CN210894704U

CN210894704U - Time-of-flight distance measuring system

Info

Publication number: CN210894704U
Application number: CN201921344988.8U
Authority: CN
Inventors: 闫敏
Original assignee: Shenzhen Oradar Technology Co Ltd
Current assignee: Shenzhen Oradar Technology Co Ltd
Priority date: 2019-08-19
Filing date: 2019-08-19
Publication date: 2020-06-30
Anticipated expiration: 2029-08-19

Abstract

The utility model provides a time flight distance measurement system, include: the transmitting module comprises an array light source consisting of a plurality of sub light sources and is used for transmitting non-floodlight carrier beams to an object; the acquisition module is used for acquiring the non-floodlight carrier beams reflected by the object; the processing circuit is connected with the transmitting module and the collecting module and is used for calculating the flight time from transmitting to collecting of the non-floodlight carrier beam; the array light source comprises a first sub light source array and a second sub light source array which are regularly arranged, and the first sub light source array and the second sub light source array are arranged in a mutually crossed mode to improve the transverse density and the longitudinal density of the sub light sources in the array light source. An array light source is adopted through a transmitting module, and non-floodlight carrier beams with uneven intensity distribution are transmitted outwards; furthermore, the array light source adopts the sub light source array which is arranged in a cross way, the transverse and longitudinal intervals of the sub light sources are smaller, and the resolution of the depth image is improved.

Description

Time-of-flight distance measuring system

Technical Field

The utility model relates to a computer technology field especially relates to a time flight distance measurement system.

Background

The Time of flight (TOF) method calculates the distance of an object by measuring the Time of flight of a light beam in space, and is widely applied to the fields of consumer electronics, unmanned driving, AR/VR, and the like due to its advantages of high precision, large measurement range, and the like.

Distance measurement systems based on the time-of-flight principle, such as time-of-flight depth cameras, lidar and other systems, often include a light source emitting end and a receiving end, where the light source emits a light beam to a target space to provide illumination, the receiving end receives the light beam reflected back by the target, and the system calculates the distance to the object by calculating the time required for the light beam to be emitted to be reflected and received. When distance sensing is performed by using a time flight depth camera and a laser radar equal-distance measuring system, ambient light interference affects measurement accuracy, for example, when ambient light intensity is high and even submerges a light beam of a light source, especially for floodlight illumination, the light beam of the light source is difficult to distinguish, so that a large measurement error occurs.

Background light suppression can be performed by adding optical methods such as optical filters and electronic methods such as subtraction circuits (the article CMOS Sensors for Time-Resolved Active Imaging) in the prior art, however, these methods still cannot essentially eliminate or reduce measurement errors caused by ambient light interference. The point scanning approach is advantageous for improving the signal-to-noise ratio, but the measurement resolution is lower compared to flood lighting. In summary, the prior art is difficult to consider signal-to-noise ratio, measurement accuracy and measurement resolution.

Disclosure of Invention

The utility model discloses a solve current problem, provide a time flight distance measurement system.

In order to solve the above problem, the utility model discloses a technical scheme as follows:

a time-of-flight distance measurement system comprising: the transmitting module comprises an array light source consisting of a plurality of sub light sources and is used for transmitting non-floodlight carrier beams to an object; the acquisition module is used for acquiring the non-floodlight carrier beams reflected by the object; the processing circuit is connected with the transmitting module and the collecting module and is used for calculating the flight time from transmitting to collecting of the non-floodlight carrier beam; the array light source comprises a first sub light source array and a second sub light source array which are regularly arranged, and the first sub light source array and the second sub light source array are arranged in a mutually crossed mode to improve the transverse density and the longitudinal density of the sub light sources in the array light source.

In an embodiment of the present invention, the array light source is a VCSEL array light source, and the VCSEL array light source includes a semiconductor substrate and an array light source composed of a plurality of VCSEL sub-light sources disposed on the semiconductor substrate. The first sub-light source array and the second sub-light source array are independently controlled.

In another embodiment of the present invention, the transmitting module has a first distortion characteristic, the collecting module has a second distortion characteristic, and the first distortion characteristic and the second distortion characteristic compensate each other. The first distortion characteristic is a barrel distortion characteristic or a pincushion distortion characteristic, and the second distortion characteristic is a pincushion distortion characteristic or a barrel distortion characteristic.

