Three-dimensional scanning equipment and control method thereof

Abstract

The invention discloses three-dimensional scanning equipment and a control method thereof, the equipment comprises a multispectral structured light generation unit used for generating structured light with at least two wavelengths to irradiate an object to be scanned, and the working face positions of the structured light with different wavelengths are different; the imaging system comprises a large-dispersion imaging lens and an image sensor, the large-dispersion imaging lens is used for collecting scattered light beams to the same imaging plane, and the scattered light beams are formed by scattering structured light with corresponding wavelengths at different working face positions of an object to be scanned; the image sensor comprises at least two channels, and different channels are used for collecting scattered light beams corresponding to the structured light with different wavelengths; the working face positions of the structured light with different wavelengths are conjugated with the imaging plane of the image sensor. Therefore, the structured light with different wavelengths can scan different working surfaces of the to-be-scanned object, and scattered light corresponding to the different working surfaces is collected and imaged to the same plane through the lens, so that large-depth-of-field scanning is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of three-dimensional scanning, and in particular to a three-dimensional scanning device and a control method thereof. Background Art

[0002] In 3D scanning equipment, the problem of insufficient scanning depth of field is often encountered. This is because for general imaging systems, there is only one position where the image is clear, and the 3D scanning accuracy at this position is also the highest. Once the position deviates from the clear imaging surface, it is necessary to use fitting algorithms such as the centroid method to solve the scanning accuracy, which often results in loss of accuracy.

[0003] Therefore, a common scanning device practice is to add a distance prompt device for the user to keep the user at a fixed position as much as possible while scanning, which makes the user operation extremely inconvenient and greatly reduces the usability and popularity of the 3D scanning device. Summary of the invention

[0004] The invention provides a three-dimensional scanning device and a control method thereof, which can realize scanning with a large depth of field.

[0005] To achieve the above-mentioned object, an embodiment of the present invention provides a three-dimensional scanning device, including: a multi-spectral structured light generating unit and at least one imaging system;

[0006] The multi-spectral structured light generating unit is used to generate structured light of at least two wavelengths to illuminate the object to be scanned, wherein the working surface positions of the structured light of different wavelengths are different;

[0007] The imaging system comprises a large dispersion imaging lens and an image sensor, wherein the large dispersion imaging lens is used to collect scattered light beams to the same imaging plane, wherein the scattered light beams are formed by scattering structured light of corresponding wavelengths at different working surface positions of the object to be scanned; the image sensor comprises at least two channels, and different channels are used to collect scattered light beams corresponding to structured light of different wavelengths; wherein the working surface positions of the structured light of different wavelengths are conjugate with the imaging plane of the image sensor.

[0008] Optionally, the imaging system includes a first imaging system and a second imaging system; the multi-spectral structured light generating unit is used to form a first scanning beam and a second scanning beam, the first imaging system is located on a transmission path of a first scattered beam, and the second imaging system is located on a transmission path of a second scattered beam, the first scattered beam is a beam of the first scanning beam scattered by a first object to be scanned, and the second scattered beam is a beam of the second scanning beam scattered by a second object to be scanned, and the first object to be scanned and the second object to be scanned are the same object or different objects.

[0009] Optionally, the three-dimensional scanning device further includes: a controller and a distance sensor, the controller being connected to the distance sensor, the multi-spectral structured light generating unit and the image sensor respectively, and the distance sensor being used to collect a working distance between the multi-spectral structured light generating unit and the object to be scanned;

[0010] The controller is used to control the multi-spectral structured light generating unit to emit structured light of a wavelength corresponding to the corresponding working surface position according to the working distance, and control the image sensor conjugate with the corresponding working surface position on the imaging plane to start.

[0011] Optionally, the large dispersion imaging lens includes at least one optical lens capable of refraction or diffraction.

[0012] Optionally, the large dispersion imaging lens comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which are sequentially arranged from the object side to the image side;

[0013] Wherein, the first lens is a convex-concave lens, the second lens is a concave-concave lens, the third lens is a convex-convex lens, the fourth lens is a convex-convex lens, and the fifth lens is a concave-concave lens;

[0014] The fourth lens and the fifth lens are cemented to form a cemented lens.

[0015] Optionally, the image sensor includes a plurality of channel components, the plurality of channel components are arranged in an array, and the total number of channels in each channel component is the square of the number of channels in a single row.

[0016] Optionally, each of the channel components includes a first channel, a second channel, a third channel and a fourth channel, and the first channel to the fourth channel are arranged in sequence to form a channel component in the form of a four-square grid; or, each of the channel components includes a first channel, a second channel, a third channel, a fourth channel, a fifth channel, a sixth channel, a seventh channel, an eighth channel and a ninth channel, and the first channel to the ninth channel are arranged in sequence to form a channel component in the form of a nine-square grid.

