CN115144842B

CN115144842B - Transmitting module, photoelectric detection device, electronic equipment and three-dimensional information detection method

Info

Publication number: CN115144842B
Application number: CN202211068138.6A
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: 2022-09-02
Publication date: 2023-03-14
Anticipated expiration: 2042-09-02
Also published as: CN115144842A

Abstract

The application provides an emission module configured to emit a sensing light beam into a detection range to perform three-dimensional information detection on an object in the detection range. The transmitting module comprises a light source module and a first light beam deflection module. The light source module is configured to emit a light beam and deflect the emitted light beam between different preset emission directions within a first deflection angle range. The first light beam deflection module is configured to deflect the light beams emitted by the light source module by different preset deflection angles respectively at a plurality of moments so as to form sensing light beams with different emergent directions within a second deflection angle range. The first light beam deflection module deflects a plurality of preset deflection angles of light beams to form an arithmetic progression according to a preset first angle interval, and the first deflection angle range is larger than or equal to the first angle interval. The application also provides a photoelectric detection device and electronic equipment comprising the emission module, and a three-dimensional information detection method applied to the photoelectric detection device and the electronic equipment.

Description

Transmitting module, photoelectric detection device, electronic equipment and three-dimensional information detection method

Technical Field

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

Background

The principle of Time of Flight (ToF) measurement is: three-dimensional information such as the distance of an object is calculated from the time of flight of the detection light reflected by the object in the 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 field angle of the detection device itself for measuring distance by using the ToF measurement principle is limited, and a larger detection range needs to be obtained by scanning by constantly changing the detection direction. At present, one of the ways of changing the detection direction is implemented by using a mechanical structure to rotate a detection device, however, such a way usually needs multiple sets of discrete devices, the complexity of debugging and assembling the optical path is high, the complex mechanical structure is easy to damage and misalign, and the appearance of the terminal equipment using the complex mechanical structure is also affected due to the large size. Another way to change the detection direction is a mixed solid scheme, which mainly uses a vibrating component to drive an 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 rotating solution, the reliability of the system is still low since the vibrating parts are still more vulnerable, 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 detecting method, which can solve the problems in the prior art.

In a first aspect, the present application provides an emission module configured to emit a sensing light beam into a detection range to perform three-dimensional information detection on an object in the detection range. The transmitting module comprises a light source module and a first light beam deflection module. The light source module is configured to emit light beams and correspondingly deflect the emitted light beams to different preset emission directions within a first deflection angle range at a plurality of moments respectively. The first light beam deflection module is configured to deflect the light beams emitted by the light source module by different preset deflection angles respectively at a plurality of moments so as to form sensing light beams with different emergent directions in a second deflection angle range. The first light beam deflection module deflects a plurality of preset deflection angles of light beams to form an equal difference array according to a preset first angle interval, the range of the first deflection angle is larger than or equal to the first angle interval, the first light beam deflection module comprises a liquid crystal half-wave plate and a plurality of liquid crystal deflection grating plates which are sequentially arranged along the emergent direction of the light beams, the deflection angles of the liquid crystal polarization grating plates to the light beams are gradually increased according to the sequence of sequentially arranging along the emergent direction of the light beams, the difference of the deflection angles of one liquid crystal polarization grating plate and the adjacent previous liquid crystal polarization grating plate to the light beams is gradually increased by two natural number power according to the sequence of sequentially arranging along the emergent direction of the light beams, and the value of the natural number is that the serial number of the liquid crystal polarization grating plate is decreased by one.

In a second aspect, the present application provides a photodetection device, which includes a receiving module, a processing circuit, and the transmitting module as described above. The receiving module is configured to sense an optical signal from within a detection range and output a corresponding optical sensing signal. The processing circuitry is configured to analytically process the light-induced signals to obtain three-dimensional information of objects within a detection range.

In a third aspect, the present application provides an electronic device, including the above-mentioned photodetection apparatus, and further including an application module, where the application module is configured to implement a corresponding function according to a detection result of the photodetection apparatus.

In a fourth aspect, the present application provides a three-dimensional information detection method, which is applicable to the photodetection device or the electronic device, and the three-dimensional information detection method includes:

controlling the deflection angle of the light beam passing through the light beam deflection module;

controlling the light source module to emit light beams, and controlling the light source module to deflect the emitted light beams within a preset first deflection angle range according to preset deflection accuracy on the basis that the emitted light beams are deflected by a preset angle through the light beam deflection module;

sensing an optical signal from within the detection range and recording a reception time of the sensed optical signal; and

the time of receipt data of the sensed light signal is analyzed and processed to obtain the time of flight of the sensing light beam reflected back from within the detection range, and three-dimensional information of the object reflecting the sensing light beam is obtained from the time of flight.

The beneficial effect of this application:

compared with the deflection of the sensing light beam realized by a mechanical rotation scheme and a mixed solid-state scheme, the deflection of the sensing light beam in the second deflection angle range is realized by the pure solid-state light source module and the light beam deflection module

The quasi-continuous deflection inside has the advantages of better reliability and compact size without depending on the rotation and vibration of components.

Drawings

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

Fig. 1 is a schematic diagram of functional modules of an electronic device according to an embodiment of the present disclosure.

Fig. 2 is a schematic diagram of functional modules of an embodiment of the photodetection device in fig. 1.

Fig. 3 is a schematic diagram of a statistical histogram obtained by the processing circuit of fig. 2.

Fig. 4 is a schematic structural diagram of the transmitting module in fig. 2.

Fig. 5 is a schematic structural diagram of the light source module in fig. 4.

Fig. 6 is a schematic view illustrating a divergence angle of a light beam emitted from the light source module shown in fig. 4.

Fig. 7 is a schematic structural diagram of an embodiment of the light source shown in fig. 5.

Fig. 8-9 are schematic structural views of different embodiments of the light source module shown in fig. 4.

Fig. 10 is a schematic structural diagram of an LCPG element in the beam deflection module shown in fig. 4.

Fig. 11-12 are schematic diagrams illustrating the deflection of the light beam when LCPG slices with different grating vector directions in the LCPG unit of fig. 10 are cascaded.

Fig. 13 is a schematic structural diagram of a binary cascaded LCPG unit according to an embodiment of the present application.

Fig. 14 is a schematic diagram of the relationship between the voltage control and the deflection angle of the two-value cascaded LCPG unit shown in fig. 13.

Fig. 15 is a schematic structural diagram of a binary-like concatenated LCPG slice according to an embodiment of the present application.

Fig. 16 is a schematic diagram illustrating the relationship between the voltage control and the deflection angle of the binary-like cascaded LCPG slices illustrated in fig. 15.

Fig. 17 is a schematic structural diagram of a ternary cascaded LCPG unit according to an embodiment of the present application.

Fig. 18 is a schematic diagram of the relationship between the voltage control and the deflection angle of the three-valued cascaded LCPG cells shown in fig. 17.

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

Fig. 20 is a schematic diagram illustrating the relationship between the voltage control and the deflection angle of the passive LCPG unit of the binary cascade in fig. 19.

Fig. 21 is a schematic structural diagram of a beam deflection module including two LCPG element groups with different scanning directions according to an embodiment of the present application.

Fig. 22 is a schematic structural diagram of the beam expansion module in fig. 4 being a cylindrical concave lens.

Fig. 23 is a side view of the cylindrical concave lens of fig. 22.

Fig. 24 is a schematic structural diagram of the beam expansion module in fig. 4 being a cylindrical convex lens.

Fig. 25 is a side view of the cylindrical convex lens of fig. 24.

Fig. 26 is a schematic structural diagram of another embodiment of the transmitter module shown in fig. 2.

Fig. 27 is a timing diagram of signals detected by the photodetection device according to an embodiment of the present application.

Fig. 28 is a schematic view of a photoelectric detection device provided in an embodiment of the present application as an automotive lidar.

Fig. 29 is a flowchart illustrating steps of a three-dimensional information detection method according to an embodiment of the present application.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application. In the description of the present application, it is to 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 implying any order or number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In the description of the present application, it should be noted that, unless explicitly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; either mechanically or electrically or in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship or combination of two or more elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

The following disclosure provides many different embodiments, or examples, for implementing different features of the application. In order to simplify the disclosure of the present application, only the components and settings of a specific example are described below. Of course, they are merely examples and are not intended to limit the present application. Moreover, the present application may repeat reference numerals and/or letters in the various examples, such repeat use is intended to provide a simplified and clear description of the present application and may not in itself dictate a particular relationship 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 only examples of implementing the technical solutions of the present application, but one of ordinary skill in the art should recognize that the technical solutions of the present application can 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. One skilled in the relevant art will recognize, however, that the subject technology can be practiced without one or more of the specific details, or with other structures, components, and so forth. In other instances, well-known structures or operations are not shown or described in detail to avoid obscuring the focus of the application.

Embodiments of the present application provide an emission module configured to emit a sensing light beam into a detection range to perform three-dimensional information detection on an object in the detection range. The transmitting module comprises a light source module and a first light beam deflection module. The light source module is configured to emit a light beam and deflect the emitted light beam within a first deflection angle range. The first light beam deflection module is configured to deflect the light beams emitted by the light source module by different preset deflection angles respectively at a plurality of moments so as to form sensing light beams with different emergent directions within a second deflection angle range. The first light beam deflection module deflects a plurality of preset deflection angles of light beams to form an arithmetic progression according to a preset first angle interval, and the first deflection angle range is larger than or equal to the first angle interval.

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, and light beams emitted by the light sources are emitted along corresponding preset emission directions after passing through the projection lens to form light beams emitted by the light source module. The light source module lights the light sources at different positions on the focal plane of the projection lens by addressing so as to correspondingly form 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 along a preset emission direction within the first deflection angle range, where the optical deflection device may be a liquid crystal on silicon phased array or an acousto-optic deflection crystal.

Optionally, in some embodiments, the transmitting module further includes:

a beam splitting device configured to split the light beam emitted by the light source module into a first light beam and a second light beam, wherein the first light beam is deflected by the first beam deflection module to form a sensing light beam within the second deflection angle range; and

the second light beam deflection module is configured to deflect the second light beam by different preset deflection angles respectively at a plurality of moments so as to form sensing light beams with different emergent directions in a third deflection angle range;

the plurality of preset deflection angles of the light beam deflected by the second light beam deflection module are in an arithmetic progression relation at preset second angle intervals, and the range of the first deflection angle is larger than or equal to the second angle intervals.

Optionally, in some embodiments, the beam splitting device is a liquid crystal polarization grating, the light beam emitted by the light source module is unpolarized light, and the first light beam and the second light beam split by the liquid crystal polarization grating are circularly polarized light; or alternatively

The beam splitting device is a polarization beam splitter, the light beam emitted by the light source module is non-polarized light, and the first light beam and the second light beam split by the polarization beam splitter are linearly polarized light.

Optionally, in some embodiments, the beam deflection module includes at least one liquid crystal polarization grating, and the beam deflection module correspondingly controls a preset deflection angle of the light beam after passing through the liquid crystal polarization grating by changing a diffraction state of the light beam passing through the liquid crystal polarization grating.

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

Optionally, in some embodiments, the beam deflection module includes a plurality of liquid crystal polarization grating units sequentially arranged along the exit 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 liquid crystal polarization grating plate gradually increases the deflection angle of the passing light beam by a natural number power of two in the sequence of sequentially arranging along the exit 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 beam deflection module includes a plurality of liquid crystal polarization grating units sequentially arranged along the exit 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 liquid crystal polarization grating plate to the passing light beam is gradually increased by three natural numbers according to the sequence sequentially arranged along the exit direction of the light beam, and the value of the natural number is that the serial number of the liquid crystal polarization grating plate is decreased by one.

Optionally, in some embodiments, the light beam deflection module includes a liquid crystal half-wave plate and a plurality of liquid crystal polarization grating plates, which are sequentially arranged along the exit direction of the light beam, and the deflection angles of the liquid crystal polarization grating plates to the light beam gradually increase according to the sequence of sequentially arranging along the exit 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 gradually increases by two natural numbers in the sequence of sequentially arranging along the exit direction of the light beam, and the value of the natural number is that the serial number of the liquid crystal polarization grating plate is decreased by one.

