Point cloud transmitting device based on super lens

Abstract

The utility model provides a superlens-based point cloud transmitting device, and relates to the technical field of point cloud transmitting devices. Comprising an array light source, a module substrate, a structural shell and a single-piece super lens, the array light source comprises a plurality of sub light sources; the array light source and the structural shell are arranged on the same side of the module substrate; the structural shell is used for protecting the array light source and the super lens and supporting the super lens; the super lens comprises a substrate and a micro-nano structure arranged on the substrate. The super lens is arranged on the light emitting side of the array light source, and the super lens is used for carrying out collimation and diffraction copying on emitted light of the array light source, so that target light spot clouds are obtained through projection. According to the invention, only one super lens is used to replace a plurality of traditional lenses in a traditional solution, so that the assembly requirements of optical elements of equipment are effectively reduced, and the total length of an optical system is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of point cloud emission devices, and specifically, the present application relates to a point cloud emission device based on a superlens. Background Art

[0002] In depth sensing and three-dimensional imaging technology, the transmitter is a key component of the system. It usually uses a dense dot matrix projector to project a regular or pseudo-random dot pattern of light spots onto the target object. This technology is widely used in ToF (Time of Flight) and structured light systems to obtain the depth information of the target and reconstruct the three-dimensional shape. Traditional structured light emitting devices usually consist of a collimating lens group and a traditional diffractive optical element (DOEs, Diffractive Optical Elements). The collimating lens group consists of three traditional lenses. Its main function is to collimate the VCSEL (Vertical Cavity Surface Emitting Laser) with a divergence angle and then irradiate it onto the traditional diffractive optical element for multi-order diffraction replication, thereby realizing the replication of the VCSEL array pattern.

[0003] Although the traditional structured light emitting device can complete its basic functions, its configuration needs to be optimized. First, since the system requires 4 optical elements (including 3 lenses and 1 DOE), this not only increases the manufacturing cost, but also makes the requirements for assembly accuracy more stringent, and puts forward high requirements on the assembly accuracy of the module. Secondly, due to the superposition of multiple optical elements, the total length of the system is relatively long, which is not conducive to the miniaturization and integrated design of the equipment. These shortcomings limit the use of traditional structured light emitting devices in specific application scenarios, such as depth sensing and three-dimensional imaging systems in mobile devices and portable devices.

[0004] Therefore, how to simplify the optical system and reduce assembly requirements while maintaining the original functions has become an urgent problem that needs to be solved. Utility Model Content

[0005] In order to solve the technical problem of high requirements for optical system assembly in the prior art, the first aspect of the present application provides a point cloud emission device based on a superlens, including: an array light source, a module substrate, a structural housing and a monolithic superlens.

[0006] The array light source includes a plurality of sub-light sources; the array light source and the structural shell are arranged on the same side of the module substrate; the structural shell is used to protect the array light source and the super lens, and to support the super lens; the super lens includes a substrate and a micro-nano structure arranged on the substrate; the super lens is arranged on the light output side of the array light source, and the super lens is used to collimate and diffract and replicate the emitted light of the array light source to project a target light spot cloud.

[0007] The superlens satisfies the relationship:

[0008]

[0009] Among them, θ is the diffraction angle of the light beam projected by the superlens, λ is the central wavelength of the emitted light of the array light source, and P is the arrangement period of the micro-nano structure.

[0010] Optionally, in the frequency domain, the light spots in the target light spot cloud are evenly arranged with equal spatial frequency intervals.

[0011] Optionally, the sub-light sources in the array light source are regularly arranged and distributed periodically; the superlens satisfies the relationship:

[0012]

[0013] Among them, f t is the spatial frequency in the target direction in the frequency domain, θ t is the line connecting the light spot and the center of the superlens, the deflection angle in the target direction of the frequency domain relative to the optical axis of the superlens, and λ is the central wavelength of the emitted light of the array light source.

[0014] Optionally, the metalens satisfies the relationship:

[0015]

[0016] Among them, n is the number of sub-light sources in the target direction; θ1 is the deflection angle of the 0th order diffraction beam of the edge sub-light source located at the first end in the target direction; θ2 is the deflection angle of the 0th order diffraction beam of the edge sub-light source located at the second end in the target direction; θ′0 is the deflection angle of the 1st order diffraction beam of the central sub-light source in the target direction.

[0017] Optionally, when θ′0<25°, the metalens satisfies the relationship:

[0018]

[0019] Among them, n is the number of sub-light sources in the target direction; θ1 is the deflection angle of the 0th order diffraction beam of the edge sub-light source located at the first end in the target direction; θ2 is the deflection angle of the 0th order diffraction beam of the edge sub-light source located at the second end in the target direction; θ′0 is the deflection angle of the 1st order diffraction beam of the central sub-light source in the target direction.

[0020] Optionally, the metalens satisfies the relationship:

[0021]

[0022] Among them, z is the projection distance of the target light spot cloud, b is the propagation attenuation coefficient of the light energy in the target environment, t is the diffraction efficiency of the superlens, q is the total number of diffracted portions of the emitted light of the array light source, E1 is the output energy of the sub-light source, and E2 is the minimum detection energy of the image sensor. The image sensor is used to sense the target light spot cloud.

[0023] Optionally, the metalens satisfies the relationship:

[0024]

[0025] Among them, γ is the full angle of the dot matrix coverage angle in the target direction; M is the number of dot matrix copies in the target direction; θ1 is the deflection angle of the 0th order diffraction beam of the edge sub-light source located at the first end in the target direction; θ2 is the deflection angle of the 0th order diffraction beam of the edge sub-light source located at the second end in the target direction; θ′0 is the deflection angle of the 1st order diffraction beam of the central sub-light source in the target direction; L1 is the distance of the replicated unit point cloud in the target direction; L2 is the maximum misalignment distance of different combined point clouds in the target direction. The combined point cloud is obtained by continuously replicating and splicing the unit point clouds in the target direction.