[0017] To achieve the above object, another embodiment of the present invention provides a control method for a three-dimensional scanning device, which is implemented by the three-dimensional scanning device according to any embodiment of the present invention. The control method includes: controlling a multi-spectral structured light generating unit to generate structured light of at least two wavelengths to illuminate an object to be scanned;

[0018] The channels corresponding to the structured light of the at least two wavelengths in the image sensor are controlled to start, so as to collect scattered light beams formed by the object to be scanned scattering the structured light of the at least two wavelengths.

[0019] Optionally, the three-dimensional scanning device further includes a distance sensor; and before the multi-spectral structured light generating unit is controlled to generate structured light of at least two wavelengths to illuminate the object to be scanned, the device further includes:

[0020] Acquiring a working distance between the multi-spectral structured light generating unit and the object to be scanned;

[0021] Determining a position of a working surface close to the object to be scanned according to the working distance;

[0022] The controlling the multi-spectral structured light generating unit to generate structured light of at least two wavelengths to illuminate the object to be scanned comprises:

[0023] Based on the working surface position and the first preset corresponding relationship, the multi-spectral structured light generating unit is controlled to emit structured light of a wavelength corresponding to the corresponding working surface position; wherein the first preset corresponding relationship is the corresponding relationship between the working surface position and the wavelength of the structured light emitted by the multi-spectral structured light generating unit;

[0024] The controlling the activation of channels corresponding to the structured light of the at least two wavelengths in the image sensor comprises:

[0025] Based on the working surface position and the second preset corresponding relationship, the image sensor on the imaging plane that is conjugate with the corresponding working surface position is controlled to start; wherein the second preset corresponding relationship is the conjugate corresponding relationship between the working surface position and the imaging plane of the image sensor.

[0026] Optionally, after starting the channels corresponding to the structured light of the at least two wavelengths in the control image sensor, the method further includes:

[0027] A first image captured by the image sensor is acquired, and according to a comparison result between the first image and the object to be scanned, the multi-spectral structured light generating unit is controlled to turn off unused wavelengths.

[0028] According to the three-dimensional scanning device and control method thereof proposed in the embodiment of the present invention, the device includes: a multi-spectral structured light generating unit and at least one imaging system; the multi-spectral structured light generating unit is used to generate structured light of at least two wavelengths to illuminate the object to be scanned, wherein the working surface positions of structured light of different wavelengths are different; the imaging system includes a large dispersion imaging lens and an image sensor, the large dispersion imaging lens is used to collect scattered light beams to the same imaging plane, and the scattered light beams are formed by scattering structured light of corresponding wavelengths at different working surface positions of the object to be scanned; the image sensor includes at least two channels, and different channels are used to collect scattered light beams corresponding to structured light of different wavelengths; wherein the working surface positions of structured light of different wavelengths are conjugate with the imaging plane of the image sensor. Thus, structured light of different wavelengths can scan different working surfaces of the object to be scanned, and then the scattered light corresponding to different working surfaces is collected and imaged to the same plane through the imaging lens, thereby realizing a large depth of field scanning of the object to be scanned.

[0029] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 is a schematic structural diagram of a three-dimensional scanning device proposed in an embodiment of the present invention;

[0032] Figure 2 is a schematic structural diagram of a three-dimensional scanning device proposed in one embodiment of the present invention;

[0033] Figure 3 is a schematic structural diagram of a three-dimensional scanning device proposed in another embodiment of the present invention;

[0034] Figure 4 is a structural schematic diagram of a three-dimensional scanning device proposed in yet another embodiment of the present invention;

[0035] Figure 5 is a schematic structural diagram of a large dispersion imaging lens in a three-dimensional scanning device provided by an embodiment of the present invention;

[0036] Figure 6 is an MTF diagram at 450nm of a large dispersion imaging lens in a three-dimensional scanning device provided in an embodiment of the present invention;

[0037] Figure 7 is an MTF diagram at 550nm of a large dispersion imaging lens in a three-dimensional scanning device provided in an embodiment of the present invention;

[0038] Figure 8 is an MTF diagram at 650nm of a large dispersion imaging lens in a three-dimensional scanning device provided in an embodiment of the present invention;

[0039] Fig. 9 is an MTF diagram at 780 nm of a large dispersion imaging lens in a three-dimensional scanning device provided in an embodiment of the present invention;

[0040] Fig.10 is an MTF diagram at 850nm of a large dispersion imaging lens in a three-dimensional scanning device provided in an embodiment of the present invention;

[0041] Fig.11 is a channel arrangement diagram of an image sensor in a three-dimensional scanning device proposed in one embodiment of the present invention;

