CN108761827A - A kind of structured light projecting device and depth camera - Google Patents

Abstract

The present invention relates to optical fields, and in particular to a kind of structured light projecting device.The structured light projecting device includes：Light source emits the light beam with two-dimentional regular pattern；Lens receive and converge the light beam；Diffraction element, includes at least two independent diffraction functional areas, and the diffraction specification of all or part of independent diffraction functional area differs；Wherein, the light beam projects the diffraction image with corresponding diffraction specification by independent diffraction functional area, also, the diffraction image synthesizes the projected image with two-dimentional irregular pattern in object space.The invention further relates to depth cameras.The present invention solves low-power light source and realizes projection high density patterns, while standard arrangement light source can realize diffraction high-density random arrangement speckle by designing a kind of structured light projecting device.

Description

A structured light projection device and a depth camera

technical field

The invention relates to the field of optics, in particular to a structured light projection device and a depth camera.

Background technique

By projecting a pre-designed pattern as a reference image (coded light source), the structured light is projected onto the surface of the object, and then the camera is used to receive the structured light pattern reflected by the object surface. In this way, two images are also obtained. The design reference image, the other one is the structured light pattern reflected by the object surface captured by the camera. Since the receiving pattern will be deformed due to the three-dimensional shape of the object, it can be calculated by the position and deformation degree of the pattern on the camera. Spatial information on the surface of an object. The common structured light method is still a depth calculation that partially adopts the principle of triangulation ranging.

Further, the reference image is not acquired, but a specially designed pattern, so the feature points are known and easier to extract from the test image. Structured light adopts triangular parallax distance measurement, and the longer the baseline (the distance between the light source and the optical center of the lens), the higher the accuracy.

In the existing depth projection projection lens, there are several schemes, 1. Set a light-emitting element with a two-dimensional irregular pattern at the light source; 2. Use two DOE lenses, one for converting the regularly arranged light source pattern into Irregular pattern, one for duplicating the pattern.

However, the above-mentioned solutions have disadvantages. For example, in the first solution, the light source needs to be specially customized, which increases the cost. For the second solution, two DOE lenses are used, which has a complicated structure and is inconvenient to install.

Contents of the invention

The technical problem to be solved by the present invention is to provide a structured light projection device to solve the problems of high cost and complex structure of the depth projection lens, aiming at the above-mentioned defects of the prior art.

The technical problem to be solved by the present invention is to provide a depth camera to solve the problems of high cost and complex structure of the depth camera in view of the above defects of the prior art.

The technical solution adopted by the present invention to solve the technical problem is to provide a structured light projection device, characterized in that the structured light projection device includes:

a light source emitting a beam of light with a two-dimensional regular pattern;

a lens for receiving and converging the light beam;

The diffraction element includes at least two independent diffraction functional areas, and the diffraction specifications of all or part of the independent diffraction functional areas are different; wherein, the light beam projects a diffraction image with corresponding diffraction specifications through the independent diffraction functional areas, and, The diffraction image is synthesized into a projected image with a two-dimensional irregular pattern in the target space.

Among them, the preferred solution is: the at least two independent diffractive functional regions are in two-dimensional space, and the projected fields of view of the at least two independent diffractive functional regions are in an overlapping state, a partially overlapping state or a spliced state.

Wherein, a preferred solution is: the diffraction element further includes a semiconductor substrate, and the independent diffraction functional area includes an etching area provided on the semiconductor substrate.

Among them, a preferred solution is: the diffraction element further includes a transparent substrate, and the semiconductor structure formed by the independent diffraction functional regions is bonded on the semiconductor substrate.

Wherein, a preferred solution is: the material of the transparent substrate is one of semiconductor material, glass material and plastic material.

Among them, the preferred solution is: the light source includes at least two light-emitting sub-light sources, and each of the light-emitting sub-light sources is equipped with a lens, or at least two of the light-emitting sub-light sources form a light-emitting sub-light source group, and the light-emitting sub-light sources The light source groups are all equipped with a lens.

