CN107039885B

CN107039885B - Laser array applied to 3D imaging

Info

Publication number: CN107039885B
Application number: CN201710309212.1A
Authority: CN
Inventors: 王兆民; 许星
Original assignee: Orbbec Inc
Current assignee: Orbbec Inc
Priority date: 2017-05-04
Filing date: 2017-05-04
Publication date: 2023-04-18
Anticipated expiration: 2037-05-04
Also published as: CN107039885A

Abstract

The invention discloses a laser array applied to 3D imaging, a pattern design method of the laser array applied to 3D imaging, a laser projection device and 3D imaging equipment, wherein the laser array applied to 3D imaging comprises the following components: the laser array comprises a semiconductor substrate and VCSEL light sources, wherein the VCSEL light sources are distributed on the surface of the semiconductor substrate in a two-dimensional array mode, the two-dimensional array is generated in a mode of rotationally copying a sector sub-array, sub-areas containing any other quadrant in any direction of the two-dimensional array obtained in a mode of simply rotationally copying the sector sub-array have irrelevance, and the two-dimensional array corresponds to the distribution condition of the VCSEL light sources, so that the VCSEL light sources distributed on the surface of the semiconductor substrate have extremely high irrelevance, and the problem that the VCSEL light sources used for 3D imaging in the prior art are low in irrelevance is solved.

Description

Laser array applied to 3D imaging

Technical Field

The invention relates to the technical field of optics and electronics, in particular to a laser array applied to 3D imaging.

Background

The 3D imaging technology especially applied to the consumption field can continuously impact and even replace the traditional 2D imaging technology, the 3D imaging technology has the capability of carrying out 2D imaging on the target object and can also acquire the depth information of the target object, and the functions of 3D scanning, scene modeling, gesture interaction and the like can be further realized according to the depth information. Depth cameras, in particular structured light depth cameras or TOF (time of flight) depth cameras are hardware devices that are currently commonly used for 3D imaging.

The core component in the depth camera is a laser projection module, and the structure and function of the laser projection module are also different according to the difference of the types of the depth camera, for example, the projection module disclosed in the prior art is used for projecting a speckle pattern into a space to realize structured light depth measurement, and the speckle structured light depth camera is also a mature and widely adopted scheme at present. With the continuous expansion of the application field of depth cameras, the optical projection module will be continuously evolving towards smaller and smaller volume and higher performance.

A depth camera using a VCSEL (vertical cavity surface emitting laser) array light source will replace an edge emitting laser emitter light source because of its advantages of small size, high power, and concentrated light beam, and the VCSEL array is characterized in that laser projection is performed by arranging a plurality of VCSEL light sources on an extremely small substrate, for example, 100 VCSEL light sources are arranged on a 5mmx5mm semiconductor substrate. For a structured light depth camera, the speckle pattern projected outward by the laser projection module is required to have extremely high irrelevancy, which increases the difficulty of designing the arrangement of the light sources on the VCSEL array.

Disclosure of Invention

In order to solve the problem of low irrelevance of the VCSEL light source used for 3D imaging, the invention provides a VCSEL array light source used for 3D imaging.

The technical problem of the invention is solved by the following technical scheme: the solution of the invention comprises a laser array applied to 3D imaging, a pattern design method of the laser array applied to 3D imaging, a laser projection device and a 3D imaging device.

Wherein, the laser array for 3D imaging comprises: the array structure comprises a semiconductor substrate and VCSEL light sources, wherein the VCSEL light sources are distributed on the surface of the semiconductor substrate in a two-dimensional array, and the two-dimensional array is arranged in a mode of rotating and copying sector sub-arrays. The central angle of the sector sub-arrays is preferably 15 °, 30 °, 45 °, 60 °, 90 ° or 120 °. The number of VCSEL sources in the sector sub-array preferably does not exceed 24 and the number of VCSEL sources in the two-dimensional array preferably does not exceed 576. The arrangement mode of the VCSEL light sources in the fan-shaped subarrays is irregular. The two-dimensional array is arranged in a mode that a sector sub-array is copied by rotating around the center of the sector sub-array. In different embodiments, two adjacent sector sub-arrays include: partial overlap, presence of spaced regions without VCSEL light sources, edge coincidence, or a combination thereof.

In addition, the pattern design method of the laser array applied to 3D imaging provided by the invention comprises the following steps: generating irregularly arranged fan-shaped subarray patterns; and rotationally copying the fan-shaped sub array pattern to obtain the pattern of the laser array.

