CN209895097U

CN209895097U - Projector and depth camera

Info

Publication number: CN209895097U
Application number: CN201920766267.XU
Authority: CN
Inventors: 武万多; 王兆民
Original assignee: Shenzhen Orbbec Co Ltd
Current assignee: Shenzhen Orbbec Co Ltd
Priority date: 2019-05-24
Filing date: 2019-05-24
Publication date: 2020-01-03
Anticipated expiration: 2029-05-24

Abstract

The utility model is suitable for the technical field of optics and electronics, and provides a projector and a depth camera; the projector comprises a laser light source, a focusing lens, a beam deflection element and a non-collimated DOE (beam of radiation), which are sequentially arranged along a light path; the laser light source is used for emitting a divergent light beam; the focusing lens is used for receiving the divergent light beam and focusing the divergent light beam to generate a non-collimated light beam; the beam deflection element receives the light beam from the focusing lens and reflects the light beam so as to change the propagation direction of the light beam; and the non-collimated DOE is used for receiving the light beam reflected by the light beam deflection element, diffracting the light beam and projecting the light beam to a preset space to form a structured light pattern. The technical scheme of the utility model can improve the utilization ratio of laser when improving the integrated level of projector and reduce the volume, reduce energy loss.

Description

Projector and depth camera

Technical Field

The utility model belongs to the technical field of optics and electron, especially, relate to a projector and depth camera.

Background

With the development of scientific technology, the 3D imaging technology is gradually becoming the core of a new generation of human-computer interaction technology, and the 3D imaging depth camera is also rapidly developing towards the direction of smaller and smaller volume and lower power consumption at present, so that it is gradually possible that the depth camera is embedded into other electronic devices, such as mobile phones, tablet computers and the like, as a built-in component.

The projector is one of the core components of the depth camera based on the structured light technology, and is also the most important factor influencing the performance of the depth camera. The projector is generally composed of a light source, a lens and other optical elements, and is used for projecting a structured light pattern to a target space after light beams emitted by the light source are collected by the lens and modulated by the other optical elements, and the structured light pattern can be collected by an imaging module of the depth camera to further calculate a depth image.

However, under the pressure of the electronic devices to continuously pursue miniaturization and thinning of the appearance and volume, the design and installation of the built-in components thereof are also facing huge challenges, and if the depth camera is to be more suitably built in the electronic devices, the problems of large volume, low integration level, large energy consumption and the like caused by the unreasonable layout among the components of the existing depth camera need to be solved.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome above-mentioned prior art not enough, provide a projector, it aims at solving the problem that current projector integrated level is low, bulky, the energy consumption is big.

The utility model provides a projector, which comprises a laser light source, a focusing lens, a beam deflection element and a non-collimation DOE, wherein the laser light source, the focusing lens, the beam deflection element and the non-collimation DOE are arranged along a light path;

wherein the laser light source is used for emitting a divergent light beam;

the focusing lens is used for receiving the divergent light beams and focusing the divergent light beams to generate non-collimated light beams;

the beam deflection element receives the light beam from the focusing lens and reflects the light beam so as to change the propagation direction of the light beam;

and the non-collimated DOE is used for receiving the light beam reflected by the light beam deflection element, diffracting the light beam and projecting the light beam to a preset space to form a structured light pattern.

Optionally, the beam deflecting element is provided at a focal point of the focusing lens.

Optionally, the non-collimated DOE is provided at a focal point of the focusing lens.

Optionally, the laser light source includes a single light source or an array of a plurality of light sources, wherein the light source includes at least one of a laser diode, an edge-emitting laser diode, and a vertical cavity surface-emitting laser.

Optionally, the focusing lens further comprises a beam shaping focusing lens for receiving and focusing the diverging beam and shaping it into a flat-topped beam output.

Optionally, the beam shaping focusing lens includes one or more of an aspheric focusing lens, a diffractive optical device, and a lens group.

Optionally, the beam deflecting element comprises at least one of a mirror or a micro-electromechanical system.

The utility model discloses still provide a degree of depth camera, this degree of depth camera includes:

the projector is used for projecting the structured light pattern;

the imaging module is used for collecting the structured light pattern; and

and the processor is respectively connected with the projector and the imaging module.

