Pattern projection system and area array scanning equipment

Abstract

The invention discloses a pattern projection system and area array scanning equipment. The pattern projection system provided by the embodiment of the invention is used for generating characteristic patterns of light beams of various different wavebands and correspondingly projecting the characteristic patterns to various different working distances. Wherein the longer the light beam wavelength of the characteristic pattern is, the farther the working distance is. According to the pattern projection system and the area array scanning equipment, the pattern projection system can generate the characteristic patterns of the light beams with different wave bands, the characteristic patterns are correspondingly projected at different working distances, and the longer the light beam wavelength of the characteristic patterns is, the farther the working distance is. Therefore, through superposition of the working distance ranges corresponding to various different wave bands, the depth range of the area array scanning equipment for scanning an object is greatly increased.

Description

Technical Field

[0001] The present application relates to the technical field of area array scanning, and in particular to a pattern projection system and an area array scanning device. Background Art

[0002] As an advanced measuring device, area array scanners have been widely used in many fields, such as industrial inspection, reverse engineering, medical diagnosis, etc. The pattern projection system is one of the cores of the area array scanner. Its main function is to project a specific structured light pattern onto the object to be measured. This process is the basis for subsequent image acquisition and three-dimensional reconstruction. At present, most of the pattern projection systems on the market use a projection optical machine with a monochrome light emitting diode (LED) light source and digital light processing (DLP) display technology. However, the use of a monochrome projection optical machine is limited by the limited depth of field of the monochrome wavelength, and there is a problem of limited depth of scanning the object. Summary of the invention

[0003] The embodiments of the present application provide a pattern projection system and an area array scanning device to solve at least one of the above-mentioned technical problems.

[0004] The pattern projection system of the embodiment of the present application is used to generate characteristic patterns of light beams of various wavelength bands and project them at various working distances accordingly;

[0005] The longer the wavelength of the light beam of the characteristic pattern is, the longer the working distance is.

[0006] In some embodiments, the pattern projection system includes a multi-band pattern projection unit, and the multi-band pattern projection unit is used to generate characteristic patterns of light beams of multiple different bands and project them at multiple different working distances; or

[0007] The pattern projection system includes a plurality of single-band pattern projection units, each of which is used to generate a characteristic pattern of a band light beam and project it at a corresponding working distance.

[0008] In some embodiments, the multi-band pattern projection unit includes a multi-band projection light engine and a first dispersion lens, wherein the multi-band projection light engine is used to generate characteristic patterns of multiple different band light beams, and the first dispersion lens is used to project the characteristic patterns of multiple different band light beams to multiple different working distances.

[0009] In some embodiments, the multi-band projection light engine includes a plurality of light sources, a beam combining system, and a modulation system, wherein the modulation system includes a display panel;

[0010] The multiple light sources are respectively used to emit light beams of multiple different wavelength bands;

[0011] The beam combining system is used to combine the light paths corresponding to the multiple light sources;

[0012] The modulation system is used to control the working state of the display panel according to the input picture information, so as to generate characteristic patterns of light beams of multiple different wavelength bands.

[0013] In some embodiments, the multi-band projection light engine includes a display panel, and the display panel is used to generate characteristic patterns of light beams in multiple different bands.

[0014] In some embodiments, the light source types of the multiple light sources are any one or more of LED, halogen lamp, VCSEL, and laser bank.

[0015] In some embodiments, the multi-band projection light engine also includes at least one variable angle system arranged between at least one light source and the beam combining system, and the at least one variable angle system is used to adjust the divergence angle of the light beam emitted by the at least one light source so that the divergence angles of the light beams emitted by the multiple light sources are close after passing through the at least one variable angle system.

[0016] In some embodiments, the at least one variable angle system is a collimation system and / or an angle expansion system.

[0017] In some embodiments, the multi-band projection light engine further includes a light homogenization system disposed between the beam combining system and the modulation system, and the light homogenization system is used to shape the light beam into a light spot with uniform light intensity distribution.

[0018] In some embodiments, the multi-band projection light engine further includes a relay system disposed between the beam combining system and the modulation system, and the relay system is used to scale the spot size.

[0019] In some embodiments, the display panel is any one of DMD, LCoS, and microLED.

[0020] In some embodiments, the modulation system further includes a spectroscopic system, which is used to control the working state of the display panel according to the input image information, so that the bright light beam is incident on the first dispersion lens through the spectroscopic system, and the dark light beam is returned through the spectroscopic system.

[0021] In some embodiments, when the display panel is a DMD, the light splitting system is a TIR prism or a RTIR prism.

[0022] In some embodiments, when the display panel is LCoS, the light splitting system is a PBS prism.

[0023] The area array scanning device of the embodiment of the present application includes the pattern projection system and image acquisition system of any of the above-mentioned embodiments, wherein the pattern projection system is used to project characteristic patterns of light beams of multiple different wavelength bands onto the object to be measured according to the distance between the object to be measured and the area array scanning device, and the image acquisition system is used to acquire the characteristic pattern modulated by the object to be measured to obtain a characteristic image.

[0024] In certain embodiments, the image acquisition system includes a second dispersive lens and a camera, wherein the second dispersive lens is used to image characteristic patterns of light beams of multiple different wavelength bands onto the camera.

[0025] In the pattern projection system and the area array scanning device of the embodiment of the present application, the pattern projection system can generate characteristic patterns of light beams of multiple different wavelength bands, and project them at multiple different working distances accordingly, and the longer the wavelength of the light beam of the characteristic pattern, the longer the working distance. In this way, by superimposing the working distance ranges corresponding to multiple different wavelength bands, the depth range of the area array scanning device scanning the object is greatly increased.

