CN113126413A

CN113126413A - Monochromatic laser projection system and 3D camera

Info

Publication number: CN113126413A
Application number: CN202110446166.6A
Authority: CN
Inventors: 高磊; 曹伟强
Original assignee: Seizet Technology Shenzhen Co Ltd
Current assignee: Seizet Technology Shenzhen Co Ltd
Priority date: 2021-04-25
Filing date: 2021-04-25
Publication date: 2021-07-16

Abstract

The invention discloses a monochromatic laser projection system, which comprises a laser component, a light path component and a projection lens component, wherein the laser component is arranged on the light path component; the light path module comprises a beam shrinking unit, a diffusion unit, a light equalizing unit, a relay unit, a prism unit and a spatial light modulator which are sequentially arranged along the advancing direction of monochromatic laser; the light path fixing component correspondingly comprises a beam shrinking tube component, a diffusion unit fixing component, a light homogenizing fixing component and a prism fixing component, monochromatic laser forms a second uniform light spot which is arranged in the same proportion with the spatial light modulator and larger than the spatial light modulator in size after being adjusted by the beam shrinking unit, the diffusion unit, the light homogenizing unit and the relay unit, the spatial light modulator is used for receiving and modulating the second uniform light spot to output a projection pattern to the projection lens, the projector structure is simplified, the cost is reduced, and meanwhile speckles generated by laser coherence are effectively reduced.

Description

Monochromatic laser projection system and 3D camera

Technical Field

The invention relates to a structured light camera projection mechanism, in particular to a monochromatic laser projection system and a 3D camera which are used in the industrial field.

Background

With the continuous development of modern precision measurement technology, the requirements of the three-dimensional measurement technology in the fields of medical treatment, archaeology, industrial design, virtual reality and the like are increasing day by day, and correspondingly, higher requirements are put forward on the precision and the speed of the three-dimensional measurement technology.

In the three-dimensional measurement technology, the detection mode comprises contact measurement and non-contact measurement, the contact measurement is carried out by scanning through a probe and a motion mechanism, and the mechanical probe is used, so that the precision is low, the practicability is low, and the probe is gradually eliminated by the market. Non-contact measurement is mainly based on optical principles and computer image processing, and is classified into time-of-flight methods, interference methods, photography methods, moire contour methods, structured light methods, and the like. They have a series of characteristics of non-contact, no damage, high precision, high speed and easy to implement automatic measurement under the control of computer. In recent years, with the development of technologies such as photoelectric, imaging, and computer, noncontact measurement technology has been rapidly developed and widely used.

The existing non-contact measuring methods mainly include a stereo vision measuring method, an interferometry method, a structured light measuring method and the like. The stereo vision measurement is a passive test measurement method, and three-dimensional information of a measured surface is calculated according to parallax after two cameras acquire two images of the same visual field. The principle is simple, the requirements on factors such as objects and backgrounds are low, the advantages are obvious in large-scale unit measurement, but the calculation amount of the multi-point matching algorithm in the two images is large, and the accuracy is low.

The basic principle of interferometry is to generate interference fringes by using the interference between the object wavefront and the reference wavefront, and to judge the geometric shape of the measured object from the deformation of the interference fringes, and such a method is one of the commonly used high-precision and high-resolution measurement methods. However, the measurement range of the system is usually small, the requirements on environmental conditions are strict, and the stability is greatly influenced by temperature, humidity, air pressure, vibration and the like.

The structured light method is an active measurement technology, and the method has the advantages of high measurement speed, high measurement precision and great application prospect in industrial detection and product design. The general technical scheme is that a carrier frequency stripe is projected to the surface of a measured object, an imaging device is utilized to record a deformed stripe image modulated by the height of the measured object from another angle, and then a three-dimensional digital image of the measured object is demodulated from the obtained deformed stripe image. The three-dimensional measurement precision is seriously influenced by the high quality of the projected structured light, and the speed and the precision of the structured light three-dimensional measurement (a 3D camera) need good sinusoidal stripe light and a precise and high-speed time shifting device.

The 3D cameras in the current market are various in types and complex in structure, the standard for measuring the product quality is basically in the two aspects of point cloud quality and operation speed, and the point cloud quality is often closely related to the projection precision and brightness of a camera projector; the light path structure in the camera projector influences the precision and quality of products, the projection precision and brightness of the projector are improved through the reasonably designed light path structure, and the method is an important link in the current 3D camera. The projector is used as an active light emitting part in a 3D camera, the projected light has great influence on the quality of point cloud, and therefore, the selection of a proper light source is an important link in the design of the projector. The current market mostly adopts LEDs as light-emitting elements of the projector, although the LEDs have small heat productivity and simple light path structures, the brightness is low, the quality of the synthesized point cloud is poor, and the LED point cloud cannot be used in the environment with higher precision requirements, such as the industrial field; therefore, laser is widely applied to structured light camera projectors due to characteristics such as high brightness, but the problems of high heat generation, complex light path and the like are also accompanied, and the complex light path is often accompanied with the problems that structural components are required to have higher precision, and some dustproof and waterproof problems need to be ensured.

Disclosure of Invention

The invention aims to provide a monochromatic laser projection system which is waterproof and dustproof, and effectively reduces speckles generated by laser coherence, ensures the imaging effect of a 3D camera while simplifying the structure of a projector, reducing the volume and weight of the system and reducing the cost.