Optionally, the depth camera further comprises a color camera module for collecting color patterns.

Optionally, the processor is further configured to calculate a depth pattern according to the structured light pattern, and fuse the depth pattern with the color pattern to obtain a color depth image.

Based on this structural design, because this projector accessible focusing lens gathers the divergent light beam that laser source sent, and then passes through the reflection of beam deflection component with the light beam after gathering and the redirecting, the non-collimation DOE just can be adjacent beam deflection component setting as far as possible to can effectively shorten the propagation path of light beam, thereby make the overall arrangement of each components and parts more integrate in the projector, the volume of projector can be designed littleer, and then more be favorable to integrating in the depth camera.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic view of an optical path structure of an embodiment of a projector according to the present invention;

fig. 2 is a schematic diagram of an optical path structure of another embodiment of the projector according to the embodiment of the present invention;

fig. 3 is a schematic diagram of functional modules of a depth camera according to an embodiment of the present invention.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				110	Laser light source	120	Focusing lens
130	Light beam deflection element	140	Non-collimated DOE
				100	Projector	200	Imaging module
300	Processor with a memory having a plurality of memory cells	400	Color camera module

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the 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.

It should be noted that the terms of left, right, upper and lower directions in the embodiments of the present invention are only relative concepts or are referred to the normal use state of the product, and should not be considered as limiting.

In the description of the present invention, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner" and "outer" indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

An embodiment of the utility model provides a projector.

Referring to fig. 1, in an embodiment of the present invention, the projector 100 can be used in a depth camera, and includes a laser source 110, a focusing lens 120, a beam deflecting element 130, and a non-collimated DOE140 sequentially disposed along an optical path; the laser light source 110 is used to emit a diverging beam; the focusing lens 120 is used for receiving the divergent light beam and focusing the divergent light beam to generate a non-collimated light beam; a beam deflecting element 130 for receiving the light beam from the focusing lens 120 and reflecting the light beam to change the propagation direction of the light beam; the non-collimated DOE140 is configured to receive the light beam reflected by the beam deflecting element 130, diffract the light beam, and project the light beam to a predetermined space to form a structured light pattern.

Based on the structural design, since the projector 100 can collect the divergent light beam emitted from the laser source 110 through the focusing lens 120, and then change the direction of the collected light beam by the reflection of the beam deflecting element 130, the non-collimated DOE140 can be disposed adjacent to the beam deflecting element 130 as much as possible, so as to effectively shorten the propagation path of the light beam, and thus the layout of each component in the projector 100 is more integrated, and the volume of the projector 100 can be designed to be smaller, thereby being more beneficial to being integrated in a depth camera.

Referring to fig. 1, in the embodiment of the present invention, the focusing lens 120 further includes a beam shaping focusing lens for receiving and focusing the divergent light beam and shaping the divergent light beam into a flat-top light beam for outputting, and since the flat-top light beam has the advantage of uniform energy distribution in the cross section of the light spot, the projector 100 can also achieve the technical effect of improving the utilization rate of the laser light to reduce energy loss through the beam shaping focusing lens. Specifically, the beam shaping focusing lens comprises one or more of an aspheric focusing lens, a diffraction type optical device and a lens group. In an embodiment, the lens group may be a combination of a diffraction optical device and an aspheric focusing lens, and a divergent light beam emitted from the laser source 110 is homogenized by the diffraction optical device and then passes through the aspheric focusing lens, so as to form a non-collimated flat-top light beam on a focal plane of the aspheric focusing lens.

As shown in fig. 1, in an embodiment of the present invention, the beam shaping focusing lens may be a single-chip aspheric focusing lens. Of course, in other embodiments, the beam shaping focusing lens may also be a curved spherical lens, a plano-convex lens, other focusing lenses or a combined focusing lens. However, in this embodiment, since the front and rear surfaces of the single lens are used to replace the plurality of lenses of the lens assembly, the light is refracted twice in the lens, so that the laser energy loss is smaller compared with the lens assembly due to the design of the single lens, and the single aspheric focusing lens has a better focusing and shaping effect on the divergent light beam, thereby effectively improving the quality of the focused light spot. In addition, in practical applications, since the laser beam generates a certain amount of heat, the lens may be made of Zn or Se material with relatively small heat absorption coefficient, so that the lens can operate in a proper temperature range, thereby ensuring the normal use of the projector 100.