[0026] Optionally, the module substrate is provided with circuit elements, and the circuit elements are used to provide electrical energy and driving control signals for the array light source.

[0027] Optionally, the structural housing is provided with a limiting structure, and the limiting structure is used to limit and fix the metalens.

[0028] Optionally, the point cloud emitting device is used for three-dimensional sensing based on time-of-flight technology, and the sub-light sources in the array light source are regularly arranged and distributed periodically.

[0029] Optionally, the point cloud emitting device is used for three-dimensional sensing based on structured light technology, and the sub-light sources in the array light source are pseudo-randomly arranged and distributed.

[0030] The technical solution in this application uses a super lens to replace a traditional lens, and only uses one super lens to replace multiple traditional lenses in the traditional solution, which effectively reduces the assembly requirements of the optical components of the device and reduces the total length of the optical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are included to provide a further understanding of the present application and are incorporated in and constitute a part of this specification. The accompanying drawings illustrate embodiments of the present application and together with the following description serve to explain the principles of the present application.

[0032] Figure 1 A schematic diagram of the structure of a point cloud emission device based on a superlens provided in an embodiment of the present application is shown;

[0033] Figure 2A schematic diagram of the structure of a conventional point cloud transmitting device provided in an embodiment of the present application is shown;

[0034] Figure 3 A schematic diagram of sub-light source deflection analysis provided in an embodiment of the present application is shown;

[0035] Figure 4 The local phase distribution diagram of the metalens of the point cloud launch device provided in the embodiment of the present application is shown;

[0036] Figure 5 A schematic diagram of a database phase distribution curve provided in an embodiment of the present application is shown;

[0037] Figure 6 A schematic diagram of structured light projection and reception provided by an embodiment of the present application is shown;

[0038] Figure 7 A schematic diagram of the arrangement of VCSEL light sources corresponding to Example 1 of the present application is shown;

[0039] Figure 8 A schematic diagram of point cloud light distribution corresponding to Example 1 of the present application is shown;

[0040] Fig. 9 A schematic diagram of the VCSEL light source arrangement corresponding to Example 2 of the present application is shown;

[0041] Fig.10 A schematic diagram of point cloud light distribution corresponding to Example 2 of the present application is shown;

[0042] Fig.11 A schematic diagram of the VCSEL light source arrangement corresponding to Example 3 of the present application is shown;

[0043] Fig.12 A schematic diagram of point cloud light distribution corresponding to Example 3 of the present application is shown;

[0044] Fig.13 A schematic diagram of the VCSEL light source arrangement corresponding to Example 4 of the present application is shown;

[0045] Fig.14 A schematic diagram of point cloud light distribution corresponding to Example 4 of the present application is shown;

[0046] Fig.15 A schematic diagram of the arrangement of VCSEL light sources corresponding to Example 5 of the present application is shown;

[0047] Fig.16 A schematic diagram of point cloud light distribution corresponding to Example 5 of the present application is shown;

[0048] Fig.17 A schematic diagram of the arrangement of VCSEL light sources corresponding to Example 6 of the present application is shown;

[0049] Fig.18 A schematic diagram of point cloud light distribution corresponding to Example 6 of the present application is shown;

[0050] Fig.19 A schematic diagram of the arrangement of VCSEL light sources corresponding to Example 7 of the present application is shown;

[0051] Fig. 20 A schematic diagram of point cloud light distribution corresponding to Example 7 of the present application is shown;

[0052] Fig.21 A schematic diagram of the arrangement of VCSEL light sources corresponding to Example 8 of the present application is shown;

[0053] Fig. 22 A schematic diagram of point cloud light distribution corresponding to Example 8 of the present application is shown;

[0054] Fig.23 A schematic diagram of the arrangement of VCSEL light sources corresponding to Example 9 of the present application is shown;

[0055] Fig.24 A schematic diagram of point cloud light distribution corresponding to Example 9 of the present application is shown;

[0056] Fig.25 A schematic diagram of the arrangement of VCSEL light sources corresponding to Example 10 of the present application is shown;

[0057] Fig.26 A schematic diagram of point cloud light distribution corresponding to Example 10 of the present application is shown;

[0058] Fig. 27 A schematic diagram of the VCSEL light source arrangement corresponding to Example 11 of the present application is shown;

[0059] Fig.28 A schematic diagram of point cloud light distribution corresponding to Example 11 of the present application is shown;

[0060] Fig.29 A schematic diagram of the arrangement of VCSEL light sources corresponding to Example 12 of the present application is shown;

[0061] Fig.30 A schematic diagram of point cloud light distribution corresponding to Example 12 of the present application is shown;

[0062] Fig.31 A schematic diagram of the arrangement of VCSEL light sources corresponding to Example 13 of the present application is shown;

[0063] Fig.32 A schematic diagram of point cloud light distribution corresponding to Example 13 of the present application is shown.

[0064] The reference numerals in the figure represent respectively:

[0065] 101: module substrate; 102: array light source; 103: structural housing;

[0066] 104: superlens; 105: substrate; 106: micro-nanostructure;

[0067] 201: module substrate; 202: VCSEL array;

[0068] 203: structural housing; 204: conventional diffractive optical element;

[0069] 205: a first collimating lens; 206: a second collimating lens;

[0070] 207: a third collimating lens; 208: a collimating lens assembly bracket. DETAILED DESCRIPTION

[0071] The present application will now be described more fully below with reference to the accompanying drawings, in which various embodiments are shown. However, the present application can be implemented in many different ways and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that the present application will be exhaustive and complete, and will fully convey the scope of the present application to those skilled in the art. The same reference numerals throughout the text represent the same components. Furthermore, in the accompanying drawings, the thickness, ratios, and sizes of the components are exaggerated for clarity.

[0072] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, "one", "the", "at least one" as used herein do not represent a limitation on quantity, but are intended to include both the singular and the plural. For example, unless the context clearly indicates otherwise, "a component" has the same meaning as "at least one component". "At least one" should not be interpreted as being limited to the number "one". "Or" means "and / or". The term "and / or" includes any and all combinations of one or more of the associated listed items.