Among them, the preferred solution is: each of the lenses is configured with an independent diffractive functional area, or at least two of the lenses form a lens group, and the lens group is configured with an independent diffractive functional area, or, the lenses are configured with multiple independent diffraction functional area.

Among them, the preferred solution is: the structured light projection device also includes a fixed housing, and the light source, lens and diffraction element are all arranged on the fixed housing; and, the material of the fixed housing includes glass, ceramics, graphite One or more of , metal and plastic.

The technical solution adopted by the present invention to solve the technical problem is to provide a structured light projection device, which includes:

a light source emitting a beam of light with a two-dimensional regular pattern;

a lens for receiving and converging the light beam;

The diffraction element includes an independent diffraction functional area; wherein, the light beam projects a diffraction image with corresponding diffraction specifications through the independent diffraction functional area, and forms a projected image with a two-dimensional irregular pattern in the target space.

The technical solution adopted by the present invention to solve the technical problem is to provide a depth camera, which includes: a structured light projection device for projecting a projected image with a two-dimensional irregular pattern into the target space; an image acquisition device , used to collect the actual image in the target space; the processor receives the actual image collected by the image acquisition device and generates the depth image of the target space; wherein, using a matching algorithm to calculate the distance between the projected image and the actual image The deviation value of is, and the depth image is calculated according to the deviation value.

The beneficial effect of the present invention is that, compared with the prior art, the present invention designs a structured light projection device, the light beam passes through the independent diffraction functional area to project a diffraction image with corresponding diffraction specifications, and the diffraction image is in the target space The projected image with two-dimensional irregular patterns is synthesized in the medium, and the low-power light source can be used to project high-density patterns. At the same time, the standard arrangement of light sources can realize the diffraction high-density random arrangement of speckles; further, the structure is simple, the manufacturing cost is low, and it is convenient for large-scale Scale production promotion.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

Fig. 1 is a structural schematic diagram of the structured light projection device of the present invention;

Fig. 2 is the structural representation of diffraction element of the present invention;

Fig. 3 is a structural schematic diagram of a structured light projection device based on multiple luminous sub-light sources of the present invention;

Fig. 4 is a schematic structural diagram of Embodiment 1 of the diffraction element of the present invention;

Fig. 5 is a schematic structural diagram of Embodiment 2 of the diffraction element of the present invention;

Fig. 6 is a schematic structural view of a structured light projection device based on a fixed housing in the present invention;

FIG. 7 is a schematic structural diagram of a depth camera of the present invention.

Detailed ways

Now in conjunction with the accompanying drawings, the preferred embodiments of the present invention will be described in detail.

As shown in FIGS. 1 to 3 , the present invention provides a preferred embodiment of a structured light projection device.

The structured light projection device includes a light source 110, a lens 120 and a diffraction element 130, the light source 110, the lens 120 and the diffraction element 130 are arranged in sequence, specifically, the light source 110 emits a beam 101 with a two-dimensional regular pattern, the The lens 120 is used to receive and converge the light beam 101. The diffraction element 130 includes at least two independent diffraction functional areas 131. The diffraction specifications of all or part of the independent diffraction functional areas 131 are different, that is, the independent diffraction functional areas 131 have different diffraction specifications. The diffraction specifications of the 131 are all different, or the diffraction specifications of the independent diffraction functional regions 131 may be partially the same, but not all of them are the same.

Further, the light beam 101 passes through the independent diffraction functional area 131 to project a diffraction image 102 with corresponding diffraction specifications, and the diffraction image 102 synthesizes a projected image 103 with a two-dimensional irregular pattern in the target space. Wherein, the two-dimensional regular pattern is a two-dimensional pattern arranged in an array, and except for the two-dimensional regular pattern, other patterns can be regarded as two-dimensional irregular patterns.