The invention provides a monochromatic laser projection system, which comprises a laser component, a light path component and a projection lens component, wherein the laser component is arranged on the light path component; the laser assembly comprises a laser module for generating monochromatic laser and a light source fixing seat for fixing the laser module; the projection lens assembly comprises a projection lens and a projection lens fixing assembly for fixing the projection lens; the optical path component comprises an optical path module and an optical path fixing component for fixing the optical path module; the optical path module comprises a beam shrinking unit, a diffusion unit, a light equalizing unit, a relay unit, a prism unit and a spatial light modulator which are sequentially arranged along the advancing direction of the monochromatic laser; the light path fixing component correspondingly comprises a beam reducing tube component for fixing the beam reducing unit, a diffusion unit fixing component for fixing the diffusion unit, a light equalizing fixing component for fixing the light equalizing unit and the relay unit and a prism fixing component for fixing the prism unit and the spatial light modulator, which are sequentially arranged, and the monochromatic laser forms a second uniform light spot which has the cross section which is in the same proportion with the spatial light modulator and is larger than the size of the spatial light modulator after being adjusted by the beam reducing unit, the diffusion unit, the light equalizing unit and the relay unit; the second uniform light spot is incident on a spatial light modulator at a preset angle through the prism unit, and the spatial light modulator is used for receiving and modulating the second uniform light spot to output a projection pattern to the projection lens.

Preferably, the beam reducing unit, the light equalizing unit, the relay unit, the prism unit and the spatial light modulator are coaxially arranged in sequence along the advancing direction of the monochromatic laser, the beam reducing unit is used for converging the monochromatic laser, the diffusing unit is used for eliminating speckles of the monochromatic laser, the size of the spatial light modulator is arranged in proportion to the size of the cross section of the light equalizing unit, and the monochromatic laser is converged onto the diffusing unit through the beam reducing unit and then is subjected to light equalizing treatment through the light equalizing unit to form a first uniform light spot with the same size as the cross section of the light equalizing unit; the relay unit is used for amplifying the first uniform light spot according to a preset proportion to form a second uniform light spot.

Further, the beam reduction unit comprises a first lens and a second lens which are coaxially arranged and used for converging the monochromatic laser light.

And/or the diffusion unit is a combination of one or more diffusion sheets; or the diffusion unit is a laser speckle attenuator.

And/or the light homogenizing unit is a square rod light guide pipe.

And/or the relay unit comprises a rear group lens, and the rear group lens comprises a third lens, a fourth lens, a fifth lens and a sixth lens which are coaxially arranged.

And/or the prism unit is a TIR prism or an RTIR prism.

And/or the spatial light modulator is a DMD chip.

Preferably, the beam-contracting tube assembly comprises a beam-contracting tube cover plate and a beam-contracting tube which are fixedly connected, the beam-contracting tube cover plate and the beam-contracting tube are both arranged in a hollow manner, the beam-contracting tube cover plate is positioned at the rear end of the light source assembly and is detachably connected with the light source fixing seat to form a first accommodating space which is arranged in a closed manner, and the laser module is positioned in the first accommodating space and is detachably fixed on the light source fixing seat; the inner wall of the beam reducing pipe is provided with a plurality of grooves corresponding to the lenses in the beam reducing unit, and each lens is fixed in the beam reducing pipe through the corresponding groove.

Furthermore, a sealing layer is arranged at the joint of the light source fixing seat and the beam-shrinking tube cover plate and used for sealing the light source fixing seat and the beam-shrinking tube cover plate.

Preferably, the light-equalizing fixing assembly comprises a light-equalizing fixing base, diffusion unit fixing interfaces and relay unit fixing interfaces which are arranged at two ends of the light-equalizing fixing base, and a light-equalizing cover plate which is buckled on the light-equalizing fixing base; a second accommodating space is arranged in the light-homogenizing fixed base corresponding to the outer contour of the light-homogenizing unit, and the light-homogenizing cover plate is detachably connected with the light-homogenizing fixed base to seal the second accommodating space; the diffusion unit fixing interface is arranged close to the side where the beam contracting pipe assembly is located and used for installing the diffusion unit fixing assembly provided with the diffusion unit; the relay unit fixing interface is arranged close to the prism unit, the relay unit is arranged in a hollow mode and is provided with grooves corresponding to the lenses in the relay unit, and each lens is fixed inside the relay unit fixing interface through the corresponding groove.

Furthermore, the light-homogenizing fixing assembly further comprises a tube pressing sheet, and the tube pressing sheet is pressed on the light-homogenizing unit and fixedly connected with the light-homogenizing fixing base so as to be matched with the light-homogenizing unit for fixing.

Preferably, the diffusion unit fixing assembly comprises a diffusion sheet seat, the diffusion sheet seat is provided with a third accommodating space corresponding to the diffusion unit, and the diffusion unit is installed in the third accommodating space and then fixedly connected with the light homogenizing fixing assembly through the diffusion sheet base.

Furthermore, the diffusion unit fixing component also comprises a diffusion sheet pressing ring, the light homogenizing fixing component is provided with a mounting groove corresponding to the diffusion sheet seat, and the diffusion sheet seat is fixedly connected with the mounting groove through the diffusion sheet pressing ring.

Preferably, the optical path module further includes a first reflecting mirror for folding the optical path, and the first reflecting mirror is located between the beam shrinking unit and the diffusing unit to reflect the monochromatic laser light converged by the beam shrinking unit to the diffusing unit.

And/or the optical path module further comprises a second reflecting mirror used for folding the optical path, and the second reflecting mirror is positioned between the relay unit and the prism unit and used for folding the optical path.