[0042] Fig.12 is a channel arrangement diagram of an image sensor in a three-dimensional scanning device provided by another embodiment of the present invention;

[0043] Fig.13 It is a flow chart of the scanning method of the three-dimensional scanning device proposed in an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0045] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0046] Figure 1 Schematic diagram of the structure of the three-dimensional scanning device proposed in the embodiment of the present invention. Figure 1 As shown, the three-dimensional scanning device includes: a multi-spectral structured light generating unit 101 and at least one imaging system 102;

[0047] A multi-spectral structured light generating unit 101 is used to generate structured light of at least two wavelengths to illuminate the object to be scanned 103, wherein the working surface positions of the structured light of different wavelengths are different;

[0048] The imaging system 102 includes a large dispersion imaging lens 1021 and an image sensor 1022. The large dispersion imaging lens 1021 is used to collect scattered light beams to the same imaging plane. The scattered light beams are formed by scattering structured light of corresponding wavelengths at different working surface positions of the object to be scanned 103; the image sensor 1022 includes at least two channels, and different channels are used to collect scattered light beams corresponding to structured light of different wavelengths; wherein the working surface positions of the structured light of different wavelengths are conjugate with the imaging plane of the image sensor 1022.

[0049] Among them, Figure 1 As shown, the at least two wavelengths of structured light may include a first wavelength of structured light 1041 and a second wavelength of structured light 1042. The working surface of the first wavelength of structured light 1041 is a first working surface 1051, and the working surface of the second wavelength of structured light 1042 is a second working surface 1052. The image sensor 1022 is provided with at least a first channel 1 for sensing the first wavelength of structured light 1041 and a second channel 2 for sensing the second wavelength of structured light 1042.

[0050] Conjugation means that in an optical system, light starts from one object plane, passes through the optical system, and forms a clear image on another plane. These two planes are conjugate planes.

[0051] The multi-spectral structured light generating unit 101 emits a structured light 1041 of a first wavelength and a structured light 1042 of a second wavelength. When the structured light 1041 of the first wavelength hits the object to be scanned 103 located at the first working surface 1051, the object to be scanned 103 scatters the structured light 1041 of the first wavelength, and the structured light is collected by the large dispersion imaging lens 1021 to the first channel 1 of the image sensor 1022. Similarly, when the structured light 1042 of the second wavelength hits the object to be scanned 103 located at the second working surface 1052, the object to be scanned 103 scatters the structured light 1042 of the second wavelength, and the structured light is collected by the large dispersion imaging lens 1021 to the second channel 2 of the image sensor 1022.

[0052] In this way, the multi-spectral structured light generating unit 101 simultaneously generates structured lights of two or more wavelengths to scan the object 103 to obtain an image of the object 103 to be scanned.

[0053] In one example, the multi-spectral structured light generating unit 101 can generate structured light of five wavelengths at the same time, such as structured light of 450nm, 550nm, 650nm, 780nm and 850nm wavelengths, and the corresponding working surface positions are positions of 150mm, 220mm, 300mm, 450mm and 550mm from the multi-spectral structured light generating unit 101. Since there is a distance of 400mm between 150mm and 550mm, the three-dimensional scanning device can capture the image of the object 103 to be scanned within a range of 400mm. Therefore, when scanning the object 103 to be scanned, the object 103 to be scanned can be placed between 150mm and 550mm, and the three-dimensional scanning device can scan the object 103 to be scanned, without moving the three-dimensional scanning device step by step to align and scan the object 103 to be scanned, and the setting of the large dispersion imaging lens can obtain a three-dimensional image of the object 103 to be scanned at one time. The more wavelengths generated by the multi-spectral structured light generating unit 101 and the corresponding number of color image sensor channels, the more positions with clear imaging and the higher the accuracy of the scanning device. In this way, the depth of field of the three-dimensional scanning device is increased, the scanning rate is greatly improved, and the corresponding scanning steps are simplified.

[0054] Optionally, Figure 2 is a schematic structural diagram of a three-dimensional scanning device provided by an embodiment of the present invention, Figure 3 is a schematic diagram of the structure of a three-dimensional scanning device proposed in another embodiment of the present invention. Figure 2 and Figure 3 As shown, the imaging system 102 includes a first imaging system 102A and a second imaging system 102B; the multi-spectral structured light generating unit 101 is used to form a first scanning beam and a second scanning beam, the first imaging system 102A is located on the transmission path of the first scattered beam, and the second imaging system 102B is located on the transmission path of the second scattered beam, the first scattered beam is a beam of light scattered by the first scanning beam by the first object to be scanned 103A, and the second scattered beam is a beam of light scattered by the second scanning beam by the second object to be scanned 103B, wherein the first object to be scanned 103A and the second object to be scanned 103B are the same object or different objects.