[0026] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without creative work. Among them:

[0028] Figure 1 is a schematic diagram of a module of an area array scanning device according to some embodiments of the present application;

[0029] Figure 2 It is one of the module schematic diagrams of the pattern projection system of certain embodiments of the present application;

[0030] Figure 3 This is the second module schematic diagram of the pattern projection system of certain embodiments of the present application;

[0031] Figure 4 is a schematic diagram of a module of a multi-band pattern projection unit in certain embodiments of the present application;

[0032] Figure 5It is a schematic diagram of the refraction of light beams of different wavelength bands through a single lens in certain embodiments of the present application;

[0033] Figure 6 It is a schematic diagram of the ideal working distances corresponding to light beams of different wavelength bands on the same imaging plane in certain embodiments of the present application;

[0034] Figure 7 is a schematic diagram of two flipping states of a reflector in a display panel according to certain embodiments of the present application;

[0035] Figure 8 is a schematic diagram of a bright-state optical path of a DMD in combination with a TIR prism in certain embodiments of the present application;

[0036] Fig. 9 is a schematic diagram of a dark state optical path of a DMD in combination with a TIR prism in certain embodiments of the present application;

[0037] Fig.10 is a schematic diagram of a bright-state optical path of an LCoS with a PBS prism in certain embodiments of the present application;

[0038] Fig.11 is a schematic diagram of a module of an image acquisition system in certain embodiments of the present application;

[0039] Fig.12 This is one of the structural schematic diagrams of a multi-band pattern projection unit in certain embodiments of the present application;

[0040] Fig.13 This is the second structural schematic diagram of the multi-band pattern projection unit of certain embodiments of the present application;

[0041] Fig.14 This is the third structural schematic diagram of the multi-band pattern projection unit of certain embodiments of the present application;

[0042] Fig.15 This is the fourth structural schematic diagram of the multi-band pattern projection unit of certain embodiments of the present application.

[0043] Description of reference numerals:

[0044] Pattern projection system 100, multi-band pattern projection unit 101, single-band pattern projection unit 102, multi-band projection light engine 10, light source 11, first light source 111, second light source 112, third light source 113, beam combining system 12, modulation system 13, display panel 131, reflector 1311, light splitting system 132, angle changing system 14, collimation system 141, angle expansion system 142, light homogenization system 15, relay system 16, first dispersion lens 20, image acquisition system 200, second dispersion lens 201, camera 202, synchronization trigger system 300, computing system 400, and area array scanning device 1000. DETAILED DESCRIPTION

[0045] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0046] See also Figures 1 to 3 The pattern projection system 100 of the embodiment of the present application is used to generate characteristic patterns of light beams of various wavelength bands and project them at various working distances accordingly. The longer the wavelength of the light beam of the characteristic pattern is, the longer the working distance is.

[0047] In the pattern projection system 100 of the embodiment of the present application, the pattern projection system 100 can generate characteristic patterns of light beams of various wavelength bands, and project them at various working distances accordingly, and the longer the wavelength of the light beam of the characteristic pattern, the longer the working distance. In this way, by superimposing the working distance ranges corresponding to various wavelength bands, the depth range of the area array scanning device 1000 scanning the object is greatly increased.

[0048] Specifically, the characteristic pattern is, for example, a structured light pattern. The form of the characteristic pattern includes but is not limited to speckle, stripe, Gray code, etc. The pattern projection system 100 is used to generate characteristic patterns of light beams of various different wavelength bands, and project them at various different working distances. It should be noted that in the embodiments of the present application, "multiple" refers to two or more than two, and similarly, "multiple" refers to two or more than two, which are not explained one by one here.

[0049] Take the example of a pattern projection system 100 used to generate characteristic patterns of two light beams of different wavelength bands and project them at two different working distances. At this time, the pattern projection system 100 may have a short-distance scanning mode and a long-distance scanning mode. For the short-distance scanning mode, the pattern projection system 100 is used to generate a characteristic pattern of a light beam of the first wavelength band, and project the characteristic pattern of the light beam of the first wavelength band at the first working distance; for the long-distance scanning mode, the pattern projection system 100 is used to generate a characteristic pattern of a light beam of the second wavelength band, and project the characteristic pattern of the light beam of the second wavelength band at the second working distance. The wavelength of the light beam of the first wavelength band is smaller than the wavelength of the light beam of the second wavelength band, and the first working distance is smaller than the second working distance.

[0050] Take the example that the pattern projection system 100 is used to generate characteristic patterns of three different wavelength band light beams and project them at three different working distances. At this time, the pattern projection system 100 may have a close-range scanning mode, a medium-range scanning mode, and a long-range scanning mode. For the close-range scanning mode, the pattern projection system 100 is used to generate a characteristic pattern of a first wavelength band light beam, and project the characteristic pattern of the first wavelength band light beam at the first working distance; for the medium-range scanning mode, the pattern projection system 100 is used to generate a characteristic pattern of a second wavelength band light beam, and project the characteristic pattern of the second wavelength band light beam at the second working distance; for the long-range scanning mode, the pattern projection system 100 is used to generate a characteristic pattern of a third wavelength band light beam, and project the characteristic pattern of the third wavelength band light beam at the third working distance. Among them, the wavelength of the first wavelength band light beam, the wavelength of the second wavelength band light beam, and the wavelength of the third wavelength band light beam increase in sequence, and the first working distance, the second working distance, and the third working distance increase in sequence.

[0051] Of course, the pattern projection system 100 can also be used to generate characteristic patterns of more beams of different wavelength bands, and project them at more different working distances. In this case, the pattern projection system 100 can have more distance scanning modes, which will not be described one by one here.

[0052] In this way, by generating characteristic patterns of light beams of multiple different wavelength bands and projecting them at multiple different working distances, the working distance ranges corresponding to the multiple different wavelength bands are superimposed, which can greatly increase the depth range of the area array scanning device 1000 scanning the object.

[0053] The pattern projection system 100 of the embodiment of the present application may include a multi-band pattern projection unit 101 or be composed of a plurality of single-band pattern projection units 102 .

[0054] See also Figure 2 In some embodiments, the pattern projection system 100 includes a multi-band pattern projection unit 101. The multi-band pattern projection unit 101 is used to generate characteristic patterns of light beams of multiple different bands and project them at multiple different working distances.