[0073] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meanings as those generally understood by those skilled in the art. Terms defined in commonly used dictionaries should be interpreted as having the same meanings as in the relevant technical context, and unless clearly defined in the specification, these terms are not interpreted as having formal meanings in an idealized or overly formal sense.

[0074] The meaning of “include” or “comprising” specifies properties, quantities, steps, operations, components, parts or a combination thereof, but does not exclude other properties, quantities, steps, operations, components, parts or a combination thereof.

[0075] Embodiments are described herein with reference to cross-sectional views as idealized embodiments. Thus, variations in shape relative to the illustrated diagram are anticipated as a result of, for example, manufacturing techniques and / or tolerances. Therefore, the embodiments described herein should not be interpreted as being limited to the specific shapes of the regions as shown herein, but should include deviations in shape due to, for example, manufacturing. For example, a region shown or described as flat may typically have rough and / or nonlinear features. Moreover, the sharp angles shown may be rounded. Therefore, the regions shown in the figures are schematic in nature, and their shapes are not intended to illustrate the precise shape of the regions and are not intended to limit the scope of the claims.

[0076] As mentioned above, in the field of point cloud emission devices, the use of traditional lenses to collimate the light emitted by the light source requires the cooperation of multiple lenses. This not only requires high assembly precision, but also makes it difficult to reduce the overall volume of the optical system, which is not conducive to system integration and miniaturization.

[0077] Based on this, the inventor provides a point cloud emission device based on a superlens.

[0078] Hereinafter, exemplary embodiments according to the present application will be described with reference to the accompanying drawings.

[0079] like Figure 1 As shown, the present application provides a point cloud emitting device based on a superlens, comprising: an array light source 102, a module substrate 101, a structural housing 103 and a monolithic superlens 104.

[0080] The array light source 102 includes a plurality of sub-light sources; the array light source 102 and the structural housing 103 are arranged on the same side of the module substrate 101; the structural housing 103 is used to protect the array light source 102 and the super lens 104, and is used to support the super lens 104; the super lens 104 includes a substrate 105 and a micro-nano structure 106 arranged on the substrate 105; the super lens 104 is arranged on the light-emitting side of the array light source 102, and the super lens 104 is used to collimate and diffract the emitted light of the array light source 102, so as to project a target light spot cloud;

[0081] The metalens 104 satisfies the relationship:

[0082]

[0083] In formula (1), θ is the diffraction angle of the light beam projected by the super lens 104 , λ is the central wavelength of the emitted light from the array light source 102 , and P is the arrangement period of the micro-nano structure 106 .

[0084] The superlens can modulate the array light source and realize the diffraction replication of the array light source, forming a scattered spot cloud of the replication pattern on any plane behind the emission end, and there is a certain FOI (Field of Illumination) angle range of the illumination area. However, due to the limitation of the diffraction limit, the maximum projection angle is shown in formula (1), which is related to the wavelength of the light beam and the period of the micro-nano structure.

[0085] In the prior art, conventional point cloud transmitting devices usually use traditional lenses to collimate the light and combine with traditional diffractive optical elements (DOEs) to achieve diffraction and beam splitting of the light. Figure 2 As shown, the structure of a conventional point cloud emitting device includes: a module substrate 201, a VCSEL (Vertical Cavity Surface Emitting Laser) array 202, a structural housing 203, a first collimating lens 205, a second collimating lens 206, a third collimating lens 207, a collimating lens group bracket 208, and a conventional diffractive optical element 204. Among them, the structural housing 203 and the VCSEL array 202 are arranged on one side of the module substrate 201, and the first collimating lens 205, the second collimating lens 206, and the third collimating lens 207 are fixed in the collimating lens group bracket 208, and together with the collimating lens group bracket 208, they form a collimating lens group. The collimating superlens group is used to collimate the light of the VCSEL array to generate a collimated light beam, and the conventional diffractive optical element 204 is used to diffract and split the collimated light beam to finally generate a point cloud.

[0086] In the technical solution provided by the present application, a super lens is used to replace a traditional lens. According to the phase superposition principle, the collimation phase and the diffraction beam splitting phase are superimposed on each other, so the phase distribution of the super lens is:

[0087]

[0088] In formula (2), represents the phase of the superlens after superposition, It represents the phase of the modulation to achieve the collimation function, Indicates the phase of the modulated diffraction beam splitting function. Using a super lens to collimate and diffract the light emitted by the light source can effectively reduce the requirements for installation accuracy and the thickness of the optical system.

[0089] Since the minimum period of the metalens is small, the diffraction angle of the light passing through it is relatively large, thereby achieving a large-angle emission beam and increasing the projection range. The phase setting of the metalens is flexible. By changing the wavelength of the light source and the arrangement of the light source, and changing the phase distribution of the micro-nano structure on the metalens according to the wavelength of the light source, the same design method can be used to manufacture metalenses suitable for point cloud projection decorations with a variety of coverage ranges.

[0090] In some embodiments, optionally, in the frequency domain, the light spots in the target light spot cloud are uniformly arranged in the form of equal spatial frequency intervals. Diffractive optical elements generally perform modulation operations in the frequency domain, so adjusting the uniform arrangement of the space in the frequency domain can achieve better debugging effects. In some embodiments, optionally, the sub-light sources in the array light source are regularly arranged and distributed periodically; the super lens satisfies the relationship:

[0091]

[0092] In formula (3), f t is the spatial frequency in the target direction in the frequency domain, θ t is the deflection angle of the line connecting the light spot and the center of the metalens in the target direction of the frequency domain relative to the optical axis of the metalens, and λ is the central wavelength of the emitted light of the array light source. t represents the target direction in the frequency domain, which can be the x-axis or y-axis direction; if t represents the x-axis direction, f t It represents the spatial frequency in the x-axis direction of the frequency domain. t can represent the direction of periodic arrangement of sub-light sources and the direction of periodic arrangement of point cloud spots.