In order to improve the light transmittance of the lens, a high-transmission film layer can be plated on the surface of the light inlet side and/or the light outlet side of the light beam shaping focusing lens. In one embodiment of the present invention, the high transmission film layer can be plated on both surfaces of the light incident side and the light emitting side of the light beam shaping focusing lens. The light transmittance of the high-transmittance film layer is at least 95% or more, preferably 99% or more, so that the focusing lens 120 can receive more divergent light beams emitted by the laser source 110, and the optical performance of the lens is improved.

In one embodiment of the present invention, the beam deflection element 130 includes at least one of a mirror or a Micro Electro Mechanical System (MEMS). However, the design is not limited thereto, and in other embodiments, the beam deflecting element 130 may be other types of devices that can change the propagation path of the laser beam. The beam deflecting element 130 is disposed at the focal point of the focusing lens 120, so that the beam deflecting element 130 with a larger reflection area can be designed as the beam deflecting element 130 with a smaller reflection area, thereby effectively reducing the overall thickness of the projector 100 and further reducing the volume of the projector 100. Of course, in some embodiments, the beam deflecting element 130 may be disposed within a certain range inside or outside the focal point of the focusing lens 120, and is not limited herein.

Referring to FIG. 2, in an embodiment of the present invention, the non-collimated DOE140 can be disposed at the focal point of the focusing lens 120. This arrangement can make the effective diffraction area of the non-collimated DOE140 smaller, thereby reducing the difficulty of design and manufacture, making the present projector 100 easier to integrate into a depth camera. Of course, in some embodiments, the non-collimated DOE140 may be disposed in a range within or outside the focal point of the focusing lens 120, and is not limited herein. It should be particularly noted that the main difference between the embodiments shown in fig. 1 and fig. 2 is that, in fig. 1, the beam deflecting element 130 is located at the focal point of the focusing lens 120, and the focused light beam at the focal point is deflected by the beam deflecting element 130 and then enters the non-collimated DOE140 in a divergent manner; whereas in fig. 2 the beam deflecting element 130 is located in front of the focal point of the focusing lens 120, the incompletely focused beams are reflected by the beam deflecting element 130 and then focused together, instead of the collimating DOE140 being arranged right at the beam focus.

The embodiment of the present invention provides a laser source 110, which has good characteristics in the aspects of directivity, brightness, monochromaticity and coherence, and is widely used in a plurality of fields such as industry, military, communication, medicine and scientific research, and under the general conditions, the spatial shape of the laser beam emitted from laser source 110 is mostly gaussian distribution, and the uniformity of the energy distribution in the light spot cross section is lower than that of the flat-top beam. The laser light source 110 includes a single laser light source 110, or an array composed of a plurality of laser light sources 110; the laser light source 110 includes at least one of a laser diode, an edge-emitting laser diode, and a vertical cavity surface-emitting laser. In some embodiments, the laser source 110 can be a VCSEL (vertical cavity surface emitting laser) having features such as small size, low power consumption, and small divergence angle. When the laser source 110 is selected as an edge emitting laser, the focusing lens 120 may be disposed on a side of the laser source 110 emitting the light beam in order to allow the focusing lens 120 to receive more divergent light beams. In general, the light generated by the laser source 110 may be visible light, infrared light, ultraviolet light, invisible light, etc., and the laser source 110 also supports a coded projection scheme of different image compositions, such as, but not limited to, images in the form of speckles, blocks, crosses, stripes, specific symbols, etc. However, since the infrared speckle pattern has the advantages of high irrelevance and uniform distribution, the structured light pattern projected by the laser source 110 can be set as the infrared speckle pattern in the embodiment.