[0055] Specifically, a multi-band pattern projection unit 101 is used to generate characteristic patterns of two different bands of light beams, and project them at two different working distances. The multi-band pattern projection unit 101 is used to generate a characteristic pattern of a first band of light beams, and project the characteristic pattern of the first band of light beams at a first working distance; and to generate a characteristic pattern of a second band of light beams, and project the characteristic pattern of the second band of light beams at a second working distance.

[0056] The embodiment of the present application utilizes a multi-band pattern projection unit 101 to generate characteristic patterns of light beams of various different bands, and projects them at various working distances accordingly. The structure is compact, which is conducive to miniaturization of the pattern projection system 100, and the component utilization rate is high.

[0057] See also Figure 3 In some embodiments, the pattern projection system 100 includes a plurality of single-band pattern projection units 102. Each single-band pattern projection unit 102 is used to generate a characteristic pattern of a band of light beams and project the pattern at a corresponding working distance.

[0058] Specifically, take the example that the pattern projection system 100 includes two single-band pattern projection units 102. The first single-band pattern projection unit 102 is used to generate a characteristic pattern of a first-band light beam, and correspondingly projects the characteristic pattern of the first-band light beam at a first working distance; the second single-band pattern projection unit 102 is used to generate a characteristic pattern of a second-band light beam, and correspondingly projects the characteristic pattern of the second-band light beam at a second working distance.

[0059] The embodiment of the present application utilizes multiple single-band pattern projection units 102 to generate characteristic patterns of light beams of multiple different bands, and projects them at multiple different working distances accordingly. The structure is simple and easy to maintain and calibrate. The characteristic pattern generated by each single-band pattern projection unit 102 has a stable wavelength and projection distance.

[0060] See also Figure 4 In some embodiments, the multi-band pattern projection unit 101 includes a multi-band projection light engine 10 and a first dispersion lens 20. The multi-band projection light engine 10 is used to generate characteristic patterns of multiple light beams of different wavelengths, and the first dispersion lens 20 is used to project the characteristic patterns of multiple light beams of different wavelengths at multiple different working distances.

[0061] Specifically, the multi-band projection light engine 10 provides a multi-band monochromatic illumination light path. The characteristic patterns of the various different band light beams generated by the multi-band projection light engine 10 are incident on the first dispersion lens 20 and projected at various different working distances through the first dispersion lens 20.

[0062] Please combine Figure 5 and Figure 6 The main difference between the first dispersive lens 20 and the traditional lens is that light beams of different wavelength bands have different focal plane positions in the first dispersive lens 20, that is, the ideal working distances of light beams of different wavelength bands at the same focal plane position of the first dispersive lens 20 are different.

[0063] The first dispersion lens 20 utilizes the difference in refractive index of light beams of different wavelength bands in the same medium, that is, the shorter the wavelength, the greater the refractive index; the longer the wavelength, the smaller the refractive index (e.g. Figure 5 As shown in Figure 1.1, the ideal working distance is 1.10, which is the distance between the lens and the object. Therefore, for an object at the same object distance, the shorter the wavelength, the closer the ideal imaging plane is to the lens; the longer the wavelength, the farther the ideal imaging plane is from the lens. That is, for the same imaging plane, the shorter the wavelength, the closer the ideal working distance is; the longer the wavelength, the farther the ideal working distance is (as shown in Figure 1.1.1). Figure 6 shown).

[0064] Take the example of a multi-band projection light engine 10 used to generate characteristic patterns of two different wavelength light beams, and a first dispersion lens 20 used to project the characteristic patterns of the two different wavelength light beams to two different working distances. The multi-band projection light engine 10 is used to generate the characteristic pattern of the first wavelength light beam and the characteristic pattern of the second wavelength light beam. Since the wavelength of the first wavelength light beam is smaller than the wavelength of the second wavelength light beam, the ideal working distance corresponding to the first wavelength light beam is smaller than the ideal working distance corresponding to the second wavelength light beam, that is, the first working distance is smaller than the second working distance. In this way, the first dispersion lens 20 can be used to project the characteristic pattern of the first wavelength light beam with a smaller wavelength to a closer first working distance, and to project the characteristic pattern of the second wavelength light beam with a larger wavelength to a farther second working distance.

[0065] See also Figure 4 and Figure 7 In some embodiments, the multi-band projection light engine 10 includes a plurality of light sources 11, a beam combining system 12, and a modulation system 13. The modulation system 13 includes a display panel 131. The plurality of light sources 11 are respectively used to emit light beams of a plurality of different wavelength bands. The beam combining system 12 is used to combine the light paths corresponding to the plurality of light sources 11. The modulation system 13 is used to control the working state of the display panel 131 according to the input image information to generate characteristic patterns of light beams of a plurality of different wavelength bands.

[0066] Specifically, along the outgoing light path direction of the multi-band pattern projection unit 101 , there are the light source 11 , the beam combining system 12 , the modulation system 13 , and the first dispersion lens 20 in sequence.

[0067] Taking the example that the multiple light sources 11 include the first light source 111 and the second light source 112, the first light source 111 and the second light source 112 are respectively used to emit light beams of different wavelength bands. In order to increase the depth of field range of the first dispersion lens 20, the first light source 111 and the second light source 112 can select light sources 11 with a large difference in the wavelength bands of the emitted light beams. For example, the first light source 111 is used to emit a light beam of a 450nm wavelength band, and the second light source 112 is used to emit a light beam of a 850nm wavelength band; for another example, the first light source 111 is used to emit a light beam of a 810nm wavelength band, and the second light source 112 is used to emit a light beam of a 455nm wavelength band. In one example, the wavelength bands of the light beams emitted by the first light source 111 and the second light source 112 differ by more than or equal to 355nm, so as to cover a larger depth of field range, thereby increasing the depth range of the area array scanning device 1000 scanning the object.

[0068] The beam combining system 12 is used to combine the light paths corresponding to the multiple light sources 11 so that the multiple light sources 11 can share the modulation system 13, the first dispersion lens 20, and the homogenization system 15 and the relay system 16 described later. Depending on the number of the multiple light sources 11, the beam combining system 12 can use different beam combining elements.

[0069] For example, when the multiple light sources 11 include a first light source 111 and a second light source 112, the beam combining system 12 may be a dichroic mirror, which achieves a beam combining effect by coating a lens plate so that light beams of different wavelengths pass through the lens plate or are transmitted or reflected. For example, a light beam of a first wavelength band is transmitted through the lens plate, while a light beam of a second wavelength band is reflected through the lens plate, thereby combining the light paths corresponding to the first light source 111 and the second light source 112.

[0070] For another example, when the plurality of light sources 11 include a first light source 111, a second light source 112, and a third light source 113 (eg Fig.14 When the light sources 11 are shown in FIG. 1 , the beam combining system 12 may be an X-prism or an X-Cube or two parallel dichroic mirrors. Among them, the X-prism is two dichroic mirrors perpendicular to each other, and the X-cube is formed by gluing four isosceles right triangles, and the gluing surface is a coating surface. Similarly, when the multiple light sources 11 include four or more light sources 11, the beam combining system 12 may be composed of more dichroic mirrors, which will not be illustrated one by one here.

[0071] The modulation system 13 is used to control the working state of the display panel 131 according to the input image information to generate a characteristic pattern. Controlling the working state of the display panel 131 specifically refers to controlling the working state of each pixel unit in the display panel 131, and the working state includes projection or non-projection. When a pixel unit is not projecting, it is in a "dark state"; when a pixel unit is projecting, it is in a "bright state". The modulation system 13 can project the bright state light beam from the first dispersion lens 20 to the area of ​​interest, and return the dark state light beam to the original optical path. The light beam is no longer projected through the first dispersion lens 20 to achieve the splitting of the bright state light beam and the dark state light beam and control whether to project through the first dispersion lens 20. The modulation system 13 controls the working state of the display panel 131 according to the image information, and can generate a corresponding characteristic pattern.

[0072] See also Figure 4 In some embodiments, the light source type of the multiple light sources 11 is any one or more of a light emitting diode (LED), a halogen lamp, a vertical cavity surface emitting laser (VCSEL), and a laser array light source (Bank).

[0073] Specifically, taking the example that the multiple light sources 11 include a first light source 111 and a second light source 112, the light source types of the first light source 111 and the second light source 112 may both be LEDs; or, the light source types of the first light source 111 and the second light source 112 may both be VCSELs; or, the light source type of the first light source 111 is LED, and the light source type of the second light source 112 is a halogen lamp; or, the light source type of the first light source 111 is VCSEL, and the light source type of the second light source 112 is laser bank, etc., which are not explained one by one here.

[0074] It should be noted that no matter the light source types of the multiple light sources 11 are one of the above or a combination of multiple types, the multiple light sources 11 must be used to emit light beams of multiple different wavelength bands respectively.

[0075] See also Figure 4 In some embodiments, the multi-band projection light engine 10 further includes at least one variable angle system 14 disposed between the at least one light source 11 and the beam combining system 12. The at least one variable angle system 14 is used to adjust the divergence angle of the light beam emitted by the at least one light source 11, so that the divergence angles of the light beams emitted by the multiple light sources 11 are close after passing through the at least one variable angle system 14.

[0076] Specifically, the variable angle system 14 is disposed between the light source 11 and the beam combining system 12. Along the direction of the outgoing light path of the multi-band pattern projection unit 101, there are the light source 11, the variable angle system 14, the beam combining system 12, the modulation system 13, and the first dispersion lens 20. The variable angle system 14 can be composed of a lens or a lens group.

[0077] In some embodiments, the number of variable angle systems 14 may be equal to the number of light sources 11. At this time, a variable angle system 14 is correspondingly arranged between each light source 11 and the beam combining system 12, and each variable angle system 14 is used to adjust the divergence angle of the light beam emitted by the corresponding light source 11, so that the divergence angles of the light beams emitted by all light sources 11 are close after passing through the corresponding variable angle system 14. Taking the multiple light sources 11 including the first light source 111 and the second light source 112 as an example, the divergence angle of the light beam emitted by the first light source 111 is 15 degrees, and the divergence angle of the light beam emitted by the second light source 112 is 5 degrees. A variable angle system 14 is arranged between the first light source 111, the second light source 112 and the beam combining system 12. After adjustment by the two variable angle systems 14, the divergence angles of the light beams emitted by the first light source 111 and the second light source 112 are both 10 degrees.

[0078] In other embodiments, the number of variable angle systems 14 may be less than the number of light sources 11. In this case, a variable angle system 14 is correspondingly arranged between some of the light sources 11 and the beam combining system 12, and each variable angle system 14 is used to adjust the divergence angle of the light beam emitted by the corresponding light source 11, so that the divergence angles of the light beams emitted by all the light sources 11 are close after passing through each variable angle system 14. Taking the multiple light sources 11 including the first light source 111 and the second light source 112 as an example, the divergence angle of the light beam emitted by the first light source 111 is 15 degrees, and the divergence angle of the light beam emitted by the second light source 112 is 10 degrees. A variable angle system 14 is arranged between the first light source 111 and the beam combining system 12. After adjustment by the variable angle system 14, the divergence angles of the light beams emitted by the first light source 111 and the second light source 112 are both 10 degrees.

[0079] It should be noted that, in the embodiments of the present application, "divergence angles are close" may mean that the difference between the divergence angles is less than a predetermined angle. Taking the predetermined angle of 1 degree as an example, when the difference between the divergence angles of the light beams emitted by the multiple light sources 11 after passing through at least one variable angle system 14 is less than 1 degree, it can be considered that the divergence angles are close. Preferably, "divergence angles are close" means that the divergence angles are equal.

[0080] In other implementations, the multi-band projection light engine 10 may not include the variable angle system 14, which is not limited herein.

[0081] See also Figure 4 and Fig.13 In some embodiments, at least one variable angle system 14 is a collimation system 141 and / or an angle expansion system 142 .

[0082] Specifically, the collimation system 141 is used to collimate the divergence angle of the light beam from a large divergence angle to a small divergence angle, and the angle expansion system 142 is used to expand the divergence angle of the light beam from a small divergence angle to a large divergence angle.

[0083] Taking the divergence angle of the light beam emitted by the first light source 111 as 15 degrees and the divergence angle of the light beam emitted by the second light source 112 as 10 degrees as an example, a collimation system 141 may be arranged between the first light source 111 and the beam combining system 12 to collimate the divergence angle of the light beam emitted by the first light source 111 from 15 degrees to 10 degrees; or, an angle expansion system 142 may be arranged between the second light source 112 and the beam combining system 12 to expand the divergence angle of the light beam emitted by the second light source 112 from 10 degrees to 15 degrees.

[0084] See also Figure 4 In some embodiments, the multi-band projection light engine 10 further includes a light homogenization system 15 disposed between the beam combining system 12 and the modulation system 13. The light homogenization system 15 is used to shape the light beam into a light spot with uniform light intensity distribution.

[0085] Specifically, the light homogenization system 15 is disposed between the beam combining system 12 and the modulation system 13. Along the direction of the outgoing light path of the multi-band pattern projection unit 101, there are the light source 11, the beam combining system 12, the light homogenization system 15, the modulation system 13, and the first dispersion lens 20 in sequence.

[0086] The light homogenization system 15 is used to shape the light beam incident from the beam combining system 12 into a light spot with uniform light intensity distribution, and the shape of the light spot is, for example, a rectangle. The light homogenization system 15 can use light homogenization devices such as a compound eye and a light rod. The working principle of the compound eye is: first, the incident light beam is divided into multiple small light sources, and then the multiple small light sources are integrated and superimposed into a light spot with uniform light intensity distribution. The working principle of the light rod is: the light beam is reflected multiple times in the light rod, and each reflection will form a virtual light source. Multiple reflections form a two-dimensional virtual light source matrix, so that the emitted light spot is more uniform.

[0087] In the embodiment of the present application, a suitable light homogenizing device can be selected according to actual needs as the light homogenizing system 15. In addition, in other embodiments, the light homogenizing system 15 may not be provided, which is not limited here.

[0088] See also Figure 4 In some embodiments, the multi-band projection light engine 10 further includes a relay system 16 disposed between the beam combining system 12 and the modulation system 13. The relay system 16 is used to scale the spot size.

[0089] Specifically, the relay system 16 is disposed between the beam combining system 12 and the modulation system 13. Along the direction of the outgoing light path of the multi-band pattern projection unit 101, there are the light source 11, the beam combining system 12, the relay system 16, the modulation system 13, and the first dispersion lens 20. The relay system 16 is used to scale the spot size to a desired size so as to project it onto the display panel 131.

[0090] See also Figure 4 and Figure 7 When the multi-band projection light engine 10 includes multiple light sources 11, at least one variable angle system 14, a beam combining system 12, a uniform light system 15, a relay system 16, and a modulation system 13, along the direction of the output light path of the multi-band pattern projection unit 101, they are the light source 11, the variable angle system 14, the beam combining system 12, the uniform light system 15, the relay system 16, the modulation system 13, and the first dispersion lens 20 in sequence. The working process is as follows: multiple light sources 11 respectively emit light beams of multiple different bands, and the divergence angles of the light beams are adjusted to the required angles through their respective angle-changing systems 14. The light paths corresponding to the multiple light sources 11 are then merged through the beam combining system 12. The light beams are then shaped into light spots with uniform light intensity distribution through the light homogenization system 15. The light spot size is scaled to the required size through the relay system 16 to be projected onto the display panel 131. The modulation system 13 controls the working state of the display panel 131 according to the input image information, and projects the bright light beam from the first dispersion lens 20 to the area of ​​interest, and returns the dark light beam to the original light path, and the light beam is no longer projected through the first dispersion lens 20.

[0091] It should be noted that the multi-band projection light engine 10 can be composed of some or all of the above components according to the actual usage scenario. In addition, the first dispersion lens 20 needs to define each band and the corresponding working distance at the beginning of the design, and then optimize the aberration by changing the surface shape, curvature, thickness, gap and material of the lens.

[0092] See also Figure 7 In some embodiments, the display panel 131 is any one of a digital micromirror device (DMD), a liquid crystal on silicon (LCoS), and a micro light emitting diode (micro LED).

[0093] Specifically, DMD has the advantages of fast switching response speed, high display resolution, good brightness, high contrast, high stability, etc. LCoS has the advantages of high resolution and high light efficiency, etc. MicroLED has the advantages of small size, low power consumption, high light efficiency, uniform and stable light emission, and long life. In practical applications, a suitable type of display panel 131 can be selected according to specific needs.

[0094] Please refer to 4. Figures 7 to 9 In some embodiments, the modulation system 13 further includes a light splitting system 132. The modulation system 13 is used to control the working state of the display panel 131 according to the input image information, so that the bright state light beam is incident on the first dispersion lens 20 through the light splitting system 132, and the dark state light beam is returned through the light splitting system 132.

[0095] In the embodiment of the present application, different types of display panels 131 can be used in conjunction with different light splitting systems 132. By controlling the working state of the display panel 131, the bright light beam can be incident on the first dispersion lens 20 through the light splitting system 132, and the dark light beam can be returned through the light splitting system 132. Of course, in other embodiments, the display panel 131 can also be used without the light splitting system 132, which is not limited here.

[0096] See also Figure 7 and Figure 8 In some embodiments, when the display panel 131 is a DMD, the optical splitting system 132 is a TIR prism or a RTIR prism.

[0097] Specifically, the DMD includes millions of micro reflectors 1311, each of which has two flip states, namely a bright state (on state) and a dark state (off state). Figure 7 The two flipping states correspond to flipping angles in two different directions, respectively. The specific values ​​of the flipping angles can be equal.

[0098] DMD can be used with TIR prism or RTIR prism. Figure 8 As shown in FIG. 1 , the bright state optical path of the DMD with the TIR prism is as follows: the incident light beam passes through the TIR prism and reaches the reflector 1311. Since the reflector 1311 is in the on state, the reflector 1311 reflects the light beam to the TIR prism and emits it through the first dispersion lens 20. Fig. 9 As shown, the dark state optical path of the DMD with TIR prism is as follows: the incident light beam passes through the TIR prism and reaches the reflector 1311. Since the reflector 1311 is in the off state, the reflector 1311 reflects the light beam to the TIR prism and returns along the original path, and fails to be emitted through the first dispersion lens 20. It should be noted that Figure 8 and Fig. 9 The middle reflector 1311 has flip angles in different directions, but since the size of the reflector 1311 is small, usually at the micron level, it is not clearly presented.

[0099] See also Fig.10In some embodiments, when the display panel 131 is an LCoS, the light splitting system 132 is a polarizing beam splitter (PBS).

[0100] Specifically, LCoS includes a liquid crystal layer, which modulates light by applying an external voltage to the pixels of the liquid crystal layer. LCoS can be used with PBS. PBS is made of two right-angled triangular prisms glued together, and one of the right-angled triangular prisms is coated with a polarization splitter film on the glued side. When P polarized light (horizontally polarized light) is incident on PBS, it will pass directly, while S polarized light (vertically polarized light) is incident on PBS and will be reflected, thereby achieving the separation of P polarized light and S polarized light.

[0101] When the external voltage of the liquid crystal layer pixel is 0, the incident S polarized light passes through the liquid crystal layer without deflection of polarization direction. After reaching the bottom of the LCoS and reflecting back, it is reflected by the PBS and returns along the original path. It will not be projected out through the first dispersion lens 20. The pixel light output is zero, that is, it is in a "dark state". Fig.10 As shown, when the external voltage applied to the pixel of the liquid crystal layer is not zero, the incident S-polarized light passes through the liquid crystal layer, the polarization direction is deflected, and the light reflected back from the bottom of the LCoS is P-polarized light, which directly passes through the PBS and is emitted by the first dispersion lens 20. This pixel appears in a "bright state" and an image is formed in the area of ​​interest.

[0102] In some embodiments, the multi-band projection light engine 10 includes a display panel 131. The display panel 131 is used to generate characteristic patterns of light beams in multiple different wavelength bands.

[0103] The embodiment of the present application utilizes the display panel 131 and the first dispersion lens 20 to realize the generation of characteristic patterns of multiple light beams of different wavelength bands, and projects them at multiple different working distances. Specifically, the display panel 131 is used to generate characteristic patterns of multiple light beams of different wavelength bands, and the first dispersion lens 20 is used to project the characteristic patterns of multiple light beams of different wavelength bands at multiple different working distances. In this case, the display panel 131 can be a microLED, and the microLED can directly generate characteristic patterns of multiple light beams of different wavelength bands without the need to set up components such as the light source 11, the variable angle system 14, the beam combining system 12, the uniform light system 15, the relay system 16, and the modulation system 13.

[0104] See also Figure 1 The area array scanning device 1000 of the embodiment of the present application includes the pattern projection system 100 and the image acquisition system 200 of any of the above embodiments. The pattern projection system 100 is used to project characteristic patterns of multiple light beams of different wavelength bands to the object to be measured according to the distance between the object to be measured and the area array scanning device 1000. The image acquisition system 200 is used to acquire the characteristic pattern modulated by the object to be measured to obtain a characteristic image.

[0105] Specifically, the area scanning device 1000 may be an area scanning scanner, etc. The distance between the object to be measured and the area scanning device 1000 may be preliminarily detected by a distance sensor or roughly determined manually.

[0106] Taking the aforementioned short-distance scanning mode and long-distance scanning mode as an example, when the distance between the object to be measured and the area array scanning device 1000 is relatively close, the pattern projection system 100 operates in the short-distance scanning mode, and the pattern projection system 100 is used to generate a characteristic pattern of the first wavelength band light beam, and correspondingly projects the characteristic pattern of the first wavelength band light beam at a first working distance, so that the characteristic pattern of the first wavelength band light beam can be projected to the object to be measured at a relatively close distance, and then, the image acquisition system 200 is used to acquire the characteristic pattern modulated by the object to be measured to obtain a characteristic image.

[0107] When the distance between the object to be measured and the area array scanning device 1000 is far, the pattern projection system 100 works in the long-distance scanning mode, and the pattern projection system 100 is used to generate a characteristic pattern of the second-band light beam, and correspondingly project the characteristic pattern of the second-band light beam to the second working distance, so that the characteristic pattern of the second-band light beam can be projected to the object to be measured at a long distance, and then, the image acquisition system 200 is used to acquire the characteristic pattern modulated by the object to be measured to obtain a characteristic image. Among them, the wavelength of the first-band light beam is smaller than the wavelength of the second-band light beam, and the first working distance is smaller than the second working distance. The characteristic pattern modulated by the object to be measured refers to the deformation pattern caused by the surface of the object to be measured.

[0108] In this way, by superimposing the working distance ranges corresponding to a plurality of different wavebands, the depth range of the object scanned by the area array scanning device 1000 is greatly increased.

[0109] See also Figure 1 In some embodiments, the area array scanning device 1000 may further include a synchronous trigger system 300. The synchronous trigger system 300 is connected to the pattern projection system 100 and the image acquisition system 200 respectively. The synchronous trigger system 300 is used to synchronously control the working states of the pattern projection system 100 and the image acquisition system 200. That is to say, while the synchronous trigger system 300 controls the pattern projection system 100 to project the characteristic pattern to the object to be measured, it controls the image acquisition system 200 to acquire the characteristic pattern modulated by the object to be measured to obtain a characteristic image. In this way, the pattern projection system 100 and the image acquisition system 200 can work precisely and synchronously, avoiding errors caused by system asynchrony, and improving the scanning accuracy of the area array scanning device 1000.