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

Optionally, in some embodiments, the liquid crystal polarization grating sheet is a passive liquid crystal polarization grating sheet which is not provided with an electrode and cannot be applied with a voltage, and the passive liquid crystal polarization grating sheet deflects a passing light beam.

The embodiment of the present application further provides a photoelectric detection apparatus, which includes the above-mentioned transmitting module, further includes a receiving module and a processing circuit. The receiving module is configured to sense a light signal from within a detection range and output a corresponding light-induced signal, and the processing circuit is configured to analyze and process the light-induced signal to obtain three-dimensional information of an object within the detection range.

Embodiments of the present application also provide an electronic device, which includes the photodetection apparatus as described above. And 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-phone, car, robot, entrance guard/monitored control system, intelligent lock, unmanned aerial vehicle etc.. The three-dimensional information is, for example: proximity information, depth information, distance information, coordinate information, and the like of the object within the detection range. The three-dimensional information may be used in the fields of 3D modeling, face recognition, automatic driving, machine vision, monitoring, unmanned aerial vehicle control, augmented Reality (AR)/Virtual Reality (VR), instant positioning and Mapping (SLAM), object proximity determination, and the like, for example, and the present application does not limit the present invention.

The photoelectric detection device may be, for example, a laser radar, and may be used to obtain three-dimensional information of an object in a detection range. The laser radar is applied to the fields of intelligent piloted vehicles, intelligent piloted airplanes, 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 to obtain point cloud data reflecting the appearance, position and motion conditions of one or more objects in the surrounding environment. Specifically, the lidar emits a laser beam to the surrounding environment, receives an echo beam reflected by each object in the surrounding environment from the laser beam, and determines distance/depth information of each object by calculating a time delay (i.e., time of flight) between the emission time of the laser beam and the return time of the echo beam. Meanwhile, the laser radar can also determine angle information describing the orientation of the detection range of the laser beam, combine the distance/depth information of each object with the angle information of the laser beam to generate a three-dimensional map including each object in the scanned surrounding environment, and can guide the intelligent driving of the unmanned vehicle by using the three-dimensional map.

An embodiment of the present application provides a three-dimensional information detection method, which is applicable to the photoelectric detection apparatus or the electronic device, and the three-dimensional information detection method includes: controlling the deflection angle of the light beam passing through the light beam deflection module; controlling the light source module to emit light beams, and controlling the light source module to deflect the emitted light beams within a preset first deflection angle range according to preset deflection accuracy on the basis that the emitted light beams are deflected by a preset angle through the light beam deflection module; sensing an optical signal from within the detection range and recording a time of receipt of the sensed optical signal; and analyzing and processing the received time data of the sensed optical signal to obtain the flight time of the sensing light beam reflected from the detection range, and obtaining the three-dimensional information of the object reflecting the sensing light beam according to the flight time.

Optionally, in some embodiments, when the emitted light beams are deflected within a preset first deflection angle range, the sensing light beams may be emitted along other deflection angles within the first deflection angle range in an interval of two adjacent emitted sensing light beams along one of the emission angles.

Hereinafter, an embodiment in which the photodetecting device is applied to the electronic apparatus will be described in detail with reference to the drawings.

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

Referring to fig. 1 and 2, the electronic device 1 comprises a photodetection means 10. The photodetection device 10 can detect the object 2 within a detection range, which can be defined as a three-dimensional space range in which the photodetection device 10 can effectively detect three-dimensional information, and can also be referred to as a field angle of the photodetection device 10, to obtain three-dimensional information of the object 2. 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 execute a preset operation or implement a corresponding function according to a detection result of the photodetection apparatus 10, such as but not limited to: whether the object 2 appears in a preset detection range in front of the electronic device 1 can be judged according to the proximity information of the object 2; or, the movement of the electronic device 1 may 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 according to depth information of the surface of the object 2. The electronic device 1 may further include a storage medium 30, and the storage medium 30 may provide support for storage requirements of the photodetecting apparatus 10 during operation.

Alternatively, in some embodiments, the photodetection device 10 may be a dToF measurement device that performs three-dimensional information sensing based on the direct Time of Flight (dToF) principle. The dToF measuring device 10 can emit a sensing beam in a detection range and receive the sensing beam reflected by an object 2 in the detection range, and the sensing beam reflected backThe time difference between the emission instant and the reception instant is called the time of flight t of the sensing beam, and by calculating half the distance traveled by the sensing beam during the time of flight t, three-dimensional information of the object 2 can be obtained

Where c is the speed of light.

Alternatively, in some other embodiments, the photodetection device 10 may also be an indiect Time of Flight (iToF) measurement device 10 that performs three-dimensional information sensing based on an 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 between when the sensing beam is emitted and when it is received by being reflected back.

In the following embodiments of the present application, the photoelectric detection device 10 is mainly described as a dtofs 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 emitting module 12 is configured to emit a sensing beam into the detection range to detect the three-dimensional information of the object 2 in the detection range, wherein a part of the sensing beam is reflected by the object 2 and returns, 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 an optical signal from the detection range and output a corresponding optical sensing signal, and the three-dimensional information detection of the object 2 in the detection range can be realized by analyzing the optical sensing signal. It is understood that the optical signal sensed by the receiving module 14 may be photons, such as photons including sensing beams reflected by the object 2 within the detection range and ambient light within the detection range. The processing circuit 15 is configured to analyze and process the light sensing signal to obtain a time when the sensing light beam is sensed by the receiving module 14, and obtain three-dimensional information of the object 2 according to a time difference between an emission time of the sensing light beam and a time when the sensing light beam is reflected back to be sensed.

The processing circuit 15 may be arranged on the photo detection means 10. Optionally, in some other embodiments, all or a part of the functional units of the processing circuit 15 may also be disposed on the electronic device 1.

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

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

Referring to fig. 2 and fig. 3 together, fig. 3 is a schematic diagram of the statistical histogram obtained by the processing circuit 15 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 obtaining unit 156, and a three-dimensional information obtaining unit 158.

The timing unit 152 is configured to determine a receiving time when the receiving module 14 senses the optical signal. The photo-detection device 10 emits multiple sensing light beams through the emitting module 12 during the detection process, the timing unit 152 starts timing from each emitting of the sensing light beam by the emitting module 12 to record the receiving time of the light signal sensed by the receiving module 14 between two adjacent emitting of the sensing light beams, during which the receiving module 14 outputs a corresponding photo-sensing signal every time a light signal is received, and the timing unit 152 records the receiving time of the sensed light signal according to the photo-sensing signal output by the receiving module 14 and counts in a time bin corresponding to the receiving time. The time binning is a minimum time unit Δ t for the timing unit 152 to record the light sensing signal generation time, and can reflect the accuracy of time recording of the light signal by the timing unit 152, and the finer the time binning is, the higher the accuracy of the recording time is. Optionally, 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 optical signal according to the optical sensing signal generated by the corresponding photosensitive pixel 142. Optionally, in some embodiments, the timing unit 152 may include a count memory 1524, the count memory 1524 has a count storage space correspondingly allocated according to time bin, and each time the TDC1522 records the receiving time of one optical signal, the count storage space of the corresponding time bin is cumulatively increased by one.

The statistical unit 154 is configured to count the optical signal counts accumulated in each time bin to obtain a statistical histogram reflecting the distribution of the receiving time of the plurality of optical signals sensed by the receiving module 14. The abscissa of the statistical histogram represents the timestamp of each corresponding time bin, and the ordinate of the statistical histogram represents the optical signal count value accumulated in each corresponding time bin. Optionally, the statistical unit 154 may include a histogram circuit 1544, the histogram circuit 1544 configured to count the light signal counts within each time bin to generate a statistical histogram. It should be understood that the statistical unit 154 performs statistical analysis on the corresponding accumulated light signal counts of the sensing light beams emitted multiple times in a detection frame, and in order to make the counts mathematically statistically significant, the emission times of the sensing light beams in a detection frame can be as many as thousands, tens of thousands, hundreds of thousands or even millions.

In the sensing process, a large number of photons of the ambient light are also sensed by the receiving module 14 to generate a corresponding light signal count. The probability that photons of these ambient light are sensed and left to count in each time bin tends to be the same, constituting a Noise floor (Noise Level) within the detection range, which is relatively high in the scenes with high ambient light intensity and relatively low in the scenes with low 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 background, so that the optical signal count in the time bin corresponding to the sensing light beam sensed moment is obviously higher than the optical signal counts of other time bins, and a prominent signal peak is formed. It is understood that the height of the signal peak count value is influenced by the optical power of the sensing beam, the reflectivity of the object 2, the detection range of the photo-detection device 10, etc., and the width of the signal peak is influenced by the pulse width of the emitted sensing beam, the time jitter of the photoelectric conversion element of the receiving module 14 and the TDC1522, etc. Thus, the time-of-flight acquisition unit 156 can obtain the time-of-flight of the associated sensing beam reflected back 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 associated sensing beam that generated 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 according to the time of flight of the sensing light beam determined by the statistical histogram, for example: the distance between the object 2 in the detection range and said photo detection means 10.

It should be understood that the emitting module 12 and the receiving module 14 are adjacently disposed side by side, the light emitting surface of the emitting module 12 and the light incident surface of the receiving module 14 both face the same side of the photodetection device 10, and a range of a distance between the emitting module 12 and the receiving module 14 may be, for example, 2 millimeters (mm) to 20mm. Because the emitting module 12 and the receiving module 14 are relatively close to each other, although the emitting path of the sensing beam from the emitting module 12 to the object 2 and the returning path of the sensing beam from the object 2 to the receiving module 14 after reflection are not completely equal, both paths are far larger than the distance between the emitting module 12 and the receiving module 14, and may be considered to be approximately equal. Thus, 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 said 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 transmitting module 12 includes a light source module 122 and a beam deflecting 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 beam emitted from the light source module 122 by corresponding different preset deflection angles at a plurality of time instants to form a sensing light beam with a plurality of different emission directions. The preset deflection angles of the beam deflection module 124 form an arithmetic progression according to a preset angle interval, the angle interval can be regarded as an angle tolerance of the arithmetic progression, 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 deflecting device 123, the light sources 121 are configured to emit light beams, and the optical deflecting device 123 is configured to deflect the light beams emitted from the light sources 121 within the first deflection angle range phi with a preset deflection accuracy.

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 light beams emitted by the light sources 121 are emitted in corresponding preset directions after passing through the projection lens 123 to form 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 has a corresponding relationship with the position of the light source 121 on the focal plane of the projection lens 123. Thus, 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 form light beams deflected between different preset emission directions within the first deflection angle range phi. It should be understood that, for convenience of illustration, only the light rays emitted from the light source 121 through the optical center of the projection lens 123 in the light beam are 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 one or more light emitting units 120 as the same light source 121 emit light simultaneously, and the emitted light beams serve as light beams 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 (VCSEL, or Vertical Cavity Surface Emitting Laser), an Edge Emitting Laser (EEL), a 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 (DFB) laser, an Electro-absorption Modulated (EML) laser, and the like, which is not limited in the embodiment of the present application.

Specifically, if the light emitting hole size of each light emitting unit 120 is

The distance between the corresponding edges of the light emitting holes of two adjacent light emitting units 120 is

Each group of light sources 121 includes n light emitting units 120, and the size of each group of light sources

Distance between centers of two adjacent groups of light sources 121

. The light beam deflection accuracy of the light source module 122 within the first deflection angle range phi may be defined as an angle difference between preset directions of the light beams emitted by two adjacent groups of light sources 121, and if the focal length of the projection lens 123 is f, the deflection accuracy of the light beam emitted by the light source module 122 is defined as

The beam divergence angle of the single light source 121 after being deflected by the projection lens 123

. The first deflection range phi of the light beam emitted by the light source module 122 is determined by the light beam deflection precision and the number of the light sources 121. Since the 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 accordingly. Taking the light emitting unit 120 as a VCSEL as an example, the size of each light source 121

，

The deflection accuracy δ and the divergence angle α of the deflected beam are both determined by the focal length f of the projection lens 123. For example, if deflection accuracy is required

The focal length of the projection lens 123

A beam divergence angle of the light beam emitted from the light source 121 after the light beam is deflected by the projection lens 123

. If the first deflection range is required to be reached

Then 20 light sources 121 need to be arranged in the light source module 122. Therefore, it can be seen that the VCSEL array with the common semiconductor substrate 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 also be arranged in a non-equidistant preset pattern, and the corresponding relationship between the arrangement positions of the light sources 121 and the preset emission directions of the emitted light beams is determined through design and calibration. However, the present application is not limited to this, and it is only necessary that the light source module 122 can correspondingly deflect the preset emitting direction of the emitted light beam by addressing and changing the position of the illuminated light source 121.