Preferably, a monochromatic laser projection system is still including being used for the fixed first speculum fixed subassembly of first speculum, first speculum fixed subassembly can be dismantled with beam contracting subassembly, diffusion unit fixed subassembly respectively and be connected, first speculum fixed subassembly includes first speculum unable adjustment base, first speculum installation base and first speculum apron, first speculum is fixed back whole install in on the first speculum installation base in the first speculum unable adjustment base, the both ends of first speculum unable adjustment base correspond diffusion unit and set up the through-hole respectively with beam contracting unit in order to be used for the light path to transmit, first speculum apron with first speculum unable adjustment base fixed connection is in order to form a confined space.

And/or, a monochromatic laser projection system is still including being used for the fixed second mirror fixed subassembly of second mirror, the second mirror fixed subassembly can be dismantled with even light fixed subassembly, prism fixed subassembly respectively and be connected, the second mirror fixed subassembly includes second mirror unable adjustment base, second mirror installation base and second mirror apron, the second mirror is fixed last back whole install in second mirror unable adjustment base, second mirror unable adjustment base's both ends correspond relay unit and prism unit and set up the through-hole respectively in order to be used for the light path transmission, second mirror apron with second mirror unable adjustment base fixed connection is in order to form a confined space.

Further, the first mirror fixing assembly and the second mirror fixing assembly further comprise an angle adjusting unit, and the first mirror is fixed on the first mirror fixing base through the angle adjusting unit so as to adjust the angle of the first mirror; the second mirror is fixed to the second mirror fixing base via the angle adjusting unit to adjust the angle of the second mirror.

Preferably, the prism fixing component comprises a prism fixing base and a prism cover plate, wherein two side faces of the prism fixing base are provided with holes for respectively connecting the relay unit and the projection lens, the prism fixing base corresponds to the prism unit and is provided with a fourth accommodating space, and the prism unit is installed behind the fourth accommodating space and sealed in the fourth accommodating space through the prism cover plate.

Furthermore, the prism fixing component also comprises a spatial light modulator mounting plate, and the spatial light modulator mounting plate is positioned on one side surface of the prism fixing base and used for mounting the spatial light modulator.

Further, the prism fixing assembly further comprises a prism fixing plate, and the prism fixing plate is arranged above the prism unit and used for fixing the prism unit.

Preferably, the lens is fixedly mounted via a clamping ring.

The invention also provides a 3D camera, which comprises the monochromatic laser projection system and at least one industrial camera, wherein the projection range of the monochromatic laser projection system is within the image acquisition range of the industrial camera.

According to the monochromatic laser projection system and the 3D camera, disclosed by the invention, the projector structure is simplified, accessories such as a fluorescent wheel and the like are removed, the volume and the weight of the system are reduced, the cost is reduced, meanwhile, speckles generated by laser coherence are effectively reduced, and the imaging effect of the 3D camera is ensured. The light path structure of the structured light camera projector respectively fixes a laser component 110, a light path component and a projection lens at a designated position through a light source fixing seat 1, a light path fixing component and a projection lens fixing component, after a laser module 2 generates monochromatic laser, the monochromatic laser passes through a beam unit, a diffusion unit, a light equalizing unit, a relay unit and a prism unit in the light path module to be sequentially processed, a second uniform light spot with the cross section being in the same proportion with a spatial light modulator and larger than the spatial light modulator is finally generated, the second uniform light spot is incident on the spatial light modulator at a preset angle through the prism unit, and therefore the spatial light modulator can be received to be modulated to output projection patterns to the projection lens.

Meanwhile, the monochromatic laser projection system and the 3D camera disclosed by the invention have the following advantages in structural design:

firstly, a laser module is used as a projection light source of the structured light camera, the power of the laser module is high, a large amount of heat generated during working is dissipated through a radiator, and the influence of overhigh temperature on the working efficiency of the laser module is avoided;

secondly, considering that the optical precision is high, the beam reducing tube assembly is designed by adopting a 'one-knife-cutting' machining process, the perpendicularity of a mounting surface and the coaxiality of related lenses in an optical path are ensured, and the mounting errors of a plurality of groups of structural parts during mounting are avoided;

thirdly, considering that monochromatic laser enters a diffusion unit through certain angle reflection and spatial light is modulated to the unit, the first reflector and the second reflector are fixed through an angle adjusting unit, wherein the angle adjusting unit adopts an adjustable structure of 'three-point plane fixation', one screw is used as a fulcrum, and in addition, 2 adjusting screws are tensioned with springs, wherein the 2 adjusting screws are used for adjusting the angles of the first reflector and the second reflector, so that the light intensity loss in a light path is ensured;

fourthly, the light-homogenizing fixing component for installing the relay unit and the light-homogenizing unit is an integrally processed structural part, so that the installation coaxiality of all the lenses can be ensured; the light guide pipe is independently installed, so that the processing difficulty of the structural part is reduced conveniently;

fifthly, the light is too concentrated when being transmitted to the circuit chip, and the generated heat is led out through a radiating fin, wherein the radiating fin is adhered to the circuit chip and coated with heat-conducting silicone grease, so that the heat conduction efficiency is enhanced; when the radiating fins are fixed, the radiating fins are fixed by spring screws, so that the circuit chip is prevented from being crushed by hard contact;

sixthly, in the monochromatic laser projection system disclosed by the invention, all components are positioned by adopting the shaft holes of the central boss, so that the relative precision among all structural components is ensured; the connection seal between the structural parts adopts a seal ring structure, so that the sealing performance of the projector is ensured.