[0110] See also Figure 1In some embodiments, the area array scanning device 1000 may further include a computing system 400. After obtaining the feature image, the computing system 400 may reconstruct the three-dimensional information of the object to be measured through algorithm calculation. The reconstructed three-dimensional information may be applied to various fields such as industrial inspection, virtual reality and augmented reality, and autonomous driving.

[0111] See also Fig.11 In some embodiments, the image acquisition system 200 includes a second dispersion lens 201 and a camera 202. The second dispersion lens 201 is used to image characteristic patterns of light beams of multiple different wavelength bands on the camera 202.

[0112] Specifically, the second dispersion lens 201 has similar characteristics to the first dispersion lens 20 , and the optimal working distances of the corresponding bands are also similar, which will not be described in detail here.

[0113] The camera 202 may use image sensors such as Charge Coupled Device (CCD) or Complementary Metal Oxide Semiconductor (CMOS). CCD image sensors have the advantages of high resolution and low noise, while CMOS image sensors have the advantages of high integration, low power consumption, and high reading speed. In practical applications, a suitable type of image sensor can be selected according to specific needs.

[0114] Still taking the example that the multi-band projection light engine 10 is used to generate characteristic patterns of two different band light beams, and the first dispersion lens 20 is used to project the characteristic patterns of the two different band light beams to two different working distances. The multi-band projection light engine 10 is used to generate the characteristic pattern of the first band light beam, the first dispersion lens 20 is used to project the characteristic pattern of the first band light beam to the first working distance, and the second dispersion lens 201 is used to image the characteristic pattern modulated by the object to be measured at the first working distance to the camera 202; the multi-band projection light engine 10 is used to generate the characteristic pattern of the second band light beam, the first dispersion lens 20 is used to project the characteristic pattern of the second band light beam to the second working distance, and the second dispersion lens 201 is used to image the characteristic pattern modulated by the object to be measured at the second working distance to the camera 202. In this way, the characteristic patterns of multiple different band light beams can be imaged on the camera 202 through the second dispersion lens 201.

[0115] The working processes of the pattern projection system 100 and the area array scanning device 1000 of the present application are described below in combination with specific embodiments.

[0116] Embodiment 1:

[0117] See also Fig.12The pattern projection system 100 uses a monochromatic LED with main wavelengths of 450nm and 850nm respectively. The collimation system 141 composed of two lenses collimates the large-angle divergent light beam into a light beam with a divergent angle of about 10 degrees. The two light paths are then combined into one light path through the beam combining system 12 composed of dichroic mirrors. The light is then shaped into a plurality of small rectangular light sources through the light homogenization system 15 composed of compound eyes. The light sources are scaled by the relay system 16 and then incident on the modulation system 13 composed of a TIR prism and a DMD. The DMD controls the flipping state of the small reflector 1311 inside the DMD according to the input image information. The light beam on the small reflector 1311 in the bright state is totally reflected by the TIR prism and then projected to the area of ​​interest by the first dispersion lens 20. The light beam on the small reflector 1311 in the dark state returns to the original light path through the TIR prism and is not emitted by the first dispersion lens 20.

[0118] The first dispersion lens 20 in the pattern projection system 100 and the second dispersion lens 201 in the image acquisition system 200 have an optimal working distance of about 500mm for the 450nm band and about 1000mm for the 850nm band. The pattern projection system 100 can switch the projected beam band according to the depth of the scanned object. Generally, when scanning the surface information of an object at a distance of about 500mm, the 450nm band can be used to project the pattern; when scanning the surface information of an object at a distance of about 1000mm, the 850nm band can be used to project the pattern. Accordingly, the image acquisition system 200 acquires images of the corresponding distance and the corresponding band. In this way, the area array scanning device 1000 utilizes the dispersion lens characteristics combined with the two-way band segmented scanning method to greatly improve the scanning range of the object.

[0119] Embodiment 2:

[0120] See also Fig.13 The pattern projection system 100 uses a VCSEL with a main wavelength of 810nm and a laser Bank with a main wavelength of 455nm. Both light sources 11 are polarized laser light sources, and the display panel 131 is LCoS. The VCSEL in the 810nm band is composed of 18 small light-emitting units with a light-emitting area of ​​1.5mm, with an interval of 0.9mm, arranged in 3 rows and 6 columns, and a beam divergence angle of about 23 degrees. The laser Bank in the 455nm band has a light-emitting area of ​​14mm*18mm, and its emission angle is close to a collimated beam of 0 degrees. The VCSEL in the 810nm band is collimated to a beam divergence angle of about 10 degrees by the collimation system 141, and the laser bank in the 455nm band is expanded to a divergence angle of about 10 degrees by the angle expansion system 142. The two light paths are combined into one light path through a dichroic mirror, and then formed into a uniformly distributed rectangular light spot through the uniform light system 15 composed of light rods, and then scaled to the required size by the relay system 16 and projected onto the LCoS through the PBS.

[0121] PBS is made of two right-angle triangular prisms glued together, and the glued side of one of the right-angle triangular prisms is coated with a polarization splitter film, which can transmit P-polarized light and reflect S-polarized light, thereby achieving the separation of P-polarized light and S-polarized light.

[0122] In order to improve the contrast of the projection system, a polarizer can be added between the LCoS and the PBS to improve the polarization of the LCoS projection light, so that more P-polarized light is transmitted from the PBS to the first dispersion lens 20, and more S-polarized light is reflected by the PBS back to the original light path, thereby making the projected image brighter in the bright state and darker in the dark state.

[0123] The working principle of the area array scanning device 1000 in the second embodiment is basically the same as that in the first embodiment, and the optimal working distance of the 455nm band is smaller than the optimal working distance of the 810nm band. The area array scanning device 1000 can switch to use different beam bands according to the distance of the scanned object. Generally, when scanning objects at a relatively close distance, the 455nm band is used to project the pattern; when scanning objects at a relatively far distance, the 810nm band is used to project the pattern. The area array scanning device 1000 uses a dispersion lens and a two-way band separate scanning method to greatly improve the scanning range of the object.