Alternatively, in some embodiments, if the divergence angle of the light beam emitted by the light emitting unit 120 is too large, the directivity of the light beam deflected by the projection lens 123 may be reduced, and the diameter of the light beam may need to be reduced before the light beam enters the projection lens 123. As shown in fig. 8 and 9, in some embodiments, the light source module 122 may further include a converging lens 125, and the converging lens 125 is configured to converge the light beam to reduce the divergence angle of the light beam emitted by the light source 121.

As shown in fig. 8, the condensing lens 125 may be a micro lens array disposed between the light source 121 and the projection lens 123, the micro lens array including a plurality of micro lens units. Alternatively, the microlens unit may be disposed 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 some other embodiments, the converging lens 125 may also be a cylindrical lens, and the converging lens 125 is disposed behind the projection lens 123 in the emitting direction of the light beam. That is, the condensing 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 condensing lens 125. The condensing lens 125 may condense a divergence angle of the light beam deflected by the projection lens 123 to improve directivity of the light beam emitted from the light source module 122.

Alternatively, in some other embodiments, the optical deflecting device 123 may be a liquid crystal on silicon (LCOS-OPAs) phased array or an acousto-optic deflecting crystal, which is not particularly limited in this application, as 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 the preset deflection accuracy δ.

As shown in fig. 10, the beam deflecting module 124 includes at least one Liquid Crystal Polarization Grating (LCPG) sheet 127. The LCPG sheet 127 is configured to diffract the light beams incident in different polarization states into different diffraction statesThe deflection angle corresponding to the order. The beam deflection module 124 correspondingly controls the deflection angle of the LCPG plate 127 to the passing light beam by changing the diffraction state of the light beam passing through the LCPG plate 127 and/or the polarization state of the light beam when the light beam is incident on the LCPG plate 127. Alternatively, the beam deflection module 124 may correspondingly change the diffraction state of the LCPG sheet 127 on the passing light beam by changing the polarization state of the light beam when the light beam is incident on the LCPG sheet 127 and/or by changing the orientation of liquid crystals in the LCPG sheet by applying a voltage. For example, when the incident light beam is circularly polarized light and the phase retardation of the LCPG sheet 127 is

The polarization state of the incident light beam and the phase delay amount of the LCPG plate 127 can be set, so that the diffracted light beam formed after passing through the LCPG plate 127 is switched among the deflection angles corresponding to the zero order, the positive order and the negative order of the grating, and the deflection angle corresponding to each diffraction order is determined by the period of the LCPG plate 127.

Alternatively, the polarization state of the light beam incident on the LCPG plate 127 may be controlled by disposing a liquid crystal half-wave plate 128. Specifically, for example: one right-handed circularly polarized light beam is changed into left-handed circularly polarized light after passing through a liquid crystal half-wave plate 128 without voltage, and is diffracted to the positive level and changed into right-handed circularly polarized light after passing through an LCPG plate 127; applying a saturation voltage to the liquid crystal half-wave plate 128 to enable the liquid crystal half-wave plate to not change the polarization state of the passing light beam, wherein the right-handed circularly polarized light is still right-handed circularly polarized light after passing through the liquid crystal half-wave plate 128, and is diffracted to a negative level and changed into left-handed circularly polarized light after passing through the LCPG plate 127; after applying a saturation voltage to the LCPG patch 127, the light beam will be diffracted to the zero order, i.e., the propagation direction and polarization state of the light beam will not be changed after passing through the LCPG patch 127. Therefore, by changing the polarization state of the light beam incident to the LCPG plate 127 by adjusting the liquid crystal half wave plate 128 and changing the diffraction state of the LCPG plate 127 by applying a voltage to the LCPG plate 127, the light beam passing through the LCPG plate 127 can be correspondingly deflected to deflection angles corresponding to three diffraction orders of zero order, positive order, and negative order. Thus, in some embodiments, the beam deflection module 124 may include LCPG cells 129, one LCPG cell 129 including one liquid crystal half-wave plate 128 and one LCPG plate 127, to achieve three discrete deflection angles. The deflection angle of the single LCPG patch 127 can be determined by the grating equation:

(1)

wherein the content of the first and second substances,

in the case of the wavelength of the incident light,

m =1,0, -1,

respectively representing the angle of incidence and the angle of emergence of the light beam.

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

When the plurality of LCPG units 129 are cascaded, the influence of the grating vector direction of the LCPG pieces 127 on the deflection of the light beam can be considered, and the LCPG pieces 127 with different grating vector directions have different deflection directions on the light beams with the same polarization state. For example: the LCPG piece 127 having a first grating vector direction deflects the incident left-handed circularly polarized light by a deflection angle corresponding to a plus one diffraction order, whereas the LCPG piece 127 having a second grating vector direction opposite to the first grating vector direction deflects the incident left-handed circularly polarized light by a deflection angle corresponding to a minus one diffraction order. Therefore, a cascade mode of deflecting light beams in different directions can be obtained by matching the grating vector directions of the LCPG plates 127, as shown in fig. 11, if the grating vector directions of the two LCPG plates 127 are the same, when a circularly polarized light beam passes through the two LCPG plates 127, because the LCPG plates 127 change the polarization state of the passed light beam, the deflection direction of the passed light beam by the next LCPG plate is opposite to the deflection direction of the passed light beam by the previous LCPG plate 127, and the total deflection angle of the light beam passing through the two LCPG plates 127 is the difference of the deflection angles of the two LCPG plates 127. As shown in fig. 12, if the grating vector directions of the two LCPG pieces 127 are opposite, when the circularly polarized light passes through the two LCPG pieces 127, the deflection direction of the light beam by the next LCPG piece 127 is the same as the deflection direction of the light beam by the previous LCPG piece 127, and the total deflection angle of the light beam after passing through the two LCPG pieces 127 is the sum of the deflection angles of the two LCPG pieces 127. Thus, when a plurality of LCPG pieces 127 are cascaded, a plurality of different deflection angles to the light beams can be obtained by setting the grating vector direction of each LCPG piece 127, so that the deflection angles to the light beams can be controlled in a mode that the plurality of LCPG pieces 127 are cascaded, and the flexibility is higher. It should be understood that the grating vector direction of the LCPG piece 127 depends on the alignment direction of the liquid crystal molecules in the LCPG piece 127.

Alternatively, as shown in fig. 13, in some embodiments, the plurality of liquid crystal half-wave plates 128 and the LCPG plate 127 of the beam deflection module 124 may be in a binary cascade manner. The light beam deflection module 124 comprises a plurality of LCPG units 129 sequentially arranged along the emitting direction of the light beam, each LCPG unit 129 comprises a liquid crystal half-wave plate 128 and an LCPG plate 127, the deflection angle of the LCPG plate 127 to the light beam is gradually increased by two natural number powers according to the sequence of sequentially arranging along the emitting direction of the light beam, and the value of the natural number is that the sequence number of the LCPG unit 129 is decreased by one. Correspondingly, the deflection angle of the light beam passing through the light beam deflection module 124 is a multiple of the minimum deflection angle of the LCPG piece 127 to the light beam passing through, and the power of the sequence number of the LCPG unit 129 with the multiple being two is reduced by one.

Specifically, if the beam deflection module 124 includes M LCPG cells 129, each LCPG cell 129 includes a liquid crystal half-wave plate 128 and an LCPG plate 127. The M LCPG units 129 are sequentially arranged along the emitting direction of the light beam, and the deflection angles of the light beam are gradually increased by two natural powers in the sequential arrangement order. That is, the first LCPG cell 129 closest to the light source module 122 is for the passing light beamThe deflection angle is the smallest, and the deflection angle of the last LCPG unit 129 farthest from the light source module 122 to the passing light beam is the largest, 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 along the emitting direction of the light beam to the passing light beam are sequentially respectively r

. Correspondingly, the whole beam deflection module 124 including the M LCPG units 129 can deflect the passing beam by the preset deflection angles in turn

It can be seen that the preset deflection angle of the light beam provided by the light beam deflection module 124 is a multiple of the minimum deflection angle r of the single LCPG unit 129 to the passing light beam, the multiple is a natural number, the maximum value of the natural number is M times of two minus one, and M is the number of the LCPG units 129 included in the light beam deflection module 124. The angle interval between the preset deflection angles of adjacent orders is r, that is, the light beam deflection module 124 distributes the preset deflection angles of the passing light beam in an arithmetic progression according to a preset angle interval, the angle interval can be regarded as the angle tolerance of the arithmetic progression, and the deflection precision of the passing light beam is r. Therefore, the beam deflection module 124 based on the cascade connection of the binary LCPG units 129 deflects the second deflection angle range of the passing light beam

And the total number of different deflection angles that can be provided

The relational expression of (1) is:

(2)

(3)

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

In use, the change in the polarization state of the passing light beam by the liquid crystal half-wave plate 128 can be controlled by applying a voltage to the liquid crystal half-wave plate 128 in the LCPG cell 129. For example, the liquid crystal half-wave plate 128 applied with a saturation voltage does not change the polarization state of the passing light beam, and the liquid crystal half-wave plate 128 applied with no voltage changes the polarization state of the passing light beam, such as: and changing the left-handed circularly polarized light into right-handed circularly polarized light. In addition, the diffraction state of the LCPG piece 127 in the LCPG unit 129 to the passing light beam can be controlled by applying a voltage thereto. For example, the LCPG piece 127 applied with the saturation voltage does not act on the passing light beam, that is, the propagation direction of the light beam passing through the LCPG piece 127 applied with the saturation voltage does not change, corresponding to the zero-order diffraction of the passing light beam by the LCPG piece 127. The LCPG sheet 127 not applied with voltage deflects the passing light beam by a predetermined deflection angle, and the deflection direction is related to the polarization state of the incident light beam and the grating vector direction of the LCPG sheet 127. Since the grating vector direction of the same LCPG plate 127 remains unchanged, that is, for the same LCPG cell 129, different polarization states of the light beam incident on the LCPG plate 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 toward different directions symmetrically distributed with respect to the incident direction, which correspond to the positive-order diffraction and the negative-order diffraction of the passing light beam by the LCPG plate 127, respectively.

Fig. 14 is a schematic diagram showing the relationship between the voltage control of the binary cascaded LCPG cell 129 and the deflection angle of the passing light beam, and the shaded area in fig. 14 indicates that the saturation voltage is applied to the corresponding liquid crystal half-wave plate 128 and LCPG plate 127, and the liquid crystal half-wave plate 128 and LCPG plate 127 do not act on the passing light beam at this time. The white areas indicate that the saturation voltages applied to the liquid crystal half-wave plates 128 and the LCPG plates 127 are turned off, the corresponding liquid crystal 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. In fig. 14, the beam deflection module 124 is exemplarily shown to include 5 LCPG cells 129 in binary cascade, each LCPG cell 129 includes a liquid crystal half-wave plate 128 and a LCPG plate 127, which are sequentially labeled as: the liquid crystal half-wave plates I and LCPG plates I, the liquid crystal half-wave plates II and LCPG plates II, the liquid crystal half-wave plates III and LCPG plates III, the liquid crystal half-wave plates IV and LCPG plates IV and the liquid crystal half-wave plates V and LCPG plates V, and the LCPG plates I-V have the same grating vector direction. The deflection angles of the LCPG pieces I-V to the light beam sequentially increase gradually to the power of two natural numbers, and the values of the natural numbers are r, 2r, 4r, 8r and 16r sequentially corresponding to the serial number of the LCPG unit 129 in which the LCPG piece I-V is located minus one. Referring to fig. 13 and 14, if the beam incident in the horizontal direction is 0 degree, the beam is deflected to the left by a positive angle and deflected to the right by a negative angle to establish a reference system, and the beam passes through the beam deflection module 124 to maintain the 0 degree direction, a saturation voltage is applied to the liquid crystal half-wave plates I-V and the LCPG plates I-V of all the LCPG cells 129 so as not to change the direction of the passing beam; if the light beam needs to deflect + r through the light beam deflection module 124, the voltage of the LCPG plate I is turned off to deflect the light beam + r, and saturation voltage is applied to the subsequent liquid crystal half-wave plates II-V and the LCPG plates II-V to maintain the angle of the light beam deflection + r; if the light beam needs to deflect +3r through the light beam deflection module 124, the voltage of the LCPG plate I needs to be turned off to deflect the light beam + r, the polarization state of the light beam is changed while the light beam is deflected through the LCPG plate I, the polarization state of the light beam passing through the LCPG plate I 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, the light beam deflected + r needs to be deflected again by +2r to obtain a deflection angle of +3r by turning off the saturation voltage applied to the LCPG plate II, and the saturation voltage is applied to the subsequent liquid crystal half-wave plates III-V and the LCPG plates III-V to maintain the angle of +3r for the light beam deflection. In analogy, the beam deflecting module 124 may also deflect the passing light beam by other preset deflection angles through the voltage applying manner as shown in fig. 14.

It should be understood that the beam deflection module 124 shown in fig. 13 and 14 can also deflect the light beam by an angle corresponding to-r to-7 r, and the polarization state of the light beam when the light beam is incident on the beam deflection module 124 needs to be changed or the polarization state of the light beam when the light beam passes through the LCPG plates 127 to which no voltage is applied needs to be adjusted by changing the voltage applied to the liquid crystal half-wave plate 128.

It should be understood that, according to the diffraction characteristics of the LCPG pieces 127, the polarization state of the incident light beam may be left-handed circularly polarized light or right-handed circularly polarized light, depending on the grating vector direction of the LCPG pieces 127 and the predefined deflection direction. The circularly polarized light can be generated by linearly polarized light or unpolarized light, and if the light beam emitted by the light source module 122 is linearly polarized light, the light beam can be changed into circularly polarized light by a quarter-wave plate; if the light emitted from the light source module 122 is unpolarized light or partially polarized light, the light may be first converted into linearly polarized light by a polarizer and then converted into circularly polarized light by a quarter-wave plate. Accordingly, 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 be corresponding circularly polarized light.

Alternatively, as shown in fig. 15, in some embodiments, the liquid crystal half-wave plate 128 and the LCPG plates 127 of the beam deflection module 124 may be cascaded in a binary-like manner. The light beam deflection module 124 comprises a liquid crystal half-wave plate 128 and a plurality of LCPG plates 127 which are sequentially arranged along the emergent direction of the light beam, the deflection angles of the LCPG plates 127 to the light beam are gradually increased step by step according to the sequence of sequentially arranging along the emergent direction of the light beam, the difference between the deflection angle of one LCPG plate 127 and the deflection angle of the adjacent previous LCPG plate 127 to the light beam is gradually increased step by step according to the power of a natural number which is two according to the sequence of sequentially arranging along the emergent direction of the light path, and the value of the natural number is that the serial number of the LCPG plate 127 is decreased by one. Correspondingly, the deflection angle of the light beam passing through the light beam deflection module 124 is a multiple of the minimum deflection angle of the LCPG piece 127 to the light beam passing through, and the multiple is a power of the serial number of the LCPG piece 127 which takes a value of two and then is reduced by one.

In particular, the beam deflection module 124, which is binary-like cascaded, includes one 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 plates 127 in the exit direction of the light beam,the M LCPG pieces 127 are sequentially arranged along the emitting direction of the light beam and gradually increase the deflection angle of the passing light beam step by step according to the sequentially arranged sequence. That is, the deflection angle of the first LCPG piece 127 closest to the light source module 122 to the passing light beam is the smallest, and the deflection angle of the last LCPG piece 127 farthest from the light source module 122 to the passing light beam is the largest, and assuming that the deflection angle of the first LCPG piece 127 to the passing light beam is r, the deflection angles of the M LCPG pieces 127 to the passing light beam sequentially arranged along the exit direction of the light beam are respectively:

. The difference between the deflection angles of one of the LCPG pieces 127 and the adjacent previous LCPG piece 127 to the light beam is sequentially arranged along the exit direction of the light beam in the following order:

that is, the natural number is gradually increased to the power of two, and the value of the natural number is the number of the LCPG piece 127 minus one. Correspondingly, the whole beam deflection module 124 including the M LCPG pieces 127 can deflect the passing beam by the preset deflection angles in turn

It can be seen that the preset deflection angle of the light beam provided by the light beam deflection module 124 is a multiple of the minimum deflection angle r of the single LCPG piece 127 to the passing light beam, the multiple is a natural number, the maximum value of the natural number is two to the M power, and then is reduced by one, and M is the number of the LCPG pieces 127 included in the light beam deflection module 124. The angle interval between the preset deflection angles of adjacent orders is r, that is, the light beam deflection module 124 distributes the preset deflection angles of the passing light beam in an arithmetic progression according to the preset angle interval, the deflection precision of the passing light beam is r, and the angle interval r can be regarded as the angle tolerance of the arithmetic progression. Therefore, the light beam deflection module 124 based on the cascade connection of the binary-like LCPG pieces 127 can deflect the passing light beam in the second angle range

And the total number of different deflection angles that can be provided

The relational expression of (1) is:

(4)

(5)

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

In use, the polarization state of a light beam incident to the LCPG plate 127 can be changed by applying a voltage to the liquid crystal half-wave plate 128 in front of the LCPG plate 127. For example, the liquid crystal half-wave plate 128 applied with a saturation voltage does not change the polarization state of the passing light beam, and the liquid crystal half-wave plate 128 applied with no voltage changes the polarization state of the passing light beam, such as: and changing the left-handed circularly polarized light into right-handed circularly polarized light. In addition, the diffraction state of the LCPG sheet 127 on the passing light beam can be controlled by applying a voltage to the LCPG sheet. For example, the LCPG piece 127 applied with the saturation voltage does not act on the passing light beam, that is, the propagation direction of the light beam after passing through the LCPG piece 127 applied with the saturation voltage is not changed, which corresponds to the zero-order diffraction of the passing light beam by the LCPG piece 127. The LCPG plate 127 without voltage applied deflects the passing light beam by a predetermined deflection angle, and the deflection direction is related to the polarization state of the incident light beam and the grating vector direction of the LCPG plate 127. Because the grating vector direction of the same LCPG sheet 127 is kept unchanged, different polarization states of the light beam when the light beam 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 preset deflection angles towards different directions which are symmetrically distributed relative to the incident direction, and respectively corresponds to the positive-order diffraction and the negative-order diffraction of the LCPG sheet 127 on the passing light beam.

Fig. 16 is a schematic diagram showing a relationship between voltage control of the binary-like cascade liquid crystal half-wave plate 128 and the LCPG plate 127 and a deflection angle of a passing light beam, and a shaded area in fig. 16 indicates that a saturation voltage is applied to the corresponding liquid crystal half-wave plate 128 and the LCPG plate 127, and the liquid crystal half-wave plate 128 and the LCPG plate 127 do not act on the passing light beam at this time. The white areas indicate that the saturation voltages applied to the liquid crystal half-wave plates 128 and the LCPG plates 127 are turned off, the corresponding liquid crystal 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. Fig. 16 shows an exemplary beam deflection module 124 comprising 1 lc half-wave plate 128 and 5 LCPG plates 127 in binary-like cascade, denoted in sequence as follows in the exit direction along the light path: the liquid crystal half-wave plate I and the LCPG plate I-V are arranged in parallel, and the LCPG plate I-V has the same grating vector direction. And the deflection angles of the LCPGI-V to the light beams are sequentially increased step by step and correspond to r, 3r, 7r, 15r and 31r. Referring to fig. 15 and 16, if the beam incident in the horizontal direction is 0 degree, the beam is deflected to the left by a positive angle and deflected to the right by a negative angle to establish a reference system, and the beam passes through the beam deflection module 124 to maintain the 0 degree direction, 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 passing beam; if the light beam needs to deflect + r through the beam deflection module 124, the voltage of the LCPG patch I is turned off to deflect the light beam + r, and a saturation voltage is applied to the subsequent LCPG patch II-V to maintain the angle of the light beam deflection + r; if the light beam needs to be deflected by +2r through the light beam deflection module 124, the voltage applied to the liquid crystal half-wave plate I is turned off to change the polarization state of the incident light beam, and the voltage applied to the LCPG plate I is turned off to deflect the light beam with the polarization state changed by the liquid crystal half-wave plate I by-r. Because the light beam is deflected by the LCPG plate I and the polarization state is changed at the same time, the voltage applied to the LCPG plate II is closed, the passing light beam is deflected by +3r on the basis of the previous-r angle to obtain a total deflection angle of +2r, and meanwhile, the saturation voltage is applied to the subsequent LCPG plate III-V to maintain the angle of +2r of the deflection of the light beam. By analogy, the beam deflection module 124 can also deflect the passing beam by other preset deflection angles through the voltage application manner as shown in fig. 16.

It should be understood that the beam deflection module 124 shown in fig. 15 and 16 can also deflect the light beam by an angle corresponding to-r to-7 r, and the polarization state of the light beam when the light beam is incident on the beam deflection module 124 needs to be changed or the polarization state of the light beam when the light beam passes through the LCPG plates 127 to which no voltage is applied needs to be adjusted by changing the voltage applied to the liquid crystal half-wave plate 128.

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

Alternatively, as shown in fig. 17, in some embodiments, the liquid crystal half-wave plate 128 and the LCPG plate 127 of the beam deflection module 124 may be cascaded in a ternary manner. The light beam deflection module 124 comprises a plurality of LCPG units 129 sequentially arranged along the emergent direction of the light beam, each LCPG unit 129 comprises a liquid crystal half-wave plate 128 and an LCPG plate 127, the deflection angle of the LCPG plate 127 to the light beam is gradually increased by three natural numbers according to the sequence sequentially arranged along the emergent direction of the light beam, and the value of the natural numbers is that the sequence number of the LCPG unit 129 is decreased by one. Correspondingly, the deflection angle of the light beam by the light beam deflection module 124 is a multiple of half of the minimum deflection angle of the LCPG sheet 127 to the passed light beam, where the multiple is equal to the power of the serial number of the LCPG unit 129 that is three minus one.

Specifically, if the beam deflection module 124 includes M LCPG cells 129, each LCPG cell 129 includes a liquid crystal half-wave plate 128 and an LCPG plate 127. The M LCPG units 129 are sequentially arranged along the emitting direction of the light beam, and the deflection angles of the light beam are gradually increased by three natural powers in the sequential arrangement order. That is, the first LCPG cell 129 closest to the light source module 122 has the smallest deflection angle to the passing light beam, and the last LCPG cell 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 cell 129 to the passing light beam is r, the first LCPG cell 129 follows the following light beamThe deflection angles of the passing beams by the M LCPG units 129 sequentially arranged in the emergent direction are respectively

It can be seen that the preset deflection angle of the light beam provided by the light beam deflection module 124 is a multiple of half of the minimum deflection angle r of the passing light beam by a single LCPG unit 129, the multiple is a natural number, the maximum value of the natural number is three to the power of M minus one, and M is the number of the LCPG units 129 included in the light beam deflection module 124. The angle interval between the preset deflection angles of adjacent orders is r, that is, the light beam deflection module 124 distributes the preset deflection angles of the passing light beam in an arithmetic progression according to the preset angle interval, the deflection precision of the passing light beam is r, and the angle interval can be regarded as the angle tolerance of the arithmetic progression. Therefore, the beam deflection module 124 cascaded based on the ternary LCPG unit 129 deflects the passing beam in the second angle range

And the total number of different deflection angles that can be provided

The relational expression of (1) is:

(6)

(7)

In use, the change in the polarization state of the passing light beam by the liquid crystal half-wave plate 128 can be controlled by applying a voltage to the liquid crystal half-wave plate 128 in the LCPG cell 129. For example, the liquid crystal half-wave plate 128 applied with a saturation voltage does not change the polarization state of the passing light beam, and the liquid crystal half-wave plate 128 applied with no voltage changes the polarization state of the passing light beam, such as: and changing the left-handed circularly polarized light into right-handed circularly polarized light. In addition, the diffraction state of the LCPG piece 127 in the LCPG unit 129 to the passing light beam can be controlled by applying a voltage thereto. For example, the LCPG piece 127 applied with the saturation voltage does not act on the passing light beam, that is, the propagation direction of the light beam after passing through the LCPG piece 127 applied with the saturation voltage is not changed, which corresponds to the zero-order diffraction of the passing light beam by the LCPG piece 127. The LCPG plate 127 without voltage applied deflects the passing light beam by a predetermined deflection angle, and the deflection direction is related to the polarization state of the incident light beam and the grating vector direction of the LCPG plate 127. Because the grating vector direction of the same LCPG plate 127 is maintained unchanged, that is, for the same LCPG unit 129, different polarization states of the light beam incident on the LCPG plate 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 toward different directions symmetrically distributed with respect to the incident direction, which respectively correspond to the positive-order diffraction and the negative-order diffraction of the passing light beam by the LCPG plate 127.

Fig. 18 is a schematic diagram showing the relationship between the voltage control of the three-valued cascade LCPG cell 129 and the deflection angle of the passing light beam, and the shaded area in fig. 18 indicates that the saturation voltage is applied to the corresponding liquid crystal half-wave plate 128 and LCPG plate 127, and the liquid crystal half-wave plate 128 and LCPG plate 127 do not act on the passing light beam at this time. The white areas indicate that the saturation voltages applied to the liquid crystal half-wave plates 128 and the LCPG plates 127 are turned off, the corresponding liquid crystal 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. Fig. 18 shows an exemplary beam deflection module 124 comprising 4 LCPG cells 129 in a ternary cascade, each LCPG cell 129 comprising a liquid crystal half-wave plate 128 and an LCPG plate 127, denoted in order along the exit direction along the optical path: the liquid crystal half-wave plates I and LCPG plates I, the liquid crystal half-wave plates II and LCPG plates II, the liquid crystal half-wave plates III and LCPG plates III and the liquid crystal half-wave plates IV and LCPG plates IV, and the LCPG plates I-IV have the same grating vector direction. The deflection angles of the LCPG pieces I to IV to the light beam sequentially increase gradually to the power of three natural numbers, and the value of the natural number is that the serial number of the LCPG unit 129 where the natural number is located is decreased by one, and is r, 3r, 9r and 27r correspondingly. Referring to fig. 17 and 18, if the beam incident in the horizontal direction is 0 degree, the beam is deflected to the left by a positive angle and deflected to the right by a negative angle to establish a reference system, and the beam passes through the beam deflection module 124 to maintain the 0 degree direction, a saturation voltage is applied to the liquid crystal half-wave plates I-IV and the LCPG plates I-IV of all the LCPG cells 129 so as not to change the direction of the passing beam; if the light beam needs to be deflected by + r through the light beam deflection module 124, the voltage of the LCPG plate I is switched off to deflect the light beam by + r, and saturation voltages are applied to the subsequent liquid crystal half-wave plates II-IV and the LCPG plates II-IV to maintain the angle of the light beam deflection + r; if the light beam needs to deflect by +2r through the light 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 turned into the polarization state when deflected by an angle of-r through the LCPG plate I after passing through the liquid crystal half-wave plate I, and is also turned back to the polarization state when incident, and then the incident light beam is kept unchanged after passing through the liquid crystal half-wave plate II to be deflected by an angle of +2r from the angle of-r when passing through the LCPG plate II with the turned-off voltage, and meanwhile, the subsequent liquid crystal half-wave plates III-IV and LCPG plates III-IV are applied with the saturation voltage to keep the angle of +2r for the light beam deflection. In analogy, the beam deflecting module 124 may also deflect the passing beam by other preset deflection angles through the voltage applying manner as shown in fig. 18.

It should be understood that the beam deflection module 124 shown in fig. 17 and 18 can also deflect the light beam by an angle corresponding to-r to-14 r, and the polarization state of the light beam when the light beam is incident on the beam deflection module 124 needs to be changed or the polarization state of the light beam when the light beam passes through the LCPG plate 127 without voltage applied is adjusted by changing the voltage applied to the liquid crystal half-wave plate 128.

Compared with the two-value cascaded LCPG elements 129, the three-value cascaded LCPG elements 129 require fewer liquid crystal devices under the same beam deflection precision and deflection range, such as: the beam deflection range of the three-value cascaded four LCPG elements 129 shown in fig. 18 is larger than that of the two-value cascaded five LCPG elements 129 shown in fig. 14, so that the three-value cascaded LCPG elements 129 have higher beam transmittance.

It should be understood that the LCPG piece 127 in the above embodiments is an active LCPG piece 127 provided with electrodes to adjust its action on the passing light beam by applying or not applying a voltage. Optionally, in some other embodiments, the LCPG piece 127 may also be a passive LCPG piece 127 without an electrode. Since the passive LCPG piece 127 is always in a diffraction state without voltage, it deflects the passing light beam by a preset deflection angle in different directions symmetrically distributed compared to the incident direction according to the polarization state of the passing light beam, and corresponds to the positive order diffraction and the negative order diffraction of the passing light beam by the LCPG piece 127, respectively. The polarization state of the light beam passing through the passive LCPG plate 127 can be adjusted by matching a liquid crystal half-wave plate 128 on the light-incident side of the passive LCPG plate 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 plate 127. The M passive LCPG units 129 are cascaded in a binary manner, and the M passive LCPG units 129 are sequentially arranged along the emitting direction of the light beam and gradually increase the deflection angle of the light beam by two natural power degrees according to the sequential arrangement order. 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 emitting direction of the light beam are sequentially respectively r

. Correspondingly, the whole beam deflection module 124 including the M passive LCPG units 129 can deflect the passing beam by the preset deflection angles in turn

It can be seen that the beam deflection module 124 can provide a beam deflection angle that is an odd multiple of the minimum deflection angle r of a single LCPG pair passing through the beam, the maximum value of the odd number is M times two minus one, and M is the number of passive LCPG units 129 included in the beam deflection module 124. The angle interval between the preset deflection angles of adjacent orders is 2r, that is, the light beam deflection module 124 distributes the preset deflection angles of the passing light beam in an arithmetic progression according to the preset angle interval, the deflection precision of the passing light beam is 2r, and the angle interval can be regarded as the angle tolerance of the arithmetic progression. Thus, the passive LCPG unit 129 based on binary cascade has the second deflection angle range of the passing light beam

And the total number of different deflection angles that can be provided

The relational expression of (1) is:

(8)

(9)

wherein, r is the minimum deflection angle of the passing light beam among the M passive LCPG elements 129, and M is the total number of the passive LCPG elements 129 in the beam deflection module 124.

In use, the polarization state of the light beam incident on the passive LCPG plate 127 in the passive LCPG cell 129 can 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 in which the light beam is diffracted when passing through the passive LCPG plate 127. For example, if the light beam passes through the liquid crystal half-wave plate 128 to which the saturation voltage is applied and then passes through the passive LCPG plate 127 to be deflected in the direction of the positive order diffraction, the light beam passes through the liquid crystal half-wave plate 128 to which the voltage is not applied and then passes through the passive LCPG plate 127 to be deflected in the direction of the negative order diffraction. Since the light beam is diffracted through the passive LCPG plate 127 and the polarization state is also changed, if the light beam is further deflected to the same diffraction order in the next passive LCPG cell 129, the voltage applied to the liquid crystal half-wave plate 128 in the next passive LCPG cell 129 needs to be turned off so that the liquid crystal half-wave plate 128 changes the polarization state of the light beam back to the polarization state before the previous deflection; to deflect the opposite diffraction order in the next passive LCPG cell 129 requires applying a saturation voltage to the half-wave plate 128 in the next passive LCPG cell 129 without changing the polarization of the passing beam.

Fig. 20 is a schematic diagram showing the relationship between the voltage control and the deflection angle of the passing light beam of the binary cascaded passive LCPG cell 129, and the shaded area in the diagram indicates that the saturation voltage is applied to the corresponding liquid crystal half-wave plate 128, and the polarization state of the passing light beam is not changed by the liquid crystal half-wave plate 128. The white areas indicate that the saturation voltage applied to the liquid crystal half-wave plate 128 is turned off and the corresponding liquid crystal half-wave plate 128 will change the polarization state of the passing light beam. Since the LCPG plates 127 are all passive, all the passive LCPG plates 127 cannot apply a voltage, and they are deflected by a predetermined angle in a direction corresponding to the positive or negative first-order diffraction according to the polarization state of the passing light beam. Fig. 20 shows an exemplary beam deflection module 124 comprising 4 passive LCPG cells 129 in a binary cascade, each LCPG cell 129 comprising a liquid crystal half-wave plate 128 and a passive LCPG plate 127, denoted in sequence along the exit direction of the beam: the liquid crystal half-wave plate I and the passive LCPG plate I, the liquid crystal half-wave plate II and the passive LCPG plate II, the liquid crystal half-wave plate III and the passive LCPG plate III, and the liquid crystal half-wave plate IV and the passive LCPG plate IV have the same grating vector direction. The deflection angles of the passive LCPG pieces I to IV to the light beam sequentially increase gradually in a natural number power of two, and the natural number is the serial number of the LCPG unit 129 minus one, which corresponds to r, 2r, 4r and 8r.

Referring to fig. 19 and 20, if the polarization state of the light beam incident to the beam deflection module 124 causes the passive LCPG plate 127 to deflect the light beam in the direction of the positive first order diffraction and the light beam passes through the whole beam deflection module 124 to obtain the deflection angle of + r, the voltage applied 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 the polarization state, and thus the passive LCPG plate I deflects the light beam-r and simultaneously changes the polarization state of the light beam back to the polarization state of the incident light beam. Since the passive LCPG plate II and the passive LCPG plate III need to deflect the light beam to the-2 r and-4 r directions, 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 to make the light beam change the polarization state before entering the corresponding passive LCPG plate II and the passive LCPG plate III. Finally, a saturation voltage is applied to the liquid crystal half-wave plate IV to maintain the polarization state of the light beam at the time of incidence 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. By analogy, the beam deflection module 124 can also deflect the passing beam by other preset deflection angles through the voltage application manner as shown in fig. 20.

It should be understood that the beam deflection module 124 shown in fig. 19 and 20 can also deflect the passing light beam by an angle from-r to-15 r, which requires changing the voltage application condition of the liquid crystal half-wave plate I-IV at the corresponding position to adjust the polarization state of the light beam before entering the corresponding passive LCPG plate I-IV, so as to obtain the corresponding opposite deflection condition.

Compared with the active LCPG unit 129, the passive LCPG unit 129 does not need to adjust the voltage to change the liquid crystal state of the passive LCPG plate 127 in the using process, and can realize the control of the corresponding beam deflection angle only by correspondingly changing the voltage applied to the liquid crystal half-wave plate 128, so that the active LCPG unit 129 has the advantages of high response speed and simple driving program.

In order to ensure the liquid crystal molecular material in the LCPG sheet 127 can work normally, 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 element 129 within a preset temperature range. The normal working temperature range 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; when the temperature control unit 1242 is in a high temperature environment, the LCPG unit 129 is cooled.

It should be understood that a plurality of LCPG elements 129 arranged in cascade may deflect a passing beam in one dimension. To achieve deflection of the light beam in a two-dimensional plane, optionally, in some embodiments, as shown in fig. 21, the light beam deflection module 124 may include a first LCPG element group 1291 and a second LCPG element group 1292, which respectively include a plurality of LCPG elements 129 arranged in cascade. The first LCPG element group 1291 is configured to deflect the passing light beams in a preset first scanning direction, and the second LCPG element group 1292 is configured to deflect the passing light beams in a preset second scanning direction, the first scanning direction being different from the second scanning direction.

Alternatively, the first scanning direction may be perpendicular to the second scanning direction. For example: in fig. 21, an orthogonal rectangular coordinate system is established with the emitting direction of the zero-order light beam as the Y axis, the horizontal direction as the X axis, and the vertical direction as the Z axis, and then 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 is to be understood that the scanning direction refers to a changing direction in which the light beam is deflected, and is understood as a direction in which a changing tendency refers when the emitting direction of the light beam is changed, unlike the emitting direction of the light beam.

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

Thus, the beam deflection module 124 can deflect the light beam in a two-dimensional plane by providing LCPG cell groups having different scanning directions so that the sensing light beam can be irradiated to a larger detection range.

As shown in fig. 4, in some embodiments, the emission module 12 further includes a beam expansion module 126, the beam deflection module 124 deflects the passing light beam along a preset first scanning direction, and the beam expansion module 126 is configured to expand a divergence angle of the light beam along a preset second scanning direction, wherein 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, an orthogonal rectangular coordinate system is established with the emitting direction of the zero-order light beam as the Y axis, the horizontal direction as the X axis, and the vertical direction as the Z axis, and then 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 a changing direction of deflecting the light beam, and is understood to mean a direction in which a changing tendency is directed when changing the emission direction of the light beam, unlike the emission direction of the light beam.

Optionally, the beam expansion module 126 may be a beam expanding lens. The beam expander lens 126 includes an optical surface that is curved in a second scanning direction to bend the light beam passing through the beam expander lens in the second scanning direction. It is to be understood that the curvature of the optical surface in the second scanning direction can be described by the variation of the curvature of the optical surface in the predetermined direction at each of the points arranged in sequence in the second scanning direction.

As shown in fig. 22 and 23, 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 based on an orthogonal rectangular coordinate system established with the first scanning direction as an X axis, the second scanning direction as a Z axis, and the emitting direction of the zero-order sensing beam as a Y axis as a reference. The cylindrical concave lens 126 includes a light incident surface 1262 and a light emitting surface 1264 sequentially arranged along the emitting direction (i.e., the Y-axis direction) of the zero-order sensing beam. At least one of the light incident surface 1262 and the light emitting surface 1264 is an optical surface curved in the second scanning direction. Optionally, the light incident surface 1262 is a concave curved surface that is concave toward the emitting direction (i.e., the Y-axis direction) of the zero-order sensing light beam, and can be used as an optical surface of the light beam that the beam expanding lens 126 bends through. Optionally, in some embodiments, the light incident surface 1262 has a varying curvature along the second scanning direction (i.e., the Z-axis direction). 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, and as shown in fig. 23, the light incident surface 1262 is a corresponding curved section line 1265 on a cross section formed by a coordinate system YOZ plane where the point is located, and the curvature of the point refers to the curvature along the tangential direction of the point on the curved section line 1265. It should be understood that the cross-section forming the curved surface section line 1265 may also be a plane perpendicular to the first scanning direction.

Alternatively, in some embodiments, the entrance surface 1262 remains flat along a first scan direction, and the intersection between the entrance surface 1262 and a plane parallel to the first scan direction (i.e., the X-axis direction) is a straight line. That is, a line connecting 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, an intersection line between the light incident surface 1262 and a plane parallel to the first scanning direction (i.e., the X-axis direction) may also be a curve.

Alternatively, the light emitting surface 1264 may be a plane perpendicular to the emitting direction (i.e., the 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 also be a non-planar surface, or the light emitting surface 1264 may also be a planar surface that is not perpendicular to the emitting direction (i.e., the Y-axis direction) of the zero-order sensing beam.

As shown in fig. 24 and 25, 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 based on an orthogonal rectangular coordinate system established with the first scanning direction as an X axis, the second scanning direction as a Z axis, and the emitting direction of the zero-order sensing beam as a Y axis as a reference. The cylindrical convex lens 126 includes a light incident surface 1262 and a light emitting surface 1264 sequentially arranged along the emitting direction (i.e., the Y-axis direction) of the zero-order sensing light beam. At least one of the light incident surface 1262 and the light emitting surface 1264 is an optical surface curved in the second scanning direction. Optionally, the light incident surface 1262 is a convex curved surface protruding away from the emitting direction (i.e., the Y-axis direction) of the zero-order sensing light beam, and can be used as an optical surface of the light beam passing through the bending of the beam expanding lens 126. Optionally, in some embodiments, the light incident surface 1262 has a varying curvature along the second scanning direction (i.e., the Z-axis direction). 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, and as shown in fig. 25, the light incident surface 1262 is a corresponding curved section line 1265 on a cross section formed by a coordinate system YOZ plane where the point is located, and the curvature of the point refers to the curvature along the tangential direction of the point on the curved section line 1265. It is to be understood that the coordinate system YOZ plane may also refer to a plane perpendicular to the first scanning direction.

Alternatively, in some embodiments, the light incident surface 1262 is 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 connecting two points aligned along the first scan 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 also be a curve.

Alternatively, the light emitting surface 1264 may be a plane perpendicular to the emitting direction (i.e., the 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 also be non-planar, or the light emitting surface 1264 may also not be perpendicular to the emitting direction (i.e. the Y-axis direction) of the zero-order sensing beam.

As shown in fig. 23 and 25, optionally, the optical axis of the beam expanding lens 126 is arranged along the emitting direction (i.e., Y-axis direction) of the zero-order sensing beam of the beam deflection module 124, and the zero-order sensing beam is located at the middle position of the angle range of the deflected beam of the beam deflection module 124. Since the beam deflection module 124 deflects the light beam only along the first scanning direction, the light beam deflected by the beam deflection module 124 is located at the middle position of the whole detection range in the second scanning direction, the divergence angle of the light beam in the second scanning direction after being expanded by the beam expansion lens 126 is symmetrically distributed with respect to the optical axis of the beam expansion lens 126, and if the divergence angle of the light beam in the second scanning direction after being expanded by the beam expansion lens 126 is equal to

The maximum deviation angle of the beam from the optical axis after being bent by the beam expanding lens 126 is

，

Satisfy the relation:

(10)

where D is the diameter of the beam and f is the focal length of the expander lens 126. For example, if the divergence angle of the sensing beam expanded by the beam expanding lens 126 is required to reach 70 degrees, the divergence angle is preset to be

Focal length of

。

It should be understood that the curvature variation of the light incident surface 1262 of the beam expanding lens 126 along the second scanning direction may be set according to any one or more of the beam diameter of the incident sensing beam, the divergence angle of the sensing beam expanded by the beam expanding lens 126, the refractive index of the material of the beam expanding lens 126, and the thickness of the beam expanding lens 126 along the emitting direction (i.e., the Y-axis direction) of the zero-order sensing beam.

Alternatively, 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 opposite to the light source module 122, or the beam deflection module 124 is 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. Therefore, when the light beam deflection module 124 deflects the light beam along the first scanning direction, the sensing light beam with the divergence angle expanded by the light beam expansion module 126 can irradiate an area which can be covered by the sensing light beam after being expanded along the second scanning direction in the process of scanning along the first scanning direction, so that the sensing light beam emitted by the emission module 12 can irradiate a two-dimensional plane area which is defined by a light beam deflection range along the first scanning direction and a light beam expansion range along the second scanning direction only by being deflected along the first scanning direction, and the detection range of the photoelectric detection device 10 is expanded.

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

Compared with the two-dimensional plane scanning of the sensing beam by the LCPG unit groups having different scanning directions, the two-dimensional plane scanning of the sensing beam by the beam expansion module 126 can reduce the time delay caused by the liquid crystal molecule reaction when the beam passes through the LCPG unit groups.

As shown in fig. 2, the photo-detection device 10 further includes a control circuit 18, and the control circuit 18 is configured to control the beam deflection module 124 and the light source module 122 to be within a second deflection angle range of the beam deflection module 124

And correspondingly adjusting the deflection angle of the emitted sensing light beam according to the preset deflection precision. Optionally, in some embodiments, the control circuit 18 may include a coarse deflection angle adjustment unit 184 and a fine deflection angle adjustment unit 186.

The deflection angle coarse tuning unit 184 is configured to control the beam deflection module 124 within a second deflection angle range

The light beams passing through the light source are deflected by preset deflection angles, and the deflected angles are arranged in an arithmetic progression according to preset angle intervals r. Alternatively, the deflection angle coarse adjustment unit 184 may control the deflection angle of the passing light beam by adjusting the voltage applied to the corresponding LCPG unit 129 in the light beam deflection module 124, for example. It should be understood that, as mentioned above, the LCPG units 129 in different cascade modes have different corresponding relations between the deflection angles of the passing light beams and the applied voltage signals. The deflection angle coarse tuning unit 184 can select the voltage control signal to be applied according to the cascade connection manner of the LCPG units 129 adopted by the beam deflection module 124 and the angle of the sensing beam to be deflected currently.

The deflection angle fine-tuning 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-tuning unit 186 may correspondingly control the deflection angle of the light beam emitted by the light source module 122, for example, by addressing and lighting the light sources 121 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 corresponding angles after passing through the projection lens 123, so that the light beams emitted by the light source module 122 can be controlled to deflect within the preset first deflection angle range Φ according to the preset deflection accuracy by addressing and lighting the light sources 121 at different positions.

When in use, the beam deflection module 124 can be controlled within a preset second deflection angle range by the deflection angle coarse adjustment unit 184

The light beam emitted by the internal pair light source module 122 is coarsely deflected with lower precision, the deflected angles are arranged in an arithmetic progression according to a preset angle interval r, and the angle interval r is the coarsely deflected precision of the light beam deflection module 124. The deflection angle fine-tuning unit 186 can control the light source module 122 to have a preset fine-tuning deflection accuracy within the first deflection angle range phi

The emitted light beam is deflected such that the light beam deflected by the beam deflection module 124 performs a fine adjustment of the deflection angle over the deflected coarse deflection angle, which may be the first deflection angle range phi. That is, by deflecting the light beam emitted from the light source module 122 within the first deflection angle range phi, the light beam primarily deflected by the light beam deflection module 124 can be deflected with a fine adjustment with higher precision within the first deflection angle range phi centered on the deflected coarse deflection angle, and the deflection precision of the emitted light beam by the light source module 122 can be further adjusted by the light beam deflection module 122

To fine tune the deflection accuracy. It should be understood that the two-stage deflection of the light beam by the light beam deflection module 124 and the light source module 122 can be achieved by setting the first deflection angle range phi to be greater than or equal to the angular interval r to achieve a second deflection angle range

And (3) carrying out quasi-continuous deflection on the sensing light beam according to preset deflection accuracy.

Compared with the deflection of the sensing light beam realized by the mechanical rotation scheme and the mixed solid-state scheme, the sensing light beam is realized in a larger second deflection angle range by the pure solid-state light source module 122 and the light beam deflection module 124

As shown in fig. 26, a single light beam deflection module 124 has a limit of a deflection angle range in the first scanning direction, and in order to deflect the sensing light beam in a larger angle range, two or more light beam deflection modules 124 having different orientations may be used to obtain the larger angle range by splicing the respective deflection angle ranges.

Specifically, in some embodiments, the transmitting module 12 includes a light source module 122, a beam splitter 123, a first beam deflection module 1241 and a second beam deflection module 1242. The light source module 122 is configured to emit a light beam and deflect the emitted light beam in a preset first scanning direction within a first deflection angle range Φ 1. The beam splitting device 123 is configured to split the light beam emitted from the light source module 122 into a first light beam 1231 and a second light beam 1232. It should be understood that the first light beam 1231 and the second light beam 1232 split by the beam splitting device 123 are emitted in different directions, respectively.

Optionally, in some embodiments, the beam splitting device 123 may be a polarizing beam splitter. The light beam emitted from the light source module 122 may be unpolarized light, and the first light beam 1231 and the second light beam 1232 split by the polarization beam splitter 123 may be linearly polarized light. Optionally, in some embodiments, the beam splitting device 123 may be a liquid crystal polarization grating, the light beam emitted by the light source module 122 is unpolarized light, and the first light beam 1231 and the second light beam 1232 split by the liquid crystal polarization grating 123 are circularly polarized light. It should be understood that, if the liquid crystal polarization grating 127 is used to deflect the sensing light beam by the first light beam deflecting module 1241 and the second light beam deflecting module 1242 which are used in combination, the first light beam 1231 and the second light beam 1232 may be deflected by directly passing through the liquid crystal polarization grating 127 when they are circularly polarized light, and for the case that the emergent first light beam 1231 and the second light beam 1232 are linearly polarized light, a quarter-wave plate may be disposed before entering the first light beam deflecting module 1241 and the second light beam deflecting module 1242 to convert the linearly polarized light into the circularly polarized light.