Drawings

FIG. 1 is a schematic view of a monochromatic laser projection system;

FIG. 2 is an exploded view of components of a monochromatic laser projection system;

FIG. 3 is a schematic diagram of the optical path structure in the embodiment shown in FIG. 1;

FIG. 4 is a schematic diagram of a monocular 3D camera according to an embodiment;

FIG. 5 is a schematic diagram of a binocular 3D camera according to an embodiment;

wherein, the light source fixing base 1, the laser module 2, the pressing ring 3, the first lens 4, the beam shrinking tube cover plate 5, the second lens 6, the beam shrinking tube 7, the first reflector 21, the first reflector fixing base 8, the first reflector mounting base 9, the first reflector fixing base cover plate 10, the diffusion sheet pressing ring 11, the diffusion sheet base 12, the diffusion sheet 13, the light guide fixing base 14, the light guide 15, the light guide pressing sheet 16, the light guide fixing base cover plate 17, the third lens 18, the fourth lens 20, the fifth lens 22, the second reflector 23, the second reflector fixing base 24, the second reflector mounting base 25, the sixth lens 27, the second reflector cover plate 28, the spatial light modulator 29, the spatial light modulator mounting plate 30, the heat sink 31, the prism fixing base 32, the prism unit 33, the prism base cover plate 34, the prism fixing plate 35, the projection lens 36, the monochromatic laser projection system 100, The laser module 110, the beam reducing tube module 120, the first reflector fixing module 130, the light homogenizing fixing module 140, the second reflector fixing module 150, the prism fixing module 160, the projection lens module 170 and the industrial camera 200.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of the invention in any way.

Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items. In the drawings, the thickness, size, and shape of an object have been slightly exaggerated for convenience of explanation. The figures are purely diagrammatic and not drawn to scale.

It will be further understood that the terms "comprises," "comprising," "includes," "including," "has," "includes" and/or "including," when used in this specification, specify the presence of stated features, steps, integers, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, integers, operations, elements, components, and/or groups thereof.

The terms "substantially", "about" and the like as used in the specification are used as terms of approximation and not as terms of degree, and are intended to account for inherent deviations in measured or calculated values that would be recognized by one of ordinary skill in the art.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Example one

As shown in fig. 1, the present invention provides a monochromatic laser projection system 100, which includes a laser assembly 110, an optical path assembly, and a projection lens assembly 170. The laser assembly 110 comprises a laser module 2 for generating monochromatic laser and a light source fixing seat 1 for fixing the laser module 2; the projection lens assembly 170 includes the projection lens 36 and a projection lens fixing assembly for fixing the projection lens 36; the light path subassembly includes the fixed subassembly of light path module and light path that is used for the light path module to fix. The optical path module comprises a beam shrinking unit, a diffusion unit, a light equalizing unit, a relay unit, a prism unit 33 and a spatial light modulator 29 which are sequentially arranged along the advancing direction of the monochromatic laser; the optical path fixing component correspondingly comprises a beam reducing pipe component 120 for fixing a beam reducing unit, a diffusion unit fixing component for fixing a diffusion unit, a light equalizing fixing component 140 for fixing the diffusion unit, the light equalizing unit and the relay unit, and a prism fixing component 160 for fixing the prism unit 33 and the spatial light modulator, which are sequentially arranged, and the monochromatic laser forms a second uniform light spot with the cross section being in the same proportion with the spatial light modulator and larger than the spatial light modulator after being adjusted by the beam reducing unit, the diffusion unit, the light equalizing unit and the relay unit; the second uniform light spot is incident on the spatial light modulator at a predetermined angle via the prism unit 33, and the spatial light modulator is configured to receive and modulate the second uniform light spot to output a projection pattern to the projection lens 36.

The monochromatic laser projection system 100 disclosed by the invention has the advantages that the projector structure is simplified, accessories such as a fluorescent wheel and the like are removed, the system volume and weight are reduced, the cost is reduced, meanwhile, speckles generated by laser coherence are effectively reduced, and the imaging effect of a 3D camera is ensured. The light path structure of the structured light camera projector respectively fixes a laser component 110, a light path component and a projection lens at a designated position through a light source fixing seat 1, a light path fixing component and a projection lens fixing component, after a laser module 2 generates monochromatic laser, the monochromatic laser passes through a beam unit, a diffusion unit, a light equalizing unit, a relay unit and a prism unit 33 in the light path module to be sequentially processed, a second uniform light spot with the cross section being in the same proportion with a spatial light modulator and larger than the spatial light modulator is finally generated, the second uniform light spot is incident on the spatial light modulator at a preset angle through the prism unit 33, and therefore the spatial light modulator can be received to be modulated to output projection patterns to the projection lens.

According to the monochromatic laser projection system 100, the laser module 2 is used as a projection light source of the structured light camera, the power of the laser module 2 is high, a large amount of heat generated during working is dissipated through the radiator, and the influence of overhigh temperature on the working efficiency of the laser module 2 is avoided.

As shown in fig. 2, in the present embodiment, the laser modules 2 are preferably parallel laser modules. The laser light source is designed in a modular mode, and the laser light source has the following advantages of 1 parallel connection relation and reliable use. 2 special module structure, the split is easy, when needs improve projection luminance, only need install more laser diode can additional, the operation is simple relatively. 3, the safety is improved. The laser light source is designed as a solid mechanism, and can be melted down when being unstable or overheated, so that the power is automatically cut off, and the hidden danger is thoroughly avoided. 4 compared with the traditional light source, the power consumption of the pure laser light source is greatly reduced, and the energy-saving effect is obvious.

In the embodiment, each group of laser modules 2 is fixed on the light source fixing seat through a positioning pin and a screw, and heat generated by the laser during working is transmitted to the radiator part through the light source fixing seat 1; meanwhile, a sealing layer is arranged at the joint of the light source fixing seat 1 and the beam-shrinking tube cover plate 5 for sealing between the light source fixing seat 1 and the beam-shrinking tube cover plate 5.

