Laser emission module and three-dimensional scanner

Abstract

The utility model relates to the technical field of scanning, and provides a laser emission module and a three-dimensional scanner, and the laser emission module comprises a laser light source, a light modulation assembly, a mask plate and a dispersion lens which are sequentially arranged; the laser light source comprises at least two sub light sources with different wavelengths and is used for emitting light beams with different wavelengths; the light modulation assembly is used for modulating the light beams emitted by the sub light sources to be in the same emission direction and transmitting the light beams to the mask; the mask is used for patterning the modulated light beam to form a structured light beam and transmitting the structured light beam to the dispersion lens; the dispersion lens is used for projecting the structured light beams to a target space, and the dispersion lens enables the light beams with different wavelengths to be focused at different distances. According to the invention, a wide scanning range can be realized, so that the performance of the three-dimensional scanner is improved.

Description

Technical Field

[0001] The present application relates to the field of scanning technology, and in particular provides a laser emission module and a three-dimensional scanner. Background Art

[0002] An optical 3D scanner is a device that uses optical imaging technology to obtain the 3D shape and data of an object. It is widely used in industrial product inspection, reverse engineering, simulation, cultural relic protection, and 3D printing. With the development of technology and the increase in application needs, users' performance requirements for 3D scanners are constantly increasing, especially the demand for scanning range is growing, and scanners are required to cover a wider range of distances. However, existing 3D scanners have limitations in depth of field, are not compatible with scanning objects at close or long distances, and cannot achieve a wider scanning range. Utility Model Content

[0003] The purpose of the embodiments of the present application is to provide a laser emission module and a three-dimensional scanner, aiming to solve the problem that the depth of field of the three-dimensional scanner in the prior art is limited and a wider scanning range cannot be achieved.

[0004] To achieve the above-mentioned purpose, the present application provides a laser emission module, comprising a laser light source, a light modulation component, a mask and a dispersion lens arranged in sequence; the laser light source comprises at least two sub-light sources with different wavelengths, which are used to emit light beams of different wavelengths; the light modulation component is used to modulate the light beams emitted by each of the sub-light sources into the same emission direction and propagate them to the mask; the mask is used to pattern the modulated light beams to form a structured light beam, and propagate the structured light beam to the dispersion lens; the dispersion lens is used to project the structured light beam into a target space, and the dispersion lens focuses the light beams of different wavelengths at different distances.

[0005] The laser emission module provided in the present application can output structured light patterns of different focal lengths by combining sub-light sources of multiple laser wavelengths, light modulation components, masks and dispersion lenses, and obtain clear structured light patterns in different ranges of depth of field in space. After superposition, super depth of field can be achieved, thereby achieving a wider scanning range and improving the performance of the three-dimensional scanner.

[0006] The present application also provides a three-dimensional scanner, comprising: the above-mentioned laser emission module, used to emit structured light beams of different wavelengths and different focal lengths to a target scanning object in a target space; an acquisition module, used to acquire the structured light beams reflected back by the target scanning object to generate a structured light image; and a control processor, used to receive the structured light image and calculate the three-dimensional data of the target scanning object based on the structured light image.

[0007] The three-dimensional scanner provided in the present application can output structured light patterns of different focal lengths through the above-mentioned laser emission module, obtain clear structured light patterns in different ranges of depth of field in space, and achieve super depth of field after superposition, thereby achieving a wider scanning range and improving the performance of the three-dimensional scanner. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 these drawings without paying any creative work.

[0009] Figure 1 A schematic diagram of the structure of a three-dimensional scanner provided in an embodiment of the present application;

[0010] Figure 2 A schematic diagram of the structure of the laser emission module provided in an embodiment of the present application.

[0011] Among them, the reference numerals in the figure are:

[0012] 10: Laser emission module;

[0013] 11: laser light source; 111: first sub-light source; 112: second sub-light source;

[0014] 12: emission optical system; 121: first collimating element;

[0015] 122: a second collimating element; 123: a semi-reflective and semi-transmissive element;

[0016] 124: mask; 125: dispersion lens;

[0017] 20: acquisition module; 21: imaging optical system; 22: image sensor;

[0018] 30: control processor; 40: target scanning object. DETAILED DESCRIPTION

[0019] 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 throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0020] In the description of the embodiments of the present application, it should be understood that the orientations or positional relationships indicated by terms such as "vertical" and "horizontal" are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of 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 embodiments of the present application.

