarization state of the light beam as it is incident on the beam-deflecting module 124 or by changing the voltage applied to the lc half wave plate 128 to correspondingly adjust the polarization state of the light beam as it passes through each of the non-voltage-applied LCPG plates 127.

The use of a three-valued cascaded LCPG unit 129 requires a smaller number of liquid crystal devices than a two-valued cascaded LCPG unit 129, such as: the beam deflection range of four LCPG units 129 in the three-valued cascade shown in fig. 18 is larger than the beam deflection range of five LCPG units 129 in the two-valued cascade shown in fig. 14, whereby the three-valued cascade of LCPG units 129 has a higher beam transmittance.

It should be appreciated that the LCPG sheet 127 in the above embodiments is an active LCPG sheet 127 provided with electrodes that can adjust their effect on the passing beam by whether or not a voltage is applied. Alternatively, in other embodiments, the LCPG sheet 127 may be a passive LCPG sheet 127 without electrodes. Since the passive LCPG sheet 127 is always in a diffraction state without voltage, it deflects the passing light beam to different directions symmetrically distributed relative to the incident direction by a preset deflection angle according to the polarization state of the passing light beam, which corresponds to the positive first-order diffraction and the negative first-order diffraction of the passing light beam by the LCPG sheet 127, respectively. The polarization of the light beam passing through the passive LCPG sheet 127 may be adjusted by incorporating a liquid crystal half-wave plate 128 on the light entrance side of the passive LCPG sheet 127.

Alternatively, as shown in fig. 19, in some embodiments, the beam deflection module 124 includes M passive LCPG cells 129, each passive LCPG cell 129 including a liquid crystal half wave plate 128 and a passive LCPG sheet 127. The M passive LCPG units 129 are connected in binary cascade, and the M passive LCPG units 129 are sequentially arranged along the emergent direction of the light beam and the deflection angles of the passing light beam are sequentially arrangedIs gradually increased to the power of two natural numbers. That is, the first passive LCPG unit 129 closest to the light source module 122 has the smallest deflection angle to the passing light beam, and the last passive LCPG unit 129 farthest from the light source module 122 has the largest deflection angle to the passing light beam, and assuming that the deflection angle of the first passive LCPG unit 129 to the passing light beam is r, the deflection angles of the M passive LCPG units 129 to the passing light beam sequentially arranged along the outgoing direction of the light beam are ±r, ±2r, ±4r, …, ±2, respectively, in order ^M-1 r. Correspondingly, the entire beam deflection module 124 including the M passive LCPG units 129 may deflect the passing beam by an angle of ±r, ±3r, ±5r …, ± (2) ^M -1) r, it can be seen that the beam deflection module 124 is capable of providing a beam deflection angle that is an odd multiple of the minimum deflection angle r of the passing beam of light for which a single LCPG is two, the odd maximum being one less to the power M, M being the number of passive LCPG units 129 comprised by the beam deflection module 124. The angular interval between the preset deflection angles of the adjacent orders is 2r, that is, the beam deflection module 124 is distributed in an arithmetic progression for the angular intervals between the preset deflection angles of the passing beam, and the deflection accuracy of the passing beam is 2r, and the angular interval can be regarded as the angular tolerance of the arithmetic progression. Thus, the relationship expression for the second deflection angle range ψ of the passing beam and the total number Ω of different deflection angles that can be provided based on the binary cascade of passive LCPG units 129 is:

Ψ＝(2 ^M -1)r (8)

Ω＝2 ^M (9)

Where r is the minimum deflection angle of the passing beam in the M passive LCPG units 129, and M is the total number of passive LCPG units 129 in the beam deflection module 124.

In use, the polarization state of a light beam incident on the passive LCPG plate 127 in the passive LCPG cell 129 may be selected by applying a voltage to the liquid crystal half-wave plate 128 in the passive LCPG cell 129, thereby correspondingly controlling the direction of deflection of the light beam as it passes through the passive LCPG plate 127. For example, if the light beam is deflected in the direction of positive first order diffraction when passing through the liquid crystal half wave plate 128 to which the saturation voltage is applied and then passing through the passive LCPG plate 127, the light beam is deflected in the direction of negative first order diffraction when passing through the liquid crystal half wave plate 128 to which the saturation voltage is not applied and then passing through the passive LCPG plate 127. Since the polarization state of the light beam is changed while being diffracted by the passive LCPG sheet 127, if the light beam is to be deflected to the same diffraction order in the next passive LCPG unit 129, the voltage applied to the liquid crystal half-wave plate 128 in the next passive LCPG unit 129 needs to be turned off so that the polarization state of the light beam passing through the liquid crystal half-wave plate 128 is changed back to the polarization state before the last deflection; to deflect towards the opposite diffraction order in the next passive LCPG cell 129 requires that a saturation voltage be applied to the liquid crystal half-wave plate 128 in the next passive LCPG cell 129 so that it does not change the polarization state of the passing light beam.