As shown in fig. 3, as a preferred scheme, in this embodiment, the beam reducing unit, the light equalizing unit, the relay unit, the prism unit 33, and the spatial light modulator 29 are coaxially arranged in sequence along the advancing direction of the monochromatic laser, the beam reducing unit is configured to converge the monochromatic laser, the diffusing unit is configured to eliminate speckle of the monochromatic laser, the size of the spatial light modulator is set in proportion to the size of the cross section of the light equalizing unit, the monochromatic laser is converged onto the diffusing unit by the beam reducing unit and then is subjected to light equalizing treatment by the light equalizing unit to form a first uniform spot having the same size as the cross section of the light equalizing unit; the relay unit is used for amplifying the first uniform light spot according to a preset proportion to form a second uniform light spot. The size of the second uniform light spot is larger than that of the spatial light modulator and is set in the same proportion with that of the spatial light modulator; the prism unit 33 is used for making the second uniform light spot incident on the spatial light modulator at a preset angle; the spatial light modulator is used for receiving and modulating the second uniform light spot to output a projection pattern to the projection lens.

The function of the beam reduction unit is focusing, and since the divergence angle of the laser beam is small, as a preferable scheme, the beam reduction unit includes a first lens 4 and a second lens 6 which are coaxially arranged for converging the monochromatic laser light in the present embodiment.

Correspondingly, the beam-reducing tube assembly 120 includes a beam-reducing tube cover plate 5 and a beam-reducing tube 7 which are fixedly connected, and the beam-reducing tube cover plate 5 and the beam-reducing tube 7 are both arranged in a hollow manner, the beam-reducing tube cover plate 5 is located at the rear end of the light source assembly, the light source fixing seat 1 and the beam-reducing tube cover plate 5 are detachably connected to form a first accommodating space which is arranged in a closed manner, in this embodiment, the beam-reducing tube cover plate 5 is a cuboid cover plate which is arranged in a hollow manner, the beam-reducing tube 7 is a cylindrical structure which is arranged in a hollow manner, the laser module 2 is located in the first accommodating space and is detachably fixed on the light source fixing seat 1, a groove is arranged in the beam-reducing tube 7 corresponding to a lens in the beam-reducing unit, the first lens 4 and the second lens 6 are fixed in the beam-reducing tube 7 through the corresponding grooves, and further, the first lens 4 and the. Meanwhile, considering that the optical precision is high, the structural design of the beam reducing tube component 120 adopts a 'one-knife-cutting' machining process, so that the perpendicularity of the mounting surface and the coaxiality of related lenses in an optical path are ensured, and the mounting errors of a plurality of groups of structural components during mounting are avoided;

in addition, in consideration of the overall length of the system, the monochromatic laser projection system 100 of the present invention further includes a first reflecting mirror 21 for folding the optical path, and the first reflecting mirror 21 is located between the beam reduction unit and the diffusion unit to reflect the monochromatic laser light condensed by the beam reduction unit onto the diffusion unit, thereby folding the optical path.

Correspondingly, the monochromatic laser projection system 100 of the present invention further includes a first reflector 21 fixing component 130 for fixing the first reflector 21, the first reflector 21 fixing component 130 is detachably connected to the beam shrinking tube component 120 and the diffusing unit fixing component, the first reflector 21 fixing component 130 includes a first reflector 21 fixing base 8, a first reflector 21 mounting base 9 and a first reflector 21 cover plate 10, the first reflector 21 is integrally mounted in the first reflector 21 fixing base 8 after being fixed on the first reflector 21 mounting base 9, two ends of the first reflector 21 fixing base 8 are respectively provided with a through hole for optical path transmission corresponding to the diffusing unit and the beam shrinking unit, and the first reflector 21 cover plate is detachably connected to the first reflector 21 fixing base 8 to form a sealed space. The first reflector 21 fixing base 8 plays a role in fixing the front group and middle group light paths, the direction of the light paths is changed through the reflectors on the first reflector 21 mounting base 9, after the light emitted by the laser module 2 is shrunk through the lenses in the beam shrinking tube 7, the light is reflected at a preset angle through the reflectors on the first reflector 21 mounting base 9, the incident direction of the light paths is changed, and the length of the light paths is shortened;

in addition, in the present embodiment, as a preferable scheme, the first reflector 21 fixing assembly 130 further includes an angle adjusting unit, and the first reflector 21 is fixed on the first reflector 21 fixing base 8 through the angle adjusting unit, so as to adjust the angle of the first reflector 21 and ensure the verticality of the emitted light. The reflectors on the first reflector 21 mounting base 9 are fixed through elastic sheets and are mounted on the first reflector 21 fixing base 8 together, and then are adjusted and fixed through a plurality of screws. The angle adjustment unit adopts the adjustable structure of "three fixed planes", and a screw is as the fulcrum, and 2 adjustment screws take the spring to be taut in addition, wherein through adjusting 2 adjustment screws that take the spring topmost, the angle of adjustment speculum, the verticality of guaranteeing the ray of penetrating.

Because the characteristics of the convergence of the monochromatic laser enable the laser to be very stable, which is a very unfavorable factor for a projection light source, in the embodiment, the converged monochromatic laser penetrates through the diffusion unit and then is changed into a usable and divergent surface light source. Meanwhile, because of the interference effect between the laser and the laser, a diffusion unit is also needed to eliminate the interference effect, and as a preferred scheme, in the embodiment, the diffusion unit is a combination of one or more diffusion sheets; or, the diffusion unit is a laser speckle attenuator, which can effectively reduce laser speckles.