[0093] In some embodiments, optionally, the metalens satisfies the relationship:

[0094]

[0095] In formula (4), n is the number of sub-light sources in the target direction; θ1 is the deflection angle of the 0th-order diffraction beam of the edge sub-light source located at the first end in the target direction; θ2 is the deflection angle of the 0th-order diffraction beam of the edge sub-light source located at the second end in the target direction; θ′0 is the deflection angle of the 1st-order diffraction beam of the central sub-light source in the target direction.

[0096] Since the spatial frequency intervals are set equal in the frequency domain, the distribution of the diffraction beam phase can be obtained based on the deflection of the modulated sub-light source. Figure 3As shown in the figure, in the case of small angles, if the angular intervals of different sub-spots are not considered first, the deflection angle of the 1st-order diffracted beam of the central sub-light source should be greater than or equal to the sum of the deflection angles of the 0th-order diffracted beams of the two most edge sub-light sources, θ1+θ2, otherwise all the beams in between cannot be accommodated in one replication area. In fact, when the deflection angle of the 1st-order diffracted beam of the central sub-light source is equal to θ1+θ2, the light beams split by the two adjacent sub-light sources will overlap in the edge area and cannot meet the requirements of uniform distribution; so if you want to achieve uniform distribution of light spots, you also need to consider the angular intervals of different sub-spots.

[0097] When considering the angular intervals of different sub-light sources, the deflection angle of the first-order diffracted light beam of the central sub-light source is θ0, which can make the light beams split by two adjacent sub-light sources not overlap in the edge area. Then the relationship that accurately expresses the uniform distribution of the light spot is:

[0098]

[0099] If the array light source is placed in the center, then θ1 = θ2, and it can be deduced that:

[0100]

[0101] Since the angle interval has little effect on the collection of depth information or three-dimensional structure information when the error is small, θ′0 can be selected as:

[0102] sinθ0-0.3sinθ 12 / (n-1)<sinθ′0<sinθ0+0.3sinθ 12 / (n-1); (7)

[0103] Combining formula (5) with formula (7), we get formula (4).

[0104] It should be noted that when the sub-light sources in the array light source are arranged periodically, the number of the sub-light sources in the target direction can be easily determined.

[0105] When the sub-light sources in the array light source are arranged pseudo-randomly, the number of sub-light sources in the target direction can be determined in the following manner: a line is drawn through the geometric center of the array light source parallel to the target direction, and the sub-light sources whose vertical distance to the line is less than a preset distance are determined as the sub-light sources in the target direction, thereby determining the number of sub-light sources in the target direction. Alternatively, if the arrangement positions of the sub-light sources in the array light source are determined by "setting tangent circles one by one and randomly selecting a point on each tangent circle as the position of a sub-light source", the number of tangent circles in the target direction can be determined as the number of sub-light sources in the target direction.

[0106] In some embodiments, optionally, when θ′0<25°, the metalens satisfies the relationship:

[0107]

[0108] Among them, n is the number of sub-light sources in the target direction; θ1 is the deflection angle of the 0th order diffraction beam of the edge sub-light source located at the first end in the target direction; θ2 is the deflection angle of the 0th order diffraction beam of the edge sub-light source located at the second end in the target direction; θ′0 is the deflection angle of the 1st order diffraction beam of the central sub-light source in the target direction.

[0109] Specifically, when θ′0<25°, θ′0≈Sinθ′0, θ1≈Sinθ1, θ2≈Sinθ2, therefore, formula (8) can be derived from formula (4).

[0110] According to the diffraction splitting phase, the sub-light source beam can be split into M*N light spots. In special cases, M=1 or N=1, that is, only the collimation phase is considered in the x direction or y direction, and the diffraction splitting phase is not considered. Figure 4 As shown, after obtaining the phase distribution of the superlens, the above phase is achieved by adjusting the micro-nano structure, and the phase usually includes a range of 0 to 2π.

[0111] like Figure 5 As shown, the wavelength of the light source is 850nm, the period of the micro-nano structure is 460nm, and the height of the micro-nano structure is 500nm, which is a solid line in the figure. The radius range of the nanocolumn is 70nm~127nm and its phase can cover 0~2π; the wavelength of the light source is 940nm, the period of the micro-nano structure is 460nm, and the height of the micro-nano structure is 500nm, which is a dotted line in the figure. The radius range of the nanocolumn is 70nm~142nm and its phase can cover 0~2π; the wavelength of the light source is 1550nm, the period of the micro-nano structure is 650nm, and the height of the micro-nano structure is 800nm, which is a dense dotted line in the figure. The radius range of the nanocolumn is 70nm~224nm and its phase can cover 0~2π.

[0112] In some embodiments, optionally, the metalens satisfies the relationship:

[0113]

[0114] Among them, z is the projection distance of the target light spot cloud, b is the propagation attenuation coefficient of the light energy in the target environment, t is the diffraction efficiency of the superlens, q is the total number of diffracted portions of the emitted light of the array light source, E1 is the output energy of the sub-light source, and E2 is the minimum detection energy of the image sensor. The image sensor is used to sense the target light spot cloud.

[0115] In an ideal indoor environment, the energy of the projected light spot from output to reception needs to be higher than the sensitivity of the receiving end in order to be detected, and then the spatial distribution information corresponding to the dot matrix can be obtained. Under the premise that the output energy of each sub-light source remains unchanged, the more spots of light that are split into sub-beams, the smaller the corresponding output energy of each spot, and the smaller the transmission distance of the spot. If the output energy of each sub-light source is increased, the transmission distance of the light spot can be increased, but at the same time, the working power of the light source is also increased, and the heat generated by the array light source is increased. Different design modes have different application scenarios. For small devices, the total number of copies is large, the total number of dot matrix points is large, but the long-distance energy is low, which is used for face recognition with a working distance of 0.2 to 2mm; the total number of copies is small, and the energy is kept at a high level at a long distance, which is used for auxiliary focus and distance detection at a working distance of 2 to 10mm.