Meanwhile, the laser projection device provided by the invention comprises:

the laser array of any of the above;

a lens for receiving and converging the light beams emitted by the laser array;

a speckle pattern generator for splitting the beam and emitting a speckle pattern beam into space.

Wherein the lens may comprise a single lens and/or a microlens array; the speckle pattern generator may comprise one or more of a micro-lens array, a DOE, a grating.

In addition, the present invention proposes a 3D imaging apparatus including: the laser projection device of any one of the above, for emitting a structured light pattern beam into space;

the image acquisition device is used for acquiring a structured light image formed by irradiating the structured light pattern beam on a target object;

and the processor receives the structured light image and calculates the depth image of the target object according to the trigonometry principle.

Compared with the prior art, the invention has the advantages that: the VCSEL light sources are distributed on the surface of the semiconductor substrate in a two-dimensional array mode, the two-dimensional array mode is generated in a mode of rotating and copying the sector sub-arrays, sub-areas containing any other quadrant in any direction (such as the direction of an x axis in the transverse direction or the direction of a y axis in the longitudinal direction) of the two-dimensional array mode acquired in a mode of simply rotating and copying the sector sub-arrays have irrelevance, and the two-dimensional array corresponds to the distribution condition of the VCSEL light sources, so that the VCSEL light sources distributed on the surface of the semiconductor substrate have extremely high irrelevance.

Drawings

FIG. 1 is a side view of a structured light depth camera system in an embodiment of the present invention.

Fig. 2 is a side view of a laser projection apparatus in an embodiment of the invention.

Figure 3 is a schematic diagram of a VCSEL array of one embodiment of the present invention.

Figure 4 is a schematic diagram of a VCSEL array of one embodiment of the present invention.

Figure 5 is a schematic diagram of a VCSEL array of one embodiment of the present invention.

Figure 6 is a schematic diagram of a VCSEL array of one embodiment of the present invention.

Figure 7 is a schematic diagram of a VCSEL array of one embodiment of the present invention.

Figure 8 is a schematic diagram of a VCSEL array of one embodiment of the present invention.

Figure 9 is a schematic diagram of a VCSEL array of one embodiment of the present invention.

Figure 10 is a schematic diagram of a VCSEL array of one embodiment of the present invention.

Detailed Description

The invention will be further described with reference to the accompanying drawings and preferred embodiments.

The invention provides a laser array applied to 3D imaging, and provides a corresponding laser projection device and a 3D imaging device based on the laser array, wherein the 3D imaging device is also called a depth camera, and a value on each pixel in an image of an object shot by the depth camera represents a depth value between corresponding points in space and the depth camera. In the following description, the laser array, the laser projection device and the depth camera are described as examples, but it is not meant that the laser array can be applied to the depth camera only, and any other devices that directly or indirectly utilize the solution should be included in the protection scope of the present invention.

FIG. 1 is a schematic side view of a structured light based depth camera. The depth camera (3D imaging device) 101 mainly includes a laser projection module (corresponding to a laser projection device) 104, an acquisition module (corresponding to an image acquisition device) 105, a main board 103, and a processor 102, and some depth cameras are further provided with an RGB camera 107. The laser projection module 104, the acquisition module 105, and the RGB camera 107 are typically mounted in the same depth camera plane and on the same baseline, with each module or camera corresponding to a light entrance window 108. Generally, the processor 102 is integrated on the motherboard 103, and the laser projection module 104 and the collection module 105 are connected to the motherboard via an interface 106, which is an FPC interface in one embodiment. The laser projection module is used for projecting coded structured light pattern beams into a target space, and the acquisition module is used for acquiring structured light images formed by irradiating the structured light pattern beams on a target object; and the processor is used for receiving the structured light image acquired by the acquisition module and calculating the depth image of the target object according to the trigonometry principle.

In one embodiment, the structured light image is an infrared laser speckle pattern having a relatively uniform distribution of particles but a high local irrelevance, where the local irrelevance is a high uniqueness of each sub-region of the pattern along a certain directional dimension (generally, along a direction where the laser projection module is connected to the collection module). The corresponding collection module 105 is an infrared camera corresponding to the optical projection module 104. The processor is used for acquiring the depth image, and specifically, after the speckle pattern acquired by the acquisition module is received, the depth image is further acquired by calculating the deviation value between the speckle pattern and the reference speckle pattern.