In a third embodiment of the present invention, the emission module includes an array light source, a projection lens and a spatial light modulator. The arrangement of the sub light sources on the array light source is a two-dimensional arrangement pattern with a first distortion characteristic; or, the projection lens has a first distortion characteristic; or, the diffraction pattern of the spatial light modulator has a first distortion characteristic; or at least two of the sub light source arrangement on the array light source, the projection lens and the diffraction pattern of the spatial light modulator are comprehensively designed to enable the emission module to have a first distortion characteristic.

In a fourth embodiment of the present invention, the emission module includes an array light source and a projection lens. The arrangement of the sub light sources on the array light source is a two-dimensional arrangement pattern with a first distortion characteristic; or, the projection lens has a first distortion characteristic; or, the arrangement of the sub-light sources on the array light source and the projection lens are comprehensively designed so that the emission module has a first distortion characteristic.

In a fifth embodiment of the present invention, the array light source emits a pulsed light beam at a frequency set according to the measurement distance; alternatively, the amplitude of the light beam emitted by the array light source is modulated to emit a continuous wave light beam of a square wave light beam, a sine wave light beam.

The utility model has the advantages that: providing a time flight distance measuring system, adopting an array light source through a transmitting module, and outwards transmitting a non-floodlight carrier beam with uneven intensity distribution; furthermore, the array light source adopts the sub light source array which is arranged in a cross way, the transverse and longitudinal intervals of the sub light sources are smaller, and the resolution of the depth image is improved.

Drawings

Fig. 1 is a schematic diagram of an array light source time-of-flight distance measurement system according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a transmitting module according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a transmitting module according to another embodiment of the present invention.

Fig. 4 is a schematic diagram illustrating the influence of parallax on imaging according to an embodiment of the present invention.

Fig. 5 is a schematic diagram of an array light source according to an embodiment of the present invention.

Fig. 6 is a schematic diagram of a distortion correction principle according to an embodiment of the present invention.

Wherein 10-distance measurement system, 11-emission module, 12-collection module, 13-processing circuit, 20-object, 30-emission beam, 40-reflection beam, 111-array light source, 112-spatial light modulator, 121-array pixel unit, 122-imaging lens unit, 201-array light source, 202-projection lens, 203-diffractive optical element, 204-beam, 205-beam, 206-beam, 301-array light source, 302-projection lens, 303-beam, 304-beam, 305-beam, 121-array pixel unit, 401-imaging position, 402-imaging position, 403-pixel, 51-array light source, 511-VCSEL sub-light source, 512-VCSEL sub-light source, 61-first distortion, 62-second distortion, 63-compensated effect.

Detailed Description

In order to make the technical problem, technical scheme and beneficial effect that the embodiment of the present invention will solve more clearly understand, the following combines the drawings and embodiment, and goes forward the further detailed description of the present invention. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element. The connection may be for fixation or for circuit connection.

It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientation or positional relationship indicated in the drawings for convenience in describing the embodiments of the present invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be construed as limiting the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of the present invention, "a plurality" means two or more unless specifically limited otherwise.

The utility model provides a distance measurement system, it has stronger anti ambient light ability and higher resolution ratio.

Fig. 1 is a schematic diagram of an array light source time-of-flight distance measurement system according to an embodiment of the present invention. The distance measuring system 10 includes an emission module 11, an acquisition module 12 and a processing circuit 13, wherein the emission module 11 provides an emission beam 30 to an object 20 in a target space to illuminate the space, at least a part of the emission beam 30 is reflected by the object 20 to form a reflection beam 40, at least a part of the reflection beam 40 is acquired by the acquisition module 12, the processing circuit 13 is respectively connected with the emission module 11 and the acquisition module 12, the trigger signals of the emission module 11 and the acquisition module 12 are synchronized to calculate the time required for the emission beam to be emitted by the emission module 11 and to be received by the acquisition module 12, i.e. the flight time t between the emission beam 30 and the reflection beam 40, further, the distance D of a corresponding point on the object can be calculated by the following formula:

D＝c·t/2 (1)

where c is the speed of light.