[0055] It should be noted that Figure 1 In the illustrated embodiment, there is one imaging system 102 . In other embodiments, there may be two or more imaging systems 102 . The number of imaging systems 102 is set according to requirements.

[0056] For example, Figure 2 As shown, there are two objects to be scanned, and the imaging system 102 may include two imaging systems, a first imaging system 102A and a second imaging system 102B. In this embodiment, the structured light emitted by the multi-spectral structured light generating unit 101 can be split, for example, divided into a first scanning beam and a second scanning beam by a beam splitting unit, and the wavelength type of the structured light emitted by each scanning beam is the same. The first scanning beam is used to scan the first object to be scanned 103A, and is scattered into a first scattered beam, and the second scanning beam is used to scan the second object to be scanned 103B, and is scattered into a second scattered beam. The first imaging system 102A is set in the transmission direction of the first scattered beam, and the second imaging system 102B is set in the transmission direction of the second scattered beam. In other embodiments, it can also be divided into three beams or four beams, etc., so as to simultaneously measure the objects to be scanned 103 in different directions. Figure 2 This is only an example and is not intended to be a specific limitation. In other embodiments, the beam splitting unit may be a polarization beam splitting prism or the like.

[0057] In another embodiment, if Figure 3 As shown, there is one object 103 to be scanned, and the structured light emitted by the multi-spectral structure generating unit 101 is still one beam, but on the transmission path of the scanning beam, a first imaging system 102A and a second imaging system 102B are set, and the first imaging system 102A is used to receive a part of the scattered light beam of the scanning beam, and the second imaging system 102B is used to receive another part of the scattered light beam of the scanning beam. In this way, on the basis of the original imaging system remaining unchanged, the wavelength types of the structured light emitted by the multi-spectral structure generating unit 101 can be increased (for example, the multi-spectral structure generating unit 101 can emit 5 types at the same time, and 5 more wavelengths can be added at this time, and the 10 wavelengths are arranged in order of size, and the first imaging system 102A can image the structured light of the first 5 wavelengths, and the second imaging system 102B can image the structured light of the last 5 wavelengths). Alternatively, on the basis that the types of wavelengths of the structured light emitted by the multi-spectral structure generating unit 101 remain unchanged, since the types of wavelengths received by a single imaging system become fewer (for example, the multi-spectral structure generating unit 101 can emit 5 types of wavelengths at the same time, and the 5 wavelengths are arranged in order of size, the first imaging system 102A can image the structured light of the first 2 wavelengths, and the second imaging system 102B can image the structured light of the last 3 wavelengths), the fewer the types of wavelengths received by the imaging system, the lower the design requirements for the imaging system.

[0058] It should be noted that in Figure 3 In the embodiment, after scanning the same object 103 to be scanned, images captured by different image sensors may be fused to obtain an overall image of the same object 103 to be scanned.

[0059] Optionally, Figure 4 is a schematic diagram of the structure of a three-dimensional scanning device proposed in another embodiment of the present invention; Figure 4 As shown, the three-dimensional scanning device also includes: a controller 106 and a distance sensor 107, the controller 106 is connected to the distance sensor 107, the multi-spectral structured light generating unit 101 and the image sensor 1022 respectively, and the distance sensor 107 is used to collect the working distance between the multi-spectral structured light generating unit 101 and the object to be scanned 103;

[0060] The controller 106 is used to control the multi-spectral structured light generating unit 101 to emit structured light of a wavelength corresponding to the corresponding working surface position according to the working distance, and control the image sensor 1022 conjugate with the corresponding working surface position on the imaging plane to start.

[0061] It is understandable that, in order to further accurately scan the object to be scanned 103, or when the size of the object to be scanned 103 is small and smaller than the overall depth of field, and in order to avoid opening all structured lights of the multi-spectral structured light generating unit 101 at the same time, causing energy waste, before scanning the object to be scanned 103, the working distance between the three-dimensional scanning device and the object to be scanned 103 can be obtained. Then, the structured light with a wavelength adapted to the working distance and the channel of the image sensor are selectively opened at the working distance.

[0062] For example, taking the example of the multi-spectral structured light generating unit 101 that can simultaneously emit structured light of five wavelengths (450nm (150mm), 550nm (220mm), 650nm (300mm), 780nm (450mm) and 850nm (550mm)), if the measured working distance is 200mm~250mm, which is close to the working surface positions of 220mm and 300mm, the structured light with wavelengths of 550nm and 650nm can be turned on, and the image sensor 1022 that can collect structured light with wavelengths of 550nm and 650nm can be started at the same time.