It is understood that, in order to enhance the heat dissipation of the projector 100, in the embodiment of the present invention, a heat sink (not shown) is attached to the heat point of the laser light source 110. It will be appreciated that the heat sink can not only prevent the laser source 110 from operating at too high a temperature, but also prolong the service life of the projector 100, and at the same time accelerate the heat dissipation of the depth camera, thereby facilitating the integration of the depth camera into various electronic devices, such as, but not limited to, mobile terminals. In addition, the heat sink is preferably made of aluminum and is very small in size so as not to substantially affect the size increase of the projector 100 and the depth camera.

The utility model also provides a depth camera, this depth camera includes aforementioned projector 100, imaging module 200 and treater 300, projector 100 is used for projecting the structured light pattern to the target space; the imaging module 200 is used for collecting a structured light pattern; the processor 300 is connected to the projector 100 and the imaging module 200 respectively, and is used for controlling the operation of the projector 100 and the imaging module 200. The specific structure of the projector 100 refers to the above embodiments, and since the depth camera adopts all technical solutions of all the above embodiments, all the beneficial effects brought by the technical solutions of the above embodiments are also achieved, and are not described in detail herein.

Further, in the embodiment of the present invention, the imaging module 200 includes a combination of an image sensor and other optical elements, and an optical filter is disposed on the image sensor. Wherein, the image sensor can be but not limited to CCD or CMOS; and the filter may be disposed to allow only the light beam projected by the projector 100 to pass therethrough, so as to avoid interference of ambient light. For example, when the structured light pattern is an infrared speckle pattern, an infrared filter may be disposed on the light incident surface of the image sensor, so as to achieve the purpose of collecting only the infrared speckle pattern.

Further, in the embodiment of the present invention, in order to further realize the multi-functionalization of the depth camera, the depth camera further includes a housing (not shown), a mounting plate (not shown) disposed in a flat plate, and a color camera module 400 for collecting color patterns; the projector 100, the imaging module 200 and the color camera module 400 are all mounted on the mounting plate, and the color camera module 400 is located between the projector 100 and the imaging module 200 and adjacent to the projector 100; the housing has windows corresponding to the projector 100, the imaging module 200 and the color camera module 400. The color camera module 400 can be, but not limited to, an RGB camera module, and the like, so that the integrated depth camera equipped with the color camera module 400 can have the capability of synchronously acquiring the depth pattern and the RGB pattern. It should be further noted that the structured light pattern collected by the imaging module 200 and the color image collected by the color camera module 400 may be further transmitted to the processor 300, and the processor 300 calculates a depth pattern according to the received structured light pattern and fuses the depth pattern and the color pattern to obtain a color depth image, so as to implement operations such as face detection, face recognition, security payment and the like according to the color depth image, thereby greatly widening the application range of the depth camera.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modification, equivalent replacement or improvement made within the spirit and principle of the present invention should be included in the present invention.

Claims

1. A projector is characterized by comprising a laser light source, a focusing lens, a beam deflection element and a non-collimated DOE, wherein the laser light source, the focusing lens, the beam deflection element and the non-collimated DOE are arranged along an optical path;

wherein the laser light source is used for emitting a divergent light beam;

2. The projector of claim 1 wherein said beam deflecting element is disposed at a focal point of said focusing lens.

3. The projector as claimed in claim 1 wherein the non-collimated DOE is disposed at a focal point of the focusing lens.

4. The projector of claim 1 wherein the laser light source comprises a single light source or an array of multiple light sources, wherein the light sources comprise at least one of laser diodes, edge-emitting laser diodes, vertical cavity surface-emitting lasers.

5. The projector as defined in claim 1 wherein the focusing lens further comprises a beam shaping focusing lens for receiving and focusing the diverging beam and shaping it into a flat-topped beam output.

6. The projector as defined in claim 5 wherein the beam shaping focusing lens comprises one or more of an aspheric focusing lens, diffractive optics, and a lens group.

7. The projector as defined in claim 1 wherein the beam deflecting element comprises at least one of a mirror or a micro-electromechanical system.

8. A depth camera, comprising:

a projector according to any of claims 1 to 7 for projecting a structured light pattern;

the imaging module is used for collecting the structured light pattern; and

9. The depth camera of claim 8, further comprising a color camera module to collect color patterns.

10. The depth camera of claim 9, wherein the processor is further configured to calculate a depth pattern from the structured light pattern and fuse the depth pattern with the color pattern to obtain a color depth image.