CN215297844U

CN215297844U - Structured light projector

Info

Publication number: CN215297844U
Application number: CN202121906641.5U
Authority: CN
Inventors: 丁最; 章颖
Original assignee: Shenzhen Muxin Intelligent Technology Co ltd
Current assignee: Shenzhen Muxin Intelligent Technology Co ltd
Priority date: 2021-08-13
Filing date: 2021-08-13
Publication date: 2021-12-24
Anticipated expiration: 2031-08-13

Abstract

The utility model discloses a structured light projector, structured light projector includes: laser light source, collimating lens group and diffractive optical element, laser light source welding is on the circuit board carrier, laser light source is vertical cavity surface emitting laser diode, be provided with the mirror seat on the circuit board carrier, collimating lens group is fixed to be set up on the mirror seat, the mirror seat sets up on the circuit board carrier, collimating lens group is the cell-phone camera lens, diffractive optical element pastes the dress and is in directly over the surface of collimating lens group. The utility model discloses a structured light projector does not rely on too high customization, does not need too high technical threshold, has the characteristics that the equipment precision is low, and the cost is more excellent.

Description

Structured light projector

Technical Field

The utility model relates to the field of optical technology, especially, relate to a structured light projector.

Background

The structured light 3D detection technology realizes the detection of a three-dimensional world by actively projecting a coding pattern, and is widely applied to 3D modeling, face payment, terrain detection, robot navigation obstacle avoidance and the like at present. The scheme can be divided into monocular and binocular structured light, and key devices comprise a receiving camera and an infrared laser projector; the two schemes are different in principle and application scenes, and the performance requirements of different application scenes on the projector are different; generally, the projector requirements for monocular solutions will be higher.

The core components of the existing structured light projector include a Laser Diode (LD), a collimating lens group, and a Diffractive Optical Element (DOE), and the principle is that the LD passes through the collimating lens group and becomes collimated light, and then enters the DOE, and a specific pattern is generated in a far-field space by phase modulation of the DOE.

Thus, there is a need for improvements and enhancements in the art.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model lies in, to the above-mentioned defect of prior art, provide a structured light projector, mainly be applicable to two mesh structured light schemes, aim at solving prior art's structured light projector and all have higher requirement on assembly process or DOE's design, lead to the higher problem of cost.

In order to solve the technical problem, the utility model discloses the technical scheme who adopts as follows:

in a first aspect, the present invention provides a structured light projector, wherein the structured light projector comprises:

the laser light source is welded on the circuit board carrier and is a vertical cavity surface emitting laser diode;

the collimating lens group is fixedly arranged on a lens base, and the lens base is arranged on the circuit board carrier;

and the diffractive optical element is attached right above the outer surface of the collimating lens group.

In one implementation, the collimating lens group is a mobile phone lens.

In one implementation, the VCSEL diode is disposed within an optical package structure.

In one implementation, the VCSEL diode is provided with a positive connection terminal and a negative connection terminal when the VCSEL diode is disposed within an optical package structure.

In one implementation, the VCSEL diode is disposed bare.

In one implementation, the circuit board carrier is a flexible circuit board or a printed circuit board.

In one implementation, the flexible circuit board or the printed circuit board is provided with a positioning hole, and the positioning hole is used for positioning the lens base.

Has the advantages that: the utility model provides a structured light projector, compared with the prior art, the utility model provides a structured light projector includes: laser light source, collimating lens group and diffractive optical element, laser light source welding is on the circuit board carrier, laser light source is vertical cavity surface emitting laser diode, collimating lens group sets up on the mirror base, the mirror base sets up on the circuit board carrier, collimating lens group is the cell-phone camera lens, diffractive optical element pastes directly over the surface of collimating lens group. The utility model discloses a what laser light source adopted in the structured light projector is that vertical cavity surface emitting laser diode, collimating lens group adopted is cell-phone camera lens, therefore the simple structure of whole structured light projector does not rely on too high customization, does not need too high technical threshold, has the characteristics that the equipment precision is low, and the cost is more excellent.

Drawings

Fig. 1 is an exploded view of a structured light projector according to an embodiment of the present invention.

Fig. 2 is an assembly view of a structured light projector according to an embodiment of the present invention.

Reference numerals:

laser light source	10	Collimating lens group	20
				Diffractive optical element	30	Circuit board carrier	40
Mirror base	50	Optical packaging structure	60

Detailed Description

In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the following description of the present invention will refer to the accompanying drawings and illustrate 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.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or wirelessly coupled. As used herein, the term "and/or" includes all or any element and all combinations of one or more of the associated listed items.

It will be understood by those within the art that, 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 invention 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 prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The research shows that the core device of the structured light projector in the prior art comprises a Laser Diode (LD), a collimating lens group and a Diffractive Optical Element (DOE), the principle is that the LD becomes collimated light after passing through the collimating lens group, and then the collimated light is incident to the DOE, and a specific pattern is generated on a far field space through the phase modulation of the DOE, the two common structured light projector schemes are provided at present, the first scheme is a VCSEL (vertical cavity surface emitting laser diode) + collimating lens group + DOE, the main application scenes are face unlocking, financial payment, door lock and the like at a mobile phone end, the structured light projector of the type is more appeared in a monocular structured light scheme, the assembly process requirement of the structured light projector is extremely high, a higher COB (Chip-on-Board) process and a 3D AA (Active Alignment) process are required, and the collimating lens group of the structured light projector is mostly customized, the cost is high, the wide use of the structured light projector is influenced, and therefore the structured light projector is single in specification and difficult to diversify. The other is an EEL (edge emitting laser diode), a single collimating lens group and a DOE (Doe), the main application scenes are three-dimensional detection, navigation obstacle avoidance and the like, and the structured light projector has higher requirements on DOE design, larger projector structure and high cost. Therefore, the structured light projector has high requirements on the assembly process or the design of the DOE at present, which results in high cost.

In order to solve the problems of the prior art, the present embodiment provides a structured light projector mainly suitable for a binocular structured light scheme, which is mainly suitable for the binocular structured light scheme, as shown in fig. 1, and the structured light projector in the present embodiment includes: laser light source 10, collimating lens group 20 and diffractive optical element 30 (DOE). Specifically, in the present embodiment, the laser light source 10 is soldered on the circuit board carrier 40, and the mirror base 50 is disposed on the circuit board carrier 40, the mirror base 50 is flatly attached on the circuit board carrier 40, and as can be seen from fig. 2, the laser light source 10 is located inside the mirror base 50 and at the middle of the inside of the mirror base 50. The collimating lens group 20 in this embodiment is disposed on the lens holder 50, and the lens holder 50 is fixed on the lens holder 50, for example, by screwing. The diffractive optical element 30(DOE) in this embodiment is attached to the outer surface of the collimating lens set 20 and is located right above the laser light source 10, and when the structured light projector in this embodiment is powered on, a speckle pattern can be generated in a far field space by the phase modulation of the DOE, and the dotted line in fig. 1 and 2 is an optical path.

In a specific application, the laser light source 10 in the present embodiment employs a vertical cavity surface emitting laser diode (VCSEL light source). VCSEL light sources have the following optical parameters: the spectral width/temperature drift/spot characteristic/polarization characteristic/two-dimensional array of light emitting holes/substrate packaging are all superior to the edge-emitting laser diode, and therefore, the VCSEL light source is selected as the laser light source 10 in this embodiment. In a specific arrangement, the VCSEL light source in this embodiment is soldered to a circuit board carrier 40 formed by a flexible circuit board (FPC) or a Printed Circuit Board (PCB), and the VCSEL light source is selectively disposed in the optical package 60 or directly exposed according to the height. When the VCSEL light source is exposed, a COB process is needed to fix the VCSEL chip on the FPC/PCB. In order to protect the VCSEL light source, the VCSEL light source may be packaged by forming an optical package structure 60 using an optical adhesive and a substrate, i.e., the VCSEL light source is provided with the protective shell of the optical package structure 60. Moreover, when the VCSEL light source is disposed in the optical package structure 60, the VCSEL light source is provided with a positive connection terminal and a negative connection terminal, has electrical properties, and can be directly energized to emit light. Because the VCSEL light source is provided with the optical packaging structure 60, the overall height of the VCSEL light source is increased, and the package size is generally 2016mm, 2835mm and 3535 mm.

In this embodiment, when the VCSEL light source is assembled, the assembly process may be selected from SMT (Surface Mount Technology) or cob (chip on board), respectively. When the COB is adopted to directly weld the VCSEL light source on the PCB/FPC (namely the circuit board carrier 40), a machine for visual positioning and a Wire Bonding process are needed, and a gold thread is used for communicating the positive connecting end and the negative connecting end of the VCSEL light source, so that the VCSEL light source has electrical performance. In this embodiment, the VCSEL light source is assembled by the COB process, so that the laser light source 10 is ultra-thin and has a strong heat dissipation capability.