[0063] In other embodiments, the position of the multi-spectral structured light generating unit 101 can also be adjusted to adjust the working distance so that the working distance is exactly equal to the working surface position, so as to achieve the best imaging effect (such as can be used when scanning fine devices); or by adjusting, when the object to be scanned 103 is not within the depth of field, the object to be scanned 103 is within the maximum depth of field.

[0064] Optionally, the large dispersion imaging lens 1021 includes at least one optical lens capable of refraction or diffraction.

[0065] Among them, for the large dispersion imaging lens 1021, the optimal object space working distance corresponding to the structured light with a wavelength of 450nm is 150mm, the optimal object space working distance corresponding to the structured light with a wavelength of 550nm is 220mm, the optimal object space working distance corresponding to the structured light with a wavelength of 650nm is 300mm, the optimal object space working distance corresponding to the structured light with a wavelength of 780nm is 450mm, and the optimal object space working distance corresponding to the structured light with a wavelength of 850nm is 550mm.

[0066] Correspondingly, the multi-spectral structured light generating unit 101 also contains structured lights of five wavelengths: 450nm, 550nm, 650nm, 780nm and 850nm. When working, the five wavelengths of structured light are emitted simultaneously. The best object space working distance of the 450nm structured light is 150mm, the best object space working distance of the 550nm structured light is 220mm, the best object space working distance of the 650nm structured light is 300mm, the best object space working distance of the 780nm structured light is 450mm, and the best object space working distance of the 850nm structured light is 550mm.

[0067] After being scattered by the object to be scanned 103, the five wavelengths of structured light are uniformly received by the large dispersion imaging lens 1021 and converged on the five-channel color image sensor 1022. The 450nm beam is received and responded by the 450nm channel, the 550nm beam is received and responded by the 550nm channel, the 650nm beam is received and responded by the 650nm channel, the 780nm beam is received and responded by the 780nm channel, and the 850nm beam is received and responded by the 850nm channel. When the entire device is fixed, there are 5 planes with clear imaging at the same time, which expands the scanning depth of field of the device and improves the accuracy of the device.

[0068] Optionally, Figure 5 is a schematic diagram of the structure of a large dispersion imaging lens in a three-dimensional scanning device according to an embodiment of the present invention; Figure 5 As shown, the large dispersion imaging lens 1021 includes a first lens L1, a second lens L2, a third lens L3, a fourth lens L4 and a fifth lens L5 which are arranged in sequence from the object side to the image side; wherein the first lens L1 is a convex-concave lens, the second lens L2 is a concave-concave lens, the third lens L3 is a convex-convex lens, the fourth lens L4 is a convex-convex lens, and the fifth lens L5 is a concave-concave lens; the fourth lens L4 and the fifth lens L5 are cemented to form a cemented lens.

[0069] It should be noted that the first lens L1 is a convex-concave lens with a negative focal power, and the object-side light is smoothly collected into the imaging system 102, so that the light enters the second lens L2 at a smaller incident angle, reducing the proportion of higher-order aberrations, while reducing the lens aperture, and is conducive to shortening the total length of the large-dispersion imaging lens. The second lens L2 is a concave-concave lens with a negative focal power, which can further smoothly collect the object-side light into the imaging system, reducing the proportion of higher-order aberrations, and also correcting the field curvature of the system. Therefore, the combination of the two can collect light at a large angle into the lens and smoothly collect it into the imaging system 102. The third lens L3 is a convex-convex lens with a positive focal power, which can collimate the light beam, and then effectively reduce the spherical aberration and chromatic aberration of the system, thereby obtaining a higher image quality. The fourth lens L4 and the fifth lens L5 are cemented lenses, which can reduce the light spot and have a focusing effect. The cementation of the two can shorten the total length of the large-dispersion imaging lens.

[0070] Optionally, the design parameters of the large dispersion imaging lens 1021 are as follows:

[0071] Surface serial number Curvature radius (mm) Thickness(mm) Refractive Index Abbe number Physical surface infinity S1 5.76 1.01 1.755 27.6 S2 30.31 0.94 S3 -7.05 1 1.65 33.6 S4 3.71 0.9 S5(Aperture) infinity 0.2 S6 7.56 3 1.755 52.3 S7 -5.62 1.34 S8 5.66 1.89 1.728 45.7 S9 -2.99 2.25 1.773 36.2 S10 6.13 1.96 Image plane infinity 0

[0072] The surface numbers S1-S10 in the above table are numbered according to the order of the surfaces of each lens. "S5" represents the aperture of the large dispersion imaging lens; the radius of curvature represents the curvature of the lens surface. A positive value represents that the surface is bent toward the image plane, and a negative value represents that the surface is bent toward the object plane. The thickness represents the central axial distance from the current surface to the next surface. The refractive index represents the ability of the material between the current surface and the next surface to deflect light. The space represents that the current position is air, and the refractive index is 1.