FIG. 2 is a diagram of one embodiment of the laser projection module 104 of FIG. 1. The laser projection module 104 includes a substrate 201, a light source 202, a lens 203, and a speckle pattern generator 204. The substrate 201 is typically a semiconductor substrate, such as a wafer, on which a plurality of light sources 202 are arranged, the substrate 201 and the light sources 202 together constituting a laser array, e.g. a VCSEL array chip. The light source 202 includes a plurality of sub light sources for emitting a plurality of sub light beams, the light source may be a laser light source such as visible light, invisible light, infrared light, ultraviolet light, etc., the light source may be a side emitting laser or a vertical cavity surface laser, in order to make the overall projection apparatus smaller in size, the optimal scheme is to select a vertical cavity surface laser emitter array (VCSEL array) as the light source, and the VCSEL array also has the advantages of a small light source divergence angle, etc. For convenience of illustration, the 3 sub-light sources are listed in only one dimension, and in fact the VCSEL array is a two-dimensional light source arranged in a fixed two-dimensional pattern. The VCSEL array chip can be a bare chip or a packaged chip, and the difference between the VCSEL array chip and the packaged chip is that the bare chip has smaller volume and thickness, and the packaged chip has better stability and more convenient connection.

In order to make the pattern emitted from the laser projection device have uniform, uncorrelated, etc., it is required that the arrangement pattern of the VCSEL array chips is an irregular pattern, i.e. the light sources are not arranged in a regular array, but arranged in a certain irregular pattern. In some embodiments, the VCSEL array chip has an overall size of only a micrometer, such as 5mm × 5mm, with tens or even hundreds of light sources arranged thereon, with a distance between the individual light sources being in the micrometer range, such as 30 μm.

The lens 203 is used to receive and focus the light beams emitted by the VCSEL array light source 202, specifically the laser array of the present invention, and in one embodiment, collimate the divergent VCSEL beams into parallel beams to ensure a more concentrated emitted spot energy. Instead of using a single lens, in one embodiment, a Micro Lens Array (MLA) may be used, where each micro lens unit in the MLA corresponds to each VCSEL array light source 202, or where one micro lens unit corresponds to multiple VCSEL array light sources 202.

The speckle pattern generator 204 is used for receiving the lens beam and emitting the beam capable of forming the speckle pattern into the space, in an embodiment, the speckle pattern generator 204 is a Diffractive Optical Element (DOE), and the DOE plays a role of beam splitting, for example, when the number of the light sources 202 is 100, that is, the beam transmitted to the DOE via the lens is 100, the DOE can split the lens beam by a certain number (for example, 200) of times, and finally emit 20000 beams into the space, ideally 20000 spots will be seen (in some cases, there is a situation that some spots overlap, resulting in a reduction in the number of spots). Instead of DOEs, any other optical element that can form spots may be used, such as MLA, gratings or one or a combination of various optical elements.

The lens 203 and the DOE204 may be fabricated on the same optical element in some embodiments to achieve the effect of reducing the volume.

Fig. 3 to 10 are schematic diagrams of light source arrangements of VCSEL arrays according to the embodiment of the present invention. In each figure, circles represent the positions of the light sources, and squares represent the semiconductor substrates. To facilitate the explanation of the inventive concept, some separation lines and circular outlines have been added to the figures, which are for illustration only and are not necessarily true in VCSEL arrays.

In the case of a structured light depth camera, especially structured light based on a speckle pattern, a key step of triangulating depth is to calculate a pixel deviation value between a speckle image and a reference speckle pattern, where this calculation step is performed by a depth processor (or a dedicated processing chip), and the most important step in performing the calculation is to find a sub-region in the speckle image, which is the same as the reference speckle image according to a matching algorithm, where the sub-region refers to a fixed-size pixel region in the image, such as 7 × 7 and 11 × 11 pixels. The matching algorithm requires that the patterns in each sub-region in the speckle image along the baseline direction are different, i.e. the speckle image has high local irrelevancy, where the baseline refers to the connection line between the laser projection module 104 and the acquisition module 105.