The first beam deflecting module 1241 is configured to deflect the first light beam 1231 by different preset deflection angles along the first scanning direction at a plurality of different moments to form a sensing light beam having different emitting directions within a second deflection angle range Φ 2. Optionally, in some embodiments, the first beam deflection module 1241 comprises at least one liquid crystal half-wave plate 128 and at least one liquid crystal polarization grating 127, and the first beam deflection module 1241 may deflect the light beam in the first scanning direction by changing a diffraction state of the light beam passing through the liquid crystal half-wave plate 128 and the liquid crystal polarization grating 127. Optionally, the liquid crystal polarization grating 127 may be an active liquid crystal polarization grating or a passive liquid crystal polarization grating. The liquid crystal half-wave plate 128 and the liquid crystal polarization grating plate 127 may be set in a binary, quasi-binary, or ternary cascade manner as described above, which is not limited in this application.

The second beam deflecting module 1242 is configured to deflect the second beam 1232 by different preset deflection angles along the first scanning direction at a plurality of different moments to form a sensing beam having different emitting directions within a third deflection angle range phi 3. Optionally, in some embodiments, the second beam deflection module 1242 includes at least one liquid crystal half-wave plate 128 and at least one liquid crystal polarization grating 127, and the second beam deflection module 1242 may deflect the light beam in the first scanning direction by changing a diffraction state of the light beam passing through the liquid crystal half-wave plate 128 and the liquid crystal polarization grating 127. Optionally, the liquid crystal polarization grating 127 may be an active liquid crystal polarization grating or a passive liquid crystal polarization grating. The liquid crystal half-wave plate 128 and the liquid crystal polarization grating plate 127 may be arranged in a binary, quasi-binary, or ternary cascade manner as described above, which is not limited in this application.

Optionally, a second deflection angle range Φ 2 of the light beam deflected by the first light beam deflection module 1241 may be equal to or different from a third deflection angle range Φ 3 of the light beam deflected by the second light beam deflection module 1242, which is not specifically limited in this application.

It should be understood that a plurality of preset deflection angles at which the first beam deflection module 1241 deflects the light beam and a plurality of preset deflection angles at which the second beam deflection module 1242 deflects the light beam are both disposed along the first scanning direction. The plurality of preset deflection angles of the first light beam deflection module 1241 for deflecting the light beam are distributed in an arithmetic progression at preset first angle intervals. The plurality of preset deflection angles of the light beam deflected by the second light beam deflection module 1242 are distributed in an arithmetic progression at preset second angle intervals. Optionally, the first angular interval may be equal to the second angular interval; alternatively, the first angular interval may not be equal to the second angular interval.

As shown in fig. 26, a second deflection angle range Φ 2 over which the first beam deflection module 1241 deflects the light beam partially overlaps with a third deflection angle range Φ 3 over which the second beam deflection module 1242 deflects the light beam. Alternatively, the second deflection angle range Φ 2 of the light beam deflected by the first light beam deflection module 1241 and the third deflection angle range Φ 3 of the light beam deflected by the second light beam deflection module 1242 may be seamlessly connected to each other.

It should be understood that in some embodiments, the light source module 122 may also include a first expanded beam module 1261 and a second expanded beam module 1262. Correspondingly, the first beam expanding module 1261 is configured to expand the divergence angle of the first light beam 1231 in the second scanning direction, and the second beam expanding module 1262 is configured to expand the divergence angle of the second light beam 1232 in the second scanning direction. Optionally, the first beam expanding module 1261 may be disposed on the light emitting side of the first beam deflecting module 1241 to expand the first light beam 1231 deflected by the first beam deflecting module 1241; alternatively, the first beam expanding module 1261 may be disposed between the beam splitting device 123 and the first beam deflection module 1241 to expand the divergence angle in the second scanning direction before the first light beam 1231 is deflected by the first beam deflection module 1241. Optionally, the second beam expanding module 1262 may be disposed on the light emitting side of the second beam deflecting module 1242 to expand the second light beam 1232 deflected by the second beam deflecting module 1242; alternatively, the second beam expanding module 1262 may be disposed between the beam splitting device 123 and the second beam deflection module 1242 to expand the divergence angle in the second scanning direction before the second light beam 1232 is deflected by the second beam deflection module 1242.

As shown in fig. 2, the receiving module 14 may include a photosensor 140 and receiving optics 144. The receiving optics 144 are disposed on the light entrance side of the photosensor 140 and are configured to propagate light signals from the detection range to the photosensor 140 for sensing. For example, in some embodiments, the receiving optics 144 include a receiving lens. Alternatively, the receiving lens 144 may include one or more lenses. The photosensor 140 is configured to sense a light signal propagating from the detection range via the receiving optics 144 and output a corresponding light-induced signal.

Optionally, in some embodiments, the receiving module 14 may further include a peripheral circuit (not shown) composed of one or more of a signal amplifier, an Analog-to-Digital Converter (ADC), and the like, and the peripheral circuit may be partially or completely 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 photo detection device 10 may include a plurality of detection areas respectively located at different positions. Optionally, the photosensitive pixels 142 of the photosensor 140 have corresponding detection areas in the detection range, and the optical signals returning from the detection areas propagate through the receiving optics 144 to the corresponding photosensitive pixels 142 for sensing. That is, the detection area corresponding to the photosensitive pixel 142 can be regarded as the spatial range covered by the field angle formed by the photosensitive pixel 142 through the receiving optical device 144. It will be appreciated that the optical signal returning from the detection region 20 comprises the sensing beam projected to the detection region 20 and reflected back by the object 2 located within the detection region, and also comprises photons of ambient light from the detection region.

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 it into a corresponding electrical signal as the optical sensing signal output. The photoelectric conversion device is, for example, a Single Photon Avalanche photodiode (SPAD), an Avalanche Photodiode (APD), a Silicon Photomultiplier (SiPM) in which a plurality of SPADs are arranged in parallel, 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 to the detection range via the emission optics 124, i.e., the sensing beam may be a periodic pulse beam with a preset frequency. The light emitting unit 120 may emit a plurality of laser pulses within one detection frame, and a time period between emission timings of two adjacent laser pulses may be defined as one emission period of the laser pulses. The light-sensitive pixels 142 have a sensing period corresponding to the emission period. For example, the light-sensing 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. Each time a laser pulse is emitted and the photosensitive pixel 142 starts sensing a photon returning from the detection range, the timing unit 152 determines the receiving time of the optical signal sensed by the receiving module 14 according to the optical sensing signal generated by the photon sensed by the receiving module 14. The counting unit 154 counts and counts the light signal receiving time determined by the timing unit 152 in a plurality of sensing periods of a detection frame in corresponding time bins to generate a corresponding statistical histogram. The length of the sensing time interval is at least larger than the flight time required by the photons to travel to and from the farthest detection value required by the corresponding detection area, so as to ensure that the photons reflected from the farthest detection value can be sensed and counted. Optionally, in some embodiments, the length of the sensing period may be set according to a distance detection farthest value required by the detection region. For example, the sensing period length of the photosensitive pixel 142 is positively correlated with the farthest detection value that the detection area to be detected should satisfy, and for the detection area with a larger farthest detection value, the sensing period of the photosensitive pixel 142 to be detected is longer; for a detection region having a smaller distance from the detection farthest value, the sensing period of the photosensitive pixel 142 performing the corresponding detection is shorter.

Alternatively, in some embodiments, all or a portion of the functional units in the control circuit 18 and/or the processing circuit 15 may be firmware solidified in the storage medium 30 or computer software codes stored in the storage medium 30 and executed by the corresponding one or more processors 40 to control the relevant components to implement the corresponding functions. The Processor 40 is, for example, but not limited to, an Application Processor (AP), a Central Processing Unit (CPU), a Micro Controller Unit (MCU), and the like. The storage medium 30 includes, but is not limited to, a Flash Memory (Flash Memory), a charged Erasable Programmable read only Memory (EEPROM), a Programmable Read Only Memory (PROM), a hard disk, and the like.

Optionally, in some embodiments, the processor 40 and/or the storage medium 30 may be disposed in the photodetection device 10, such as: integrated on the same circuit board as the transmitter module 12 or the receiver module 14. Optionally, in some other embodiments, the processor 40 and/or the storage medium 30 may also be disposed at other positions of the electronic device 1, such as: on the main circuit board of the electronic device 1.

Optionally, in some embodiments, part or all of the functional units of the control circuit 18 and/or the processing circuit 15 may also be implemented by hardware, for example, by any one or a combination of the following technologies: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or 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 device 10. The above-mentioned hardware for implementing the functions of the control circuit 18 and/or the processing circuit 15 may also be disposed at other locations of the electronic device 1, such as: is provided on the main circuit board of the electronic device 1.

It will be appreciated that 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 installed at a plurality of different positions on the automobile to detect the distance information of objects in the peripheral range of the automobile and accordingly realize driving control.

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

The embodiments of the photodetecting device and the electronic device applied thereto are described in detail above with reference to fig. 1 to 27, and the embodiments of the method for performing three-dimensional information detection by using or applying the photodetecting device are described in detail below with reference to fig. 29. It should be understood that the description of the method embodiments corresponds to the description of the apparatus embodiments described above, and therefore, some contents of the method embodiments that are not described in detail can be referred to the description of the apparatus embodiments described above.

Fig. 29 is a flowchart illustrating exemplary steps of a three-dimensional information detection method provided in an embodiment of the present application, which may be used to obtain three-dimensional information of an object in a detection range, such as, but not limited to, distance information, surface depth information, and three-dimensional coordinate information of the object in the detection range. The three-dimensional information detection method shown in fig. 29 is applicable to the photodetection device 10 of the embodiment of the present application or an electronic device/terminal device equipped with the photodetection device 10. Referring to fig. 2, the photo-detection device includes a transmitting module 12, a receiving module 14, a processing circuit 15, and a control circuit 18. The emitting module 12 includes a light source module 122 and a light beam deflection module 124, wherein the light source module 122 is configured to emit a light beam, and the light beam deflection module 124 is configured to correspondingly deflect the light beam emitted from the light source module 122 by different preset deflection angles at a plurality of times to form a sensing light beam with different emitting directions. The control circuit 18 is configured to control the beam deflection module 124 to configure the deflection angle of the passing beam. The control circuit 18 is further configured to control the light source module 122 to adjust the deflection angle of the emitted light beam within a preset first deflection angle range according to a preset deflection accuracy on the basis that the emitted light beam is deflected by a predetermined angle by the light beam deflection module 124. The receiving module 14 includes at least one photosensitive pixel 142 configured to receive an optical signal from a detection range and output a corresponding photosensitive signal. The processing circuitry 15 is configured to analytically process the light-induced signals to obtain three-dimensional information of objects within a detection range. The three-dimensional information detection method comprises the following steps:

step S101, controlling the beam deflection module 124 to configure the deflection angle of the passing beam.

Optionally, in some embodiments, the beam deflection module 124 deflects the propagation direction of the passing light beam through the LCPG plate 127 and the liquid crystal half-wave plate 128. The deflection angle coarse adjustment unit 184 of the control circuit 18 can control the deflection angle of the beam deflection module 124 on the passing light beam by adjusting the voltages applied to the LCPG plate 127 and the liquid crystal half-wave plate 128. It should be understood that the correspondence between the deflection angle of the LCPG piece 127 to the passing light beam and the applied voltage signal depends on the cascade mode of the LCPG piece 127, and the correspondence is different for different cascade modes.

As mentioned above, the beam deflection module 124 deflecting the light beam based on the LCPG principle can be in the second deflection angle range

The light beams passing through are deflected at preset angle intervals r, and the formed deflection angles of the light beams are distributed in an arithmetic progression. The angle interval r is the minimum deflection angle of the passing light beam in the cascaded LCPG pieces 127, and the light beam deflection module 124 adopting the LCPG deflection principle is in the second deflection angle range

The deflection accuracy of the inner pair of passing beams. It should be understood that the time required for step S101 is determined by the response speed of the LCPG piece 127, and mainly depends on the characteristics of the liquid crystal material used for the LCPG piece, and is in the order of milliseconds (ms), for example, 1-10ms.

Alternatively, in some other embodiments, the beam deflecting module 124 may also perform coarse deflection on the light beam emitted from the light source module 122 within a preset deflection angle range by other means, for example, deflecting the light beam emitted from the light source module 122 in an Optical Phase Array (OPA) manner or a Liquid Crystal Metasurface (LCM) manner, which is not limited in this application.

Step S102, controlling the light source module 122 to emit a light beam, and controlling the light source module 122 to deflect the emitted light beam within a preset first deflection angle range according to a preset deflection accuracy on the basis that the emitted light beam has been deflected by a preset angle by the light beam deflection module 124.