Fig. 20 is a schematic diagram showing the relationship between the voltage control of the binary cascaded passive LCPG unit 129 and the deflection angle of the passing light beam, wherein the shaded area indicates that the saturation voltage is applied to the corresponding lc half-wave plate 128, and the lc half-wave plate 128 does not change the polarization state of the passing light beam. The white area indicates that the voltage applied to the lc half wave plate 128 is turned off and the corresponding lc half wave plate 128 will change the polarization state of the passing light beam. Because the LCPG sheets 127 are all passive, no voltage can be applied to all the passive LCPG sheets 127, and the light beam is deflected by a predetermined angle in the direction corresponding to the positive or negative diffraction according to the polarization state of the light beam. The beam deflection module 124 is exemplarily shown in fig. 20 to include 4 passive LCPG units 129 in binary cascade, where each LCPG unit 129 includes a liquid crystal half-wave plate 128 and a passive LCPG plate 127, and is labeled as follows in order along the outgoing direction of the beam: the liquid crystal half-wave plate I and the passive LCPG piece I, the liquid crystal half-wave plate II and the passive LCPG piece II, the liquid crystal half-wave plate III and the passive LCPG piece III, and the liquid crystal half-wave plate IV and the passive LCPG piece IV have the same grating vector direction. Wherein, the deflection angle of the passive LCPG sheets I-IV to the light beam sequentially increases step by step in a way of a natural number of two, the natural number is the number of the LCPG unit 129 where the natural number is located minus one, and the values are r, 2r, 4r and 8r.

Referring to fig. 19 and 20 together, the light beam incident in the horizontal direction is 0 degrees, deflected to the left as a positive angle, deflected to the right as a negative angle, and a reference system is established, if the polarization state of the light beam incident on the light beam deflection module 124 causes the passive LCPG sheet 127 to deflect the light beam in the direction of positive first-order diffraction, and the light beam passes through the whole light beam deflection module 124 to obtain a deflection angle of +r, the voltage to the liquid crystal half wave plate I is turned off, so that the light beam passing through the liquid crystal half wave plate I is first converted into its polarization state, and thus the passive LCPG sheet I deflects the light beam passing through-r and simultaneously converts the polarization state of the light beam back into the polarization state when the light beam is incident. Since the passive LCPG plate II and the passive LCPG plate III need to deflect the light beams in the directions of-2 r and-4 r respectively, the voltages of the liquid crystal half-wave plate II and the liquid crystal half-wave plate III need to be correspondingly turned off so that the light beams are converted into polarization states before entering the corresponding passive LCPG plate II and the passive LCPG plate III. Finally, a saturation voltage is applied to the lc half-wave plate IV to maintain the polarization state of the light beam at the time of incidence, which is recovered after passing through the passive LCPG plate III, so that the light beam can be deflected back to +8r in the opposite direction to the previous direction when passing through the passive plate IV to finally obtain the deflection direction of +r. Similarly, the beam deflection module 124 may deflect the passing beam by other preset deflection angles by applying a voltage as shown in fig. 20.

It should be understood that the beam deflection module 124 shown in fig. 19 and 20 may also deflect the passing light beam by an angle of-r to-15 r, and the voltage application condition of the corresponding liquid crystal half wave plates I-IV needs to be changed to adjust the polarization state before the light beam enters the corresponding passive LCPG plates I-IV, so as to obtain a corresponding opposite deflection condition.

Compared with the active LCPG unit 129, the passive LCPG unit 129 does not need to adjust voltage to change the liquid crystal state of the passive LCPG plate 127 in the use process, and can realize the control of the corresponding beam deflection angle by only correspondingly changing the voltage applied to the liquid crystal half-wave plate 128.

To ensure proper operation of the liquid crystal molecular material within the LCPG sheet 127, the temperature of the beam deflection module 124 needs to be controlled to be within a certain temperature range. Thus, in some embodiments, as shown in fig. 4, the beam deflection module 124 may further include a temperature control unit 1242, the temperature control unit 1242 being configured to control the temperature of the LCPG unit 129 within a preset temperature range. The temperature range of the normal operation of the liquid crystal material is 0-70 ℃, and when the liquid crystal material is in a low-temperature environment, the temperature control unit 1242 heats the LCPG unit 129; the temperature control unit 1242 cools the LCPG unit 129 while in a high temperature environment.

It should be appreciated that a plurality of LCPG units 129 arranged in tandem may deflect the passing light beam in one dimension. To achieve deflection of the beam in a two-dimensional plane, optionally, in some embodiments, as shown in fig. 21, the beam deflection module 124 may include a first set of LCPG cells 1291 and a second set of LCPG cells 1292, the first set of LCPG cells 1291 and the second set of LCPG cells 1292 each including a plurality of LCPG cells 129 arranged in a cascade. The first set of LCPG cells 1291 is configured to deflect the passing light beam in a preset first scan direction, and the second set of LCPG cells 1292 is configured to deflect the passing light beam in a preset second scan direction, the first scan direction being different from the second scan direction.

Alternatively, the first scanning direction may be perpendicular to the second scanning direction. For example: in fig. 21, the emission direction of the zero-order beam is taken as the Y axis, the horizontal direction is taken as the X axis, the vertical direction is taken as the Z axis, and an orthogonal rectangular coordinate system is established, so that the first scanning direction may be the horizontal direction along the X axis, and the second scanning direction may be the vertical direction along the Z axis. It should be understood that the scanning direction refers to the direction of change of deflection of the light beam, and is different from the emission direction of the light beam, and may be understood as the direction of change of the direction of emission of the light beam.

Optionally, one or more parameters of the first LCPG unit group 1291, such as the deflection angle range, the deflection precision, and the number of deflection angles that can be provided for the passing light beam, may be the same as or different from the second LCPG unit group 1292, which is not limited in the present application.

Thus, the beam deflection module 124 may deflect the light beam in a two-dimensional plane by providing the LCPG cell groups with different scan directions to enable the sensing light beam to illuminate a larger detection range.

Optionally, in other embodiments, the beam deflection module 124 may also perform coarse deflection on the beam emitted by the light source module 122 within a preset deflection angle range in other manners, for example, deflect the beam emitted by the light source module 122 in a manner of an optical phased array (Optical Phased Array, OPA) or a liquid crystal metasurface (Liquid Crystal Metasurface, LCM), which is not limited in this application.

