Disclosure of Invention
In view of the shortcomings in the prior art, it is an object of the present invention to provide a structured light projector and a three-dimensional imaging device.
According to the present invention there is provided a structured light projector comprising: a substrate, a light source, a projection lens, and a diffractive optical element;
the number of the light sources is multiple, and the light sources are arranged on the substrate and are arranged on the substrate in a quasi-crystal shape;
the projection lens is arranged on the light-emitting side of the light source, is configured to receive the light emitted by the light source and projects a light beam array arranged in a quasi-crystal shape;
the diffraction optical element is arranged on the light outlet side of the projection lens and is used for expanding the plurality of light beams arranged in the shape of the quasi-crystal to project a plurality of light beam arrays arranged in the shape of the quasi-crystal and adjacent to each other.
Preferably, the light source comprises a vertical cavity surface emitting laser diode.
Preferably, the quasi-crystal shape comprises a plurality of lattice units;
each lattice unit comprises a light source lattice which is periodically arranged;
the lattice units are arranged periodically, and light sources in different lattice units are arranged randomly.
Preferably, the spot lattice periodically arranged in the lattice unit is in any one or more of the following shapes:
straight line shape; a triangle shape; a quadrilateral; a rectangle shape; a circular shape; a hexagon; a pentagon shape; a heptagon; an octagon; a star shape; a vertebral shape; a trapezoid shape; an oval shape; a multi-focus circle; a crescent shape; an arcuate shape; a sector shape; a diamond shape.
Preferably, the substrate is a semiconductor substrate.
Preferably, the device further comprises a first driver and a second driver;
the plurality of light sources are arranged into a first light source group and a second light source group; the first light source group and the second light source group both comprise a plurality of light sources arranged in a quasi-crystal shape;
the first light source groups and the second light source groups are arranged on the substrate in a staggered manner;
the first driver and the second driver are respectively connected with the first light source group and the second light source group to separately drive the first light source group and the second light source group, so that the first light source group and the second light source group emit light respectively or simultaneously.
Preferably, the first light source group comprises a plurality of light sources arranged in a quasi-crystal shape;
the second light source group comprises a plurality of light sources which are arranged in another quasi-crystal shape.
Preferably, the projection lens and the diffractive optical element are formed on opposite sides of an optical substrate.
The three-dimensional imaging device provided by the invention comprises the structured light projector and a light detector array imager;
the structured light projector is used for projecting a plurality of light beams which are arranged in a quasi-crystal shape to a target object;
and the light detector array imager is used for receiving the multiple light beams reflected by the target object and obtaining the depth data of the surface of the target object according to the light spot lattice image formed by the multiple light beams.
Preferably, the photodetector array imager employs an infrared camera.
Compared with the prior art, the invention has the following beneficial effects:
according to the invention, the plurality of light sources are arranged on the substrate and are arranged on the substrate in a quasi-crystal shape, so that light spot lattices arranged in a quasi-crystal shape can be projected, the arrangement of the light spot lattices is wholly random and has certain regularity locally, lost points can be recovered through local information of the light spot lattices, and the robustness of the structured light camera is enhanced; the light spot lattice is arranged in a quasi-crystal manner, so that each light spot can be conveniently searched, the pattern transformation of the light spot lattice can be controlled, and the depth map calculation is convenient.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.
It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element. The connection may be for fixation or for circuit connection.
It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for convenience in describing the embodiments of the present invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed in a particular orientation, and be in any way limiting of the present invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed 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 that feature. In the description of the embodiments of the present invention, "a plurality" means two or more unless specifically limited otherwise.
Fig. 2 is a schematic structural diagram of a structured light projector according to an embodiment of the present invention, and as shown in fig. 2, the structured light projector according to the present invention includes: a substrate 2, a light source 1, a projection lens 3, and a diffractive optical element 4;
the number of the light sources 1 is multiple, the light sources 1 are arranged on the substrate 2, and the light sources are arranged on the substrate 2 in a quasi-crystal shape;
the projection lens 3 is arranged at the light-emitting side of the light source 1, is configured to receive the light emitted by the light source 1 and projects a light beam array arranged in a quasi-crystal shape;
and the diffractive optical element 4 is arranged on the light outlet side of the projection lens 3 and is used for expanding the plurality of light beams arranged in the quasi-crystal shape to project a plurality of light beam arrays arranged in the quasi-crystal shape and adjacent to each other.
The substrate 2 is a semiconductor substrate. The projection lens and the diffractive optical element 4 are formed on opposite sides of an optical substrate.
In the embodiment of the invention, the plurality of light sources 1 are arranged on the substrate 2 and are arranged on the substrate 2 in a quasi-crystal shape, so that light spot lattices arranged in a quasi-crystal shape can be projected, the arrangement of the light spot lattices is wholly random and has certain regularity locally, lost points can be recovered through local information of the light spot lattices, and the robustness of the structured light camera is enhanced.