The emitting module 11 includes an array light source 111 and a spatial light modulator 112. The array light source 111 may be an array of light sources such as Light Emitting Diodes (LEDs), Edge Emitting Lasers (EELs), Vertical Cavity Surface Emitting Lasers (VCSELs), and preferably, the array light source 111 is a VCSEL array light source chip formed by generating a plurality of VCSEL light sources on a single semiconductor substrate, and the light beam emitted by the array light source 111 may be visible light, infrared light, ultraviolet light, and the like. The array light source 111 emits a light beam outwards under the control of the processing circuit 13, for example, in an embodiment, the array light source 111 emits a pulse light beam at a certain frequency under the control of the processing circuit 13, which can be used in Direct time of flight (Direct TOF) measurement, where the frequency is set according to a measurement distance, for example, the frequency can be set to 1 MHz-100 MHz, and the measurement distance is several meters to several hundred meters; in one embodiment, the light source 111 emits a light beam whose amplitude is modulated under the control of the processing circuitry 13 to emit a continuous wave light beam, such as a square wave light beam, a sine wave light beam, or the like, which can be used in Indirect time of flight (infrared TOF) measurements. It will be appreciated that the light source 111 may be controlled to emit the associated light beam, either as part of the processing circuitry 13 or independently of sub-circuits present in the processing circuitry 13, such as a pulse signal generator.

The spatial light modulator 112 receives the carrier beam from the light source 111 and spatially modulates the carrier beam, i.e., modulates the distribution of the carrier beam in space to form a non-flood carrier beam with a non-uniform intensity distribution for emission. Compared with the traditional floodlight beam, the non-floodlight beam has uneven intensity distribution, so that the area with higher intensity distribution has higher anti-interference performance on the ambient light under the condition of the same light source power; in addition, in the case of the same projection field angle, the floodlighting needs higher power consumption due to the non-uniformity of the intensity distribution, that is, to achieve the same ambient light anti-interference performance. In some embodiments, the spatial light modulator 112 is further configured to expand the received carrier beam to expand the field of view.

The processing circuit 13 may be a stand-alone dedicated circuit, such as a dedicated SOC chip, an FPGA chip, an ASIC chip, etc., or may comprise a general-purpose processor, such as when the depth camera is integrated into a smart terminal, such as a mobile phone, a television, a computer, etc., where the processor in the terminal may be at least a part of the processing circuit 13.

The collecting module 12 comprises an array pixel unit 121 and an imaging lens unit 122, wherein the imaging lens unit 122 receives and guides at least part of the non-floodlight carrier beam reflected by the object to at least part of the array pixel unit 121. In one embodiment, the array pixel unit 121 may be a Charge Coupled Device (CCD), a Complementary Metal Oxide Semiconductor (CMOS), an Avalanche Diode (AD), a Single Photon Avalanche Diode (SPAD), etc., and the array size of the array pixel unit 121 represents the resolution of the depth camera, such as 320 × 240, etc. Generally, a readout circuit (not shown) including one or more of a signal amplifier, a time-to-digital converter (TDC), an analog-to-digital converter (ADC), and the like is further included in connection with the array pixel unit 121.

In some embodiments, the distance measurement system 10 may further include a color camera, an infrared camera, an IMU, etc., and a combination thereof may implement more rich functions, such as 3D texture modeling, infrared face recognition, SLAM, etc.

Fig. 2 is a schematic diagram of a transmitting module according to an embodiment of the present invention. The emission module 11 includes an array light source 201, a projection lens 202, and a Diffractive Optical Element (DOE)203, where the array light source 201 emits a pulse, square wave, or sine wave modulated light beam under power time modulation of the processing circuit 13, the light beam is collimated or focused by the projection lens 202 and then enters the DOE203, and the DOE203 spatially modulates, i.e., diffracts, the incident light beam. In one embodiment, DOE203 splits an incident beam and emits

multiple beams

204, 205, and 206, such as tens of thousands of beams, into a target space, each of which forms a spot on the surface of object 20. In one embodiment, the DOE203 will form a pattern of regularly arranged spots (meaning that the angular offsets of the individual spots are evenly distributed, the regular arrangement is incident on the surface of the 3D object, and the arrangement will be reconstructed) by diffraction of the incident beam. In one embodiment, the DOE203 will form a speckle pattern by diffracting the incident light beam, i.e., the arrangement of the spots in the spot pattern has a certain randomness.