[0073] Under this large dispersion imaging lens, Figures 6 to 10 4 is an MTF curve diagram of the large dispersion imaging lens of this embodiment at 450nm-850nm. Figures 6 to 10 In the figure, the T line represents the change in sharpness from the center to the edge of the image in the horizontal direction, and the R line represents the change in sharpness from the center to the edge of the image in the vertical direction. Figures 6 to 10 It can be seen that the large dispersion imaging lens has high resolution.

[0074] Optionally, Fig.11 is a channel arrangement diagram of an image sensor in a three-dimensional scanning device proposed in one embodiment of the present invention; Fig.12 is a channel arrangement diagram of an image sensor in a three-dimensional scanning device according to another embodiment of the present invention; Fig.11 and Fig.12As shown, the image sensor 1022 includes a plurality of channel components 001, and the plurality of channel components 001 are arranged in an array form, and the total number of channels included in each channel component 001 is the square of the number of channels in a single row. Exemplarily, each channel component 001 includes a first channel, a second channel, a third channel, and a fourth channel, and the first channel to the fourth channel are sequentially arranged to form a channel component in the form of a four-square grid, or each channel component includes a first channel, a second channel, a third channel, a fourth channel, a fifth channel, a sixth channel, a seventh channel, an eighth channel, and a ninth channel, and the first channel to the ninth channel are sequentially arranged to form a channel component in the form of a nine-square grid. That is, the channels in the channel component are arranged in rows and columns, and the number of channels in each row is the same as the number of channels in each column.

[0075] When arranged in the above example, it is beneficial to the manufacture of the device and the subsequent channel extraction. The more channels there are, the higher the accuracy of the extracted object 103 to be scanned.

[0076] Optionally, the multi-spectral structured light generating unit 101 includes an edge-emitting LD light source or a VCSEL light source. The edge-emitting LD light source or the VCSEL light source can emit a laser beam, and the light source bandwidth is less than ±2nm. The filter unit in the image sensor 1022 is a narrow-band filter with a bandwidth of ±2nm, which only allows light of a single wavelength to pass through.

[0077] Fig.13 is a flow chart of a scanning method of a three-dimensional scanning device proposed in an embodiment of the present invention. The method is implemented by a three-dimensional scanning device of any embodiment of the present invention, such as Fig.13 As shown, the scanning methods include:

[0078] S101, controlling a multi-spectral structured light generating unit to generate structured light of at least two wavelengths to illuminate an object to be scanned.

[0079] S102, controlling the channels corresponding to the structured light of at least two wavelengths in the image sensor to start, so as to collect scattered light beams formed by the object to be scanned scattering the structured light of at least two wavelengths.

[0080] Among them, the correspondence between wavelengths and channels can be stored in advance in the device. When the three-dimensional scanning device is scanning, the multi-spectral structured light generating unit simultaneously emits structured light of at least two wavelengths, the structured light of the first wavelength is clearly projected on the first working surface, and the structured light of the second wavelength is clearly projected on the second working surface; after the structured light of several wavelengths is scattered by the scanned object, it is uniformly received by the large dispersion imaging lens and converged on the image sensor. The special optical design of the large dispersion imaging lens makes the first working surface of the first wavelength and the second working surface of the second wavelength conjugate with the image sensor, so that the imaging system has at least two working surfaces with clear imaging, which expands the working depth of field of the device, and there is no need to move the imaging system, ensuring the stability and imaging accuracy of the device.

[0081] Among them, the image sensor can be a color image sensor, which is composed of a filter and a photosensitive unit. Its single channel can only respond to a single wavelength. The color image sensor contains at least two channels, which correspond one-to-one to the wavelength of the structured light.

[0082] It should be noted that if the imaging system is multiple groups and the light beam generated by the multi-spectral structured light generating unit is split into multiple beams, multiple image sensors can be turned on simultaneously when scanning multiple objects to be scanned. If the number of objects to be scanned is less than the number of image sensors, it can be selected to turn on only the image sensors corresponding to the objects to be scanned.