[0021] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0022] Figure 1 The present application provides a structural schematic diagram of a three-dimensional scanner, which includes a laser emission module 10, a collection module 20 and a control processor 30. The laser emission module 10 is used to emit structured light beams of different wavelengths and different focal lengths to a target scanning object 40 in a target space, and the collection module 20 is used to collect the structured light beams reflected by the target scanning object 40 to generate a structured light image; the control processor 30 is used to receive the structured light image and calculate the three-dimensional data of the target scanning object 40 according to the structured light image, such as point cloud, height, depth and other data.

[0023] In one embodiment, the laser emission module 10 includes a laser light source 11 and an emission optical system 12, wherein the laser light source 11 includes a plurality of sub-light sources of different wavelengths, and is used to emit light beams of different wavelengths and different focal lengths toward a target scanning object 40 in a target space. The emission optical system 12 in the laser emission module 10 has different modulation effects on the light beams emitted by the sub-light sources of different wavelengths, and is used to modulate the laser beam and output a structured light laser beam, such as a speckle structured light beam or a line structured light beam, so that the acquisition module 20 acquires structured light images in different depths of field.

[0024] In one embodiment, the acquisition module 20 includes an imaging optical system 21 and an image sensor 22. The imaging optical system 21 is used to modulate the reflected structured light beam so that it is imaged on the image sensor 22. The image sensor 22 is used to receive the modulated structured light beam and generate a structured light image. It should be noted that the number of acquisition modules 20 in the present application can be one or two. When there are two acquisition modules, a binocular stereo imaging system can be formed, and the present application does not limit this.

[0025] Furthermore, the imaging optical system 21 includes a dispersion lens. When the laser emission module 10 emits light beams of different wavelengths such as λ1, λ2, λ3...λn to the target space, the dispersion lens in the acquisition module 20 modulates the reflected light beams of different wavelengths such as λ1, λ2, λ3...λn to form multiple structured light images with different focal lengths on the image sensor. At this time, the control processor 30 can obtain a structured light image with super depth of field by synthesizing multiple structured light images with different focal lengths, thereby calculating the three-dimensional data of the target scanning object 40 based on the structured light image with super depth of field, or directly calculating the three-dimensional data of the target scanning object 40 based on the structured light images with different focal lengths.

[0026] Figure 2 A detailed structural diagram of a laser emission module 10 provided in the present application. The laser light source 11 in the laser emission module 10 includes at least two sub-light sources of different wavelengths for emitting laser beams; the emission optical system 12 in the laser emission module 10 includes an optical modulation component, a mask 124 and a dispersion lens 125 arranged in sequence, wherein the optical modulation component is used to modulate the light beams emitted by each sub-light source into the same emission direction M and propagate to the mask 124, and the emission direction M can be, for example, a horizontal rightward direction; the mask 124 is used to pattern the modulated light beam to obtain a structured light beam, and propagate the structured light beam to the dispersion lens 125; the dispersion lens 125 is used to project the structured light beam into the target space, and the dispersion lens 125 focuses light beams of different wavelengths at different distances.

[0027] In this embodiment of the present application, the laser light source 11 is used to emit a laser beam, and the laser light source 11 may be a VCSEL array, a VCSEL point light source, an edge-emitting laser, etc. The present application combines and designs a plurality of sub-light sources of different wavelengths, so that light beams of different wavelengths are focused at different distances due to the dispersion effect when passing through the dispersion lens 125, thus breaking the limitation of the traditional single-wavelength light source and laying a foundation for the subsequent realization of the super depth of field effect.

[0028] The light modulation component is used to ensure that the light beams emitted by all sub-light sources can be modulated to the same emission direction M and propagate to the mask 124. In this way, the integrity and consistency of light beams of different wavelengths emitted by different sub-light sources can be maintained.

[0029] The mask plate 124 is provided with a mask pattern, and is used to receive the light beam modulated by the light modulation component and output a structured light beam having the mask pattern. Preferably, the mask plate 124 is arranged on the object side of the dispersion lens 125, so that the structured light beam can be accurately output to the dispersion lens 125, thereby improving the clarity and integrity of the light beam.