As shown in fig. 22, in some embodiments, the light emitted by the light source module 122 is unpolarized light, the beam deflection module 124 includes a first liquid crystal polarization grating 1241 and a combination of a liquid crystal half-wave plate 128 and a liquid crystal polarization grating 127 that are arranged in cascade along the light propagation direction, where the first liquid crystal polarization grating 1241 is configured to split the unpolarized light emitted by the light source module 122 into left-handed circularly polarized light and right-handed circularly polarized light, and the split left-handed circularly polarized light and right-handed circularly polarized light may be synchronously incident to the combination of the liquid crystal half-wave plate 128 and the liquid crystal polarization grating 127 that are arranged in cascade behind. It should be understood that the combination of the lc half-wave plates 128 and the lc polarization gratings 127 in a cascade arrangement is a plurality of combinations of one or more lc half-wave plates 128 and at least one lc polarization grating 127, and the number of lc half-wave plates 128 and the number of lc polarization gratings 127, and their respective beam deflection capabilities, may be designed according to the beam deflection angles that are desired. Alternatively, the combination of the lc half-wave plate 128 and the lc polarization grating 127 may be a binary cascade as shown in fig. 13, a binary-like cascade as shown in fig. 15, a ternary cascade as shown in fig. 17, a binary cascade of passive LCPG cells as shown in fig. 19, or any other suitable cascade, which is not particularly limited by the present application.

Since the combination of the cascaded liquid crystal half wave plate 128 and the liquid crystal polarization grating 127 under the same voltage configuration has opposite deflection characteristics for the left-handed circularly polarized light and the right-handed circularly polarized light, respectively, for each voltage configuration (except for the voltage configuration with the deflection angle of 0) of the combination of the cascaded liquid crystal half wave plate 128 and the liquid crystal polarization grating 127, the left-handed circularly polarized light and the right-handed circularly polarized light separated by the first liquid crystal polarization grating 1241 can be deflected to two deflection angles symmetrically distributed about the zero-order beam direction, respectively, for scanning.

Therefore, compared with the scheme that only one polarization state beam is scanned by the beam deflection module 124 in the other embodiments, the frequency of switching the voltage configuration states of the cascaded liquid crystal half-wave plate 128 and the liquid crystal polarization grating 127 in the process of scanning the complete deflection angle range in the scheme that the original beam is split into different polarization states and the split beam is synchronously deflected to symmetrical polarization angles in the embodiment is reduced by half, and the time spent waiting for switching the states of the liquid crystal half-wave plate 128 and/or the liquid crystal polarization grating 127 can be correspondingly reduced by half. Moreover, because the beam splitting of different polarization states can synchronously scan two polarization angles symmetrically distributed in the whole deflection angle range, the scanning efficiency can be doubled, and the scanning frame rate can be obviously improved. Furthermore, the light emitted directly by the light emitting unit 120 of the light source module 122 is usually unpolarized light, so for other embodiments that use a single polarized light beam to deflect through the beam deflection module 124, it is necessary to convert the unpolarized light emitted by the light emitting unit 120 into light with a specific polarization state by using a polarizing device before the light beam enters the beam deflection module 124, and this conversion process wastes a portion of the light beam energy, and in this embodiment, all the split light beams with different polarization states split from the original light beam are utilized to scan, which also improves the utilization ratio of the light beam energy.

As shown in fig. 4, in some embodiments, the emission module 12 further includes a beam expansion module 126, and the beam deflection module 124 deflects the passing beam along a preset first scanning direction, and the beam expansion module 126 is configured to expand the divergence angle of the beam along a preset second scanning direction, where the first scanning direction is different from the second scanning direction. Alternatively, the first scanning direction may be perpendicular to the second scanning direction. For example: in fig. 4, the emission direction of the zero-order beam is taken as a Y axis, the horizontal direction is taken as an X axis, the vertical direction is taken as a Z axis, and an orthogonal rectangular coordinate system is established, so that the first scanning direction may be the horizontal direction along the X axis, and the second scanning direction may be the vertical direction along the Y axis. It should be understood that the scanning direction refers to the direction of change of deflection of the light beam, and is different from the emission direction of the light beam, and may be understood as the direction of change of the direction of emission of the light beam.

Alternatively, the beam expansion module 126 may be a beam expansion lens. The beam expander lens 126 includes an optical surface curved in a second scanning direction to bend the light beam passing through the beam expander lens in the second scanning direction. It should be appreciated that the curvature of the optical surface along the second scanning direction may be described by a change in curvature and/or slope of points on the optical surface along the second scanning direction that are sequentially arranged along the predetermined direction.

As shown in fig. 23 and 24, in some embodiments, the beam expanding lens 126 may be a cylindrical concave lens. The shape of the cylindrical concave lens 126 can be described by taking the orthogonal rectangular coordinate system established by taking the first scanning direction as the X axis, the second scanning direction as the Z axis, and the zero-order sensing beam emitting direction as the Y axis as a reference. The cylindrical concave lens 126 includes a light incident surface 1262 and a light emergent surface 1264 sequentially arranged along a Y axis where the zero-order sensing beam is emitted. At least one of the light-in surface 1262 and the light-out surface 1264 is an optical surface curved along the second scanning direction. Optionally, the light incident surface 1262 is a concave curved surface that is concave toward the Y-axis where the zero-order sensing beam is emitted, and can be used as an optical curved surface for bending the passing beam by the beam expander lens 126. Optionally, in some embodiments, the light incident surface 1262 has a curvature that varies along a Z axis in which the second scanning direction is located. That is, the curvature of each point on the light incident surface 1262 changes with the change of the coordinate of the point on the Z axis in the second scanning direction, as shown in fig. 23, the light incident surface 1262 is a curved section line 1265 corresponding to the cross section formed by the plane of the coordinate system YOZ in which the point is located, and the curvature of the point refers to the curvature of the curved section line 1265 along the tangential direction of the point. It should be appreciated that the cross-section forming the curved intercept 1265 may also be a plane perpendicular to the first scan direction.