[0124] Embodiment three:

[0125] See also Fig.14 and Fig.15 The pattern projection system 100 uses monochromatic LEDs with main wavelengths of 450nm, 810nm, and 940nm, respectively. After passing through the respective variable angle systems 14, the divergence angles of the light beams are collimated to approximately equal small divergence angles, and then through the beam combining system 12 composed of X-prisms, the three light paths are combined into one light path, and then through the relay system 16 composed of reflective elements, the light is reflected to the DMD, and the bright reflector 1311 on the DMD reflects the incident light beam to the dispersion lens to project it to the target area, and the dark reflector 1311 on the DMD reflects the incident light beam back to the original light path. The first dispersion lens 20 in the pattern projection system 100 and the second dispersion lens 201 in the image acquisition system 200 have an optimal working distance corresponding to the 450nm band of about 500mm, an optimal working distance corresponding to the 810nm band of about 1000mm, and an optimal working distance corresponding to the 940nm band of about 1500mm.

[0126] The area array scanning device 1000 can select different projection bands according to the specific scanning distance, and the combination of the three bands greatly increases the depth range of the area array scanning device 1000. Among them, the pattern projection system 100 does not use the uniform light system 15, and the brightness uniformity of its projected picture is about 80%, which is slightly lower than that of the conventional projection system, and is suitable for application scenarios that do not require high brightness uniformity of the projected picture.

[0127] In summary, in the pattern projection system 100 and the area array scanning device 1000 of the embodiment of the present application, the pattern projection system 100 can generate characteristic patterns of light beams of various wavelength bands, and project them at various working distances accordingly, and the longer the wavelength of the light beam of the characteristic pattern, the longer the working distance. In this way, by superimposing the working distance ranges corresponding to various wavelength bands, the depth range of the area array scanning device 1000 scanning the object is greatly increased.

[0128] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0129] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0130] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0131] The disclosure above provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described above. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides various specific processes and examples of materials, but those of ordinary skill in the art can appreciate the application of other processes and / or the use of other materials.

[0132] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "example", "specific example", "some examples", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0133] Although the embodiments of the present application have been shown and described above, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A pattern projection system, characterized in that: The pattern projection system is used to generate characteristic patterns of light beams of various wavelength bands and project them at various working distances accordingly; The longer the wavelength of the light beam of the characteristic pattern is, the longer the working distance is.

2. The pattern projection system according to claim 1, characterized in that: The pattern projection system includes a multi-band pattern projection unit, and the multi-band pattern projection unit is used to generate characteristic patterns of light beams of multiple different bands and project them at multiple different working distances accordingly; or The pattern projection system includes a plurality of single-band pattern projection units, each of which is used to generate a characteristic pattern of a band light beam and project it at a corresponding working distance.

3. The pattern projection system according to claim 2, characterized in that: The multi-band pattern projection unit includes a multi-band projection light engine and a first dispersion lens. The multi-band projection light engine is used to generate characteristic patterns of multiple light beams of different bands. The first dispersion lens is used to project the characteristic patterns of multiple light beams of different bands at multiple different working distances.

4. The pattern projection system according to claim 3, characterized in that: The multi-band projection light engine includes a plurality of light sources, a beam combining system and a modulation system, and the modulation system includes a display panel; The multiple light sources are respectively used to emit light beams of multiple different wavelength bands; The beam combining system is used to combine the light paths corresponding to the multiple light sources; The modulation system is used to control the working state of the display panel according to the input picture information to generate characteristic patterns of light beams in multiple different wavelength bands.

5. The pattern projection system according to claim 3, characterized in that: The multi-band projection light engine comprises a display panel, and the display panel is used to generate characteristic patterns of light beams of multiple different bands.

6. The pattern projection system according to claim 4, characterized in that: The light source types of the multiple light sources are any one or more of LED, halogen lamp, VCSEL, and laser bank.

7. The pattern projection system according to claim 4, characterized in that: The multi-band projection light engine also includes at least one variable angle system arranged between at least one light source and the beam combining system, and the at least one variable angle system is used to adjust the divergence angle of the light beam emitted by the at least one light source so that the divergence angles of the light beams emitted by the multiple light sources are close after passing through the at least one variable angle system.

8. The pattern projection system according to claim 7, characterized in that: The at least one variable angle system is a collimation system and / or an angle expansion system.

9. The pattern projection system according to claim 4, characterized in that: The multi-band projection light engine further comprises a light homogenization system disposed between the beam combining system and the modulation system, wherein the light homogenization system is used to shape the light beam into a light spot with uniform light intensity distribution.

10. The pattern projection system according to claim 4, characterized in that: The multi-band projection light engine further includes a relay system disposed between the beam combining system and the modulation system, and the relay system is used to scale the light spot size.

11. The pattern projection system according to claim 4, characterized in that: The display panel is any one of DMD, LCoS, and microLED.

12. The pattern projection system according to claim 4, characterized in that: The modulation system also includes a spectroscopic system, which is used to control the working state of the display panel according to the input image information, so that the bright light beam is incident on the first dispersion lens through the spectroscopic system, and the dark light beam is returned through the spectroscopic system.

13. The pattern projection system according to claim 12, characterized in that: When the display panel is a DMD, the light splitting system is a TIR prism or a RTIR prism.

14. The pattern projection system according to claim 12, characterized in that: When the display panel is LCoS, the light splitting system is a PBS prism.

15. An area scanning device, characterized in that: It comprises the pattern projection system and image acquisition system as described in any one of claims 1 to 14, wherein the pattern projection system is used to project characteristic patterns of light beams of multiple different wavelength bands onto the object to be measured according to the distance between the object to be measured and the area array scanning device, and the image acquisition system is used to acquire the characteristic pattern modulated by the object to be measured to obtain a characteristic image.

16. The area scanning device according to claim 15, characterized in that: The image acquisition system includes a second dispersion lens and a camera, wherein the second dispersion lens is used to image characteristic patterns of light beams of multiple different wavelength bands on the camera.

Images