CN112433382A

CN112433382A - Speckle projection device and method, electronic device and distance measurement system

Info

Publication number: CN112433382A
Application number: CN202011341448.1A
Authority: CN
Inventors: 王华林
Original assignee: Oppo Chongqing Intelligent Technology Co Ltd
Current assignee: Oppo Chongqing Intelligent Technology Co Ltd
Priority date: 2020-11-25
Filing date: 2020-11-25
Publication date: 2021-03-02
Anticipated expiration: 2040-11-25
Also published as: CN112433382B

Abstract

The disclosure provides a speckle projection device and method, electronic equipment and a distance measurement system, and relates to the technical field of laser ranging. The device includes: a light source module for generating linear light; and the diffraction module is arranged on the light path of the linear light and is used for carrying out one-dimensional beam splitting processing on the linear light to obtain the speckle projection array without pincushion distortion. The speckle projection array without pincushion distortion can be generated, and the problem of speckle point waste caused by pincushion distortion is avoided.

Description

Speckle projection device and method, electronic device and distance measurement system

Technical Field

The present disclosure relates to the field of laser ranging technologies, and in particular, to a speckle projection apparatus, a speckle projection method, a computer-readable medium, an electronic device, and a distance measurement system.

Background

With the development of scientific technology, Time of Flight (TOF) is gaining more and more attention. TOF techniques can be further divided into Direct TOF (DTOF) and Indirect TOF (ITOF). Since the farther the distance measured by the TOF module is, the larger the field angle is, the higher the light energy that the transmitting module needs to provide is, under the limitation of the system power consumption of the TOF module, in order to be able to measure the farther distance, a scattered-Spot Indirect Time of Flight (Spot-ITOF) technique is used.

The light source pattern that the transmission module of Spot-ITOF projected is the speckle pointolite, concentrates on the speckle pointolite through with original projection area light source energy, under the prerequisite of guaranteeing three-dimensional range finding precision, has promoted the range finding scope. However, a Spot ITOF emission module includes a Diffractive Optical Element (DOE), and the influence of the DOE diffraction angle inevitably causes pincushion distortion in the speckle projection array in order to ensure seamless splicing of the array scattered spots of each diffraction order.

At present, in a related technical solution for solving pincushion distortion, a distortion compensation structure is disposed on a reflected light path of a speckle array of pincushion distortion to implement distortion compensation of the speckle array. However, this solution requires an additional distortion compensation structure, which increases the manufacturing cost; meanwhile, due to the introduction of a new hardware structure, the volume of the Spot-ITOF system is increased; secondly, after the distortion compensation structure is manufactured, the distortion compensation structure is strictly bound with the pincushion distortion speckle array which can be compensated, flexible adjustment cannot be achieved, and the application range is small.

Disclosure of Invention

The present disclosure is directed to a speckle projection method, a speckle projection apparatus, a computer readable medium, and an electronic device, which avoid, at least to some extent, the problems of high manufacturing cost, large system size, and poor flexibility due to the introduction of an additional distortion compensation structure.

According to a first aspect of the present disclosure, there is provided a speckle projection apparatus comprising:

a light source module for generating linear light;

and the diffraction module is arranged on the light path of the linear light and is used for carrying out one-dimensional beam splitting processing on the linear light to obtain the speckle projection array without pincushion distortion.

According to a second aspect of the present disclosure, there is provided a speckle projection method, comprising:

generating linear light by a light source module;

and carrying out one-dimensional beam splitting treatment on the linear light to obtain a speckle projection array without pincushion distortion.

According to a third aspect of the present disclosure, there is provided a distance measurement system comprising:

the speckle projection device is used for emitting a speckle projection array without pincushion distortion to a target area, and the speckle projection array is reflected at the target area to generate a reflection speckle array;

a receiving device for receiving the reflective speckle array;

and the control device is electrically connected with the speckle projection device and the receiving device and used for recording the phase when the speckle projection device emits the speckle projection array and outputting the phase difference when the receiving device receives the reflection speckle array so as to calculate the real distance between the target area and the target area according to the phase difference.

According to a fourth aspect of the present disclosure, a computer-readable medium is provided, on which a computer program is stored, which computer program, when being executed by a processor, is adapted to carry out the above-mentioned method.

According to a fifth aspect of the present disclosure, there is provided an electronic apparatus, comprising:

a processor; and

a memory for storing one or more programs that, when executed by the one or more processors, cause the one or more processors to implement the above-described method.