Optionally, in some embodiments, the light incident surface 1262 is kept straight along the first scanning direction, and an intersecting line between the light incident surface 1262 and a plane parallel to the X-axis along which the first scanning direction is located is a straight line, that is, a connecting line between two points on the light incident surface 1262 aligned along the X-axis along which the first scanning direction is located is a straight line. However, the present application is not limited thereto, and in other embodiments, the intersection line between the light incident surface 1262 and the plane parallel to the X-axis of the first scanning direction may be a curve.

Alternatively, the light-emitting surface 1264 may be a plane perpendicular to the Y-axis in which the zero-order sensing beam emits. However, the present application is not limited thereto, and in other embodiments, the light-emitting surface 1264 may be a non-planar surface, or the light-emitting surface 1264 may be a plane that is not perpendicular to the Y-axis in which the zero-order sensing beam is emitted.

As shown in fig. 25 and 26, in some embodiments, the beam expanding lens 126 may be a cylindrical convex lens. The shape of the cylindrical convex lens 126 can be described by taking the orthogonal rectangular coordinate system established by taking the first scanning direction as the X axis, the second scanning direction as the Z axis, and the zero-order sensing beam emitting direction as the Y axis as a reference. The cylindrical convex lens 126 includes a light incident surface 1262 and a light emergent surface 1264 sequentially arranged along the Y axis where the zero-order sensing beam is emitted. At least one of the light incident surface 1262 and the light emergent surface 1264 is an optical curved surface curved along the second scanning direction. Optionally, the light incident surface 1262 is a convex curved surface protruding from the Y axis where the zero-order sensing beam is emitted, and can be used as an optical surface of the beam passing through by the beam expanding lens 126. Optionally, in some embodiments, the light incident surface 1262 has a curvature that varies along a Z axis in which the second scanning direction is located. That is, the curvature of each point on the light incident surface 1262 changes with the change of the coordinate of the point on the Z axis in the second scanning direction, as shown in fig. 25, the light incident surface 1262 is a curved section line 1265 corresponding to the cross section formed by the plane of the coordinate system YOZ in which the point is located, and the curvature of the point refers to the curvature of the curved section line 1265 along the tangential direction of the point. It is understood that the coordinate system YOZ plane may also refer to a plane perpendicular to the first scanning direction.

Optionally, in some embodiments, the light incident surface 1262 is kept straight along the first scanning direction, and an intersection line between the light incident surface 1262 and a plane parallel to the first scanning direction (i.e., the X-axis direction) is a straight line. That is, a line between two points aligned along the first scanning direction (i.e., the X-axis direction) on the light incident surface 1262 is a straight line. However, the present application is not limited thereto, and in other embodiments, the intersection line between the light incident surface 1262 and the plane parallel to the first scanning direction (i.e. the X-axis direction) may be a curve.

Alternatively, the light-emitting surface 1264 may be a plane perpendicular to the emitting direction (i.e., Y-axis direction) of the zero-order sensing beam. However, the present application is not limited thereto, and in other embodiments, the light-emitting surface 1264 may be non-planar, or the light-emitting surface 1264 may not be perpendicular to the emitting direction (i.e. the Y-axis direction) of the zero-order sensing beam.

As shown in fig. 24 and 26, optionally, the optical axis of the beam expander lens 126 is disposed along the emitting direction (i.e., the Z-axis direction) of the zero-order sensing beam of the beam deflector module 124, and the zero-order sensing beam is located at a middle position of the angular range of the beam deflector module 124. Since the beam deflection module 124 deflects the beam only along the first scanning direction, the beam deflected by the beam deflection module 124 is located at a middle position of the whole detection range in the second scanning direction, the divergence angle of the beam along the second scanning direction after being expanded by the beam expansion lens 126 is symmetrically distributed about the optical axis of the beam expansion lens 126, if the divergence angle of the beam along the second scanning direction after being expanded by the beam expansion lens 126 is 2θ, the maximum deviation angle of the beam after being bent by the beam expansion lens 126 compared with the optical axis is θ, and θ satisfies the following equation:

Where D is the beam diameter and f is the focal length of the beam expander lens 126. For example, if the divergence angle of the sensing beam after being expanded by the beam expander lens 126 is preset to be 70 degrees, θ=0.61 rad, focal length

It should be understood that the curvature change of the light incident surface 1262 of the beam expander lens 126 along the second scanning direction may be set according to any one or more of the beam diameter when the sensing beam is incident, the divergence angle of the sensing beam after being expanded by the beam expander lens 126, the refractive index of the material of the beam expander lens 126, and the thickness of the beam expander lens 126 along the Y-axis where the zero-order sensing beam is emitted.