[0083] Optionally, the three-dimensional scanning device further includes a distance sensor; before controlling the multi-spectral structured light generating unit to generate structured light of at least two wavelengths to illuminate the object to be scanned, it also includes:

[0084] Obtaining a working distance between a multi-spectral structured light generating unit and an object to be scanned;

[0085] Determine the position of the working surface close to the object to be scanned according to the working distance;

[0086] S101 controls the multi-spectral structured light generating unit to generate structured light of at least two wavelengths to illuminate the object to be scanned, including:

[0087] Based on the working surface position and the first preset corresponding relationship, the multi-spectral structured light generating unit is controlled to emit structured light of a wavelength corresponding to the corresponding working surface position; wherein the first preset corresponding relationship is the corresponding relationship between the working surface position and the wavelength of the structured light emitted by the multi-spectral structured light generating unit;

[0088] S102 controls the activation of channels corresponding to the structured light of at least two wavelengths in the image sensor, including:

[0089] Based on the working surface position and the second preset corresponding relationship, the image sensor whose imaging plane is conjugate with the corresponding working surface position is controlled to start; wherein the second preset corresponding relationship is the conjugate corresponding relationship between the working surface position and the imaging plane of the image sensor.

[0090] The first preset corresponding relationship and the second preset corresponding relationship can be calibrated in advance. In order to further accurately scan the object to be scanned, or when the size of the object to be scanned is small and smaller than the overall depth of field, in order to avoid turning on all structured lights of the multi-spectral structured light generating unit at the same time, causing energy waste, before scanning the object to be scanned, the working distance between the three-dimensional scanning device and the object to be scanned can be obtained. Then, the structured light with a wavelength adapted to the working distance and the channel of the image sensor are selectively turned on at the working distance.

[0091] For example, taking the example of a multi-spectral structured light generating unit that can simultaneously emit structured light of five wavelengths (450nm (150mm), 550nm (220mm), 650nm (300mm), 780nm (450mm) and 850nm (550mm)), if the measured working distance is 200mm~250mm, which is close to the working surface positions of 220mm and 300mm, the structured light with wavelengths of 550nm and 650nm can be turned on, and the image sensor that can collect structured light with wavelengths of 550nm and 650nm can be started at the same time.

[0092] In other embodiments, the position of the multi-spectral structured light generating unit (i.e., the position of the scanner) can also be adjusted to adjust the working distance so that the working distance is exactly equal to the working surface position, thereby achieving the best imaging effect (such as can be used for fine scanning); or when the object to be scanned is not within the depth of field, the object to be scanned can be adjusted to be within the maximum depth of field.

[0093] Optionally, after the channels corresponding to the structured light of at least two wavelengths in the control image sensor are started, the method further includes:

[0094] A first image captured by an image sensor is acquired, and according to a comparison result between the first image and the object to be scanned, an unused wavelength generated by a multi-spectral structured light generating unit is controlled to be turned off.

[0095] That is to say, when there is no distance sensor or the scanning accuracy required is low (such as scanning the hood of a vehicle), the object to be scanned can be placed within the depth of field of the device through empirical judgment. Then, all wavelengths of structured light that can be generated by the multi-spectral structured light generating unit are turned on, and based on the collected image, the structured light that is not effectively used is adjusted to be turned off to save energy consumption of the device.

[0096] Among them, in the first image, if the scattered light spots corresponding to the object to be scanned can be seen, the structured light of the wavelength corresponding to the channel of the image sensor is utilized, otherwise, the structured light generated by the multi-spectral structured light generating unit is not scattered by the object to be scanned, and the scattered light spots of the structured light of this wavelength cannot be captured in the image sensor, and thus, it is not utilized, and the light source in the multi-spectral structured light generating unit that generates the structured light of this wavelength can be turned off.

[0097] In summary, according to the three-dimensional scanning device and its control method proposed in the embodiment of the present invention, the device includes: a multi-spectral structured light generating unit and at least one imaging system; the multi-spectral structured light generating unit is used to generate structured light of at least two wavelengths to illuminate the object to be scanned, wherein the working surface positions of structured light of different wavelengths are different; the imaging system includes a large dispersion imaging lens and an image sensor, the large dispersion imaging lens is used to collect scattered light beams to the same imaging plane, and the scattered light beams are formed by scattering the structured light of corresponding wavelengths at different working surface positions of the object to be scanned; the image sensor includes at least two channels, and different channels are used to collect scattered light beams corresponding to structured light of different wavelengths; wherein the working surface positions of structured light of different wavelengths are conjugate with the imaging plane of the image sensor. Thus, structured light of different wavelengths can scan different working surfaces of the object to be scanned, and then the scattered light corresponding to the different working surfaces is collected and imaged to the same plane through the imaging lens, thereby realizing a large depth of field scanning of the object to be scanned.

[0098] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0099] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A three-dimensional scanning device, characterized in that: include: A multi-spectral structured light generating unit and at least one imaging system; The multi-spectral structured light generating unit is used to generate structured light of at least two wavelengths to illuminate the object to be scanned, wherein the working surface positions of the structured light of different wavelengths are different; The imaging system comprises a large dispersion imaging lens and an image sensor, wherein the large dispersion imaging lens is used to collect scattered light beams to the same imaging plane, wherein the scattered light beams are formed by scattering structured light of corresponding wavelengths at different working surface positions of the object to be scanned; the image sensor comprises at least two channels, and different channels are used to collect scattered light beams corresponding to structured light of different wavelengths; wherein the working surface positions of the structured light of different wavelengths are conjugate with the imaging plane of the image sensor.