Firstly, the projected image 103 projected by the diffractive element 130 can be a two-dimensional irregular pattern composed of random points in the whole screen; secondly, the projected image 103 projected by the diffractive element 130 can also be divided into multiple arrays or other regular arrangements. Each projection area can be regarded as a two-dimensional irregular pattern composed of random points in the whole area. Further, each independent diffractive functional area 131 can project a projection area, or project several projection areas arranged in an array or other regular arrangement, and the projection areas of multiple independent diffractive functional areas 131 in the target space A projected image 103 having a two-dimensional irregular pattern is synthesized in the process.

In this embodiment, the specific process is as follows: firstly, the light beam 101 emitted by the light source 110 is a plurality of light beams with two-dimensional regular patterns. Generally speaking, the multiple light beams with two-dimensional regular patterns are preferably arranged in an array and the light beam 101 emitted by the light source 110 is incident on the diffraction element 130 after being converged by the corresponding lens 120; secondly, the diffraction element 130 includes two or more independent diffraction functional areas 131, and each independent diffraction functional area 131 has A semiconductor region with a specific diffraction specification, that is, the light beam 101 passing through an independent diffraction functional area 131 with different specific diffraction specifications will produce different diffraction images 102, and multiple diffraction images 102 are synthesized in the target space with a two-dimensional irregular pattern The projected image 103 .

Preferably, different luminous flux independent diffraction functional areas 131 diffract patterns with different diffraction rules, and all diffraction images 102 are projected into the target space, and the at least two independent diffraction functional areas 131 are in a two-dimensional space , and the projected fields of view of the at least two independent diffractive functional regions 131 are in an overlapping state, a partially overlapping state or a spliced state, forming a two-dimensional irregular pattern. Wherein, the at least two independent diffractive functional areas 131 are both in a two-dimensional plane, or the at least two independent diffractive functional areas 131 are in a two-dimensional space, and different independent diffractive functional areas 131 may exist difference in location.

And, the way of synthesizing the projected image 103 with two-dimensional irregular patterns in the target space is:

The function of the diffraction element 130 can be regarded as generating structured light patterns with a greater number, greater density, and higher randomness by duplicating and cross-overlapping a limited number of light beams. Can adopt DOE structure, also can be grating. The DOE structure is a diffractive optical element (Diffractive Optical Elements, DOE). Multiple DOE optical structures are spliced with the semiconductor substrate 211 to form a composite structure, and the integrated arrangement of the diffractive element 130 is realized.

Regarding specific diffraction specifications, specifically, reorganize regularly arranged two-dimensional regular patterns with different specific diffraction specifications, or perform recombination of more than two different specific diffraction specifications in the same independent diffraction functional area 131, such as performing splicing and recombination , superposition recombination, rotation recombination, dislocation recombination, etc. And, the diffraction is performed by the independent diffraction functional area 131, so that the "two-dimensional irregular pattern" and "diffraction" can be performed simultaneously. There is no need to use a specific light source 110, and there is no need to set up a complicated optical system (optical lens), and the optical lens can be placed away from the light source 110 to reduce the impact of the heat energy of the light source 110 on the optical lens, thereby realizing the structure of the structured light projection device. Miniaturization, realize compact design, and improve the stability and anti-interference of the overall structure, thereby reducing production costs and improving product quality.

Preferably, the light source 110 may be a laser light source 110 such as visible light or invisible light such as infrared or ultraviolet. For example, VCSEL is used, the full name is Vertical Cavity Surface Emitting Laser (Vertical Cavity Surface Emitting Laser), which is developed on the basis of gallium arsenide semiconductor materials, which is different from other light sources such as LED (light-emitting diode) and LD (Laser Diode, laser diode). 110, has the advantages of small size, circular output spot, single longitudinal mode output, small threshold current, low price, and easy integration into a large-area array, and is widely used in optical communication, optical interconnection, optical storage and other fields.

As shown in Fig. 4 and Fig. 5, the present invention provides a preferred embodiment of the diffractive element.

The diffraction element 130 also includes a semiconductor substrate 211 , and the independent diffraction functional regions 131 are all disposed on the semiconductor substrate 211 , further, the independent diffraction functional regions 131 are arranged in an array on the semiconductor substrate 211 . Wherein, semiconductor (semiconductor) refers to a material whose conductivity at normal temperature is between that of a conductor (conductor) and an insulator (insulator). By arranging the independent diffractive functional regions 131 on the semiconductor substrate 211 , the integrated design of the diffractive element 130 is realized, which facilitates the production and installation of the diffractive element 130 .

At the same time, the diffraction element 130 can be provided with a plurality of semiconductor substrates 211, and a plurality of independent diffraction functional regions 131 are arranged on each semiconductor substrate 211, and a plurality of semiconductor substrates 211 are combined to form a new diffraction element 130, and the expansion of the diffraction element 130 is realized. , and facilitate the production and processing of the diffraction element 130.

Preferably, the independent diffractive functional region 131 is an etched region 212 on the semiconductor substrate 211 to realize an integrated structure. That is, the independent diffractive functional region 131 is disposed on the semiconductor substrate 211 by etching to form the independent diffractive functional region 131 . Among them, etching, English is Etch, it is a very important step in semiconductor manufacturing process, microelectronic IC manufacturing process and micro-nano manufacturing process. It is a main process of pattern processing associated with lithography. The so-called etching, in fact, is understood in a narrow sense as photolithography etching. First, the photoresist is subjected to photolithography exposure treatment by photolithography, and then the part to be removed is etched by other means. With the development of micro-manufacturing technology, in a broad sense, etching has become a general term for stripping and removing materials through solutions, reactive ions or other mechanical methods, and has become a common name for micro-processing.

Also, the independent diffractive functional region 131 may be a DOE optical structure 213 , and the DOE optical structures 213 are all disposed on the semiconductor substrate 211 . Among them, Diffractive Optical Elements (DOE) are a series of movable mirrors in a lithography machine, which are used to generate light sources required for lithography.

Of course, the semiconductor substrate 211 may also be made of other translucent materials. For example, glass substrates and transparent plastic substrates.

As shown in Figure 3, the present invention provides a preferred embodiment of the light source.

The light source 110 includes at least two light-emitting sub-light sources 110, and each of the light-emitting sub-light sources 110 is equipped with a lens 120, or at least two of the light-emitting sub-light sources 110 form a group of light-emitting sub-light sources 110, and the light-emitting sub-light sources Each of the 110 groups is equipped with a lens 120 .

Each light emitting sub-light source 110 is provided with one or more light source 110 emitting heads, or laser emitting heads, or light emitting LEDs, or other light emitting elements, and the light emitting elements form a two-dimensional regular pattern on each light emitting sub light source 110 . Correspondingly, the lens 120 is preferably an array lens 120, through which the light beams 101 emitted by each light-emitting sub-light source 110 are converged.

And, each of the lenses 120 is configured with an independent diffraction function area 131 , or at least two of the lenses 120 form a lens 120 group, and the lens 120 group is configured with an independent diffraction function area 131 .

As shown in FIG. 6 , the present invention provides a preferred embodiment of a structured light projection device.

The structured light projection device also includes a fixed housing 140, on which the light source 110, the lens 120 and the diffraction element 130 are all arranged; and, the material of the fixed housing 140 includes glass, ceramics, graphite, One or more of metal and plastic.

First, the fixed housing 140 can be provided with a uniform material, such as glass, ceramics, and graphite with low thermal conductivity as the material of the fixed housing 140, and the light source 110, the lens 120 and the diffraction element 130 are sequentially arranged on the fixed housing 140. Of course, the fixed housing 140 may include structural components such as a base, a cylinder body, and a light outlet, and the light source 110, the lens 120, and the diffractive element 130 are arranged in corresponding structural components. And, different materials can also be used as the material of the fixed housing 140, that is, different structures in the fixed housing 140 adopt different materials, for example, the cylinder body is made of glass, the light outlet is made of ceramics, and the base is also made of ceramics, etc., and the light source 110 is set On the base, the lens 120 is arranged on the cylinder body, and the diffraction element 130 is arranged on the light outlet, so as to isolate the heat of the light source 110 as much as possible and prevent the fixed housing 140 from being deformed due to heat.