Alternatively, in other embodiments, the curvature change of the light incident surface 1262 of the beam expander lens 126 along the Z axis of the second scanning direction may also be described by the slope change of each point on the light incident surface 1262 along the second scanning direction. As shown in fig. 24, a YOZ plane is defined by a Z axis in which the second scanning direction is located and a Y axis in which the emission direction of the zero-order beam is located, and in a cross section of the beam expander 126 formed by the YOZ plane, the light incident surface 1262 of the beam expander 126 correspondingly forms a first curved-surface cross section 1265, and a slope of each point on the first curved-surface cross section 1265 changes according to the Y-axis coordinate of the point. That is, in the cross section of the beam expander 126 perpendicular to the first scanning direction, the slope of each point on the first curved-surface intercept 1265 correspondingly formed on the light incident surface 1262 varies with the position of the point on the Y-axis along which the second scanning direction is located. Taking the beam expander lens 126 as a cylindrical concave lens as an example, the light incident surface 1262 is a concave curved surface recessed toward the zero-order beam emission direction, and the slope of each point distributed from top to bottom along the Z axis of the second scanning direction on the first curved surface section line 1265 correspondingly formed by the light incident surface 1262 gradually decreases. That is, the slope of each point on the light incident surface 1262 varies with the position of the point on the Z-axis along which the second scanning direction is located. As shown in fig. 26, taking the beam expander lens 126 as an example of a cylindrical convex lens, the light incident surface 1262 is an outer convex surface protruding from the direction of emitting the zero-order sensing beam, and the slope of each point on the first curved surface section line 1265 formed correspondingly on the light incident surface 1262 and distributed from top to bottom along the Z axis of the second scanning direction gradually increases. That is, the slope of each point on the light incident surface 1262 varies with the position of the point on the Y-axis along which the second scanning direction is located.

Optionally, in some embodiments, the beam expansion module 126 may be disposed behind the beam deflection module 124 in the emission direction of the zero-order sensing beam. That is, the beam expansion module 126 may be located on a side of the beam deflection module 124 facing away from the light source module 122, or the beam deflection module 124 may be located between the light source module 122 and the beam expansion module 126. Correspondingly, the beam expansion module 126 is configured to expand the divergence angle of the beam deflected by the beam deflection module 124 along the preset second scanning direction. Thus, when the beam deflection module 124 deflects the beam along the first scanning direction, the sensing beam with the expanded divergence angle through the beam expansion module 126 can irradiate the area covered by the sensing beam after being expanded along the second scanning direction in the process of scanning along the first scanning direction, so that the sensing beam emitted by the emission module 12 can irradiate the two-dimensional plane area defined by the beam deflection range along the first scanning direction and the beam expansion range along the second scanning direction only by deflecting along the first scanning direction, and the detection range of the photodetection device 10 is enlarged.

Optionally, in some embodiments, the beam expansion module 126 may also be disposed in front of the beam deflection module 124 along the emission direction of the zero-order sensing beam. That is, the beam expansion module 126 may be located at a position between the light source module 122 and the beam deflection module 124. Correspondingly, the beam expansion module 126 is configured to expand the divergence angle of the beam emitted from the light source module 122 along the second scanning direction. On this basis, the beam deflection module 124 deflects the beam whose divergence angle is expanded in the first scanning direction to form a sensing beam capable of irradiating a two-dimensional plane area defined by a beam deflection range in the first scanning direction and a beam expansion range in the second scanning direction together.

The implementation of the two-dimensional planar scanning of the sensing beam by the beam expansion module 126 may reduce delay caused by liquid crystal molecular reactions when the beam passes through the LCPG cell group, compared to the implementation of the two-dimensional planar scanning of the sensing beam by the LCPG cell group having different scanning directions, respectively.

As shown in fig. 2, the photo-detection device 10 further includes a control circuit 18, and the control circuit 18 is configured to correspondingly adjust the deflection angle of the emitted sensing beam within the second deflection angle range ψ of the beam deflection module 124 by controlling the beam deflection module 124 and the light source module 122 according to a preset deflection accuracy. Optionally, in some embodiments, the control circuit 18 may include a yaw angle coarse adjustment unit 184 and a yaw angle fine adjustment unit 186.

The coarse deflection angle adjustment unit 184 is configured to control the beam deflection module 124 to deflect the passing beam by a preset deflection angle within the second deflection angle range ψ, the deflected angles being arranged in an arithmetic progression with a preset angle interval r. Alternatively, the coarse angle of deflection unit 184 may control the angle of deflection of the passing light beam, for example, by adjusting the voltage applied to the corresponding LCPG unit 129 in the light beam deflection module 124. It should be appreciated that, as previously described, the different cascade of LCPG cells 129 may differ in the correspondence between the angle of deflection of the passing beam and the applied voltage signal. The coarse angle of deflection adjustment unit 184 may select the voltage control signal to be applied based on the cascaded manner of the LCPG units 129 employed by the beam deflection module 124 and the angle at which the sensing beam is currently being deflected.

The deflection angle fine adjustment unit 186 is configured to control the light source module 122 to change the angle of the emitted light beam within a preset first deflection angle range phi with a preset deflection accuracy. Alternatively, in some embodiments, the deflection angle fine adjustment unit 186 can correspondingly control the deflection angle of the light beam emitted by the light source module 122 by, for example, addressing the light sources 121 that are located at different positions. As described above, the light sources 121 in the light source module 122 are disposed on the focal plane of the projection lens 123, and the light beams emitted by the light sources 121 at different positions on the focal plane are emitted at different angles through the projection lens 123, so that the light beams emitted by the light source module 122 can be controlled to deflect within a preset first deflection angle range phi according to a preset deflection precision by addressing and lighting the light sources 121 at different positions.