[0116] In some embodiments, optionally, the metalens satisfies the relationship:

[0117]

[0118] In formula (10), γ is the full angle of the dot matrix coverage angle in the target direction; M is the number of dot matrix copies in the target direction; θ1 is the deflection angle of the 0th order diffraction beam of the edge sub-light source located at the first end in the target direction; θ2 is the deflection angle of the 0th order diffraction beam of the edge sub-light source located at the second end in the target direction; θ′0 is the deflection angle of the 1st order diffraction beam of the central sub-light source in the target direction; L1 is the distance of the replicated unit point cloud in the target direction; L2 is the maximum misalignment distance of different combined point clouds in the target direction, and the combined point cloud is obtained by continuously replicating and splicing the unit point cloud in the target direction.

[0119] Specifically, θ w is the splicing margin, which satisfies the relationship:

[0120] sinθ0+sinθ w = sinθ′0; (11)

[0121] A small deviation in the angle interval, i.e., θ, has little impact on the collection of depth information and 3D structure information. w ,θ w Satisfies the relationship:

[0122]

[0123] Formula (12) shows that the smaller interval is the splicing margin θ w The corresponding spatial frequency does not exceed 30% of the original dot matrix spatial frequency interval.

[0124] The target spot cloud is copied and spliced ​​from the unit point cloud. In the frequency domain, the pattern of each unit point cloud can be a part of the pattern of the array light source or the whole pattern of the array light source. The unit point cloud can be continuously copied and spliced ​​in the target direction to obtain the corresponding combined point cloud, and the combined point clouds can have a certain misalignment in the target direction. The occurrence of misalignment can come from the misalignment between different sub-light source sets in the array light source on the one hand, and on the other hand, it can come from the misalignment actively provided by the designer according to the application requirements when designing the target spot cloud.

[0125] For example, the sub-light sources in the array light source are periodically distributed in the horizontal direction to form two rows of completely identical sub-light source sets, and these two rows of sub-light source sets are offset in the horizontal direction. Therefore, the pattern of the array light source is a parallelogram; the upper base of the parallelogram is the first row of sub-light source sets, and the lower base is the second row of sub-light source sets.

[0126] Since the pattern of the first row of sub-light source sets is exactly the same as the pattern of the second row of sub-light source sets, the point cloud corresponding to the first row of sub-light source sets can be used as a unit point cloud only in the one-dimensional direction corresponding to the target direction, and then copied and spliced ​​in the horizontal direction to obtain a first combined point cloud (the first combined point cloud can be regarded as a plurality of first row of sub-light source sets spliced ​​in sequence in the horizontal direction); at the same time, the point cloud corresponding to the second row of sub-light source sets is used as a unit point cloud, and then copied and spliced ​​in the horizontal direction to obtain a second combined point cloud (the second combined point cloud can be regarded as a plurality of second row of sub-light source sets spliced ​​in sequence in the horizontal direction). Since there is a certain misalignment between the first row of sub-light source sets and the second row of sub-light source sets in the horizontal direction, the first combined point cloud and the second combined point cloud obtained in this way also have a certain misalignment in the horizontal direction.

[0127] Alternatively, the point cloud corresponding to the entire array light source can be directly used as a unit point cloud in the two-dimensional direction including the target direction, and then copied and spliced ​​in the horizontal direction to obtain a first combined point cloud (the first combined point cloud can be regarded as a plurality of array light sources sequentially spliced ​​in the horizontal direction); then the first combined point cloud is copied to obtain a second combined point cloud with a completely consistent pattern (the second combined point cloud can also be regarded as a plurality of array light sources sequentially spliced ​​in the horizontal direction), and the first combined point cloud and the second combined point cloud are spliced ​​in the vertical direction. When splicing the first combined point cloud and the second combined point cloud in the vertical direction, the designer can actively displace the first combined point cloud and the second combined point cloud in the horizontal direction according to application requirements.

[0128] Assuming that the full angle of the dot matrix coverage in the target direction is γ, the number of dot matrix copies in the target direction is M, and there is no misalignment between different combined point clouds in the target direction, the following relationship is satisfied:

[0129]

[0130] Combining formula (5), formula (11) and formula (13), we get the following relationship:

[0131]

[0132] The distance of the unit point cloud in the target direction is L1, and the maximum misalignment distance of different combined point clouds in the target direction is L2. Among them, the misalignment distances of different combined point clouds in the target direction may be different; select the maximum value among them to get the maximum misalignment distance. For example: the unit point cloud is continuously copied and spliced ​​in the horizontal direction to obtain S rows of combined point clouds. If each row of combined point cloud is misaligned to the right by a distance D compared to the previous row of combined point cloud, the maximum misalignment distance is D*(S-1); if the second row of point cloud is misaligned to the right by a distance D compared to the first row of point cloud, the third row of point cloud is misaligned to the left by a distance D compared to the second row of point cloud, and the fourth row of point cloud is misaligned to the right by a distance D compared to the third row of point cloud, and the misalignment is repeated in this way, the maximum misalignment distance is D.

[0133] Therefore, considering the misalignment between different combined point clouds in the target direction, based on formula (14), formula (10) can be derived.

[0134] It should be noted that in the data provided in the following embodiments, the data of each angle are basically rounded, so after substituting into formula (10), the values ​​on both sides of the equal sign are not completely equal; however, this does not mean that formula (10) is wrong.

[0135] In some embodiments, the structural housing is optionally provided with a limiting structure, and the limiting structure is used to limit and fix the metalens. Reasonable limiting of the position of the metalens can make the metalens perform better in a suitable position.

[0136] In some embodiments, optionally, the point cloud emitting device is used to perform three-dimensional sensing based on time-of-flight technology, and the sub-light sources in the array light source are regularly arranged and distributed periodically.

[0137] In some embodiments, optionally, the point cloud emitting device is used to perform three-dimensional sensing based on structured light technology, and the sub-light sources in the array light source are pseudo-randomly arranged and distributed.