In this embodiment, the diffusion unit fixing assembly includes a diffusion sheet holder 12, the diffusion sheet holder 12 has a third accommodating space corresponding to the diffusion unit, and the diffusion sheet 13 in the diffusion unit is installed in the third accommodating space and then fixedly connected to the light-equalizing fixing assembly 140 via the diffusion sheet holder. The diffusion sheets 13 can be fixed on the lens mounting grooves in the third accommodating space through the pressing ring.

The light equalizing unit is used for forming a first uniform light spot with the same cross section size, and as a preferred scheme, in the embodiment, the light equalizing unit is a square rod light pipe, and the size and the reflection times of the square rod light pipe meet the following requirements:

wherein, N is the reflection times, L is the length of the square rod light guide pipe, θ max is the maximum aperture angle of the light beam in the integrating rod, and h and w respectively represent the height and the width of the square rod light guide pipe.

Corresponding to the above-mentioned light-equalizing unit composition, as a preferred scheme, in this embodiment, the light-equalizing fixing assembly 140 includes a light pipe fixing seat 14, a diffusion unit fixing interface and a relay unit fixing interface disposed at two ends of the light pipe fixing seat 14, and a light pipe fixing seat cover plate 17 fastened on the light pipe fixing seat 14. A second accommodating space is arranged in the light pipe fixing seat 14 corresponding to the outer contour of the light homogenizing unit, and the square rod light pipe is arranged in the second accommodating space and then is sealed in the sealed space formed by the light pipe fixing seat cover plate 17 and the light pipe fixing seat 14; furthermore, the light-equalizing fixing assembly 140 further includes a tube pressing sheet, which is pressed on the square-bar light guide tube and is fixedly connected to the light guide tube fixing seat 14 to cooperate with the square-bar light guide tube for fixing. In this embodiment, the tube pressing plate is a spring 16, and the light pipe 15 is fixed on the light pipe fixing seat 14 through the spring 16.

The light-equalizing fixing component 140 in this embodiment is used for installing the diffusion sheet 13, the light guide 15, the third lens 18, the fourth lens 20 and the fifth lens 22, and is detachably connected to the first reflector 21 fixing component 130 and the second reflector 23 fixing component 150 through a diffusion unit fixing interface and a relay unit fixing interface, respectively, wherein the diffusion unit fixing interface is disposed near the side where the beam-shrinking tube component 120 is located and used for installing the diffusion unit fixing component installed with the diffusion sheet 13; the relay unit fixing interface located at the other side of the light pipe fixing seat 14 is used for fixedly connecting with the relay unit.

In the projection illumination system, due to the light-emitting characteristics of the square-bar light pipe and the limitation of the system structure, the first uniform light spot passing through the square-bar light pipe cannot be directly projected onto the spatial light modulator 29, and therefore, a relay unit is required to achieve the purpose. The relay unit is used for amplifying the first uniform light spot on a spatial light modulator 29 chip in proportion, and under a general condition, the projection relay system can meet the requirement of the quality of the system illumination light spot by adopting a double telecentric structure of 3-4 spherical lenses. As a preferable mode, in the present embodiment, the relay unit includes a sixth lens including a third lens 18, a fourth lens 20, a fifth lens 22, and a sixth lens 27, which are coaxially disposed. The third lens is used for diffusing light rays to amplify light spots coming out of the square rod in equal proportion, the negative lens can be selected, the fourth lens is used for collecting and gathering light rays, the curvature of the front surface of the lens is negative, the curvature of the rear surface of the lens is positive, the fifth lens and the sixth lens are used for turning the light path and adjusting the size of the light spots irradiated on the DMD by controlling the distance between the fifth lens and the sixth lens, and therefore in the embodiment, the fifth lens is selected as the positive lens, the negative lens is selected as the sixth lens, and the symmetrical structure is adopted to reduce aberration.

Correspondingly, the relay unit fixing interface is arranged close to the side where the prism unit 33 is located, the relay unit is arranged in a hollow mode, grooves are formed in the relay unit corresponding to the lenses, and the lenses are fixed in the relay unit fixing interface through the corresponding grooves and are fixed on the grooves through pressing rings. In this embodiment, the third lens 18, the fourth lens 20, and the fifth lens 22 are fixed to the relay unit fixing interfaces by corresponding press rings.

Preferably, the optical path module further includes a second reflecting mirror 23 for folding the optical path, and the second reflecting mirror 23 is located between the relay unit and the prism unit 33 for folding the optical path. In this embodiment, the second reflecting mirror 23 is located between the fifth lens 22 and the sixth lens 27.

Correspondingly, the monochromatic laser projection system 100 of the present invention further includes a second reflector 23 fixing component 150 for fixing the second reflector 23, the second reflector 23 fixing component 150 is located between the light-equalizing fixing component 140 and the prism fixing component 160, the second reflector 23 fixing component 150 includes a second reflector 23 fixing base 24, a second reflector 23 mounting base 25 and a second reflector 23 cover plate 28, the second reflector 23 is integrally mounted in the second reflector 23 fixing base 24 after being fixed on the second reflector 23 mounting base 25, two ends of the second reflector 23 fixing base 24 corresponding to the relay unit and the prism unit 33 are respectively provided with through holes for optical path transmission, and the second reflector 23 cover plate is fixedly connected with the second reflector 23 fixing base to form a sealed space.

Further, the second reflector 23 fixing assembly 150 further includes an angle adjusting unit, and the second reflector 23 is fixed on the second reflector 23 fixing base through the angle adjusting unit to adjust the angle of the second reflector 23, so as to ensure the verticality of the emitted light. In this embodiment, the angle of the second reflector 23 is adjusted by adjusting the screws and the springs on the mounting base 25 of the second reflector 23 and the fixing base 24 of the second reflector 23, and the method is the same as the method for adjusting the angle of the first reflector 21, which is not described herein again.