In use, the coarse deflection angle adjustment unit 184 may control the beam deflection module 124 to configure coarse deflection angles with lower accuracy for the beam emitted from the light source module 122 within the preset second deflection angle range ψ, where the coarse deflection angles are arranged in an arithmetic progression according to a preset angle interval r, where the angle interval r is the coarse deflection accuracy of the beam deflection module 124. The light source module 122 may be controlled to emit a light beam by the deflection angle fine adjustment unit 186, and the emission angle of the emitted light beam may be changed with a preset fine adjustment deflection precision delta within the first deflection angle range phi, so that the light beam deflected by the light beam deflection module 124 may be finely adjusted in deflection angle on the deflected coarse deflection angle, and the fine adjustment range of deflection angle may be the first deflection angle range phi. That is, by changing the emission angle of the light beam emitted from the light source module 122 within the first deflection angle range Φ, the light beam deflected for the first time by the light beam deflection module 124 can be deflected in a fine adjustment with higher accuracy within the first deflection angle range Φ centered on the coarse deflection angle that has been deflected, and the deflection accuracy δ of the light source module 122 for the emitted light beam is the fine adjustment deflection accuracy. It will be appreciated that by setting the first deflection angle range phi to be greater than or equal to the angular interval r, two-stage deflection of the light beam by the beam deflection module 124 and the light source module 122 can be achieved to achieve a quasi-continuous deflection of the sensing beam with a preset deflection accuracy within the second deflection angle range ψ.

It will be appreciated that the time required for the beam deflection module 124 configured to deflect a beam based on the LCPG principle to coarse tune the angle of deflection of the passing beam is determined by the response speed of the LCPG sheet 127, and is primarily on the order of milliseconds (ms), e.g., 1-10ms, depending on the characteristics of the liquid crystal material used by the LCPG sheet.

The time required for the deflection angle fine adjustment unit 186 to control the light source module 122 to perform the beam fine adjustment scanning based on a coarse deflection angle depends on the time required for one complete transmission and reception of the sensing beam and the number of times required for transmitting and receiving the sensing beam per frame detection. The time required for one complete transmission and reception of the sensing beam is at least greater than the time of flight of the furthest distance detection value that the outgoing sensing beam needs to meet. For example, if the distance detection maximum to be satisfied is 50 meters, the time of flight required for the sensing beam to traverse 50 meters is 334 nanoseconds (ns), and the time required for one complete transmission and reception of the sensing beam is about 600ns, considering the redundancy amount of the random time interval required for interference rejection. In order to improve the signal-to-noise ratio of the detection, it is assumed that the number of transmissions of the sensing beam needs to reach 1000 times for each fine-tuned deflection angle, so that the time required for transmission and reception of the sensing beam is 1000×600ns=0.6 ms for each fine-tuned deflection angle. As described above, the deflection angle fine adjustment unit 186 needs to address and illuminate the light sources 121 at different positions to change the emission angle of the emitted light beam, and the time required to complete one round of addressing is in the order of ns.

To further reduce time consumption, the control circuit 18 may control the light source module 122 to address and illuminate the other light sources 121 synchronously in intervals of two adjacent emitted sensing light beams along one of the fine-tuned deflection angles to emit light beams along other fine-tuned deflection angles within the first deflection angle range phi. Thus, the time required for scanning detection of all fine deflection angles within the first deflection angle range phi over one coarse deflection angle is approximately equal to the total time required to emit a preset plurality of sensing beams along one of the fine deflection angles.

It should be appreciated that for each coarse deflection angle of the sensing beam provided by the beam deflection module 124 within the second deflection angle range ψ, the deflection angle fine adjustment unit 186 can control the light source 122 to acquire sensing data at the corresponding firing angle from the sensing beam with a preset fine deflection accuracy within the first deflection angle range φ around the selected coarse deflection angle. On the basis of this, the processing circuit 15 processes and analyzes the sensed data obtained by emitting the sensed light beams at different emission angles to obtain three-dimensional information at the corresponding emission angles.

For the whole process of three-dimensional information detection, in addition to the scanning time of the sensing beam along a plurality of angles, the time for processing the data generated by sensing the optical signal needs to be considered. In order to improve sensing speed, the embodiment of the application can adopt a parallel mode of scanning and data processing to cache the sensing data obtained by emitting the sensing light beam at one preset angle in the detection range, so as to process the cached sensing data in parallel while scanning and sensing the next emission angle.

Alternatively, in some embodiments, if the amount of sensed data corresponding to one emission angle is large, the data processing time may be prolonged by increasing the storage space in such a way that sensed data corresponding to a plurality of emission angles is buffered.

Alternatively, in some embodiments, the data processing may be struggled for by extending the sensing beam fine-tuning scan duration without increasing the memory space. For example: in some embodiments, the coarse angular adjustment of the sensing beam takes 4ms, and the fine scanning of the sensing beam on the basis of the coarse deflection angle takes up to 2ms, i.e. the time required for scanning and sensing of the sensing beam is 6ms in total for one coarse deflection angle. If the beam deflection module 124 employs a binary or quasi-binary concatenation of three active LCPG cells 129, a 2 will be provided ³⁺¹ Coarse deflection angle of 1=15 sensing beams, the total time required to complete one frame scan and sensing of the sensing beams is 15×6=90 ms, corresponding to a frame rate of 11.1 hertz (Hz). If the beam deflection module 124 employs binary concatenation of four passive LCPG cells 129, 2 may be provided ⁴ The total time required to complete one frame scan and sensing of the sensing beams is 16×6=96 ms, with a corresponding frame rate of 10.4Hz.

Compared with the deflection of the sensing light beam realized by a mechanical rotation scheme and a mixed solid state scheme, the application realizes the quasi-continuous deflection of the sensing light beam in the second deflection angle range psi by the pure solid state light source module 122 and the light beam deflection module 124, does not need to rely on rotation and vibration of components, and has the beneficial effects of better reliability and compact size.

Referring also to fig. 2, the receiving module 14 may include a photosensor 140 and receiving optics 144. The receiving optics 144 is disposed on the light-in side of the photosensor 140 and is configured to propagate an optical signal from a detection range to the photosensor 140 for sensing. For example, in some embodiments, the receiving optics 144 includes a receiving lens. Alternatively, the receiving lens 144 may include one lens or a plurality of lenses. The photosensor 140 is configured to sense optical signals propagating from the detection range via the receiving optics 144 and output corresponding photo-sensing signals.

Optionally, 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.

Alternatively, in some embodiments, the photosensor 140 includes a single photosensitive pixel 142 or includes a plurality of photosensitive pixels 142 to form a photosensitive pixel array, for example. The detection range of the photodetection device 10 may include a plurality of detection regions each located at a different position. Optionally, the photosensitive pixels 142 of the photosensor 140 have corresponding detection areas in a detection range, and optical signals returned from the detection areas propagate to the corresponding photosensitive pixels 142 via the receiving optics 144 for sensing. That is, the detection area corresponding to the photosensitive pixel 142 can be regarded as a spatial range covered by the angle of view of the photosensitive pixel 142 formed by the receiving optical device 144. It will be appreciated that the optical signal returned from the detection zone 20 comprises a sensing beam projected onto the detection zone 20 and reflected back by the object 2 located within the detection zone, as well as photons of ambient light from the detection zone.

Alternatively, 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. Such as single photon avalanche diodes (Single Photon Avalanche Diode, SPADs), avalanche photodiodes (Avalanche Photon Diode, APDs), silicon photomultiplier tubes (Silicon Photomultiplier, sipms) arranged in parallel by a plurality of SPADs, and/or other suitable photoelectric conversion elements.

As shown in fig. 27, in some embodiments, the light emitting unit 120 periodically emits laser pulses at a preset frequency, and the laser pulses form the sensing beam to be projected toward the detection range through the emitting optical device 124, that is, the sensing beam may be a periodic pulse beam having a preset frequency. The light emitting unit 120 may emit a plurality of laser pulses within one detection frame, and a period between emission timings of two adjacent laser pulses may be defined as one emission period of the laser pulses. The photosensitive pixels 142 have a sensing period corresponding to the emission period. For example, the photosensitive pixels 142 periodically perform sensing at the same preset frequency as the emission period, the sensing period having a start time and an end time coincident with the emission period. The photosensitive pixel 142 starts to sense the photons returned from the detection range at the same time when one laser pulse is emitted, and the timing unit 152 determines the receiving time when the receiving module 14 senses the optical signal according to the photo-sensing signal generated by the receiving module 14 sensing the photons. The statistics unit 154 counts the light signal receiving time determined by the timing unit 152 in a plurality of sensing periods of one detection frame in a corresponding time bin to generate a corresponding statistical histogram. The length of the sensing period is at least greater than the time of flight required for photons to traverse the distance detection furthest value required by the corresponding detection zone to ensure that photons reflected back from the distance detection furthest value can be sensed and counted. Alternatively, in some embodiments, the length of the sensing period may be set correspondingly according to the distance required by the detection area to detect the furthest value. For example, the sensing period length of the photosensitive pixel 142 is in positive correlation with the distance detection furthest value to be satisfied by the corresponding detected detection region, and for the detection region with a larger distance detection furthest value, the sensing period of the photosensitive pixel 142 for performing the corresponding detection is longer; for a detection region where the distance detection furthest value is smaller, the sensing period of the photosensitive pixel 142 where the corresponding detection is performed is shorter.

Alternatively, in some embodiments, all or a portion of the functional elements of the control circuitry 18 and/or processing circuitry 15 may be firmware that is solidified within the storage medium 30 or computer software code that is stored within the storage medium 30 and executed by the corresponding one or more processors 40 to control the relevant components to implement the corresponding functions. Such as, but not limited to, an application processor (Application Processor, AP), a central processing unit (Central Processing Unit, CPU), a microcontroller (Micro Controller Unit, MCU), etc. 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.

Alternatively, in some embodiments, the processor 40 and/or the storage medium 30 may be disposed within the photodetection device 10, such as: is integrated on the same circuit board as the transmitting module 12 or the receiving module 14. Alternatively, in other embodiments, the processor 40 and/or the storage medium 30 may be located elsewhere in the electronic device 1, such as: on the main circuit board of the electronic device 1.

Optionally, in some embodiments, some or all of the functional units of the control circuit 18 and/or the processing circuit 15 may also be implemented in hardware, for example by any one or a combination of the following technologies: discrete logic circuits having logic gates for implementing logic functions on data signals, application specific integrated circuits having suitable combinational logic gates, programmable Gate Arrays (PGAs), field Programmable Gate Arrays (FPGAs), and the like. It will be appreciated that the hardware described above for implementing the functions of the control circuit 18 and/or processing circuit 15 may be provided within the photo detection means 10. The hardware described above for implementing the functions of the control circuit 18 and/or the processing circuit 15 may also be provided in other locations of the electronic device 1, such as: is provided on a main circuit board of the electronic device 1.

As shown in fig. 28, 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.

Compared with the laser radar adopting a mechanical rotation mode and a mixed solid state mode to realize the scanning of the sensing light beam, the laser radar 10 provided by the application adopts a pure solid LCPG mode to realize the deflection scanning of the sensing light beam, has higher reliability and more compact structure because rotation or vibration components are not needed, is easier to pass through strict requirements of a vehicle gauge, and has less influence on the appearance of an automobile.

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.

It is to be understood that portions of embodiments of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, the plurality of functional units may be implemented in software or firmware stored in a storage medium and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, may be implemented using any one or combination of the following techniques, as is well known in the art: discrete logic circuits having logic gates for implementing logic functions on data signals, application specific integrated circuits having suitable combinational logic gates, programmable Gate Arrays (PGAs), field Programmable Gate Arrays (FPGAs), and the like.

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. An emission module configured to emit a sensing beam into a detection range for three-dimensional information detection of an object in the detection range, comprising:

A control circuit configured to correspondingly adjust different voltage configurations applied to the cascade-arranged liquid crystal half wave plate and liquid crystal polarization grating plate at a plurality of moments to correspondingly deflect the left-handed circularly polarized light and the right-handed circularly polarized light by different preset deflection angles at the moments to form sensing light beams with different emergent directions in a second deflection angle range;

2. The transmitting module according to claim 1, wherein the light source module includes a plurality of light sources and a projection lens, the plurality of light sources are disposed on a focal plane of the projection lens, the light beams emitted from the light sources are emitted in corresponding preset transmitting directions after passing through the projection lens to form the light beams emitted from the light source module, the preset transmitting directions emitted from the light sources after passing through the projection lens have corresponding relations with positions of the light sources on the focal plane of the projection lens, and the light source module lightens the light sources at different positions on the focal plane of the projection lens by addressing to correspond to the light beams deflected between the different preset transmitting directions formed in the first deflection angle range.

3. The transmitting module of claim 1, wherein the light source module comprises a light source configured to emit a light beam and an optical deflection device configured to deflect the light beam emitted by the light source in a preset transmitting direction within the first deflection angle range, and the optical deflection device may be a liquid crystal on silicon phased array or an acousto-optic deflection crystal.

4. The emission module of claim 1, wherein the light source module and the beam deflection module deflect the passing beam along a first scan direction, the emission module further comprising a beam expansion module configured to expand a divergence angle of the passing beam along a predetermined second scan direction, the second scan direction being perpendicular to or at a predetermined angle from the first scan direction.

5. The transmitting module according to claim 4, wherein the beam expansion module includes a beam expansion lens including a light entrance surface and a light exit surface disposed in order along a zero-order beam emission direction, the zero-order beam being a beam positioned at an intermediate angular position within a corresponding deflection angle range of the beam deflection module, at least one of the light entrance surface and the light exit surface being an optical surface curved along the second scanning direction to expand a divergence angle of the beam transmitted through the beam expansion lens along the second scanning direction.

6. The emission module as recited in claim 5, wherein the beam expander lens is a cylindrical concave lens, and the optical surface is a concave curved surface concave toward the zero-order beam emission direction; or alternatively

7. The transmitting module of claim 1, wherein the beam deflection module further comprises a temperature control unit configured to control the temperature of the liquid crystal deflection grating sheet within a preset temperature range.

8. The transmitting module of claim 1, wherein the combination of the cascade-arranged liquid crystal half wave plates and the liquid crystal polarization grating plates comprises a plurality of liquid crystal polarization grating units sequentially arranged along the outgoing direction of the light beam, each liquid crystal polarization grating unit comprises a liquid crystal half wave plate and a liquid crystal polarization grating plate, the deflection angle of the passing light beam is gradually increased in a way of being two natural numbers in the order of being sequentially arranged along the outgoing direction of the light beam, and the value of the natural numbers is the serial number of the liquid crystal polarization grating plates minus one.

9. The transmitting module of claim 1, wherein the combination of the cascade-arranged liquid crystal half wave plates and the liquid crystal polarization grating plates comprises a plurality of liquid crystal polarization grating units sequentially arranged along the outgoing direction of the light beam, each liquid crystal polarization grating unit comprises a liquid crystal half wave plate and a liquid crystal polarization grating plate, the deflection angles of the passing light beam are gradually increased in three natural powers according to the sequential arrangement order along the outgoing direction of the light beam, and the value of the natural number is the serial number of the liquid crystal polarization grating plate minus one.

10. The transmitting module of claim 1, wherein the combination of the liquid crystal half wave plate and the liquid crystal polarization grating plates arranged in cascade comprises one liquid crystal half wave plate and a plurality of liquid crystal polarization grating plates which are sequentially arranged along the emergent direction of the light beam, the deflection angle of the liquid crystal polarization grating plates to the light beam is gradually increased according to the sequential arrangement along the emergent direction of the light beam, the difference between the deflection angles of one liquid crystal polarization grating plate and the adjacent previous liquid crystal polarization grating plate to the light beam is gradually increased according to the sequential arrangement along the emergent direction of the light beam in a way of being in a natural number of two and the value of the natural number is the serial number of the liquid crystal polarization grating plate minus one.

11. The transmitting module according to any one of claims 8, 9 and 10, wherein the liquid crystal polarization grating is an active liquid crystal polarization grating provided with electrodes capable of being applied with a saturation voltage, the active liquid crystal polarization grating not deflecting the passing light beam when the saturation voltage is applied, the active liquid crystal polarization grating deflecting the passing light beam when the voltage is not applied.

12. The transmitting module of claim 8, wherein the lc polarization grating is a passive lc polarization grating that is not provided with electrodes and cannot be applied with a voltage, the passive lc polarization grating deflecting the passing light beam.

13. A photo-detection device comprising a transmitting module according to any one of claims 1-12, the photo-detection device further comprising a receiving module configured to sense light signals from a detection range and to output corresponding light-induced signals, and a processing circuit configured to analyze and process the light-induced signals to obtain three-dimensional information of an object within the detection range.

14. An electronic device comprising the photodetection means according to claim 13, further comprising an application module configured to implement a corresponding function according to the detection result of the photodetection means.