2. The three-dimensional scanning device according to claim 1, characterized in that: The imaging system includes a first imaging system and a second imaging system; the multi-spectral structured light generating unit is used to form a first scanning beam and a second scanning beam, the first imaging system is located on a transmission path of a first scattered beam, and the second imaging system is located on a transmission path of a second scattered beam, the first scattered beam is a beam of the first scanning beam scattered by a first object to be scanned, and the second scattered beam is a beam of the second scanning beam scattered by a second object to be scanned, and the first object to be scanned and the second object to be scanned are the same object or different objects.

3. The three-dimensional scanning device according to claim 1 or 2, characterized in that: Also includes: A controller and a distance sensor, wherein the controller is connected to the distance sensor, the multi-spectral structured light generating unit and the image sensor respectively, and the distance sensor is used to collect the working distance between the multi-spectral structured light generating unit and the object to be scanned; The controller is used to control the multi-spectral structured light generating unit to emit structured light of a wavelength corresponding to the corresponding working surface position according to the working distance, and control the image sensor conjugate with the corresponding working surface position on the imaging plane to start.

4. The three-dimensional scanning device according to claim 1, characterized in that: The large dispersion imaging lens comprises at least one refractive or diffractive optical lens.

5. The three-dimensional scanning device according to claim 1, characterized in that: The large dispersion imaging lens comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which are arranged in sequence from the object side to the image side; Wherein, the first lens is a convex-concave lens, the second lens is a concave-concave lens, the third lens is a convex-convex lens, the fourth lens is a convex-convex lens, and the fifth lens is a concave-concave lens; The fourth lens and the fifth lens are cemented to form a cemented lens.

6. The three-dimensional scanning device according to claim 1, characterized in that: The image sensor comprises a plurality of channel components, the plurality of channel components are arranged in an array, and the total number of channels in each channel component is the square of the number of channels in a single row.

7. The three-dimensional scanning device according to claim 6, characterized in that: Each of the channel components comprises a first channel, a second channel, a third channel and a fourth channel, and the first channel to the fourth channel are sequentially arranged to form a channel component in a four-square grid; Alternatively, each of the channel components includes a first channel, a second channel, a third channel, a fourth channel, a fifth channel, a sixth channel, a seventh channel, an eighth channel and a ninth channel, and the first to ninth channels are arranged in sequence to form a channel component in the form of a nine-square grid.

8. A control method for a three-dimensional scanning device, characterized in that: The control method is implemented by the three-dimensional scanning device according to any one of claims 1 to 7, wherein the control method comprises: Controlling the multi-spectral structured light generating unit to generate structured light of at least two wavelengths to illuminate the object to be scanned; The channels corresponding to the structured light of the at least two wavelengths in the image sensor are controlled to start, so as to collect scattered light beams formed by the object to be scanned scattering the structured light of the at least two wavelengths.

9. The control method of the three-dimensional scanning device according to claim 8, characterized in that: The three-dimensional scanning device further includes a distance sensor; before the multi-spectral structured light generating unit is controlled to generate structured light of at least two wavelengths to illuminate the object to be scanned, the device further includes: Acquire a working distance between the multi-spectral structured light generating unit and the object to be scanned; Determining a position of a working surface close to the object to be scanned according to the working distance; The controlling the multi-spectral structured light generating unit to generate structured light of at least two wavelengths to illuminate the object to be scanned comprises: Based on the working surface position and the first preset corresponding relationship, the multi-spectral structured light generating unit is controlled to emit structured light of a wavelength corresponding to the corresponding working surface position; wherein the first preset corresponding relationship is the corresponding relationship between the working surface position and the wavelength of the structured light emitted by the multi-spectral structured light generating unit; The controlling the activation of channels corresponding to the structured light of the at least two wavelengths in the image sensor comprises: Based on the working surface position and the second preset corresponding relationship, the image sensor on the imaging plane that is conjugate with the corresponding working surface position is controlled to start; wherein the second preset corresponding relationship is the conjugate corresponding relationship between the working surface position and the imaging plane of the image sensor.

10. The control method of the three-dimensional scanning device according to claim 8, characterized in that: After the channels corresponding to the structured light of the at least two wavelengths in the control image sensor are started, the method further includes: A first image captured by the image sensor is acquired, and according to a comparison result between the first image and the object to be scanned, the multi-spectral structured light generating unit is controlled to turn off unused wavelengths.

Images