As shown in FIG. 7 , the present invention provides a preferred embodiment of a depth camera.

A depth camera, characterized in that the depth camera includes a structured light projection device 310, an image acquisition device 320 and a processor 330, wherein,

The structured light projection device 310 is used to project a projected image 103 having a two-dimensional irregular pattern into the target space, such as the projected image 103 projected on the projected image 301 in the target space, and the image acquisition device 320 is used to Acquiring an actual image in the target space, the processor 330 receives the actual image collected by the image acquisition device 320 and generates a depth image of the target space; further, using a matching algorithm to calculate the difference between the projected image and the actual image The deviation value between, and calculate the depth image according to the deviation value.

Of course, the processor is also connected to the structured light projection device to realize the control of the structured light projection device. The above are only the best embodiments of the present invention, and are not used to limit the scope of the present invention. All equivalent changes or modifications made according to the patent scope of the present invention are covered by the present invention.

Claims (11)

1. A structured light projection device, characterized in that, the structured light projection device comprises: a light source emitting a beam of light with a two-dimensional regular pattern; a lens for receiving and converging the light beam; A diffractive element comprising at least two independent diffractive functional areas, all or part of which have different diffractive specifications; Wherein, the beam passes through the independent diffraction functional area to project a diffraction image with corresponding diffraction specifications, and the diffraction image synthesizes a projected image with a two-dimensional irregular pattern in the target space. 2. The structured light projection device according to claim 1, characterized in that: the at least two independent diffractive functional areas are in two-dimensional space, and the projection fields of view of the at least two independent diffractive functional areas are in an overlapping state, Partially overlapped state or stitched state. 3 . The structured light projection device according to claim 1 , wherein the diffractive element further comprises a semiconductor substrate, and the independent diffractive functional area comprises an etched area provided on the semiconductor substrate. 4 . 4 . The structured light projection device according to claim 1 , wherein the diffractive element further comprises a transparent substrate, and the semiconductor structure formed by the independent diffractive functional regions is bonded on the semiconductor substrate. 5. The structured light projection device according to claim 1, wherein the material of the transparent substrate is one of semiconductor material, glass material and plastic material. 6. The structured light projection device according to any one of claims 1 to 5, characterized in that: the independent diffractive functional areas are arranged in an array. 7. The structured light projection device according to claim 1, wherein the light source comprises at least two light-emitting sub-light sources, and each of the light-emitting sub-light sources is equipped with a lens, or at least two of the light-emitting sub-light sources constitute a A light emitting sub-light source group, and each of the light emitting sub light source groups is configured with a lens. 8. The structured light projection device according to claim 1 or 7, characterized in that: each of the lenses is configured with an independent diffraction functional area, or at least two of the lenses form a lens group, and the lens group is configured with a Independent diffractive functional areas, or, the lenses are configured with a plurality of independent diffractive functional areas. 9. The structured light projection device according to claim 1, characterized in that: the structured light projection device further comprises a fixed housing, and the light source, lens and diffraction element are all arranged on the fixed housing; and, the The material of the fixed housing includes one or more of glass, ceramics, graphite, metal and plastic. 10. A structured light projection device, characterized in that the structured light projection device comprises: a light source emitting a beam of light with a two-dimensional regular pattern; a lens for receiving and converging the light beam; A diffractive element comprising an independent diffractive functional area; Wherein, the light beam projects a diffraction image with a corresponding diffraction specification through the independent diffraction functional area, and forms a projection image with a two-dimensional irregular pattern in the target space. 11. A depth camera, characterized in that the depth camera comprises: The structured light projection device according to any one of claims 1 to 10, used for projecting a projected image with a two-dimensional irregular pattern into the target space; an image acquisition device for acquiring actual images in the target space; a processor, receiving an actual image captured by the image capture device and generating a depth image of the target space; Wherein, a matching algorithm is used to calculate a deviation value between the projected image and an actual image, and the depth image is calculated according to the deviation value.