[0138] In the field of depth sensing and 3D imaging, the entire system is usually divided into three main parts: the transmitter, the reflector, and the receiver. The transmitter consists of a dense array of projectors that can generate light spots with regular or pseudo-random dot patterns. These light spots are not only used to illuminate the target object, person or scene, but also carry information for depth measurement. The reflector is responsible for accurately projecting the light spots generated by the transmitter onto the target. When the light spots touch the target surface, they will produce different reflection effects due to their shape and distance. These reflected light spots are then captured by the receiver and used to extract depth information. The receiver is usually a highly sensitive camera or image sensor that is used to capture the reflected light spots carrying depth information. By analyzing the images of these light spots, the system can reconstruct the 3D shape of the target.

[0139] like Figure 6 As shown in the figure, ToF (Time of Flight) technology is a major method for achieving depth sensing and three-dimensional imaging. It relies on measuring the time required for light to be emitted and received, that is, the round-trip flight time of light. To do this, the ToF system usually uses multiple scans, lighting up a portion of the light source each time. By recording the moment each light source is lit and the moment the corresponding reflected light spot is received, the system can calculate the round-trip time of the light, thereby inferring the transmission distance from the light source to the target object. Since speckles (i.e., light spots) at different positions are projected onto the surface of objects at different distances, they will have different round-trip times. By analyzing these time differences, the system can obtain the depth information of the target object and reconstruct the three-dimensional shape.

[0140] Structured light technology is a method for 3D imaging and measurement that relies on projecting dot patterns with specific geometric structures onto the surface of the target object and restoring the 3D structure of the object by analyzing the deformation or distribution changes of these patterns on the surface of the object. This technology mainly utilizes the reflection or scattering characteristics of light at different positions on the surface of the object, and how these characteristics change with the change of spatial distance.

[0141] In structured light systems, densely and pseudo-randomly arranged VCSELs are usually used as light sources in order to obtain the geometric structure of the target object in more detail. VCSELs can produce high-quality, high-density dot patterns, which will be deformed due to the shape and surface characteristics of the object when projected onto the surface of the object. By capturing and analyzing these deformed patterns, the system can accurately calculate the depth information of the object's surface and reconstruct the object's three-dimensional structure.

[0142] Due to the density and pseudo-random arrangement of VCSELs, structured light systems can obtain more detailed and accurate geometric structure information. This makes structured light technology widely used in many fields, such as industrial automation, robot vision, medical imaging, etc., where high-precision three-dimensional measurement and imaging are required.

[0143] The following content introduces the embodiments of the present application, wherein θ0, θ 12 , θ′0 is marked as: θ 0x ,θ 12x ,θ′ 0x , θ0, θ in the y direction 12 , θ′0 is marked as: θ 0y ,θ 12y ,θ′ 0y In the embodiment shown below, if there are multiple copies in the y direction, the rows of combined point clouds obtained by continuous copying and splicing in the x direction will be misaligned in the x direction, and the maximum misalignment distance is 0.5 times the period of the light spot arrangement in the x direction.

[0144] Example 1

[0145] like Figure 7 As shown, the array light source selects VCSEL array, the light source wavelength is 940nm, the light source size is 680um*480um, the number of sub-light sources in the x direction is 8, the number of sub-light sources in the y direction is 8, the size of the super lens is 1.7mm*1.7mm, the distance between the super lens and the light source is 1.8mm, and 3×3 replication is performed. By calculation, θ′ 0x =23.9 degrees, θ′ 0y =17.8 degrees, θ 12x =20.51 degrees, θ 12y =15.4 degrees, θ 0x =23.8 degrees, θ 0y = 17.4 degrees. The point cloud emission effect is as follows Figure 8 As shown, FOI is achieved: 73 degrees × 52 degrees of dot matrix coverage, with a total of 576 points.

[0146] Example 2

[0147] like Fig. 9 As shown, the array light source selects VCSEL array, the light source wavelength is 940nm, the light source size is 320um*800um, the number of sub-light sources in the x direction is 8, the number of sub-light sources in the y direction is 24, the size of the super lens is 0.8mm*1.3mm, the distance between the super lens and the light source is 0.86mm, and a 3×1 replication is performed. By calculation, θ′ 0x =23.9 degrees, θ 12x =20.51 degrees, θ 0x= 23.8 degrees. The point cloud emission effect is as follows Fig.10 As shown, FOI is achieved: 73 degrees × 55 degrees of dot matrix coverage, with a total of 576 points.

[0148] Example 3

[0149] like Fig.11 As shown, the array light source selects VCSEL array, the light source wavelength is 940nm, the light source size is 720um*210um, the number of sub-light sources in the x direction is 11, the number of sub-light sources in the y direction is 4, the size of the super lens is 1.8mm*1.4mm, the distance between the super lens and the light source is 2.2mm, and 5×3 replication is performed. By calculation, θ′ 0x =19.5 degrees, θ′ 0y =7.1 degrees, θ 12x =17.3 degrees, θ 12y =5.3 degrees, θ 0x =19.2 degrees, θ 0y =7.1 degrees. The point cloud emission effect is as follows Fig.12 As shown, FOI is achieved: 110 degrees × 20 degrees dot matrix coverage, with a total of 660 points.

[0150] Example 4

[0151] like Fig.13 As shown, the array light source selects VCSEL array, the light source wavelength is 940nm, the light source size is 470um*680um, the number of sub-light sources in the x direction is 8, the number of sub-light sources in the y direction is 11, the size of the super lens is 1.6mm*1.8mm, the distance between the super lens and the light source is 2.1mm, and a 7×1 replication is performed. By calculation, θ′ 0x =14.6 degrees, θ 12x =12.8 degrees, θ 0x = 14.6 degrees. The point cloud emission effect is as follows Fig.14 As shown, FOI is achieved: 120 degrees × 19 degrees of dot matrix coverage, with a total of 616 points.