[0030] The dispersion lens 125 is used to project structured light beams of different wavelengths to different distances, so that the structured light patterns at different distances can remain clear, and the depth information capture in a wider range is realized, thereby achieving a super depth of field effect. Specifically, the dispersion lens 125 focuses light beams of different wavelengths at different distances, that is, the focusing points of light beams of different wavelengths on the light-emitting side after passing through the dispersion lens 125 are not on the same plane, that is, the positions of the clear structured light beams in space are different, so that the laser emission module 10 has different depths of field, thereby achieving a wider scanning range.

[0031] Compared with a traditional lens with only one focus, the dispersion lens 125 has multiple focuses, and the depth of field range of the laser emission module 10 can be expanded by using sub-light sources with different wavelengths. If the above laser emission module 10 is equipped with a three-dimensional scanner, the three-dimensional scanner drives sub-light sources with different wavelengths at different times, and the light beams pass through the dispersion lens so that the laser emission module 10 has a depth of field with different ranges. By repeatedly and alternately using sub-light sources with different wavelengths, the superimposed depth of field will be larger than that of a traditional lens, thereby enabling the three-dimensional scanner to have ultra-depth of field scanning.

[0032] Specifically, Figure 2 As shown, at least two sub-light sources of different wavelengths in the laser light source 11 include a first sub-light source 111 arranged along a first direction I and at least two second sub-light sources 112 arranged along a second direction II, wherein the second direction II is perpendicular to the first direction I, wherein each second sub-light source 112 is arranged between the first sub-light source 111 and the mask 124 along the second direction II, and the first sub-light source and part of the second sub-light sources emit light beams of different wavelengths. In the present application, the first direction I is preferably a vertical direction, and the second direction II is preferably a horizontal direction. By arranging the first sub-light source 111 along the first direction I and arranging at least two second sub-light sources 112 along the second direction II, it is helpful to evenly distribute light sources of different wavelengths in space, which is conducive to miniaturization, and also ensures the density and uniformity of structured light patterns of different wavelengths in the entire target space.

[0033] In one embodiment, each sub-light source emits a light beam of a different wavelength, and these sub-light sources are cross-arranged in two directions, which means that the structured light beams obtained after the light beams of different wavelengths pass through the light modulation component and the dispersion lens 125 will form structured light patterns on multiple focal planes in space, and each focal plane corresponds to a different depth of field range. In this way, the scanner can obtain information at different depths more comprehensively in three-dimensional space, thereby improving the comprehensiveness and accuracy of the scan. At the same time, the projected structured light pattern can remain clear within a wider depth range, effectively solving the problem of limited depth of field of traditional three-dimensional scanners, which is conducive to expanding the scanning range and improving the scanning accuracy.

[0034] In one embodiment, the light modulation component includes a first collimating element 121, at least two second collimating elements 122 and at least two semi-reflective and semi-transmissive elements 123. The first collimating element 121 is arranged on the light-emitting side of the first sub-light source 111, and is used to collimate the light beam emitted by the first sub-light source 111 into a first parallel light beam; at least two second collimating elements 122 are correspondingly arranged on the light-emitting sides of at least two second sub-light sources 112, and are used to collimate the light beams emitted by each second sub-light source 112 into a second parallel light beam; a semi-reflective and semi-transmissive element 123 is arranged at the intersection of the optical paths of the first parallel light beam and each second parallel light beam, and the semi-reflective and semi-transmissive element 123 is used to modulate the first parallel light beam and the second parallel light beam into the same emission direction M and output them to the mask 124. In this way, the light beams emitted by different sub-light sources can be precisely aligned and guided to the mask 124 after being modulated by the light modulation component, so as to generate a high-quality structured light pattern.

[0035] Specifically, the first collimating element 121 and the second collimating element 122 are respectively used to convert the light beams emitted by the first sub-light source 111 and the second sub-light source 112 into parallel light beams, which is beneficial to the precise control and effective superposition of subsequent light beams, can avoid energy loss and image blur caused by beam divergence, ensure the quality of the light beam, and ensure that the structured light pattern remains clear and uniform in space.

[0036] The semi-reflective and semi-transparent element 123 is arranged at the intersection of the first parallel light beam and the second parallel light beam. It not only plays the role of merging the light paths, but also modulates the parallel light beams from different directions to the same emission direction M to generate a light beam with uniform directionality. It not only reduces the loss and complexity in the light path, efficiently integrates the light beams of multiple light sources, but also ensures the consistency and directionality of the structured light in the final output, thereby improving the utilization rate of light energy.