In order to meet the requirement of local irrelevance, generally, the arrangement of the light sources 202 in the VCSEL array requires irregular arrangement, and a common scheme is to randomly generate position information of the light sources 202 on the substrate 201 during design, which has the advantages of clear design idea and simple design implementation; the disadvantage is that the uncontrollable pattern of the light source 202 is relatively strong, a lot of experiments and verifications are often needed to generate a relatively good uncorrelated pattern, on the other hand, the positioning accuracy of each spot in the chip manufacturing process is difficult to be grasped, and the accuracy, efficiency and other aspects of the manufacturing process of the VCSEL chip with some regular arrangement or symmetrical characteristics are better. The invention provides a laser array applied to 3D imaging, which has extremely high irrelevance. The laser array comprises VCSEL light sources which are distributed on the surface of the semiconductor substrate in a two-dimensional array, wherein the two-dimensional array is arranged in a mode of rotating and copying through at least one sub array. The two-dimensional array comprises a plurality of sub-arrays, and the sub-arrays share the same circle center. When the arrangement mode of the two-dimensional array is generated by the rotary copying form of the sector sub-arrays, the two-dimensional array comprises a plurality of same sector sub-arrays, and the sector sub-arrays share the same circle center. The VCSEL array in the embodiment of fig. 3-10 can be understood to be similar to the description of the laser array, but is not limited thereto.

In fig. 3, which is a schematic diagram of a VCSEL array according to an embodiment of the present invention, a plurality of light sources 202 are arranged on a substrate 201, and the light sources 202 are distributed within a circular boundary 208 and can be divided into 4 sectors with an angle of 90 degrees. The relationship between the four sector areas is that one of the two adjacent areas can be regarded as an area formed by rotating the adjacent area by 90 degrees around the center of the sector, for example, the area 210 can be regarded as an area formed by rotating the area 209 clockwise by 90 degrees around the center of the sector, or an area formed by rotating the area 205 counterclockwise by 90 degrees around the center of the sector. In other embodiments, the central angle of the sector sub-array may be 15 °, 30 °, 45 °, 60 °, 120 °, or the like, and related embodiments are listed below. In this embodiment, the edges of adjacent regions overlap, and the patterns do not overlap. When designing the pattern, as long as the pattern of any one of the sector areas is generated at any time, the patterns of the other sector areas can be copied by a rotation method until the whole area is filled up. The concrete mode is as follows:

taking fig. 3 as an example, if a rectangular coordinate system is established with the center of a circle as the origin, the quadrant in which the sector area 203 is located is the first quadrant. The coordinates of a plurality of (for example 24) spots are first randomly generated in the first quadrant:

wherein the superscript 1 represents the first quadrant, if represented in polar coordinates, is ^ er>

Secondly, the coordinates of the spots in the second, third and fourth quadrants are calculated, wherein：

The coordinates of each spot in the second quadrant are:

the coordinates of each spot in the third quadrant are:

the coordinates of each spot in the fourth quadrant are:

thus, as long as the coordinates of each spot in the sector area represented by the first quadrant are available, the coordinates of each point in the other sector areas can be directly obtained according to the above formula.

Besides the fact that the speckle of the whole area can be generated by only randomly generating the speckle in a partial area to improve the controllability, the rotation copy method has the greatest advantage that the sub-areas in any direction (such as the x-axis direction in the transverse direction or the y-axis direction in the longitudinal direction) have high irrelevancy. Since the spots in each sector are randomly generated, the spots in the sector have irrelevancy, and further, since the spots are rotated and copied, the subregions including any other quadrant in any direction have irrelevancy, for example, in fig. 3, in the transverse direction (x-axis direction), one subregion 206 (referring to a subregion centered at any point in the transverse direction) is arbitrarily selected, and the shape of the subregion 207 centered at any point in the transverse direction in the first quadrant may not be the same as that of the subregion 206, so that the irrelevancy of the subregion height is ensured. In this embodiment, spots can also be placed on the edges of the sector.

Figure 4 shows another embodiment of VCSEL array chip arrangement where the angular extent of the fan-shaped region is 45 degrees and the replication of adjacent fan-shaped regions is performed by rotating the fan-shaped region 45 degrees clockwise/counterclockwise until the entire region is filled, for a total of 8 fan-shaped regions. The increased number of rotational replications increases the number and density of spots compared to figure 3 when the number of spots in the sector area is the same, which is twice the number of VCSEL arrays as in figure 3.