The light source module 122 includes a plurality of light sources 121 and an optical deflecting device 123. The light source 121 is configured to emit a light beam. The optical deflecting device 123 is configured to deflect the light beam emitted by the light source 121 with a preset deflection accuracy in the first deflection angle range phi. It should be understood that the deflection accuracy of the optical deflection device 123 for the light beam is higher than that of the light beam deflection module 124 for the passed light beam, and after the light beam deflection module 124 performs coarse deflection on the passed light beam with a lower coarse deflection accuracy, the light source module 122 deflects the emitted light beam with a higher fine deflection accuracy based on the angle of the coarse deflection, so as to achieve high-accuracy deflection of the sensing light beam within a large angle range. Optionally, a first deflection angle range phi of the light source module 122 deflecting the emitted light beam is greater than or equal to an angle interval of the light beam deflection module 124 deflecting the light beam, so that the sensing light beam formed by two-stage deflection of the light beam deflection module 124 and the light source module 122 can be in a larger second deflection angle range

Quasi-continuous deflection is achieved with fine tuning of deflection accuracy.

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 light beams emitted by the light sources 121 are emitted in corresponding preset directions after passing through the projection lens 123 to form 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 has a corresponding relationship with the position of the light source 121 on the focal plane of the projection lens 123. Thus, the control circuit 18 can control the light source module 122 to deflect the emitted light beam within the first deflection angle range phi with a preset fine-tuning deflection accuracy by addressing the light sources 121 illuminating different positions on the focal plane of the projection lens 123.

Alternatively, in some other embodiments, the optical deflecting device 123 may also be a liquid crystal on silicon (LCOS-OPAs) or an acousto-optic deflecting crystal, which is not particularly limited in this application, as 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 fine-tuning deflection accuracy.

It should be understood that the time required for step S102 depends on the time required for one complete emission and reception of the sensing beam and the number of times the sensing beam needs to be emitted and received for each frame detection. The time required for one complete emission and reception of the sensing beam is at least greater than the time of flight of the emitted sensing beam to and from the farthest value of the distance detection to be satisfied. For example, if the distance detection maximum to be satisfied is 50 meters, the flight time required for the sensing beam to travel 50 meters back and forth is 334 nanoseconds (ns), and the time required for one complete transmission and reception of the sensing beam is about 600ns in consideration of the redundancy of random time intervals to be inserted for interference resistance. In order to improve the signal-to-noise ratio of the detection, it is assumed that the number of times of emission of the sensing beam needs to reach 1000 times for each fine deflection angle, and thus the time required for step S102 is 1000 × 600ns =0.6ms for each fine deflection angle. As described above, step S102 requires addressing and lighting of light sources at different positions to deflect the emitted light beam, and the time required to complete a round of addressing is in the order of ns. To further reduce the time consumption, the control circuit 18 may control the light source module 122 to synchronously address and light the other light sources 121 in the interval of the sensing light beams emitted twice adjacent along one of the fine deflection angles to emit light beams along other fine deflection angles within the first deflection angle range phi. Thus, the time required for the whole step S102 is approximately equal to the total time required for emitting the preset multiple sensing beams along one of the fine adjustment deflection angles.

Step S103, sensing the optical signal from within the detection range, and recording the reception time of the sensed optical signal.

Optionally, in some embodiments, the control circuit 18 controls the corresponding photosensitive pixels 142 on the receiving module 14 to start sensing the optical signal from within the detection range in synchronization with the emission of the sensing light beam. The light-sensing pixels 142 are configured to sense received optical signals and output corresponding optical sensing signals. The timing unit 152 of the processing circuit 15 determines the receiving time of the sensed optical signal according to the optical sensing signal and counts in a time bin corresponding to the receiving time. The time binning is a minimum time unit Δ t for the timing unit 152 to record the light sensing signal generation time, and can reflect the accuracy of time recording of the light signal by the timing unit 152, and the finer the time binning is, the higher the accuracy of the recording time is.

It should be understood that for each emission angle of the sensing light beam, a corresponding photosensitive pixel 142 is disposed on the receiving module 14 for sensing the light signal returning from the emission angle. Since different emission angles of the sensing light beams are respectively emitted by deflection at a plurality of moments, the corresponding photosensitive pixels 142 also start to perform sensing at a plurality of corresponding sensing periods respectively.

It should be understood that steps S102 and S103 may be performed synchronously, that is, while the sensing light beam is emitted at each deflection angle, the corresponding photosensitive pixel 142 starts sensing the light signal returning from the angle synchronously and counts according to the sensed light signal receiving time.

Optionally, in some embodiments, the timing unit 152 may include a count memory 1524, the count memory 1524 has a count storage space correspondingly allocated according to the time bin, and the timing unit 152 records the receiving time of the sensed optical signal by adding one to the count storage space of the corresponding time bin. Thus, the received time distribution data generated by sensing the optical signal in step S103 can be stored in the count memory 1524.

Step S104, analyzing and processing the receiving time data of the sensed optical signal to obtain the flight time of the sensing light beam reflected back from the detection range, and obtaining the three-dimensional information of the object reflecting the sensing light beam according to the flight time.

Optionally, in some embodiments, the statistical unit 154 of the processing circuit 15 performs a statistical analysis on the accumulated light signal counts in each time bin to obtain a statistical histogram capable of reflecting the time distribution of the time at which the light signal is sensed. The time-of-flight obtaining unit 156 of the processing circuit 15 determines the receiving time of the reflected sensing beam according to the timestamp t1 of the time bin corresponding to the peak value of the signal peak in the statistical histogram, and obtains the time-of-flight of the reflected sensing beam according to the time difference between the receiving time of the sensing beam and the corresponding emitting time. The three-dimensional information acquiring unit 158 of the processing circuit 15 calculates three-dimensional information between the object 2 reflecting the sensing light beam and the photodetecting device 10 according to the flight time of the reflected sensing light beam, for example: the distance between the object 2 and said photo detection means 10 in the detection range.

It should be understood that for each coarse deflection angle of the sensing light beam provided by the light beam deflection module 124 within the second deflection angle range, steps S101, S102 and S103 may be repeated to obtain sensing data at the corresponding emission angle by the sensing light beam within a first deflection angle range phi around the selected coarse deflection angle with a preset fine deflection accuracy. On this basis, the sensing data acquired by emitting the sensing light beams at different emission angles is processed and analyzed to obtain three-dimensional information at the corresponding emission angles through step S104.

For the whole process of three-dimensional information detection, in addition to considering the scanning time of the sensing light beam along a plurality of angles, the time for processing the data generated by sensing the light signal needs to be considered. In order to increase the sensing speed, the embodiment of the present application may buffer the sensing data generated in step S102 and step S103 in a parallel manner of scanning and data processing, and perform step S104 to process the buffered sensing data while repeating step S102 and step S103 to perform scanning sensing on the next emission angle.

Alternatively, in some embodiments, if the amount of the sensing data corresponding to one emission angle is large, the time for data processing in step S104 may be prolonged by increasing the storage space to buffer the sensing data corresponding to a plurality of emission angles.

Optionally, in some embodiments, the time for data processing may be obtained by extending the duration of step S102 and step S103 without increasing the storage space. For example: in some embodiments, the time taken for step S101 is 4ms and the time taken for steps S102 and S103 is increased to 2ms, i.e. the total time required for scanning and sensing of the sensing beam is 6ms for one coarse deflection angle. If the beam deflection module 124 employs a binary or quasi-binary cascade of three active LCPG elements 129, it may provide

The coarse deflection angle of each sensing beam, the total time required for completing one frame scanning and sensing of the sensing beam is

The corresponding frame rate reaches 11.1 hertz (Hz). If the beam deflection module 124 employs a binary cascade of four passive LCPG elements 129, it can provide

The corresponding frame rate reaches 10.4Hz.

Thereby, the beam deflection module 124 can deflect the light beam in a larger second deflection angle range

The coarse deflection with low precision and the fine deflection with high precision of the light source module 122 in a smaller first deflection angle range phi can make the sensing light beam emitted by the photo-detection device 10 in a larger second deflection angle range

Quasi-continuous scanning with high internal precisionThe detection range of the photoelectric detection device 10 is expanded, and the detection precision of the photoelectric detection device 10 is improved.

It should be noted that the technical solutions claimed in the present application may satisfy only one of the above embodiments or satisfy a plurality of the above embodiments at the same time, that is, an embodiment in which one or more of the above embodiments are combined also belongs to the protection scope of the present application.

In the description herein, references to the description of the terms "one embodiment," "certain embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples," etc., mean 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, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. 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 should be understood that portions of embodiments of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, a plurality of functional units may be implemented by 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, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.

The above description is only a preferred embodiment of the present application and should not be taken as limiting the present application, and any modifications, equivalents, improvements, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. 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, comprising:

the light source module is configured to emit light beams and correspondingly deflect the emitted light beams to different preset emission directions within a first deflection angle range at a plurality of moments; and

the first light beam deflection module is configured to deflect the light beams emitted by the light source module by different preset deflection angles respectively at a plurality of moments so as to form sensing light beams with different emergent directions within a second deflection angle range;

the first light beam deflection module deflects a plurality of preset deflection angles of light beams to form an equal difference array according to a preset first angle interval, the range of the first deflection angle is larger than or equal to the first angle interval, the first light beam deflection module comprises a 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 beams, the deflection angles of the liquid crystal polarization grating plates to the light beams are gradually increased according to the sequence of sequentially arranging along the emergent direction of the light beams, the difference of the deflection angles of one liquid crystal polarization grating plate and the adjacent previous liquid crystal polarization grating plate to the light beams is gradually increased by a natural number power of two according to the sequence of sequentially arranging along the emergent direction of the light beams, and the value of the natural number is that the serial number of the liquid crystal polarization grating plate is decreased by one.

2. The emission module as claimed in 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 along corresponding predetermined emission directions after passing through the projection lens to form the light beams emitted from the light source module, the predetermined emission directions emitted from the light beams emitted from the light sources after passing through the projection lens have corresponding relationships with positions of the light sources on the focal plane of the projection lens, and the light source module illuminates the light sources at different positions on the focal plane of the projection lens by addressing to form the light beams deflected between different predetermined emission directions within the first deflection angle range.

3. The transmit 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 the first deflection angle range along a preset emission direction, and wherein the optical deflection device may be a liquid crystal on silicon phased array or an acousto-optic deflection crystal.

4. The transmitter module of claim 1, further comprising:

the second light beam deflection module is configured to deflect the second light beam by different preset deflection angles respectively at multiple moments so as to form sensing light beams with different emergent directions within a third deflection angle range;

5. The transmitter module as claimed in claim 4, wherein the beam splitter is a liquid crystal polarization grating plate, the light beam emitted from the light source module is unpolarized light, and the first light beam and the second light beam split by the liquid crystal polarization grating plate are circularly polarized light; or

6. The transmit module of claim 1, wherein the beam deflection module further comprises a temperature control unit configured to control a temperature of the lc deflection grating sheet within a preset temperature range.

7. The transmitter module as claimed in claim 1, wherein the lc polarization grating is an active lc polarization grating having electrodes capable of being applied with a saturation voltage, the active lc polarization grating does not deflect the passing light beam when the saturation voltage is applied, and the active lc polarization grating deflects the passing light beam when the saturation voltage is not applied.

8. A photodetecting device comprising the emitting module according to any one of claims 1-7, the photodetecting device further comprising a receiving module and a processing circuit, the receiving module being configured to sense the optical signal from the detection range and output a corresponding photo-induced signal, the processing circuit being configured to analyze and process the photo-induced signal to obtain three-dimensional information of the object in the detection range.

9. An electronic device comprising the photodetecting apparatus according to claim 8, wherein the electronic device further comprises an application module configured to implement a corresponding function according to a detection result of the photodetecting apparatus.

10. A three-dimensional information detection method applied to the photodetection device according to claim 8 or the electronic apparatus according to claim 9, the three-dimensional information detection method comprising:

11. The three-dimensional information detecting method according to claim 10, wherein when the emitted light beams are deflected within a preset first deflection angle range, the sensing light beams may be emitted along other deflection angles within the first deflection angle range in an interval where the sensing light beams are emitted twice adjacent along one of the emission angles.