[0037] Through such an optical path design, the stability and output accuracy of the entire laser emission module 10 can be significantly improved, which not only optimizes the overall performance of the optical system, but also provides more ideal input conditions for the subsequent dispersion lens 125, and enhances the accuracy and reliability of the final scanning result. In addition, this design also takes into account the compactness and efficiency of integration, saves space through reasonable component layout, and is conducive to the miniaturization, portability and cost control of equipment in practical applications.

[0038] In one embodiment, the light emitting direction of the first collimating element 121 is the same as the emission direction M, and the light emitting directions of the second collimating elements 122 are perpendicular to the emission direction M, that is, the first parallel light beam collimated by the first collimating element 121 is perpendicular to the second parallel light beam collimated by the second collimating element 122. By arranging the first parallel light beam and the second parallel light beam to be perpendicular to each other, the mutual influence between the light beams is minimized, and the orthogonal distribution of the light beams in space is achieved, which helps to reduce crosstalk and interference in the optical system, maintain the independence and purity of each light beam, and at the same time, the projection method of the vertical light beam helps it to form a more accurate structured light beam after passing through the mask 124, thereby improving the stability and output quality of the overall optical system.

[0039] In one embodiment, Figure 2 As shown, the semi-reflective and semi-transmissive elements 123 are arranged along the third direction III, and the third direction III has an angle a with the emission direction M, and the angle a is an acute angle. Preferably, the angle a may be 45°.

[0040] Specifically, the semi-reflective and semi-transmissive element 123 is mainly used to transmit and reflect the corresponding light beams. For example, the wavelength of the first sub-light source 111 is λ1, and the wavelengths of the second sub-light sources 112 are λ2, λ3, λ4...λn (n≥2) in sequence. The light beam emitted by the first sub-light source 111 with a wavelength of λ1 becomes a first parallel light beam after passing through the first collimating element 121, and is transmitted to the mask 124 through each semi-reflective and semi-transmissive element 123 in sequence; the light beam emitted by the second sub-light source 112 with a wavelength of λ2 becomes a second parallel light beam after passing through the corresponding second collimating element 122, is reflected by the corresponding semi-reflective and semi-transmissive element 123, and is transmitted to the mask 124 through the remaining semi-reflective and semi-transmissive elements 123 in sequence; the light beam emitted by the second sub-light source 112 with a wavelength of λ3 becomes a second parallel light beam after passing through the corresponding second collimating element 122, is reflected by the corresponding semi-reflective and semi-transmissive element 123, and is transmitted to the mask 124 through the remaining semi-reflective and semi-transmissive elements 123 in sequence. By analogy, the light beam emitted by the second sub-light source 112 with a wavelength of λn passes through the corresponding second collimating element 122 to form a second parallel light beam, which is then reflected by the corresponding semi-reflective and semi-transmissive element 123 and propagates to the mask 124 .

[0041] The embodiment of the present application can achieve coaxiality of the light beams emitted by each sub-light source by tilting the semi-reflective and semi-transmissive element 123 at the intersection of the light paths of the first parallel light beam and each second parallel light beam, thereby achieving effective integration of the light paths.

[0042] As an embodiment, the semi-reflective and semi-transmissive element 123 includes a semi-reflective and semi-transmissive film and a flat glass. By coating the flat glass with semi-reflective and semi-transmissive films of different thicknesses and / or different numbers of layers, the semi-reflective and semi-transmissive element 123 can have the optical properties of transmitting and reflecting light beams of corresponding wavelengths. Figure 2 For example, the semi-reflective and semi-transparent membrane of the first semi-reflective and semi-transparent element 123 from left to right is used to reflect a light beam with a wavelength of λ2 and transmit a light beam with a wavelength of λ1, the semi-reflective and semi-transparent membrane on the second semi-reflective and semi-transparent element 123 is used to transmit light beams with wavelengths of λ1 and λ2 and reflect a light beam with a wavelength of λ3, and the semi-reflective and semi-transparent membrane on the n-1th semi-reflective and semi-transparent element 123 is used to transmit light beams with wavelengths of λ1, λ2, λ3...λn-1, and reflect a light beam with a wavelength of λn.