In some embodiments, the DOE203 may also be replaced by a mask plate, which includes a two-dimensional pattern for modulating the incident light beam into a non-flood light beam, so that the incident light beam can be spatially modulated by the mask plate to form a two-dimensional code pattern carrier light beam.

Fig. 3 is a schematic diagram of a transmitting module according to another embodiment of the present invention. The emission module 11 includes an array light source 301 and a projection lens 302, the projection lens 302 can be designed into a single-chip or multi-chip form as required, the array light source 301 emits a light beam to a target space through the projection lens 302 to emit

light beams

303, 304, 305, and finally a projection pattern, i.e. a speckle pattern, is formed in accordance with the light source arrangement pattern on the array light source 301. Processing circuitry 13 performs time-sequential power modulation on array light source 301 to emit a pulsed, square wave or sine wave modulated light beam. In one embodiment, the array light source 301 is a VCSEL array light source.

Fig. 4 is a schematic diagram illustrating the influence of parallax on imaging according to another embodiment of the present invention. Fig. 4 only exemplarily shows a part of the array pixel unit 121, including 32 pixels 403 in total of 4 rows (R1, R2, R3, R4) and 8 columns (C1, C2, C3, C4, C5, C6, C7, C8). The light beam reflected by the target is imaged on the array pixel unit 121 through the imaging lens 122, and in this embodiment, assuming that a single light beam is imaged on about 4 pixels 2x2, the 4 pixels 2x2 may be referred to as macro-pixels, and the single macro-pixel corresponds to the light spot formed by the single light beam. It should be understood that "imaging" herein may refer to integrating incident light signals by a CCD or CMOS image sensor using a general photon integration function, and may also refer to counting incident light signals by a SPAD image sensor.

In the present application, as shown in fig. 1, the distance imaging system 10 has the emission module 11 and the collection module 12 disposed off-axis, and there is a certain parallax between them, so when the emission module 11 emits the light beam 30 to the target 20, when the distance of the target 20 changes, the parallax will cause the imaging position of the light beam on the array pixel unit 121 to deviate. Taking any light beam as an example for explanation, if the measurement range of the range imaging system is [ D1, D2], when the target 20 is located at the D1 position, the imaging position corresponding to the light beam is 401; when the target is located at the position D2 and the imaging position of the light beam is 402, the size of the light spot will be slightly changed in consideration of the imaging multiple. Therefore, when actual measurement is performed, it is often necessary to determine the deviation range of the good spot in advance from the measurement range to guide the distance analysis and calculation performed later by the processor.

Fig. 5 is a schematic diagram of an array light source according to an embodiment of the present invention. The array light source 51 includes a semiconductor substrate and a plurality of VCSEL

sub-light sources

511 and 512 disposed on the substrate. For the emission module 11 shown in fig. 2 or fig. 3, the arrangement density of the sub-light sources in the array light source 51 determines the pattern density of the light beam 30 projected by the final emission module 11, thereby further affecting the resolution of the depth calculation. However, due to factors such as manufacturing process, diameter of single sub-light source, mutual influence of multiple sub-light sources, etc., it is impossible to bring two sub-light sources 511 into infinite proximity, for example, the current spacing between two sub-light sources 511 can reach um level at the minimum.

To further increase the resolution, in the present embodiment, the array light source 51 is configured as a cross-regularly arranged array light source, that is, a first sub light source array composed of a plurality of first sub light sources 511 and a second sub light source array composed of a plurality of second sub light sources 512 are formed by crossing, and the first sub light sources 511 and the second sub light sources 512 are drawn in two different forms for illustration, without any limitation to the actual properties of the two sub light sources. Assuming that the minimum physical interval between the two light sources at the time of manufacturing is D, the distances between the two light sources closest to each other in the transverse direction and the longitudinal direction after crossing each other are x and y, respectively, and x < D, y < D, i.e. the transverse and longitudinal intervals in the cross arrangement are smaller. When the projection light beam formed by the array light source is further used for depth calculation, the resolution of the formed depth image is improved, namely, compared with a regular array light source with the distance D between the horizontal direction and the longitudinal direction, the resolution of the array light source arranged in a cross mode can be improved in the horizontal direction and the longitudinal direction.

In one embodiment, the first sub-light source array and the second sub-light source array can be independently controlled to be independently turned on or turned on all in different applications.

In addition to affecting resolution due to manufacturing physical size limitations, parallax causes imaging effects to also affect resolution to some extent. As shown in fig. 4, after the baseline between the emission module 11 and the collection module 12 and the measurement range of the distance measurement system 10 are determined, the interval of the light spot deviation value caused by the parallax is also determined, and in order to avoid that two adjacent light spots are mistakenly identified, for example, if the interval between two horizontal pixels is smaller than 8 pixels corresponding to the interval on the array pixel unit 121, the misrecognition is caused, that is, at least two light spots exist on the same interval, so that the measurement error is caused. To avoid causing false identifications, there is a minimum limit on the lateral separation of adjacent sub-light sources (determined by parallax, measurement range, etc.). The resolution can be improved in the lateral direction by the crossed light source arrangement shown in fig. 5, and in addition, the longitudinal resolution is improved under the premise of the limit of the manufacturing process due to the staggered arrangement in the lateral direction.

Fig. 6 is a schematic diagram of a distortion correction principle according to an embodiment of the present invention. In the above embodiments, the influence of system distortion is not considered, and in an actual distance measurement system, distortion, such as barrel distortion and pincushion distortion, is brought about by the projection lens and/or the imaging lens. For structured light technologies, distortion can increase the uncorrelation of structured light images and is therefore often allowed, whereas for time-of-flight distance measurements, especially for off-axis systems in this application, larger distortions are not allowed. As shown in fig. 4, if there is a large distortion, the deviation of the light spot due to parallax will not be along the horizontal direction any more, and there will also be a deviation in the vertical direction, and when the vertical deviation is too large, for example, exceeds the line interval corresponding to the macro-pixel, it will cause a large error in the measurement. In order to reduce the distortion, the present embodiment provides a principle of distortion compensation, that is, two opposite distortion characteristics are designed to achieve the compensation purpose in the distance measuring system, namely, a first (positive) distortion 61 and a second (negative) distortion 62, and the compensated effect is shown as 63, i.e., the pincushion distortion is the negative distortion if the barrel distortion is called the positive distortion.

In one embodiment, the array light source and/or the DOE and the projection lens in the emission module 11 are designed to have positive and negative distortion respectively to reduce the distortion of the projection pattern. For example, for the embodiment shown in fig. 2 and 3, if the projection lens 202 has a barrel (pillow) shape distortion, one way may be to design the arrangement of the sub-light sources on the array light source 201 as a two-dimensional arrangement pattern of the barrel (pillow) shape distortion, and the other way may be to design the diffraction pattern of the DOE203 as a two-dimensional diffraction pattern of the barrel (pillow) shape distortion. It is of course also possible to compensate for the distortion effect caused by the projection lens by simultaneously designing the arrangement of the sub-light sources on the array light source 201 and the diffraction pattern of the DOE 203. It is understood that the light source modem is a DOE here, and may be other devices having the same or similar functions, and the like in the following embodiments.

In one embodiment, the emission module 11 and the collection module 12 are respectively designed to have positive and negative distortion characteristics to reduce the distortion of the projected pattern. If the imaging lens 122 in the collection module 12 is a barrel (pillow) shaped distortion, the speckle pattern emitted by the emission module 11 is designed to be a speckle pattern with the characteristic of the barrel (pillow) shaped distortion, and the design of the barrel (pillow) shaped distortion speckle pattern can also be realized in various ways. For the transmit module embodiment shown in fig. 2: firstly, directly arranging and designing the sub-light sources on the array light source 201 into a two-dimensional arrangement pattern with pillow (barrel) shaped distortion characteristics; secondly, designing the projection lens into a pillow (barrel) shaped distortion lens; thirdly, designing the diffraction pattern of the DOE into a pillow (barrel) shaped distorted two-dimensional diffraction pattern (for the case that the emission module has the DOE); and fourthly, comprehensively designing at least two of the array light source arrangement pattern, the projection lens and the DOE diffraction pattern to project a pincushion (barrel) distorted spot pattern. For the transmit module embodiment shown in fig. 3: firstly, directly arranging and designing the sub-light sources on the array light source 301 into a two-dimensional arrangement pattern with pillow (barrel) shaped distortion characteristics; secondly, designing the projection lens into a pillow (barrel) shaped distortion lens; thirdly, array light source arrangement patterns and projection lenses are comprehensively designed to project pillow (barrel) shaped distorted spot patterns.

The distortion correction scheme shown in fig. 6 realizes distortion compensation on hardware, and compared with the traditional scheme for realizing distortion compensation through an algorithm, the distortion correction scheme not only reduces the requirement on the algorithm, but also can solve the distortion problem from the source, and has better effect.

It can be understood that when will the utility model discloses a can make corresponding structure or part change in order to adapt to the demand when distance measuring system imbeds in device or the hardware, its essence still adopts the utility model discloses a distance measuring system, so should regard as the utility model discloses a protection scope.

The foregoing is a more detailed description of the present invention, taken in conjunction with the specific preferred embodiments thereof, and it is not intended that the invention be limited to the specific embodiments shown and described. To the technical field of the utility model belongs to the prerequisite of not deviating from the utility model discloses, can also make a plurality of equal substitution or obvious variants, performance or usage are the same moreover, all should regard as belonging to the utility model's scope of protection.

Claims

1. A time-of-flight distance measurement system, comprising:

the transmitting module comprises an array light source consisting of a plurality of sub light sources and is used for transmitting non-floodlight carrier beams to an object;

the acquisition module is used for acquiring the non-floodlight carrier beams reflected by the object;

the processing circuit is connected with the transmitting module and the collecting module and is used for calculating the flight time from transmitting to collecting of the non-floodlight carrier beam;

the array light source comprises a first sub light source array and a second sub light source array which are regularly arranged, and the first sub light source array and the second sub light source array are arranged in a mutually crossed mode to improve the transverse density and the longitudinal density of the sub light sources in the array light source.

2. The time-of-flight distance measurement system of claim 1, wherein the array light source is a VCSEL array light source, the VCSEL array light source comprising a semiconductor substrate and an array light source of a plurality of VCSEL sub-light sources disposed on the semiconductor substrate.

3. The time-of-flight distance measurement system of claim 1, wherein the first sub-light source array and the second sub-light source array are independently controlled.

4. The time-of-flight distance measurement system of claim 1, wherein the transmit module has a first distortion characteristic and the acquisition module has a second distortion characteristic, the first distortion characteristic and the second distortion characteristic compensating for each other.

5. The time-of-flight distance measurement system of claim 4, wherein the first distortion characteristic is a barrel distortion characteristic or a pincushion distortion characteristic and the second distortion characteristic is a pincushion distortion characteristic or a barrel distortion characteristic.

6. The time-of-flight distance measurement system of claim 4, wherein the transmit module comprises an array light source, a projection lens, and a spatial light modulator.

7. The time-of-flight distance measurement system of claim 6, wherein the arrangement of the sub light sources on the array light source is a two-dimensional arrangement pattern having a first distortion characteristic;

or, the projection lens has a first distortion characteristic;

or, the diffraction pattern of the spatial light modulator has a first distortion characteristic;

or at least two of the sub light source arrangement on the array light source, the projection lens and the diffraction pattern of the spatial light modulator are comprehensively designed to enable the emission module to have a first distortion characteristic.

8. The time-of-flight distance measurement system of claim 4, wherein the transmit module comprises an array light source and a projection lens.

9. The time-of-flight distance measurement system of claim 8, wherein the arrangement of the sub light sources on the array light source is a two-dimensional arrangement pattern having a first distortion characteristic;

or, the projection lens has a first distortion characteristic;

or, the arrangement of the sub-light sources on the array light source and the projection lens are comprehensively designed so that the emission module has a first distortion characteristic.

10. The time-of-flight distance measurement system of claim 1, wherein the array light source emits a pulsed light beam at a frequency set according to a measurement distance; alternatively, the amplitude of the light beam emitted by the array light source is modulated to emit a continuous wave light beam of a square wave light beam, a sine wave light beam.