Fig. 5 shows a situation where two adjacent sector areas overlap, and compared with fig. 3, the angle of the sector area in fig. 3 is 90 degrees, and a total of 4 sector areas are generated by rotating 90 degrees for duplication, while the angle of the sector area in fig. 5 is also 90 degrees, but the rotation angle is 72 degrees, and finally 5 sector areas are generated, and there is a partial overlap between two adjacent sector areas, as shown in fig. 5. It is also possible to set the rotation angle to be variable, for example, to rotate alternately 72 degrees and 90 degrees until the entire area is filled, and there is a simultaneous partial overlap and edge coincidence between two adjacent sector sub-arrays of the two-dimensional array thus obtained.

In fig. 6, the spacing between two adjacent fan-shaped regions is shown, and compared with fig. 4, the angle of the fan-shaped region in fig. 4 is 45 degrees, and 8 fan-shaped regions are generated in total by rotating 45 to copy, while the angle of the fan-shaped region in fig. 6 is still 45 degrees, but the rotation angle is every 90 degrees, and finally, a spacing region without a VCSEL light source exists between two adjacent fan-shaped regions. The VCSEL array generated by the mode is sparse, and the sparse array is beneficial to obtaining a depth image in a short distance. The two-dimensional array can also be rotated by 90 degrees, 45 degrees and 30 degrees alternately, the sector sub-arrays of the two-dimensional array obtained in the way comprise three conditions of partial mutual overlapping, existence of interval areas without VCSEL light sources and edge overlapping, and the two-dimensional array with a plurality of or one of the three conditions can be obtained by changing the rotation angle.

Through demonstration, the inventor finds that the size of the sector area, namely the central angle, is preferably set to be 15 degrees, 30 degrees, 45 degrees, 60 degrees, 90 degrees or 120 degrees, and the angle of the rotating duplication is preferably set according to the angle of the sector area, and finally the whole area is filled, the edges of the adjacent sector areas are overlapped and the contents of the adjacent sector areas are not overlapped. For example, when the size of the sector is 15 °, the angle of the rotated copy is 15 °, and 24 sectors are generated in total.

In the embodiment shown in fig. 7, the rotationally replicated sub-arrays are located in a sector area 701 and a plurality of

annular areas

702 and 703, and the number and arrangement of light sources in the three sub-arrays may be the same or different. The arrangement of the light sources in each annular area can be controlled to achieve the effect of arranging the whole light sources, for example, the density of the light sources from inside to outside is smaller and smaller, so that the closer the whole light source arrangement is to the circle center, the denser the whole light source arrangement is. The arrangement of the VCSEL light sources in the sub-arrays is in an irregular pattern. In addition, the angles of the respective annular regions and the rotation angle may be different, but not limited thereto, as shown in fig. 8, the angle of the sector region of the inner circle is 45 degrees, the angle of the rotational copy is also 45 degrees, the angles of the two annular regions of the outer circle are 60 degrees and 90 degrees, respectively, the rotation angles are 60 degrees and 90 degrees, respectively, and the density of the spots (i.e., the light sources) from the inside to the outside is smaller. In still other embodiments, the sector area angle of the inner circle is 90 degrees, the rotational duplication angle is 72 degrees, the angles of the two annular areas of the outer circle are 120 degrees and 45 degrees, respectively, and the rotational angles are 120 degrees and 90 degrees, respectively, and the two adjacent sub-arrays in the corresponding two-dimensional array include: the three conditions of partial mutual overlapping, existence of interval area without VCSEL light source and edge superposition can be obtained by changing the rotation angle, and a plurality of or one two-dimensional array with the three conditions can be obtained.

The sub-array distribution area includes sector areas and/or ring areas, in this embodiment, the number of the sector areas is 1, and the number of the ring areas is 2, in other embodiments, there may not be sub-arrays of sector areas, and the number of the ring areas may be other numbers.

As shown in fig. 9, compared to the single sector area in fig. 3 to 6, there are two different sector areas, 901 and 902 respectively, the angles are 15 degrees and 30 degrees respectively, the rotation angles are 45 degrees, and the number of light sources in the area is different. It will be appreciated that the angular size of the sector and the spot distribution may be otherwise arbitrary.

The rotation angles may be different from sector to sector, and as shown in fig. 10, the rotation angle of the sector 901 is 75 degrees, while the rotation angle of the sector 902 changes, that is, 30 degrees, 60 degrees, and 30 degrees.

As can be seen from the methods described in fig. 3 to 10, a variety of pattern shapes can be generated by setting the distribution area shape (sector and/or ring shape), size, number, spot arrangement (including density) and the angle of the rotation copy of the sub-arrays according to different requirements. When the number of the sub-arrays is not less than 2, at least one of the size, the distribution area shape, and the rotation angle of the sub-arrays is different. Therefore, the above description is not intended to limit the present invention, but to exemplify the idea of the present invention.

However, it is not always possible to arbitrarily set the size of the region where the sub-arrays are located and the angle of the rotational reproduction, and when the sector area is too small or the angle of the rotational reproduction is too small, the irrelevancy is reduced. In addition, the number of spots in the region of the subarray may also affect the irrelevancy.

Through demonstration, the inventor finds that the size, namely the angle, of the fan-shaped or annular area is preferably set to be 15 degrees, 30 degrees, 45 degrees, 60 degrees, 90 degrees, 120 degrees and the like, and the angle of the rotary copying is preferably set according to the angle of the fan-shaped or annular area, so that the whole area is filled, the edges of the adjacent areas are overlapped, and the contents of the adjacent areas are not overlapped. For example, when the size of the sector area is 15 °, the angle of the rotational copy is 15 °, resulting in 24 sector areas in total. When the size of the annular region is 30 °, the angle of the rotational replication is 30 °, resulting in 12 annular regions in total.

In addition, the number of light sources in the subarray area is not too large, and the inventors found that the number of light sources is preferably not more than 24, and the number of light sources in the whole VCSEL array is preferably not more than 576, so that the best effect can be achieved. The spacing between the light sources is generally in the range of 8 μm to 30 μm, on average, depending on the requirements of the manufacturing process.

In the present invention, the arrangement pattern of the light sources in the VCSEL chip in the embodiment shown in fig. 3 to 10 is understood as a description of similar patterns, and a design method for generating the pattern is correspondingly provided, i.e. one or more sub-arrays are firstly generated, and then the sub-arrays are rotated and copied to finally generate the whole pattern. It is not excluded that other design methods are used to achieve the same effect as using the sub-array rotation replication, i.e. to generate a pattern with the same characteristics as the rotation replication, and it is understood that any VCSEL pattern with any other design method achieving the same effect as the rotation replication also falls within the scope of the present invention.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several equivalent substitutions or obvious modifications can be made without departing from the spirit of the invention, and all the properties or uses are considered to be within the scope of the invention.

Claims

1. A laser array for 3D imaging, comprising: the device comprises a semiconductor substrate and VCSEL light sources, wherein the VCSEL light sources are distributed on the surface of the semiconductor substrate in a two-dimensional array, the two-dimensional array is arranged in a mode of being rotationally copied through fan-shaped sub-arrays, and therefore sub-areas of the VCSEL light sources in any one direction have high irrelevancy so as to generate a structured light speckle pattern with relatively uniform particle distribution and high local irrelevancy.

2. The laser array for 3D imaging as claimed in claim 1, wherein: the central angles of the sector sub-arrays comprise 15 degrees, 30 degrees, 45 degrees, 60 degrees, 90 degrees or 120 degrees.

3. The laser array applied to 3D imaging of claim 1, wherein the number of VCSEL light sources in the sector subarray is no more than 24 and the number of VCSEL light sources in the two dimensional array is no more than 576.

4. The laser array applied to 3D imaging according to claim 1, wherein the arrangement of the VCSEL light sources in the sector sub-array is irregular.

5. The laser array for 3D imaging according to claim 1, wherein the two-dimensional array is arranged in a manner that a sector sub-array is reproduced by rotation around its center.

6. The laser array applied to 3D imaging according to claim 1, wherein two adjacent sector sub-arrays include: partial overlap, presence of spaced regions without VCSEL light sources, edge coincidence, or a combination thereof.

7. A method of patterning a laser array for 3D imaging as claimed in any of claims 1 to 6, comprising: generating irregularly arranged fan-shaped subarray patterns; rotationally replicating the fan sub-array pattern captures the pattern of the laser array such that sub-regions of the VCSEL light source in either direction have a high degree of irrelevancy to produce a structured light speckle pattern with a relatively uniform particle distribution but a high degree of local irrelevancy.

8. A laser projection device, comprising:

the laser array of any of claims 1-6;

a lens for receiving and converging the light beams emitted by the laser array;

9. The laser projection device of claim 8, wherein the lens comprises a single lens and/or a micro-lens array; the speckle pattern generator comprises one or more of a micro-lens array, a DOE, a grating.

10. A 3D imaging device, comprising:

the laser projection device of any of claims 8-9, for emitting a structured light pattern beam into space;