The light reflected by the first reflector 21 on the base 9 of the first reflector 21 uniformly enters the light guide pipe 22 through the diffusion sheet 13, then is emitted to the second reflector 23 of the second reflector 23 mounting base 25 through the third lens 18, the fourth lens 20 and the fifth lens 22, and is reflected into the sixth lens 27 and the prism unit 33 through the second reflector 23; preferably, in this embodiment, the prism unit 33 is a TIR prism or an RTIR prism.

Correspondingly, the prism fixing assembly 160 includes a prism fixing base 32 and a prism cover 34, the prism fixing base 32 has a fourth accommodating space corresponding to the prism unit 33, and the prism unit 33 is installed in the fourth accommodating space and then sealed in the fourth accommodating space via the prism cover 34. In addition, the prism fixing assembly 160 further includes a prism fixing plate 35, wherein the prism fixing plate 35 is located below the prism cover plate 34, and is fixed by the prism fixing plate 35 after the prism unit 33 is placed in the fourth accommodating space.

The prism fixing base 32 is further provided with an interface at a side close to the second reflecting mirror 23 fixing component 150, the sixth lens 27 of the relay unit is fixed at the interface of the prism fixing base 32 through a pressing ring, and the prism fixing base 32 is fixedly connected with the second reflecting mirror 23 fixing base 24 through screws, of course, the interface can also be provided on the second reflecting mirror 23 fixing component 150.

As a preferable scheme, in this embodiment, the spatial light modulator 29 is a DMD chip, and can project a high-quality structured light stripe pattern by using DLP, and since the stripe pattern is generated by computer simulation, the phase shift and the stripe width can be precisely controlled by a program, which satisfies the characteristic of stripe pattern adaptive projection.

Correspondingly, the prism fixing assembly 160 further includes a spatial light modulator mounting plate 30, and the spatial light modulator mounting plate 30 is located on a side surface of the prism fixing base 32 and is used for mounting the DMD chip.

In this embodiment, the light is reflected by the second reflecting mirror 23, then passes through the sixth lens 27 and the prism 33, acts on the DMD chip, and is reflected to the lens 36 by the DMD chip to be emitted; the right part of the prism fixed base 32 is connected with the second reflector 23 fixed base 24, the front part is connected with the projection lens 36, the middle part is provided with the prism unit 33, and the rear part is provided with the DMD chip and the radiator 31; the spatial light modulator mounting plate 30 plays a role in fixing the DMD chip and the radiator 31, the radiator 31 is used for radiating heat generated by focusing light on the DMD chip and is fastened through spring screws, the radiator 31 is tightly attached to the DMD chip, and good heat conductivity is guaranteed.

Example two

As shown in fig. 4, the present invention further provides a 3D camera, which includes the monochromatic laser projection system 100 and an industrial camera 200 according to the first embodiment, wherein the projection range of the monochromatic laser projection system 100 is within the image capture range of the industrial camera 200.

Due to the adoption of the monochromatic laser projection system 100, the 3D camera disclosed by the invention has the advantages of large visual field, high precision and strong adaptive capacity to ambient light change, and when the 3D camera is used for a large-visual-field 3D vision guide robot or other scenes, the acquired point cloud has high precision and stable imaging.

EXAMPLE III

As shown in fig. 5, the present invention further provides a 3D camera, which includes the monochromatic laser projection system 100 and two industrial cameras 200 according to the first embodiment, wherein the two industrial cameras 200 are located at two sides of the monochromatic laser projection system 100, and the projection range of the monochromatic laser projection system 100 is within the image capture range of each of the two industrial cameras 200.

It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A monochromatic laser projection system is characterized by comprising a laser component, a light path component and a projection lens component;

the laser assembly comprises a laser module for generating monochromatic laser and a light source fixing seat for fixing the laser module; the projection lens assembly comprises a projection lens and a projection lens fixing assembly for fixing the projection lens;

the optical path component comprises an optical path module and an optical path fixing component for fixing the optical path module; the optical path module comprises a beam shrinking unit, a diffusion unit, a light equalizing unit, a relay unit, a prism unit and a spatial light modulator which are sequentially arranged along the advancing direction of the monochromatic laser; the light path fixing component correspondingly comprises a beam reducing tube component for fixing the beam reducing unit, a diffusion unit fixing component for fixing the diffusion unit, a light equalizing fixing component for fixing the light equalizing unit and the relay unit and a prism fixing component for fixing the prism unit and the spatial light modulator, which are sequentially arranged, and the monochromatic laser forms a second uniform light spot which has the cross section which is in the same proportion with the spatial light modulator and is larger than the size of the spatial light modulator after being adjusted by the beam reducing unit, the diffusion unit, the light equalizing unit and the relay unit; the second uniform light spot is incident on a spatial light modulator at a preset angle through the prism unit, and the spatial light modulator is used for receiving and modulating the second uniform light spot to output a projection pattern to the projection lens.

2. The monochromatic laser projection system according to claim 1, wherein the beam-reducing unit, the light-equalizing unit, the relay unit, the prism unit, and the spatial light modulator are coaxially arranged in sequence along the advancing direction of the monochromatic laser, the beam-reducing unit is configured to converge the monochromatic laser, the diffusing unit is configured to eliminate speckle of the monochromatic laser, the size of the spatial light modulator is set in the same proportion as the size of the cross section of the light-equalizing unit, and the monochromatic laser is converged onto the diffusing unit by the beam-reducing unit and then is subjected to light-equalizing processing by the light-equalizing unit to form a first uniform spot having the same size as the cross section of the light-equalizing unit; the relay unit is used for amplifying the first uniform light spot according to a preset proportion to form a second uniform light spot.

3. The monochromatic laser projection system according to claim 1 or 2, wherein the beam reduction unit comprises a first lens and a second lens which are coaxially arranged for converging the monochromatic laser light;

and/or the diffusion unit is a combination of one or more diffusion sheets; or the diffusion unit is a laser speckle attenuator;

and/or the light homogenizing unit is a square rod light guide pipe;

and/or the relay unit comprises a rear group lens, and the rear group lens comprises a third lens, a fourth lens, a fifth lens and a sixth lens which are coaxially arranged;

and/or the prism unit is a TIR prism or an RTIR prism;

and/or the spatial light modulator is a DMD chip.

4. The monochromatic laser projection system of claim 1, wherein the beam-reducing tube assembly comprises a beam-reducing tube cover plate and a beam-reducing tube which are fixedly connected, the beam-reducing tube cover plate and the beam-reducing tube are both arranged in a hollow manner, the beam-reducing tube cover plate is located at the rear end of the light source assembly and is detachably connected with the light source fixing seat to form a first accommodating space which is arranged in a closed manner, and the laser module is located in the first accommodating space and is detachably fixed on the light source fixing seat; the inner wall of the beam reducing pipe is provided with a plurality of grooves corresponding to the lenses in the beam reducing unit, and each lens is fixed in the beam reducing pipe through the corresponding groove.

5. The monochromatic laser projection system of claim 1, wherein the light-equalizing fixing assembly comprises a light-equalizing fixing base, a diffusion unit fixing interface and a relay unit fixing interface arranged at two ends of the light-equalizing fixing base, and a light-equalizing cover plate fastened on the light-equalizing fixing base;

a second accommodating space is arranged in the light-homogenizing fixed base corresponding to the outer contour of the light-homogenizing unit, and the light-homogenizing cover plate is detachably connected with the light-homogenizing fixed base to seal the second accommodating space;

the diffusion unit fixing interface is arranged close to the side where the beam contracting pipe assembly is located and used for installing the diffusion unit fixing assembly provided with the diffusion unit;

the relay unit fixing interface is arranged close to the prism unit, the relay unit is arranged in a hollow mode and is provided with grooves corresponding to the lenses in the relay unit, and each lens is fixed inside the relay unit fixing interface through the corresponding groove.

6. The monochromatic laser projection system of claim 5, wherein the light-homogenizing fixing assembly further comprises a tube pressing sheet, and the tube pressing sheet is pressed on the light-homogenizing unit and fixedly connected with the light-homogenizing fixing base so as to be matched for fixing the light-homogenizing unit.

7. The monochromatic laser projection system of claim 1, wherein the diffusion unit fixing assembly comprises a diffusion sheet holder, a third accommodating space is formed in the diffusion sheet holder corresponding to the diffusion unit, and the diffusion unit is installed in the third accommodating space and then fixedly connected with the uniform light fixing assembly through the diffusion sheet base.

8. The monochromatic laser projection system of claim 1, wherein the optical path module further comprises a first reflecting mirror for folding the optical path, the first reflecting mirror is located between the beam reduction unit and the diffusion unit to reflect the monochromatic laser light converged by the beam reduction unit onto the diffusion unit;

9. The monochromatic laser projection system of claim 8, further comprising a first reflector fixing assembly for fixing the first reflector, wherein the first reflector fixing assembly is detachably connected with the beam reducing tube assembly and the diffusion unit fixing assembly respectively, the first reflector fixing assembly comprises a first reflector fixing base, a first reflector mounting base and a first reflector cover plate, the first reflector is integrally mounted in the first reflector fixing base after being fixed on the first reflector mounting base, through holes are respectively formed at two ends of the first reflector fixing base corresponding to the diffusion unit and the beam reducing unit for light path transmission, and the first reflector cover plate is fixedly connected with the first reflector fixing base to form a sealed space;

and/or, still including being used for the fixed second mirror fixed subassembly of second mirror, the second mirror fixed subassembly can be dismantled with the fixed subassembly of even light, prism fixed subassembly respectively and be connected, the second mirror fixed subassembly includes second mirror unable adjustment base, second mirror installation base and second mirror apron, the second mirror is fixed the second mirror installation base is gone up the back whole install in the second mirror unable adjustment base, the second mirror unable adjustment base's both ends correspond relay unit and set up the through-hole respectively with the prism unit so that be used for the light path transmission, the second mirror apron with second mirror unable adjustment base fixed connection is in order to form a confined space.

10. The monochromatic laser projection system of claim 9, wherein the first mirror fixing assembly and the second mirror fixing assembly further comprise an angle adjusting unit, and the first mirror is fixed on the first mirror fixing base via the angle adjusting unit to adjust the angle of the first mirror; the second mirror is fixed to the second mirror fixing base via the angle adjusting unit to adjust the angle of the second mirror.

11. The monochromatic laser projection system of claim 1, wherein the prism fixing assembly includes a prism fixing base and a prism cover plate, the prism fixing base has openings on two sides thereof for connecting the relay unit and the projection lens, and the prism fixing base has a fourth receiving space corresponding to the prism unit, and the prism unit is mounted in the fourth receiving space and then sealed in the fourth receiving space via the prism cover plate.

12. The monochromatic laser projection system of claim 11, wherein the prism holding assembly further comprises a spatial light modulator mounting plate, the spatial light modulator mounting plate is positioned on one side of the prism holding base for mounting of the spatial light modulator.

13. A3D camera, comprising: a monochromatic laser projection system as claimed in any one of claims 1 to 12 and an industrial camera, the projection range of said monochromatic laser projection system being within the image acquisition range of said industrial camera.