[0152] Example 5

[0153] like Fig.15 As shown, the array light source selects VCSEL array, the light source wavelength is 940nm, the light source size is 960um*1380um, the number of sub-light sources in the x direction is 12, the number of sub-light sources in the y direction is 20, the size of the super lens is 2.9mm*3.3mm, the distance between the super lens and the light source is 2.9mm, and 5×3 replication is performed. By calculation, θ′ 0x = 20.3 degrees, θ′ 0y =30.0 degrees, θ 12x =18.3 degrees, θ 12y =28 degrees, θ0x =19.9 degrees, θ 0y = 29.3 degrees. The point cloud emission effect is as follows Fig.16 As shown, FOI is achieved: 117 degrees × 94 degrees of dot matrix coverage, with a total of 2600 points.

[0154] Example 6

[0155] like Fig.17 As shown, the array light source selects VCSEL array, the light source wavelength is 940nm, the light source size is 560um*820um, the number of sub-light sources in the x direction is 15, the number of sub-light sources in the y direction is 29, the size of the super lens is 1.6mm*1.6mm, the distance between the super lens and the light source is 1.5mm, and 5×3 replication is performed. By calculation, θ′ 0x =20.5 degrees, θ′ 0y =29.8 degrees, θ 12x =18.8 degrees, θ 12y =28.5 degrees, θ 0x =20.6 degrees, θ 0y = 29.6 degrees. The point cloud emission effect is as follows Fig.18 As shown, FOI is achieved: 120 degrees × 95 degrees dot matrix coverage, with a total of 5725 points.

[0156] Example 7

[0157] like Fig.19 As shown, the array light source selects VCSEL array, the light source wavelength is 940nm, the light source size is 400um*600um, the number of sub-light sources is 403, the arrangement form is pseudo-random distribution, the super lens size is 2.62mm*2.43mm, the distance between the super lens and the light source is 3.7mm, and 7×11 replication is performed. Through calculation, it is found that the maximum angular interval of each VCSEL point in the two-axis direction of y=0 and x=0 is 0.3 degrees and 0.3 degrees, θ′ 0x =9.6 degrees, θ′ 0y =6.7 degrees, θ 12x =9.3 degrees, θ 12y =6.3 degrees, θ 0x =9.6 degrees, θ 0y = 6.6 degrees. The point cloud emission effect is as follows Fig. 20 As shown, FOI is achieved: 72 degrees × 79 degrees dot matrix coverage, with a total of 31031 points.

[0158] Example 8

[0159] like Fig.21As shown, the array light source selects VCSEL array, the light source wavelength is 940nm, the light source size is 400um*600um, the number of sub-light sources is 403, the arrangement form is pseudo-random distribution, the super lens size is 2.2mm*2.0mm, the distance between the super lens and the light source is 2.95mm, and 5×9 replication is performed. Through calculation, it is found that the maximum angular interval of each VCSEL point in the two-axis direction of y=0 and x=0 is 0.3 degrees and 0.3 degrees, θ′ 0x = 12.3 degrees, θ′ 0y =8.4 degrees, θ 12x =11.8 degrees, θ 12y =7.9 degrees, θ 0x =12.3 degrees, θ 0y = 8.4 degrees. The point cloud emission effect is as follows Fig. 22 As shown, FOI is achieved: 64 degrees × 82 degrees dot matrix coverage, with a total of 18135 points.

[0160] Example 9

[0161] like Fig.23 As shown, the array light source selects VCSEL array, the light source wavelength is 940nm, the light source size is 300um*680um, the number of sub-light sources is 243, the arrangement form is pseudo-random distribution, the super lens size is 1.8mm*2.2mm, the distance between the super lens and the light source is 2.9mm, and the replication is performed in the form of 13×5. Through calculation, it is found that the maximum angle interval of each point of VCSEL in the two-axis direction of y=0 and x=0 is 0.2 degrees and 0.2 degrees, θ′ 0x =5.2 degrees, θ′ 0y =12.5 degrees, θ 12x =5.3 degrees, θ 12y =12.6 degrees, θ 0x =5.2 degrees, θ 0y = 12.5 degrees. The point cloud emission effect is as follows Fig.24 As shown, FOI is achieved: 72 degrees × 66 degrees of dot matrix coverage, with a total of 15795 points.

[0162] Example 10

[0163] like Fig.25 As shown, the array light source selects VCSEL array, the light source wavelength is 850nm, the light source size is 300um*680um, the number of sub-light sources is 243, the arrangement form is pseudo-random distribution, the super lens size is 1.0mm*1.0mm, the distance between the super lens and the light source is 0.69mm, and 3×1 replication is performed. By calculation, it is found that the maximum angle interval of each VCSEL point in the y=0 direction is 0.8 degrees, θ′ 0x =22.6 degrees, θ 12x =21.7 degrees, θ0x = 22.5 degrees. The point cloud emission effect is as follows Fig.26 As shown, FOI is achieved: 70 degrees × 55 degrees of dot matrix coverage, with a total of 729 points.

[0164] Embodiment 11

[0165] like Fig. 27 As shown, the array light source selects VCSEL array, the light source wavelength is 850nm, the light source size is 680um*620um, the number of sub-light sources in the x direction is 10, the number of sub-light sources in the y direction is 10, the size of the super lens is 1.9mm*1.9mm, the distance between the super lens and the light source is 2.0mm, and 3×3 replication is performed. By calculation, θ′ 0x =27.1 degrees, θ′ 0y =19.7 degrees, θ 12x =23.9 degrees, θ 12y =17.6 degrees, θ 0x =27.0 degrees, θ 0y = 19.6 degrees. The point cloud emission effect is as follows Fig.28 As shown, FOI is achieved: 83 degrees × 59 degrees of dot matrix coverage, with a total of 900 points.