[0043] In one embodiment, the mask 124 is arranged on the object side of the dispersion lens 125 along the first direction I, and the wavelengths of the first sub-light source 111 and each second sub-light source 112 decrease in sequence along the emission direction M, that is, the wavelengths λ1, λ2, λ3...λn of each sub-light source decrease in sequence from long to short. Since the dispersion lens 125 focuses light beams of different wavelengths at different distances, the light beams with longer wavelengths will have different focal positions compared to the light beams with shorter wavelengths. For example, the focal points corresponding to different wavelengths λ1, λ2, λ3...λn are d1, d2, d3...dn, respectively. By arranging the light sources in descending order of wavelength, the dispersion characteristics of the dispersion lens 125 can be more efficiently utilized, so that the structured light patterns formed by the structured light beams emitted by the scanner at different depth positions in the target space can maintain good clarity and contrast, which helps to expand the depth of field of the scanner and achieve a wider range of depth perception.

[0044] The above are only preferred embodiments of the present application and are not intended to limit the embodiments of the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the embodiments of the present application should be included in the protection scope of the embodiments of the present application.

Claims

1. A laser emission module, characterized in that: The invention comprises a laser light source, a light modulation component, a mask and a dispersion lens which are arranged in sequence, wherein: The laser light source comprises at least two sub-light sources with different wavelengths, which are used to emit light beams with different wavelengths; The light modulation component is used to modulate the light beams emitted by each of the sub-light sources into the same emission direction and transmit the light beams to the mask; The mask is used to pattern the modulated light beam to form a structured light beam, and propagate the structured light beam to the dispersion lens; The dispersion lens is used to project the structured light beam into a target space, and the dispersion lens focuses the light beams of different wavelengths at different distances.

2. The laser emission module according to claim 1, characterized in that: The sub-light sources include a first sub-light source arranged along a first direction and at least two second sub-light sources arranged along a second direction, wherein the second direction is perpendicular to the first direction, wherein: The at least two second sub-light sources are arranged between the first sub-light source and the mask along the second direction at intervals, and the first sub-light source and part of the second sub-light sources emit light beams of different wavelengths.

3. The laser emission module according to claim 2, characterized in that: The light modulation component comprises: a first collimating element, at least two second collimating elements and at least two semi-reflective and semi-transmissive elements; The first collimating element is provided at the light-emitting side of the first sub-light source, and is used to collimate the light beam emitted by the first sub-light source into a first parallel light beam; The at least two second collimating elements are correspondingly arranged at the light emitting side of each of the second sub-light sources, and are used to collimate the light beams emitted by each of the second sub-light sources into second parallel light beams; The at least two semi-reflective and semi-transmissive elements are correspondingly arranged at the intersection of the optical paths of the first parallel light beam and each of the second parallel light beams, and are used to modulate the first parallel light beam and the second parallel light beam to the same emission direction and propagate them to the mask.

4. The laser emission module according to claim 3, characterized in that: The light emitting direction of the first collimating element is the same as the emission direction, and the light emitting direction of each of the second collimating elements is perpendicular to the emission direction.

5. The laser emission module according to claim 3, characterized in that: The semi-reflective and semi-transmissive elements are arranged along a third direction, the third direction and the emitting direction have an included angle, and the included angle is an acute angle.

6. The laser emission module according to claim 5, characterized in that: The angle is 45°.

7. The laser emission module according to claim 2, characterized in that: The mask is arranged on the object side of the dispersion lens along the first direction.

8. The laser emission module according to any one of claims 2 to 7, characterized in that: The wavelengths of the first sub-light source and each of the second sub-light sources decrease in sequence along the emission direction.

9. A three-dimensional scanner, characterized in that: include: The laser emission module according to any one of claims 1 to 8, used for emitting structured light beams of different wavelengths and different focal lengths to a target scanning object in a target space; A collection module, used for collecting the structured light beam reflected by the target scanning object to generate a structured light image; A control processor is used to receive the structured light image and calculate the three-dimensional data of the target scanned object according to the structured light image.

10. The three-dimensional scanner according to claim 9, characterized in that: The acquisition module includes an imaging optical system and an image sensor. The imaging optical system includes a dispersion lens. The dispersion lens modulates structured light beams of different wavelengths reflected back by the target scanning object to form multiple structured light images with different focal lengths on the image sensor.

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