The structured light projector provided by the present invention can be implemented on a variety of systems or devices, such as cell phones, computers, tablets, wearable devices, vehicles, and the like.
In an embodiment of the present invention, the light source 1 includes a vertical cavity surface emitting laser diode (VCSEL).
In a variant of the invention, the light source 1 comprises a Light Emitting Diode (LED) or the like, which may also employ light collimation. Alternatively, the light source 1 may also comprise a plurality of lasers or diodes, such as an edge emitting laser array, a VCSEL array, an LED array, etc.
In embodiments of the present invention, the projection lens 3 may be configured to increase or decrease the field of view of the projection beam array. For example, the projection lens 3 may increase the field of view by diverging the projection beam array, or decrease the field of view by converging the projection beam array.
In an embodiment of the invention, the projection lens 3 may be configured to collimate each of the coupled-out light beams. For example, the laser beam waist of the projection beam array collimated by the projection lens 3 varies from 10mm to 1m according to the working distance requirements of different applications. In this way, the projection lens 3 can collimate the output light to form a sharp image, e.g., a spot lattice, at a distance of observation, e.g., in the range of 10cm to 10m, depending on the application.
FIG. 3 is a schematic diagram of an embodiment of the invention in which the light spot lattice is arranged in a quasi-crystal shape, as shown in FIG. 3, the quasi-crystal shape includes a plurality of lattice units;
each lattice unit comprises a light source lattice which is periodically arranged;
the lattice units are arranged periodically, and light sources in different lattice units are arranged randomly.
In the embodiment of the invention, the spot lattice periodically arranged in the lattice unit is in any one or more of the following shapes:
straight line shape; a triangle shape; a quadrilateral; a rectangle shape; a circular shape; a hexagon; a pentagon shape; a heptagon; an octagon; a star shape; a vertebral shape; a trapezoid shape; an oval shape; a multi-focus circle; a crescent shape; an arcuate shape; a sector shape; a diamond shape.
Fig. 4 is a schematic diagram of an application example of a quasi-crystal shape-arranged light spot lattice in an embodiment of the present invention, and as shown in fig. 4, light spot lattices with various shapes are formed by arranging lattice units with various shapes.
Fig. 5 is a schematic layout view of light sources according to an embodiment of the present invention, and as shown in fig. 5, a plurality of light sources 1 are arranged on the substrate 2 in a quasi-crystal shape.
In a variation of the present invention, the structured light projector further comprises a first driver and a second driver;
a plurality of the light sources 1 are arranged into a first light source group and a second light source group; the first light source group and the second light source group both comprise a plurality of light sources arranged in a quasi-crystal shape;
the first light source groups and the second light source groups are arranged on the substrate 2 in a staggered manner;
the first driver and the second driver are respectively connected with the first light source group and the second light source group to separately drive the first light source group and the second light source group, so that the first light source group and the second light source group emit light respectively or simultaneously.
In this modification, one set of light sources can be controlled to project light beams independently, and two sets of light sources can be controlled to project light spot lattices with different densities at the same time, so that the method is suitable for application scenes with different resolutions.
The first light source group comprises a plurality of light sources which are arranged in a quasi-crystal shape; the second light source group comprises a plurality of light sources which are arranged in another quasi-crystal shape.
In this modification, the first light source group and the second light source group have different light source arrangement shapes, so that spot lattices with different patterns can be projected.
FIG. 6 is a schematic structural diagram of a three-dimensional imaging apparatus according to an embodiment of the present invention, and as shown in FIG. 6, the three-dimensional imaging apparatus according to the present invention includes the structured light projector 100 and further includes a light detector array imager 200;
the structured light projector 100 for projecting a plurality of light beams arranged in a quasi-crystal shape toward the target object 300;
the photodetector array imager 200 is configured to receive the plurality of light beams reflected by the target object 300 and obtain depth data of the target object surface according to a light spot lattice image formed by the plurality of light beams.
The photodetector array imager 200 employs an infrared camera.
In the embodiment of the present invention, the photodetector array imager 200 is an infrared camera.
When a plurality of light beams irradiate on a target object, a light spot dot matrix image can be formed, wherein the light spot pattern can be deformed or displaced, and after the light spot pattern on the surface of the target is obtained through shooting by the light detector array imager, a depth image of the surface of the target object can be obtained according to the deformation or displacement of the light spot pattern, so that the depth information of the surface of the target object, namely the unevenness, can be obtained.
According to the invention, the plurality of light sources are arranged on the substrate and are arranged on the substrate in a quasi-crystal shape, so that light spot lattices arranged in a quasi-crystal shape can be projected, the arrangement of the light spot lattices is wholly random and has certain regularity locally, lost points can be recovered through local information of the light spot lattices, and the robustness of the structured light camera is enhanced; the light spot lattice is arranged in a quasi-crystal manner, so that each light spot can be conveniently searched, the pattern transformation of the light spot lattice can be controlled, and the depth map calculation is convenient.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes and modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention.