CN108508623B - Laser Projection Modules, Depth Cameras and Electronics - Google Patents

Abstract

The present invention discloses a laser projection module, a depth camera and an electronic device. The laser projection module includes a light source, a collimating element and a diffractive optical element. The light source is used to emit laser light. The collimating element is used to collimate the laser light. The collimating element includes one or more lenses, and the one or more lenses are arranged on the light path of the light source, and the lenses are made of glass. The diffractive optical element is used to diffract the laser collimated by the collimating element to form a laser pattern. In the laser projection module, the depth camera and the electronic device of the embodiments of the present invention, the lenses of the collimating element are all made of glass, which solves the problem of temperature drift of the lens when the ambient temperature changes.

Description

Laser Projection Modules, Depth Cameras and Electronics

technical field

The present invention relates to the field of imaging technology, in particular to a laser projection module, a depth camera and an electronic device.

Background technique

The laser projection module consists of a light source, a collimating element and a diffractive optical element (DOE). The collimating element generally includes a lens structure. When the ambient temperature changes, the lens will have a temperature drift phenomenon. When the temperature drift is large, the focus of the lens will even change, which will affect the laser projection module projected into the target space. The precision of the pattern.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a laser projection module, a depth camera and an electronic device.

The laser projection module of the embodiment of the present invention includes:

a light source for emitting laser light;

A collimating element, the collimating element is used for collimating the laser light, the collimating element includes one or more lenses, and the one or more lenses are arranged on the light-emitting light path of the light source, and the lenses adopt made of glass; and

A diffractive optical element, the diffractive optical element is used for diffracting the laser collimated by the collimating element to form a laser pattern.

In some embodiments, the collimating element includes a first lens, the first lens includes a first light incident surface and a first light exit surface opposite to each other, the first light incident surface is a concave surface, and the first light incident surface is a concave surface. A light-emitting surface is a convex surface.

In some embodiments, the collimating element includes a plurality of lenses, and the plurality of lenses are arranged coaxially and sequentially on the light-emitting light path of the light source.

In some embodiments, a plurality of the lenses includes a first lens and a second lens, the first lens includes a first light incident surface and a first light exit surface opposite to each other, and the second lens includes opposite The second light incident surface and the second light emitting surface, the apex of the first light emitting surface is in conflict with the apex of the second light incident surface, the first light incident surface is a concave surface, and the second light emitting surface is a convex surface.

In some embodiments, the first light-emitting surface and the second light-incident surface are both convex surfaces.

In some embodiments, the plurality of lenses includes a first lens, a second lens, and a third lens, the first lens includes a first light incident surface and a first light exit surface opposite to each other, the second lens The lens includes a second light incident surface and a second light exit surface opposite to each other, the third lens includes a third light entrance surface and a third light exit surface opposite to each other, the third light incident surface is concave, and the third light incident surface is concave. The light-emitting surface is convex.

In some embodiments, the first light incident surface is a convex surface, the first light exit surface is a concave surface, the second light incident surface is a concave surface, and the second light exit surface is a concave surface.

In some embodiments, the collimating element includes a plurality of lenses, the plurality of lenses are sequentially arranged on the light-emitting optical path of the light source, and the optical axis of at least one of the lenses is relative to the optical axes of the other lenses. offset.

In some embodiments, the collimating element includes a plurality of lenses, and optical centers of at least two of the lenses are located on the same plane perpendicular to a first direction, the first direction being from the light source to the Orientation of diffractive optical elements.

In certain embodiments, the optical axis of at least one of the lenses is parallel to the optical axis of the other of the lenses.

In certain embodiments, the light source is a vertical cavity surface emitting laser; or the light source is an edge emitting laser.

In some embodiments, the light source is an edge-emitting laser, and the light source includes a light-emitting surface facing the collimating element.

The depth camera of the embodiment of the present invention includes:

The laser projection module according to any one of the above embodiments;

an image collector for collecting the laser pattern projected into the target space after passing through the diffractive optical element; and

a processor connected to the laser projection module and the image collector respectively, and the processor is used for processing the laser pattern to obtain a depth image.

The electronic device according to the embodiment of the present invention includes:

the shell; and

The depth camera according to any one of the above embodiments, the depth camera is disposed in the casing and exposed from the casing to acquire a depth image.

In the laser projection module, the depth camera and the electronic device according to the embodiments of the present invention, the lenses of the collimating elements are all made of glass material, which solves the problem of temperature drift of the lenses when the ambient temperature changes.

Additional aspects and advantages of embodiments of the present invention will be set forth, in part, from the following description, and in part will become apparent from the following description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will be apparent and readily understood from the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

1 is a schematic structural diagram of a laser projection module according to some embodiments of the present invention;

2 to 4 are partial structural diagrams of a laser projection module according to some embodiments of the present invention;

5 to 16 are partial structural schematic diagrams of the collimating elements of the laser projection module according to some embodiments of the present invention;

17 is a schematic structural diagram of a depth camera according to some embodiments of the present invention;

18 is a schematic structural diagram of an electronic device according to some embodiments of the present invention;

Description of main components and symbols:

Laser projection module 100, substrate assembly 10, substrate 11, heat dissipation holes 111, circuit board 12, via holes 121, lens barrel 20, receiving cavity 21, top 22, bottom 23, through holes 24, carrier 25, first section Structure 26, second segment structure 27, protective cover 30, contact surface 31, light-transmitting hole 32, light source 40, light-emitting surface 41, side surface 42, collimating element 50, first lens 51, first incident surface 511, first A light exit surface 512, a second lens 52, a second light entrance surface 521, a second light exit surface 522, a third lens 53, a third light entrance surface 531, a third light exit surface 532, a fourth lens 54, a fifth lens 55 , sixth lens 56, diffractive optical element 60, diffractive exit surface 61, diffractive incident surface 62, sealant 70, support block 80, depth camera 400, projection window 401, acquisition window 402, image collector 200, processor 300, Electronic device 1000 , housing 500 .

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, only used to explain the embodiments of the present invention, and should not be construed as limitations on the embodiments of the present invention.

In the description of the embodiments of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front" ", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. The orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, a specific orientation, and a specific orientation. The orientation configuration and operation of the present invention should not be construed as a limitation on the embodiments of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, features defined as "first", "second" may expressly or implicitly include one or more of said features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it may be a fixed connection or a It is a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection or can communicate with each other; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication of two components or two components. interaction relationship. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

The following disclosure provides many different embodiments or examples for implementing different structures of embodiments of the invention. In order to simplify the disclosure of the embodiments of the present invention, the components and arrangements of specific examples are described below. Of course, they are only examples and are not intended to limit the invention. Furthermore, embodiments of the present invention may repeat reference numerals and/or reference letters in different instances, such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and/or arrangements discussed . In addition, the embodiments of the present invention provide examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

Referring to FIG. 1 , the laser projection module 100 according to the embodiment of the present invention includes a substrate assembly 10 , a lens barrel 20 , a protective cover 30 , a light source 40 , a collimating element 50 , and a diffractive optical element 60 .

The substrate assembly 10 includes a substrate 11 and a circuit board 12 carried on the substrate 11 . The material of the substrate 11 can be plastic, for example, polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA). Any one or more of polyimide (PI). In this way, the substrate 11 is light in weight and has sufficient supporting strength. The circuit board 12 may be a rigid board, a flex board or a rigid-flex board. Via holes 121 are formed on the circuit board 12 . The light source 40 is fixed on the substrate 11 through the via hole 121 and is electrically connected to the circuit board 12 . Heat dissipation holes 111 may be opened on the substrate 11 , and the heat generated by the light source 40 or the circuit board 12 may be dissipated through the heat dissipation holes 111 , and the heat dissipation holes 111 may be filled with thermally conductive glue to further improve the heat dissipation performance of the substrate assembly 10 .

The lens barrel 20 is disposed on the base plate assembly 10 and forms a receiving cavity 21 together with the base plate assembly 10 . The light source 40 , the collimating element 50 , and the diffractive optical element 60 are all accommodated in the accommodating cavity 21 . The collimating element 50 and the diffractive optical element 60 are sequentially arranged on the light-emitting light path of the light source 40 . The lens barrel 20 includes a top 22 and a bottom 23 that are opposite to each other. The lens barrel 20 is formed with a through hole 24 penetrating the top portion 22 and the bottom portion 23 . The bottom portion 23 is carried on the substrate assembly 10 , and can be fixed on the circuit board 12 by glue. An annular bearing platform 25 extends from the inner wall of the lens barrel 20 toward the center of the through hole 24 , and the diffractive optical element 60 is supported on the bearing platform 25 .

The protective cover 30 is disposed on the top 22 , and the protective cover 30 includes a contact surface 31 located in the receiving cavity 21 and opposite to the substrate 11 . The protective cover 30 and the stage 25 respectively contact the diffractive optical element 60 from opposite sides of the diffractive optical element 60 . The conflicting surface 31 is a surface of the protective cover 30 that is in conflict with the diffractive optical element 60 . The laser projection module 100 uses the protective cover 30 to abut the diffractive optical element 60 so that the diffractive optical element 60 is accommodated in the receiving cavity 21 and prevents the diffractive optical element 60 from falling off along the light-emitting direction.

In some embodiments, the protective cover 30 may be made of metallic materials, such as nano-silver wires, metallic silver wires, copper sheets, and the like. The protective cover 30 is provided with a light-transmitting hole 32 . The light-transmitting holes 32 are aligned with the through holes 24 . The light-transmitting hole 32 is used to output the laser pattern projected by the diffractive optical element 60 . The aperture size of the light-transmitting hole 32 is smaller than at least one of the width or the length of the diffractive optical element 60 to confine the diffractive optical element 60 in the receiving cavity 21 .

In some embodiments, the protective cover 30 can be made of a light-transmitting material, such as glass, polymethyl methacrylate (PMMA), polycarbonate (PC), polyimide (PI) )Wait. Since light-transmitting materials such as glass, PMMA, PC, and PI all have excellent light-transmitting properties, the protective cover 30 does not need to have a light-transmitting hole 32 . In this way, the protective cover 30 can prevent the diffractive optical element 60 from falling off, and at the same time prevent the diffractive optical element 60 from being exposed outside the lens barrel 20 , so that the diffractive optical element 60 can be waterproof and dustproof.

The light source 40 is used to emit laser light. The light source 40 may be a Vertical Cavity Surface Emitting Laser (VCSEL) or an edge-emitting laser (EEL). In the embodiment shown in FIG. 1 , the light source 40 is an edge-emitting laser, and specifically, the light source 40 may be a distributed feedback laser (Distributed Feedback Laser, DFB). The light source 40 is used to emit laser light into the receiving cavity 21 . Referring to FIG. 2 , the light source 40 is in the shape of a column as a whole. An end face of the light source 40 away from the substrate assembly 10 forms a light-emitting surface 41 . The laser is emitted from the light-emitting surface 41 . The collimated optical axis is vertical, and the collimated optical axis passes through the center of the light-emitting surface 51 . The light source 40 is fixed on the substrate assembly 10 . Specifically, the light source 40 may be bonded to the substrate assembly 10 through the sealant 70 . 1 and 3, the side surface 42 of the light source 40 can also be bonded to the substrate assembly 10, and the sealant 70 can wrap around the side surfaces 42, or only a certain surface of the side surface 42 can be bonded to the substrate assembly 10 or the substrate assembly 10. Certain surfaces are bonded to the substrate assembly 10 . At this time, the encapsulant 70 may be a thermally conductive adhesive, so as to conduct the heat generated by the operation of the light source 40 to the substrate assembly 10 .

The light source 40 of the above-mentioned laser projection module 100 adopts an edge emitting laser. On the one hand, the temperature drift of the edge emitting laser is smaller than that of the VCSEL array. , the cost of the light source 40 of the laser projection module 100 is low.

When the laser light of the distributed feedback laser propagates, the power gain is obtained through the feedback of the grating structure. To increase the power of the distributed feedback laser, it is necessary to increase the injection current and/or increase the length of the distributed feedback laser. Since increasing the injection current will increase the power consumption of the distributed feedback laser and cause serious heating problems, therefore , in order to ensure that the distributed feedback laser can work normally, the length of the distributed feedback laser needs to be increased, resulting in the distributed feedback laser generally having a slender structure. When the light-emitting surface 41 of the edge-emitting laser faces the collimating element 50, the edge-emitting laser is placed vertically. Since the edge-emitting laser has a slender structure, the edge-emitting laser is prone to accidents such as dropping, shifting or shaking. Therefore, by setting The encapsulant 70 can fix the edge emitting laser to prevent the edge emitting laser from being dropped, displaced or shaken.

In some embodiments, the light source 40 may also be fixed on the base plate assembly 10 in a fixing manner as shown in FIG. 4 . Specifically, the laser projection module 100 includes a plurality of support blocks 80 , the support blocks 80 can be fixed on the substrate assembly 10 , and the plurality of support blocks 80 together surround the light source 40 , and the light source 40 can be directly installed on the plurality of support blocks during installation between 80. In one example, a plurality of support blocks 80 jointly hold the light source 40 to further prevent the light source 40 from shaking.

The collimating element 50 is used to collimate the laser light emitted by the light source 40 . The collimating element 50 is fixed on the lens barrel 20 , and the bearing platform 25 is located between the collimating element 50 and the diffractive optical element 60 . The collimating element 50 includes one or more lenses, and the one or more lenses are arranged on the light-emitting light path of the light source 40 , and the lenses are made of glass material. Since the lenses of the collimating element 50 according to the embodiment of the present invention are all made of glass material, the problem of temperature drift of the lens when the ambient temperature changes is solved.

Please refer to FIG. 1 and FIG. 5 together. In some embodiments, the collimating element 50 may only include a first lens 51 , and the first lens 51 includes a first light incident surface 511 and a first light exit surface 512 opposite to each other. The first light incident surface 511 is the surface of the first lens 51 close to the light source 40 , and the first light exit surface 512 is the surface of the first lens 51 close to the diffractive optical element 60 . The first light incident surface 511 is a concave surface, and the first light exit surface 512 is a convex surface. The surface type of the first lens 51 may be an aspheric surface, a spherical surface, a Fresnel surface, or a binary optical surface. The diaphragm is arranged between the light source 40 and the first lens 51 to limit the light beam.

In some embodiments, the collimating element 50 may include a plurality of lenses, and the plurality of lenses are coaxially disposed on the light-emitting light path of the light source 40 in sequence. The surface type of each lens can be any one of aspheric surface, spherical surface, Fresnel surface, and binary optical surface.

For example, please refer to FIG. 1 and FIG. 6 together, the plurality of lenses may include a first lens 51 and a second lens 52 . The first lens 51 and the second lens 52 are coaxially disposed on the light-emitting light path of the light source 40 in sequence. The first lens 51 includes a first light incident surface 511 and a first light exit surface 512 opposite to each other. The first light incident surface 511 is the surface of the first lens 51 close to the light source 40 , and the first light exit surface 512 is the surface of the first lens 51 close to the diffractive optical element 60 . The second lens 52 includes a second light incident surface 521 and a second light exit surface 522 opposite to each other. The second light incident surface 521 is the surface of the second lens 52 close to the light source 40 , and the second light exit surface 522 is the surface of the second lens 52 close to the diffractive optical element 60 . The apex of the first light emitting surface 512 is in conflict with the apex of the second light incident surface 521 , the first light incident surface 511 is a concave surface, and the second light emitting surface 522 is a convex surface. The diaphragm is arranged on the second light incident surface 521 to limit the light beam. Further, both the first light exit surface 512 and the second light entrance surface 521 may be convex surfaces. In this way, it is convenient for the apex of the first light-emitting surface 512 to collide with the apex of the second light-incident surface 521 . The curvature radius of the first light exit surface 512 is smaller than the curvature of the second light entrance surface 521 .

Please refer to FIG. 1 and FIG. 7 together, the plurality of lenses may further include a first lens 51 , a second lens 52 , and a third lens 53 . The first lens 51 , the second lens 52 , and the third lens 53 are coaxially disposed on the light-emitting optical path of the light source 40 in sequence. The first lens 51 includes a first light incident surface 511 and a first light exit surface 512 opposite to each other. The first light incident surface 511 is the surface of the first lens 51 close to the light source 40 , and the first light exit surface 512 is the surface of the first lens 51 close to the diffractive optical element 60 . The second lens 52 includes a second light incident surface 521 and a second light exit surface 522 opposite to each other. The second light incident surface 521 is the surface of the second lens 52 close to the light source 40 , and the second light exit surface 522 is the surface of the second lens 52 close to the diffractive optical element 60 . The third lens 53 includes a third light incident surface 531 and a third light exit surface 532 opposite to each other. The third light incident surface 531 is the surface of the third lens 53 close to the light source 40 , and the third light exit surface 532 is the surface of the third lens 53 close to the diffractive optical element 60 . The third light incident surface 531 is a concave surface, and the third light exit surface 532 is a convex surface. The diaphragm is arranged on the third light emitting surface 532 to limit the light beam. Further, the first light incident surface 511 may be a convex surface, the first light exit surface 512 may be a concave surface, the second light incident surface 521 may be a concave surface, and the second light exit surface 522 may be a concave surface.

In some embodiments, collimating element 50 includes a plurality of lenses. A plurality of lenses are arranged on the light-emitting optical path of the light source 40 in sequence, and the optical axis of at least one lens is offset with respect to the optical axes of the other lenses. At this time, the structure of the lens barrel 20 may be a one-segment or multiple-segment structure, and each segment of the structure is used to install a corresponding lens.

For example, please refer to FIG. 8 to FIG. 12 together, the collimating element 50 includes a first lens 51 , a second lens 52 and a third lens 53 . The first lens 51 , the second lens 52 and the third lens 53 are sequentially arranged on the light-emitting light path of the light source 40 . The optical axis of the second lens 52 is offset with respect to the optical axis of the first lens 51 , and the optical axis of the first lens 51 coincides with the optical axis of the third lens 53 (as shown in FIG. 8 ). Further, the second lens 52 The optical axis of the lens barrel 20 can be parallel to the optical axis of the first lens 51. At this time, the structure of the lens barrel 20 can be a two-segment structure. The first-segment structure 26 is used to install the first lens 51 and the second lens 52. 27 is used to install the third lens 53, the first segment structure 26 and the second segment structure 27 are connected obliquely, and the second lens 52 is installed at the junction of the first segment structure 26 and the second segment structure 27. In this way, a plurality of The curved structure of the lens is beneficial to increase the optical path, thereby reducing the overall height of the laser projection module 100. The inner walls of the first segment structure 26 and the second segment structure 27 are coated with a reflective coating, and the reflective coating is used for Reflect the light, so that the light emitted by the light source 40 can pass through the first light incident surface 511, the first light exit surface 512, the second light entrance surface 521, the second light exit surface 522, the third light entrance surface 531, and the third light exit surface in sequence surface 532; of course, in other embodiments, the first segment structure 26 and the second segment structure 27 can also be reflective elements independent of the lens barrel 20, the reflective elements are arranged on the lens barrel 20, and the reflective elements are prisms or mirrors etc., the reflective element is used to reflect the light to change the direction of the optical path; or, the optical axis of the first lens 51 is offset with respect to the optical axis of the second lens 52 , and the optical axis of the second lens 52 is different from the optical axis of the third lens 53 Coincidence (as shown in FIG. 9 ), further, the optical axis of the first lens 51 may be parallel to the optical axis of the second lens 52 ; or, the optical axis of the third lens 53 is offset relative to the optical axis of the first lens 51 , the optical axis of the first lens 51 coincides with the optical axis of the second lens 52 (as shown in FIG. 10 ), and further, the optical axis of the third lens 53 can be parallel to the optical axis of the first lens 51; The optical axis of the lens 52 is offset relative to the optical axis of the first lens 51 , the optical axis of the third lens 53 is offset relative to the optical axis of the first lens 51 , the optical axis of the second lens 52 and the optical axis of the third lens 53 The axis is located on the same side of the optical axis of the first lens 51 (as shown in FIG. 11 ). Further, the optical axis of the first lens 51 can be parallel to the optical axis of the second lens 52, and the optical axis of the first lens 51 is parallel to the optical axis of the second lens 52. The optical axes of the three lenses 53 are parallel, and the optical axis of the second lens 52 is parallel to the optical axis of the third lens 53; The optical axis of the first lens 51 is offset with respect to the optical axis of the first lens 51, the optical axis of the second lens 52 and the optical axis of the third lens 53 are located on opposite sides of the optical axis of the first lens 51 (as shown in FIG. 12), and further Ground, the optical axis of the first lens 51 may be parallel to the optical axis of the second lens 52 , the optical axis of the first lens 51 may be parallel to the optical axis of the third lens 53 , and the optical axis of the second lens 52 may be parallel to the optical axis of the third lens 53 . The optical axes are parallel.

Preferably, the optical axis of the second lens 52 is offset relative to the optical axis of the first lens 51 , the optical axis of the third lens 53 is offset relative to the optical axis of the first lens 51 , and the optical axis of the second lens 52 and The optical axis of the third lens 53 is located on the opposite side of the optical axis of the first lens 51 . In this way, the bending-shaped structure formed by the plurality of lenses is beneficial to increase the optical path, increase the focal length, and reduce the height of the laser projection module 100 . Of course, the collimating element 50 may also include more lenses, for example, please refer to FIG. 13 , the collimating element 50 includes a first lens 51 , a second lens 52 , a third lens 53 , a fourth lens 54 , and a fifth lens 55 , and the sixth lens 56 . The first lens 51 , the second lens 52 , the third lens 53 , the fourth lens 54 , the fifth lens 55 , and the sixth lens 56 are sequentially arranged on the light-emitting optical path of the light source 40 . The optical axis of the second lens 52 is offset with respect to the optical axis of the first lens 51 , the optical axis of the third lens 53 is offset with respect to the optical axis of the first lens 51 , the optical axis of the second lens 52 and the third lens 53 The optical axis of the first lens 51 is located on the opposite side of the optical axis of the first lens 51, the optical axis of the fourth lens 54 coincides with the optical axis of the second lens 52, the optical axis of the fifth lens 55 coincides with the optical axis of the third lens 53, The optical axis of the six lenses 56 coincides with the optical axis of the first lens 51 .

It should be pointed out that, in the laser projection module 100 shown in FIGS. 9 to 13 , the structure of the lens barrel 20 is the same as or similar to that of the lens barrel 20 shown in FIG. The multi-segment structure is not repeated here.

In some embodiments, the collimating element 50 includes a plurality of lenses, and the optical centers of at least two lenses are located on the same plane perpendicular to the first direction, the first direction being the direction from the light source 40 to the diffractive optical element 60 .

For example, please refer to FIGS. 14 to 16 together, the collimating element 50 includes a first lens 51 , a second lens 52 and a third lens 53 . The optical center of the first lens 51 and the optical center of the second lens 52 are located on the same plane (as shown in FIG. 14 ), and the optical axis of the first lens 51 and the optical axis of the second lens 52 Or, the optical center of the second lens 52 and the optical center of the third lens 53 are located on the same plane (as shown in FIG. 15 ), and the optical axis of the second lens 52 and the optical axis of the third lens 53 can be located on the opposite side of the optical axis of the first lens 51; or, the optical center of the first lens 51 and the optical center of the third lens 53 are located on the same plane; or, the optical center of the first lens 51, the optical center of the second lens 52 Both the center and the optical center of the third lens 53 are located on the same plane (as shown in FIG. 16 ). Further, the optical axis of the first lens 51 may be parallel to the optical axis of the second lens 52 , the optical axis of the first lens 51 may be parallel to the optical axis of the third lens 53 , and the optical axis of the second lens 52 may be parallel to the third lens 53 The optical axes are parallel.

Please refer to FIG. 1 again, the diffractive optical element 60 is used for diffracting the laser collimated by the collimating element 50 to form a laser pattern. The diffractive optical element 60 includes a diffractive exit surface 61 and a diffractive entrance surface 62 that are opposite to each other. The protective cover 30 can be pasted on the top 22 by glue, the abutting surface 31 collides with the diffractive exit surface 61 , and the diffractive incident surface 62 collides with the bearing platform 25 , so that the diffractive optical element 60 will not fall off from the receiving cavity 21 along the light exit direction. The diffractive optical element 60 may be made of glass material, or may be made of composite plastic (eg, PET).

When assembling the above-mentioned laser projection module 100 , the collimating element 50 and the substrate assembly 10 on which the light source 40 is installed are sequentially placed into the through hole 24 from the bottom 23 of the lens barrel 20 along the optical path. The light source 40 can be installed on the base plate assembly 10 first, and then the base plate assembly 10 on which the light source 40 is installed can be fixed to the bottom 23 . Put the diffractive optical element 60 into the through hole 24 from the top 22 against the direction of the optical path and carry it on the bearing platform 25, and then install the protective cover 30, and make the diffractive exit surface 61 of the diffractive optical element 60 and the protective cover 30 conflict, The diffractive incident surface 62 collides with the stage 25 . The laser projection module 100 has a simple structure and is easy to assemble.

Referring to FIG. 17 , the depth camera 400 according to the embodiment of the present invention includes the laser projection module 100 , the image collector 200 , and the processor 300 according to any of the above-mentioned embodiments. The image collector 200 is used to collect the laser pattern projected into the target space after passing through the diffractive optical element 50 . The processor 300 is connected to the laser projection module 100 and the image collector 200 respectively. The processor 300 is used to process the laser pattern to obtain a depth image.

Specifically, the laser projection module 100 projects the laser pattern projected into the target space outward through the projection window 401 , and the image collector 200 collects the laser pattern modulated by the target object through the acquisition window 402 . The image collector 200 can be an infrared camera, and the processor 300 uses an image matching algorithm to calculate the deviation value of each pixel point in the laser pattern and the corresponding pixel point in the reference pattern, and then further obtains the depth of the laser pattern according to the deviation value. image. The image matching algorithm may be a digital image correlation (Digital Image Correlation, DIC) algorithm. Of course, other image matching algorithms can also be used instead of the DIC algorithm.

In the depth camera 400 according to the embodiment of the present invention, the lenses of the collimating element 50 are all made of glass material, which solves the problem of temperature drift of the lens when the ambient temperature changes.

Referring to FIG. 18 , the electronic device 1000 according to the embodiment of the present invention includes a casing 500 and the depth camera 400 according to the above-mentioned embodiment. The depth camera 400 is disposed inside the casing 500 and exposed from the casing 500 to acquire depth images. The electronic device 1000 includes, but is not limited to, a mobile phone, a tablet computer, a notebook computer, a smart bracelet, a smart watch, a smart helmet, and smart glasses.

In the electronic device 1000 according to the embodiment of the present invention, the lenses of the collimating element 50 are all made of glass material, which solves the problem of temperature drift of the lens when the ambient temperature changes.

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples" or the like is meant to be used in conjunction with the described embodiments. A particular feature, structure, material or characteristic described by way or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and alterations.

Claims (5)

1. A laser projection module, comprising:

a light source for emitting laser light;

the collimating element is used for collimating the laser, and comprises a plurality of lenses, and the lenses are made of glass materials; the plurality of lenses comprise a first lens, a second lens and a third lens, the first lens, the second lens and the third lens are sequentially arranged on a light emitting optical path of the light source, an optical axis of the second lens is offset relative to an optical axis of the first lens, and an optical axis of the first lens is coincident with an optical axis of the third lens;

the lens cone comprises a first section structure and a second section structure, the first section structure is connected with the second section structure in an inclined mode, the first section structure is used for mounting the first lens and the second lens, the second section structure is used for mounting the third lens, the inner walls of the first section structure and the second section structure are coated with a reflecting coating, and the reflecting coating is used for reflecting light rays so that the light rays emitted by the light source can sequentially pass through the first lens, the second lens and the third lens; and

a diffractive optical element for diffracting the laser light collimated by the collimating element to form a laser light pattern.

2. The laser projection module of claim 1, wherein the light source is a vertical cavity surface emitting laser; or the light source is an edge-emitting laser.

3. The laser projection module of claim 1, wherein the light source is an edge emitting laser and the light source comprises a light emitting face facing the collimating element.

4. A depth camera, comprising:

the laser projection module of any of claims 1-3;

the image collector is used for collecting the laser patterns projected into the target space after passing through the diffractive optical element; and

and the processor is respectively connected with the laser projection module and the image collector and is used for processing the laser pattern to obtain a depth image.

5. An electronic device, comprising:

a housing; and

the depth camera of claim 4, disposed within and exposed from the housing to acquire a depth image.

Images