According to the speckle projection device provided by the embodiment of the disclosure, linear light is generated by the light source module; and arranging the diffraction module on the light path of the linear light, and performing one-dimensional beam splitting processing on the linear light to obtain the speckle projection array without pincushion distortion. On one hand, the speckle projection array without pincushion distortion can be directly obtained through one-dimensional beam splitting processing of linear light, and compared with the conventional scheme of carrying out two-dimensional beam splitting processing on a point light source, the speckle projection array without pincushion distortion can be realized, and waste of scattered spots (energy) is avoided; on the other hand, a new hardware structure is not added, only the original structure is changed, the problem of increased manufacturing cost caused by the introduction of the new hardware structure is solved, and the volume of the system is not increased; on the other hand, when different speckle arrays need to be generated by adjustment, only the parameters of the generated linear light and the parameters of the diffraction module need to be adjusted, and the overall hardware does not need to be changed, so that the flexibility and the application range are improved, and the cost is saved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure. It is to be understood that the drawings in the following description are merely exemplary of the disclosure, and that other drawings may be derived from those drawings by one of ordinary skill in the art without the exercise of inventive faculty. In the drawings:

FIG. 1 shows a schematic diagram of an electronic device to which embodiments of the present disclosure may be applied;

FIG. 2 is a schematic diagram schematically illustrating a speckle projection array with pincushion distortion generated in a related art scheme in an exemplary embodiment of the present disclosure;

fig. 3 schematically illustrates a structural schematic diagram of a speckle projection apparatus in an exemplary embodiment of the disclosure;

FIG. 4 schematically illustrates an apparatus for generating a pincushion-free speckle projection array in an exemplary embodiment of the disclosure;

FIG. 5 schematically illustrates a diagram of diffraction order energy distribution data in an exemplary embodiment of the disclosure;

FIG. 6 schematically illustrates another apparatus for generating a pincushion-free speckle projection array in an exemplary embodiment of the disclosure;

FIG. 7 schematically illustrates a schematic view of an aspheric cylindrical lens in an exemplary embodiment of the present disclosure;

FIG. 8 schematically illustrates a schematic diagram of yet another apparatus for generating a pincushion-free speckle projection array in an exemplary embodiment of the present disclosure;

FIG. 9 schematically illustrates a schematic structural diagram of a distance measurement system in an exemplary embodiment of the present disclosure;

FIG. 10 schematically illustrates a flow chart of a speckle projection method in an exemplary embodiment of the disclosure;

fig. 11 schematically illustrates a flow chart of brightness compensation for linear light in an exemplary embodiment of the present disclosure.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus their repetitive description will be omitted. Some of the block diagrams shown in the figures are functional entities and do not necessarily correspond to physically or logically separate entities. These functional entities may be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different networks and/or processor devices and/or microcontroller devices.

Exemplary embodiments of the present disclosure provide an electronic device applying a speckle projection apparatus or for implementing a speckle projection method. The electronic device includes at least a processor and a memory for storing executable instructions of the processor, the processor being configured to perform the speckle projection method via execution of the executable instructions.

The following takes the mobile terminal 100 in fig. 1 as an example, and exemplifies the configuration of the electronic device. It will be appreciated by those skilled in the art that the configuration of figure 1 can also be applied to fixed type devices, in addition to components specifically intended for mobile purposes. In other embodiments, mobile terminal 100 may include more or fewer components than shown, or some components may be combined, some components may be split, or a different arrangement of components. The illustrated components may be implemented in hardware, software, or a combination of software and hardware. The interfacing relationship between the components is only schematically illustrated and does not constitute a structural limitation of the mobile terminal 100. In other embodiments, the mobile terminal 100 may also interface differently than shown in fig. 1, or a combination of multiple interfaces.

As shown in fig. 1, the mobile terminal 100 may specifically include: a processor 110, an internal memory 121, an external memory interface 122, a Universal Serial Bus (USB) interface 130, a charging management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 171, a receiver 172, a microphone 173, an earphone interface 174, a sensor module 180, a display 190, a camera module 191, an indicator 192, a motor 193, a button 194, and a Subscriber Identity Module (SIM) card interface 195, and the like. Wherein the sensor module 180 may include a depth sensor 1801, a pressure sensor 1802, a gyroscope sensor 1803, and the like.

Processor 110 may include one or more processing units, such as: the Processor 110 may include an Application Processor (AP), a modem Processor, a Graphics Processing Unit (GPU), an Image Signal Processor (ISP), a controller, a video codec, a Digital Signal Processor (DSP), a baseband Processor, and/or a Neural-Network Processing Unit (NPU), and the like. The different processing units may be separate devices or may be integrated into one or more processors.

The NPU is a Neural-Network (NN) computing processor, which processes input information quickly by using a biological Neural Network structure, for example, by using a transfer mode between neurons of a human brain, and can also learn by itself continuously. The NPU may implement applications such as intelligent recognition of the mobile terminal 100, for example: image recognition, face recognition, speech recognition, text understanding, and the like.

A memory is provided in the processor 110. The memory may store instructions for implementing six modular functions: detection instructions, connection instructions, information management instructions, analysis instructions, data transmission instructions, and notification instructions, and are controlled to be executed by the processor 110.

The charging management module 140 is configured to receive charging input from a charger. The power management module 141 is used for connecting the battery 142, the charging management module 140 and the processor 110. The power management module 141 receives the input of the battery 142 and/or the charging management module 140, and supplies power to the processor 110, the internal memory 121, the display screen 190, the camera module 191, the wireless communication module 160, and the like.

The wireless communication function of the mobile terminal 100 may be implemented by the antenna 1, the antenna 2, the mobile communication module 150, the wireless communication module 160, a modem processor, a baseband processor, and the like. Wherein, the antenna 1 and the antenna 2 are used for transmitting and receiving electromagnetic wave signals; the mobile communication module 150 may provide a solution including wireless communication of 2G/3G/4G/5G, etc. applied to the mobile terminal 100; the modem processor may include a modulator and a demodulator; the Wireless communication module 160 may provide a solution for Wireless communication including Wireless Local Area Network (WLAN) (e.g., Wireless Fidelity (Wi-Fi) network), Bluetooth (BT), and the like, applied to the mobile terminal 100. In some embodiments, the antenna 1 of the mobile terminal 100 is coupled to the mobile communication module 150 and the antenna 2 is coupled to the wireless communication module 160 so that the mobile terminal 100 can communicate with networks and other devices through wireless communication techniques.

The mobile terminal 100 implements a display function through the GPU, the display screen 190, the application processor, and the like. The GPU is a microprocessor for image processing, and is connected to a display screen 190 and an application processor. The GPU is used to perform mathematical and geometric calculations for graphics rendering. The processor 110 may include one or more GPUs that execute program instructions to generate or alter display information.

The mobile terminal 100 may implement a photographing function through the ISP, the camera module 191, the video codec, the GPU, the display screen 190, the application processor, and the like. The ISP is used for processing data fed back by the camera module 191; the camera module 191 is used for capturing still images or videos; the digital signal processor is used for processing digital signals, and can process other digital signals besides digital image signals; the video codec is used to compress or decompress digital video, and the mobile terminal 100 may also support one or more video codecs.

The external memory interface 122 may be used to connect an external memory card, such as a Micro SD card, to extend the memory capability of the mobile terminal 100. The external memory card communicates with the processor 110 through the external memory interface 122 to implement a data storage function. For example, files such as music, video, etc. are saved in an external memory card.

The internal memory 121 may be used to store computer-executable program code, which includes instructions. The internal memory 121 may include a program storage area and a data storage area. The storage program area may store an operating system, an application program (such as a sound playing function, an image playing function, etc.) required by at least one function, and the like. The storage data area may store data (e.g., audio data, a phonebook, etc.) created during use of the mobile terminal 100, and the like. In addition, the internal memory 121 may include a high-speed random access memory, and may further include a nonvolatile memory, such as at least one magnetic disk Storage device, a Flash memory device, a Universal Flash Storage (UFS), and the like. The processor 110 executes various functional applications of the mobile terminal 100 and data processing by executing instructions stored in the internal memory 121 and/or instructions stored in a memory provided in the processor.

The mobile terminal 100 may implement an audio function through the audio module 170, the speaker 171, the receiver 172, the microphone 173, the earphone interface 174, and the application processor. Such as music playing, recording, etc.

The depth sensor 1801 is used to acquire depth information of a scene. In some embodiments, the depth sensor may be disposed in the camera module 191. The depth sensor 1801 may be a ToF lens capable of measuring the true distance from the time of flight of the laser (calculated from the phase difference or time difference).

The pressure sensor 1802 is used to sense a pressure signal, which can be converted into an electrical signal. In some embodiments, the pressure sensor 1802 may be disposed on the display screen 190. The pressure sensors 1802 can be of a wide variety, such as resistive pressure sensors, inductive pressure sensors, capacitive pressure sensors, and the like.

The gyro sensor 1803 may be used to determine a motion gesture of the mobile terminal 100. In some embodiments, the angular velocity of the mobile terminal 100 about three axes (i.e., x, y, and z axes) may be determined by the gyro sensors 1803. The gyro sensor 1803 may be used to photograph anti-shake, navigation, body-feel game scenes, and the like.

In addition, sensors with other functions, such as an air pressure sensor, a magnetic sensor, an acceleration sensor, a distance sensor, a proximity light sensor, a fingerprint sensor, a temperature sensor, a touch sensor, an ambient light sensor, a bone conduction sensor, etc., may be provided in the sensor module 180 according to actual needs.

Other devices for providing auxiliary functions may also be included in the mobile terminal 100. For example, the keys 194 include a power-on key, a volume key, etc., through which a user can generate key signal inputs related to user settings and function control of the mobile terminal 100. As another example, indicator 192, motor 193, SIM card interface 195, etc.

In the related art, the distortion problem of the emission module speckle projection array for TOF is that a diffraction angle direction of a Laser beam emitted by a Vertical-Cavity Surface-Emitting Laser (VCSEL) is deflected after passing through a collimating mirror and a diffractive optical element DOE. Wherein, the laser beam of the central diffraction order propagates according to the original optical axis direction, and the beam directions of other diffraction orders are deflected according to the diffraction angle in the following relation (1) under the restriction of the DOE diffraction angle:

θ＝arcsin(m·λ/d) (1)

where m may represent the diffraction order, λ may represent the laser wavelength, and d may represent the microstructure period of the diffractive optical element DOE. Then, the beam is split according to the diffraction angle in relation (1), and the speckle projection array projected to the spatial plane necessarily has pincushion distortion. Secondly, the related technical scheme is to adopt a point light source, split (duplicate) the point light source emitted by a laser into thousands of speckle points, and the scheme duplicates too many beam splits, but the luminous power of the laser is not high, and the requirement of the optical energy density of the duplicated speckle points cannot be met.

In one technical scheme, by convolution superposition of two diffraction optical elements DOE, original small-angle lattice patterns are subjected to convolution superposition to generate a large-angle-range projection lattice. The scheme is also directed at single-point laser, and can solve the speckle projection of a large field of view (FOV), but cannot solve the problem of pincushion distortion of speckle points caused by the combination of a VCSEL laser dot matrix and DOE beam splitting.

In another technical scheme, a spot pattern light beam with a first distortion characteristic is emitted through an emission module, and then the reflected spot pattern light beam is collected through an imaging lens with a second distortion characteristic and a collection module of an array pixel unit, wherein the first distortion characteristic and the second distortion characteristic are mutually compensated. The scheme realizes the distortion compensation of the spot pattern beam with the first distortion characteristic by introducing an additional imaging lens with the second distortion characteristic, but the introduction of a new hardware structure causes the increase of the manufacturing cost and the increase of the volume of the system; meanwhile, after the distortion compensation structure is manufactured, the distortion compensation structure is strictly bound with the pincushion distortion speckle array which can be compensated, flexible adjustment cannot be achieved, and the application range is small.

Fig. 2 schematically illustrates a schematic diagram of generating a speckle projection array with pincushion distortion in a related art scheme in an exemplary embodiment of the present disclosure.

Referring to fig. 2, a conventional speckle projection array generation apparatus may include a light source module 201, where the light source module 201 generates a point laser 202, the point laser 202 is collimated by a collimator mirror 203, and passes through a two-dimensional diffractive optical element DOE (two-dimensional beam splitter) 204 to deflect a diffraction angle direction of the point laser 202, so as to perform beam splitting (replication) in a horizontal direction and a vertical direction, where a point laser beam of a central diffraction order propagates along an original optical axis direction, and point laser beam directions of other diffraction orders are distorted under the restriction of a DOE diffraction angle, so as to generate a speckle projection array 205 with pincushion distortion.

Due to the pincushion distortion in the speckle projection array 205, the image Sensor in the receiving module can only receive scattered spots in a speckle inscribed rectangular area, and scattered spots (energy) are wasted. Due to the pincushion distortion in the speckle projection array 205, the size and the spacing of scattered spots in the central area and the size and the spacing of speckle points in the edge field of view are different, wherein the larger the FOV of the field of view is, the larger the size and the spacing of the speckle points are, the lower the energy density of the speckle points is, the lower the imaging signal-to-noise ratio of the image sensor is, and the distance imaging of the edge field of view on the image sensor is affected. Due to the pillow-shaped distortion in the speckle projection array 205, the energy density of the speckles is reduced, so that the detection distance of the edge field of the image Sensor is shortened, or the energy of the DOE high-order diffraction order needs to be compensated, so as to improve the light spot brightness of the edge field, but the DOE design specification can make the DOE design and processing more difficult.

In view of one or more of the above problems, in the present exemplary embodiment, a distance measuring device is first provided. Fig. 3 shows a schematic structural diagram of a speckle projection apparatus in this exemplary embodiment, and referring to fig. 3, the speckle projection apparatus in this exemplary embodiment may include a light source module 310 and a diffraction module 320. Wherein: the light source module 310 is used for generating linear light; the diffraction module 320 is disposed on the light path of the linear light, and is configured to perform one-dimensional beam splitting on the linear light generated by the light source module 310, so as to obtain a speckle projection array without pincushion distortion.

In an example embodiment, the light source module 310 may be a linear array laser array, and the linear array laser array may be an array obtained by arranging a plurality of spot lasers in a linear array, for example, the linear array laser array may be a 1 × 10 row spot laser array, or a 1 × 200 row spot laser array, and of course, may also be a 1 × N row spot laser array, where N may be a value between 10 and 200, and N may also be greater than 200 according to an actual requirement, and a specific value may be set in a user-defined manner according to a required number of speckle points in the speckle projection array and a fraction split by the diffraction module, which is not particularly limited in this example embodiment.

The linear array Laser array may be an array of 1 × N columns designed by a Vertical-Cavity Surface-Emitting Laser (VCSEL), or an array of 1 × N columns designed by other dot-source type lasers that can be used in a TOF lens, and this exemplary embodiment is not limited thereto.

Specifically, the emitting aperture of the laser corresponding to the dot laser of the line array laser array may be determined according to parameters of other parts in the system, for example, the aperture of the laser in the line array laser array may be determined according to the pixel size of the image sensor of the receiving module of the reflected speckle projection array, the aperture of the laser in the line array laser array may also be determined according to parameters such as the focal length of the optical system, and of course, the emitting aperture may also be determined according to parameters of other parts in the system, which is not particularly limited in this example embodiment. Taking the example that the linear array laser array is composed of the vertical cavity surface laser, the emission aperture of the vertical cavity surface laser is generally set between 6um and 20um, which is, of course, only schematically illustrated here and should not cause any particular limitation to this exemplary embodiment.

In this exemplary embodiment, the diffraction module 320 may be an element structure capable of one-dimensionally splitting (duplicating) the linear light, for example, the diffraction module 320 may be a Diffractive Optical Element (DOE) having a one-dimensionally splitting function, or may be another element structure capable of one-dimensionally splitting (duplicating) the linear light, and this exemplary embodiment is not limited thereto.

In particular, the conventional diffractive optical element DOE for the Spot TOF transmitting module is a two-dimensional dammann grating (or two-dimensional beam splitter), that is, the VCSEL emits light through a collimating mirror, and then the DOE splits the light in the horizontal direction and the vertical direction. Due to the beam splitting of two dimensions of the DOE and the limitation and requirement of the DOE on the incident angle, collimated beams with different angles (view fields) are caused to have different diffraction included angles after passing through the DOE, and finally the phenomenon that serious pincushion distortion exists in speckle points of beam splitting projection is reflected. In the present exemplary embodiment, the linear light generated by the light source module 310 is split horizontally or vertically (where the horizontal direction or the vertical direction depends on the arrangement direction of the linear array laser array) by the diffraction module 320 (corresponding to a one-dimensional dammann grating or a two-dimensional beam splitter) having a one-dimensional beam splitting function, so as to implement a speckle projection array without pincushion distortion.

Preferably, a collimating module may be disposed between the light source module 310 and the diffraction module 320 to collimate the linear light generated by the light source module 310 and to allow the collimated linear light to pass through the diffraction module 320. The collimating module may be a structure of elements capable of transforming a divergent light path into a parallel light path for collimating the divergent light, for example, the collimating module may include, but is not limited to, a collimating mirror (e.g., a zinc selenide lens, similar to a convex lens). The linear light generated by the linear array laser array can be collimated by the collimating module, so that the generated linear light is completely used for generating the speckle projection array, and the waste of light energy is avoided.

Fig. 4 schematically illustrates an apparatus for generating a pincushion-free speckle projection array in an exemplary embodiment of the disclosure.

Referring to fig. 4, the speckle projection apparatus may include a light source module 401, where the light source module 401 may be a linear array laser array 402, and after the linear light generated by the linear array laser array 402 is collimated by a collimating mirror 403, and passes through a one-dimensional diffractive optical element DOE (one-dimensional beam splitter) 404, the linear light generated by the linear array laser array 402 is split (copied) in the horizontal direction or the vertical direction, so as to generate a speckle projection array 405 without pincushion distortion.

Further, in order to satisfy the consistency of the receiving illumination of the photosensitive pixels of the receiving module, it can be known from the relative illumination curve of the lens of the receiving module that the relative illumination decreases according to the relationship of Cos (θ) ^4 as the angle of view increases, where θ can represent the diffraction angle of the diffraction module, and the detailed reference to the relationship (1) is omitted here. Therefore, when designing the diffraction module 320, i.e. the one-dimensional DOE beam splitter, the brightness compensation problem of the fringe field of view needs to be considered,

fig. 5 schematically illustrates a diagram of diffraction order energy distribution data in an exemplary embodiment of the disclosure.

Referring to fig. 5, the energy density distribution of each diffraction order can be designed according to the diffraction efficiency ratio configuration shown in the figure, so as to ensure the uniformity of the receiving illumination of the photosensitive pixels of the receiving module.

In another exemplary embodiment, the light source module 310 may be an Edge Emitting Laser (EEL) and refers to a Laser capable of directly generating line Laser, for example, the Edge Emitting Laser may be a Distributed Feedback Laser (DFB), a Distributed Bragg Reflector (DBR), or other Lasers capable of directly generating line Laser, which is not particularly limited in this exemplary embodiment. Correspondingly, in the present exemplary embodiment, when the light source module 310 is an edge-emitting laser, the generated speckle projection array is an array formed by the light spots of the line structure.

In this exemplary embodiment, the diffraction module 320 may have an element structure capable of one-dimensionally splitting (duplicating) the linear light (linear laser), for example, the diffraction module 320 may be a Diffractive Optical Element (DOE) having a one-dimensionally splitting function, or may have another element structure capable of one-dimensionally splitting (duplicating) the linear light (linear laser), which is not limited in this exemplary embodiment.

Specifically, a collimation module may be disposed between the light source module 310 and the diffraction module 320, and is configured to collimate the linear light generated by the straight-edge emission laser, and perform one-dimensional beam splitting processing on the collimated linear light through the diffraction module 320 to obtain a speckle projection array formed by the light spots with the line structure.

Fig. 6 schematically illustrates another apparatus for generating a pincushion-free speckle projection array in an exemplary embodiment of the disclosure.

Referring to fig. 6, the speckle projection apparatus may include a light source module 601, where the light source module 601 may be an edge-emitting laser 602, linear light (linear laser) generated by the edge-emitting laser 602 is collimated by a collimator lens 603, and then passes through a one-dimensional diffractive optical element DOE (one-dimensional beam splitter) 604, so that the linear light (linear laser) generated by the edge-emitting laser 602 is split (copied) in a horizontal direction or a vertical direction, and a pincushion-distortion-free speckle projection array 605 is generated, where the speckle projection array 605 is an array formed by linear spots.

Particularly, since the laser emission angles in the fast axis and slow axis directions of the edge-emitting laser are different, when the light source module 310 is the edge-emitting laser, the collimating module may be replaced with an aspheric cylindrical lens, and then the linear light (linear laser) is collimated by the aspheric cylindrical lens, and then is subjected to one-dimensional beam splitting processing in the horizontal direction or the vertical direction (where the horizontal direction or the vertical direction depends on the arrangement direction of the edge-emitting laser) by the diffraction module 320 to obtain the speckle projection array formed by the spots with the linear structure.

Fig. 7 schematically illustrates a schematic diagram of an aspheric cylindrical lens in an exemplary embodiment of the present disclosure.

Referring to fig. 7, the linear light (line laser) generated by the edge-emitting laser 602 may be collimated in the vertical direction by the aspheric cylindrical lens 701, and the linear light (line laser) generated by the edge-emitting laser 602 may be collimated in the horizontal direction by the aspheric cylindrical lens 702, however, the aspheric cylindrical lens 701 and the aspheric cylindrical lens 702 in fig. 7 are substantially the same aspheric cylindrical lens, and the collimating process in different directions is only separately illustrated here, and should not be limited to this exemplary embodiment.

Further, when designing the diffraction module 320, i.e. the one-dimensional DOE beam splitter, the problem of brightness compensation of the edge field of view needs to be considered, and with reference to fig. 5, the energy density distribution of each diffraction order may be designed according to the diffraction efficiency ratio configuration shown in the figure, so as to ensure the uniformity of the receiving illumination of the photosensitive pixels of the receiving module.

In another exemplary embodiment, from the viewpoint of reducing the cost and the device complexity of the emission module, when the light source module 310 is an edge-emitting laser, the collimating module may not be provided, and the linear light (linear laser) generated by the edge-emitting laser and the diffraction module 320, i.e., the one-dimensional DOE beam splitter, are directly used to design the speckle projection array without pincushion distortion.

Specifically, the fast axis included angle of line laser emission can be adjusted through the size of the emission hole of the control limit emission laser, when the included angle of the fast axis of line laser emission and the slow axis is too small, the diffraction module 320, namely the one-dimensional DOE beam splitter, can be directly used for one-dimensional beam splitting, and the aspheric surface column lens is not needed any more for collimation. Through getting rid of the collimation module, the size of the emission hole of adjustment limit transmission laser can reduce speckle projection arrangement 300 volume size and manufacturing cost to owing to reduced the collimation module, can be simpler in the module assembly process of TOF, improve the yield.

Fig. 8 schematically illustrates a schematic diagram of another apparatus for generating a pincushion-free speckle projection array in an exemplary embodiment of the disclosure.

Referring to fig. 8, the speckle projection apparatus may include a light source module 801, wherein the light source module 801 may be an edge-emitting laser 802, a linear light (linear laser) generated by the edge-emitting laser 802 may not be collimated by a collimating mirror, a fast axis included angle of the linear laser emission may be adjusted by controlling a size of an emission hole of the edge-emitting laser, when an included angle between the fast axis and the slow axis of the linear laser emission is too small, a beam splitting (copying) in a horizontal direction or a vertical direction may be directly performed by a one-dimensional diffractive optical element DOE (one-dimensional beam splitter) 803, so as to generate a speckle projection array 804 without pincushion distortion, and the speckle projection array 804 is an array formed by light spots of a line structure.

In summary, in the present exemplary embodiment, the light source module generates linear light; and arranging the diffraction module on the light path of the linear light, and performing one-dimensional beam splitting processing on the linear light to obtain the speckle projection array without pincushion distortion. On one hand, the speckle projection array without pincushion distortion can be directly obtained through one-dimensional beam splitting processing of linear light, and compared with the conventional scheme of carrying out two-dimensional beam splitting processing on a point light source, the speckle projection array without pincushion distortion can be realized, and waste of scattered spots (energy) is avoided; on the other hand, a new hardware structure is not added, only the original structure is changed, the problem of increased manufacturing cost caused by the introduction of the new hardware structure is solved, and the volume of the system is not increased; on the other hand, when different speckle arrays need to be generated by adjustment, only the parameters of the generated linear light and the parameters of the diffraction module need to be adjusted, and the overall hardware does not need to be changed, so that the flexibility and the application range are improved, and the cost is saved.

Also provided in the exemplary embodiment is a distance measurement system, and as shown in fig. 9, the distance measurement system 900 may include a speckle projection device 910, a receiving device 920, and a control device 930. Wherein:

the speckle projection device 910 is used for emitting a speckle projection array without pincushion distortion to the target area, and the speckle projection array can be reflected at the target area to generate a reflective speckle array;

the receiving device 920 is used for receiving the reflective speckle array;

the control device 930 is electrically connected to the speckle projection device 910 and the receiving device 920, and is configured to record a phase when the speckle projection device 910 emits the speckle projection array, and output a phase difference when the receiving device 920 receives the reflected speckle array, so as to calculate a real distance to the target area according to the phase difference.

Further, referring to fig. 10, the embodiment of the present example also provides a speckle projection method, which may include steps S1010 and S1020. Wherein:

step S1010, generating linear light through a light source module;

step S1020, performing one-dimensional beam splitting processing on the linear light to obtain a speckle projection array without pincushion distortion.

In an exemplary embodiment, the light source module may include a line array laser array or an edge-emitting laser, and in particular, the line-shaped light may be generated by the line array laser array or the edge-emitting laser.

In an exemplary embodiment, after the linear light is generated by the light source module, the linear light may be collimated to obtain collimated linear light. For example, after the light source module generates the linear light, before the linear light is subjected to the one-dimensional beam splitting processing, the collimating module may be arranged to obtain the collimated linear light, and the one-dimensional beam splitting processing may be performed on the collimated linear light.

By means of the collimation treatment of the linear light, the divergent light path corresponding to the linear light generated by the linear array laser array or the edge-emitting laser can be converted into the parallel light path, so that the linear light generated by the linear array laser array or the edge-emitting laser is completely used for generating the speckle projection array, and the waste of speckles (energy) is avoided.

In an exemplary embodiment, after the one-dimensional beam splitting processing is performed on the linear light, brightness compensation may be further performed on the linear light through the steps in fig. 11 to achieve uniform illuminance of the generated speckle projection array, which is shown in fig. 11, and specifically includes:

step S1110, acquiring preset diffraction order energy distribution data;

step S1120, performing brightness compensation on the linear light after the one-dimensional beam splitting processing according to the diffraction order energy distribution data.

The diffraction level energy distribution data are configured according to the proportion of diffraction efficiency set according to a relative illumination curve of the receiving module lens, the linear light after one-dimensional beam splitting processing can be subjected to brightness compensation through the diffraction level energy distribution data, the generated speckle projection arrays are uniform in illumination, the brightness of the reflected speckle projection arrays reaching photosensitive pixels is kept consistent, the accuracy of results obtained by measuring the photosensitive pixels is improved, and the measuring precision is improved.

The specific details of each step in the above method have been described in detail in the embodiment of the apparatus part, and the details that are not disclosed can be referred to the embodiment of the apparatus part, and thus are not described again.

It is noted that the above-mentioned figures are merely schematic illustrations of processes involved in methods according to exemplary embodiments of the present disclosure, and are not intended to be limiting. It will be readily understood that the processes shown in the above figures are not intended to indicate or limit the chronological order of the processes. In addition, it is also readily understood that these processes may be performed synchronously or asynchronously, e.g., in multiple modules.

As will be appreciated by one skilled in the art, aspects of the present disclosure may be embodied as a system, method or program product. Accordingly, various aspects of the present disclosure may be embodied in the form of: an entirely hardware embodiment, an entirely software embodiment (including firmware, microcode, etc.) or an embodiment combining hardware and software aspects that may all generally be referred to herein as a "circuit," module "or" system.

Exemplary embodiments of the present disclosure also provide a computer-readable storage medium having stored thereon a program product capable of implementing the above-described method of the present specification. In some possible embodiments, various aspects of the disclosure may also be implemented in the form of a program product including program code for causing a terminal device to perform the steps according to various exemplary embodiments of the disclosure described in the above-mentioned "exemplary methods" section of this specification, when the program product is run on the terminal device, for example, any one or more of the steps in fig. 3 to 8 may be performed.

It should be noted that the computer readable media shown in the present disclosure may be computer readable signal media or computer readable storage media or any combination of the two. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the foregoing. More specific examples of the computer readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

In the present disclosure, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. In contrast, in the present disclosure, a computer readable signal medium may comprise a propagated data signal with computer readable program code embodied therein, either in baseband or as part of a carrier wave. Such a propagated data signal may take many forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, fiber optic cable, RF, etc., or any suitable combination of the foregoing.

Furthermore, program code for carrying out operations of the present disclosure may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, C + + or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computing device, partly on the user's device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computing device (e.g., through the internet using an internet service provider).

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It will be understood that the present disclosure is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is to be limited only by the terms of the appended claims.

Claims

1. A speckle projection apparatus, comprising:

a light source module for generating linear light;

2. The apparatus of claim 1, wherein the speckle projection apparatus further comprises a collimation module disposed between the light source module and the diffraction module for collimating the linear light.

3. The apparatus of claim 2, wherein the light source module comprises a linear array laser array, and the light source module generates the linear light through the linear array laser array.

4. The apparatus of claim 2, wherein the light source module comprises an edge-emitting laser, and the light source module generates the line-shaped light through the edge-emitting laser.

5. The apparatus of any of claims 2 or 4, wherein the collimating module comprises an aspheric cylindrical lens for collimating the line-shaped light generated by the edge-emitting laser.

6. The apparatus according to any one of claims 1 to 4, wherein the diffraction module comprises an illumination compensation unit, and the illumination compensation unit is configured to perform illumination compensation on the linear light after one-dimensional beam splitting processing according to preset diffraction order energy distribution data.

7. A distance measuring system, comprising:

a receiving device for receiving the reflective speckle array;

8. A speckle projection method, comprising:

generating linear light by a light source module;

9. The method of claim 8, wherein the generating line-shaped light by the light source module further comprises:

and carrying out collimation treatment on the linear light to obtain the collimated linear light.

10. The method according to any one of claims 8 or 9, wherein the light source module comprises a linear array laser array or an edge-emitting laser; the generating of the linear light by the light source module includes:

and generating linear light by the linear array type laser array or the edge emitting laser.

11. The method of claim 8, wherein the one-dimensional beam splitting processing of the linear light further comprises:

acquiring preset diffraction order energy distribution data;

and performing brightness compensation on the linear light subjected to the one-dimensional beam splitting treatment according to the diffraction order energy distribution data.

12. An electronic device, comprising:

a processor; and

a memory for storing executable instructions of the processor;

wherein the processor is configured to perform the method of any of claims 8 to 11 via execution of the executable instructions.