After the VCSEL light source is assembled, the present embodiment covers the mirror base 50 on the PCB/FPC (i.e., circuit board carrier 40). To achieve the accuracy requirements, the present embodiment can select mechanical positioning or visual positioning to position the lens holder 50. When the mechanical positioning is selected, the Flexible Printed Circuit (FPC) or the Printed Circuit Board (PCB) in this embodiment is provided with the positioning hole, so that the positioning can be realized through the positioning hole, and the lens holder 50 is fixed, and the assembling manner is simple. When the visual positioning mode is selected to position the lens holder 50, the present embodiment may acquire an image through a CCD (charge coupled device) camera, and then precisely cover the lens holder 50 on a specific position of the PCB/FPC by combining a mechanical arm/manipulator in an image recognition mode, so as to realize high-precision positioning of the lens holder 50.

In a specific application, the collimating lens group 20 in this embodiment is a mobile phone lens. The collimating lens group 20 of the prior art structured light projectors is typically custom made and relatively expensive. The mobile phone lens is characterized in that light rays emitted or reflected by an external object are collected, then the object is imaged on the photosensitive chip through correction of the lens group, and the mobile phone lens can be used for projecting or collimating laser emitted by the VCSEL light source to generate a pattern after the laser is incident on the DOE in consideration of the conjugate relation or reversible light path of the object image. Therefore, the collimating lens group 20 of the present embodiment adopts a mobile phone lens, and the types of mobile phone lenses in the market are various, so that when selecting, a suitable mobile phone lens can be selected according to the actual requirements for the parameters such as the volume, the focal length, the luminous flux, the transmittance, the temperature resistance of the lens, and the dot density of the projection pattern. Generally, the higher the lens luminous flux, transmittance and temperature resistance of the lens, the better. In the embodiment, the lens of the mobile phone is used as the collimating lens group 20, so that the problem of customizing the collimating lens group 20 in the prior art can be solved. Of course, the lens of the mobile phone of the present embodiment may also be customized and developed according to the requirement, and the present embodiment is not limited thereto. When the mobile phone lens is assembled, the camera module can be assembled and focused by the technology of the camera module, and semi-automatic/full-automatic assembly can be easily realized.

It can be seen that the core device of the structured light projector in the present embodiment includes: a VCSEL light source, a cell phone lens, and a diffractive optical element 30 (DOE). The structured light projector of the present embodiment has the following advantages:

1. the replication multiple of the diffractive optical element 30(DOE) in this embodiment is several tens to one hundred or so, the yield is high, the cost is controllable, and the DOE technology threshold is reduced. The industrial chain of the mobile phone lens is mature, so the requirements of two key devices in the structured light projector in the embodiment are reduced, and the cost is reduced.

2. The structured light projector of the embodiment is mainly suitable for a binocular structured light scheme, difficulty of key devices (DOE and a mobile phone lens) is reduced, an assembling process of the mobile phone lens can continue to use a mobile phone assembling and focusing process, and the technology is mature, so that the assembling process of the structured light projector is simpler than that of an existing monocular structured light projector.

3. The structured light projector of the embodiment adopts the VCSEL light source, the projection pattern performance is excellent, the zero-order proportion is low, and the light spot energy is concentrated.

4. The product is diversified, because the mobile phone lens industry chain is mature, and the mobile phone lens type is various on the market, and different camera lens parameters can produce the light spot of different size, density, and the DOE of deuterogamying can make the speckle pattern more diversified, consequently can satisfy different application scenarios.

To sum up, the utility model discloses a structured light projector, structured light projector includes: laser light source, collimating lens group and diffractive optical element, laser light source welding is on the circuit board carrier, laser light source is vertical cavity surface emitting laser diode, collimating lens group is fixed to be set up on the mirror base, the mirror base sets up on the circuit board carrier, collimating lens group is the cell-phone camera lens, diffractive optical element pastes and installs directly over the surface of collimating lens group. The utility model discloses a structured light projector's simple structure, and assembly process are more simple, the cost is lower for the optical projector on the market.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.

Claims

1. A structured light projector, the structured light projector comprising:

2. The structured light projector of claim 1 wherein the set of collimating lenses are cell phone lenses.

3. The structured light projector of claim 1, wherein the vertical cavity surface emitting laser diodes are disposed within an optical package.

4. The structured light projector of claim 3, wherein the VCSEL diode is provided with a positive connection end and a negative connection end when the VCSEL diode is disposed within an optical package structure.

5. The structured light projector of claim 1 wherein the vertical cavity surface emitting laser diodes are disposed bare.

6. The structured light projector of claim 1, wherein the circuit board carrier is a flexible circuit board or a printed circuit board.

7. The structured light projector of claim 6 wherein the flexible circuit board or printed circuit board is provided with locating holes for enabling positioning of the mirror mount.