[0166] Example 12

[0167] like Fig.29 As shown, the array light source selects VCSEL array, the light source wavelength is 1550nm, the light source size is 680um*620um, the number of sub-light sources in the x direction is 8, the number of sub-light sources in the y direction is 10, the size of the super lens is 1.7mm*1.7mm, the distance between the super lens and the light source is 1.87mm, and a 3×3 replication is performed. By calculation, θ′ 0x =23.5 degrees, θ′ 0y =21.0 degrees, θ 12x =19.9 degrees, θ 12y =19.4 degrees, θ 0x =23.5 degrees, θ 0y = 21.0 degrees. The point cloud emission effect is as follows Fig.30 As shown, FOI is achieved: 70 degrees × 64 degrees of dot matrix coverage, with a total of 720 points.

[0168] Example 13

[0169] like Fig.31 As shown, the array light source selects VCSEL array, the light source wavelength is 1550nm, the light source size is 700um*410um, the number of sub-light sources in the x direction is 12, the number of sub-light sources in the y direction is 10, the size of the super lens is 2.1mm*2.2mm, the distance between the super lens and the light source is 2.68mm, and 5×7 replication is performed. By calculation, θ′0x =15.8 degrees, θ′ 0y =9.9 degrees, θ 12x =14.7 degrees, θ 12y =8.7 degrees, θ 0x =15.8 degrees, θ 0y = 9.9 degrees. The point cloud emission effect is as follows Fig.32 As shown, FOI is achieved: 85 degrees × 73 degrees of dot matrix coverage, with a total of 4200 points.

[0170] The above is only a specific implementation of the embodiment of the present application, but the protection scope of the embodiment of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the embodiment of the present application, which should be included in the protection scope of the embodiment of the present application. Therefore, the protection scope of the embodiment of the present application shall be based on the protection scope of the claims.

Claims

1. A point cloud emission device based on a superlens, characterized in that: include: An array light source (102), a module substrate (101), a structural housing (103) and a monolithic super lens (104); The array light source (102) comprises a plurality of sub-light sources; the array light source (102) and the structural housing (103) are arranged on the same side of the module substrate (101); the structural housing (103) is used to protect the array light source (102) and the super lens (104), and is used to support the super lens (104); the super lens (104) comprises a substrate (105) and a micro-nano structure (106) arranged on the substrate (105); the super lens (104) is arranged on the light-emitting side of the array light source (102), and the super lens (104) is used to collimate and diffract the emitted light of the array light source (102) to project a target light spot cloud; The metalens (104) satisfies the relationship: Wherein, θ is the diffraction angle of the light beam projected by the super lens (104), λ is the central wavelength of the emitted light of the array light source (102), and P is the arrangement period of the micro-nano structure (106).

2. The point cloud transmitting device based on superlens according to claim 1, characterized in that: In the frequency domain, the light spots in the target light spot cloud are evenly arranged with equal spatial frequency intervals.

3. The point cloud transmitting device based on superlens according to claim 2, characterized in that: The sub-light sources in the array light source are regularly arranged and distributed periodically; the super lens satisfies the relationship: Among them, f t is the spatial frequency in the target direction in the frequency domain, θ t is the line connecting the light spot and the center of the super lens, the deflection angle in the target direction of the frequency domain relative to the optical axis of the super lens, and λ is the central wavelength of the emitted light of the array light source (102).

4. The point cloud transmitting device based on superlens according to claim 2, characterized in that: The metalens satisfies the relationship: Wherein, n is the number of the sub-light sources in the target direction; θ1 is the deflection angle of the 0th-order diffraction beam of the edge sub-light source located at the first end in the target direction; θ2 is the deflection angle of the 0th-order diffraction beam of the edge sub-light source located at the second end in the target direction; θ'0 is the deflection angle of the 1st-order diffraction beam of the central sub-light source in the target direction.

5. The point cloud transmitting device based on superlens according to claim 2, characterized in that: When θ'0<25°, the metalens satisfies the relationship: Wherein, n is the number of the sub-light sources in the target direction; θ1 is the deflection angle of the 0th-order diffraction beam of the edge sub-light source located at the first end in the target direction; θ2 is the deflection angle of the 0th-order diffraction beam of the edge sub-light source located at the second end in the target direction; θ'0 is the deflection angle of the 1st-order diffraction beam of the central sub-light source in the target direction.

6. The point cloud transmitting device based on superlens according to claim 1, characterized in that: The metalens satisfies the relationship: Among them, z is the projection distance of the target light spot cloud, b is the propagation attenuation coefficient of the light energy in the target environment, t is the diffraction efficiency of the superlens, q is the total number of diffracted portions of the emitted light of the array light source, E1 is the output energy of the sub-light source, and E2 is the minimum detection energy of the image sensor, which is used to sense the target light spot cloud.

7. The point cloud transmitting device based on superlens according to claim 1, characterized in that: The metalens satisfies the relationship: Among them, γ is the full angle of the dot matrix coverage angle in the target direction; M is the number of dot matrix copies in the target direction; θ1 is the deflection angle of the 0th order diffraction beam of the edge sub-light source located at the first end in the target direction; θ2 is the deflection angle of the 0th order diffraction beam of the edge sub-light source located at the second end in the target direction; θ'0 is the deflection angle of the 1st order diffraction beam of the central sub-light source in the target direction; L1 is the distance of the replicated unit point cloud in the target direction; L2 is the maximum misalignment distance of different combined point clouds in the target direction, and the combined point cloud is obtained by continuously replicating and splicing the unit point cloud in the target direction.

8. The point cloud transmitting device based on superlens according to claim 1, characterized in that: The structural housing is provided with a limiting structure, and the limiting structure is used to limit and fix the super lens.

9. The point cloud transmitting device based on superlens according to claim 1, characterized in that: The point cloud emitting device is used for three-dimensional sensing based on time-of-flight technology, and the sub-light sources in the array light source are regularly arranged and distributed periodically.

10. The point cloud transmitting device based on superlens according to claim 1, characterized in that: The point cloud emitting device is used for three-dimensional sensing based on structured light technology, and the sub-light sources in the array light source are pseudo-randomly arranged and distributed.

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