CN108490631B

CN108490631B - Structured light projector, image acquisition structure, and electronic device

Info

Publication number: CN108490631B
Application number: CN201810201691.XA
Authority: CN
Inventors: 张学勇
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2018-03-12
Filing date: 2018-03-12
Publication date: 2020-08-21
Anticipated expiration: 2038-03-12
Also published as: CN108490631A

Abstract

The invention discloses a structured light projector. The structured light projector includes a substrate assembly, a lens barrel, a light source, a collimating element, and a diffractive optical element. The lens cone comprises a lens cone side wall, and the lens cone side wall and the substrate component jointly form an accommodating cavity. The light source is disposed on the substrate assembly and is for emitting laser light. The collimating element is used for collimating laser and comprises a plurality of lenses, the lenses are arranged on a light emitting optical path of the light source, the lenses comprise at least one first lens, at least one second lens made of glass materials and at least one liquid lens, and the liquid lens can change the focal length under the action of voltage. The diffractive optical element is mounted on the lens barrel. The invention also discloses an image acquisition structure and an electronic device. The problem of temperature drift of the lens is improved by combining a plurality of lenses, the temperature drift is reduced by utilizing the characteristic of small temperature drift of glass materials of the second type of lens, and the problem of reduced accuracy of laser patterns is solved by utilizing the liquid lens to change the focal length.

Description

Structured light projector, image acquisition structure, and electronic device

Technical Field

The present invention relates to the field of optical and electronic technology, and more particularly, to a structured light projector, an image acquisition structure, and an electronic device.

Background

Structured light projectors generally consist of a light source, a collimating element, and a Diffractive Optical Elements (DOEs). The collimating element comprises a lens, when the environmental temperature changes, the lens can generate a temperature drift phenomenon, and when the temperature drift is larger, the focus of the lens can be changed, so that the accuracy of the laser pattern projected into the target space by the structured light projector is influenced.

Disclosure of Invention

The embodiment of the invention provides a structured light projector, an image acquisition structure and an electronic device.

The structured light projector of an embodiment of the present invention includes:

a substrate assembly;

the lens barrel comprises a lens barrel side wall, and the lens barrel side wall is arranged on the substrate assembly and forms an accommodating cavity together with the substrate assembly;

a light source disposed on the substrate assembly and configured to emit laser light to the accommodation cavity;

the collimating element is used for collimating the laser, the collimating element comprises a plurality of lenses, the lenses are arranged on a light emitting optical path of the light source, the lenses comprise at least one first-class lens, at least one second-class lens and at least one liquid lens, the first-class lens comprises a light transmitting substrate, the light transmitting substrate comprises an upper surface and a lower surface which are opposite, the first-class lens further comprises an upper sub-lens formed on the upper surface and a lower sub-lens formed on the lower surface, the upper sub-lens corresponds to the lower sub-lens, the second-class lens is made of glass materials, the liquid lens is installed on the lens barrel, and the liquid lens can change the focal length under the action of voltage; and

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

An image acquisition structure of an embodiment of the present invention includes:

the structured light projector described above;

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 structured light projector and the image collector and is used for processing the laser pattern to obtain a depth image.

An electronic device according to an embodiment of the present invention includes:

a housing; and

the image capture structure of the above embodiment, disposed within and exposed from the housing for capturing a depth image.

The structured light projector, the image acquisition structure and the electronic device of the embodiment of the invention improve the problem of temperature drift of the lens by combining a plurality of lenses, and can reduce the temperature drift by utilizing the characteristic of small temperature drift of the glass material because the second type of lens is made of the glass material. In addition, the liquid lens can be used for changing the focal length to solve the problem of reduced accuracy of the laser pattern caused by the temperature drift phenomenon.

Additional aspects and advantages of embodiments of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of embodiments of the invention.

Drawings

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

FIG. 1 is a schematic structural diagram of an electronic device according to an embodiment of the invention;

FIG. 2 is a schematic structural diagram of an image acquisition architecture according to an embodiment of the present invention;

FIG. 3 is a schematic structural view of a structured light projector according to an embodiment of the present invention;

FIG. 4 is a schematic view of a first type of lens for a collimating element of a structured light projector according to an embodiment of the present invention;

FIGS. 5 and 6 are schematic illustrations of the configuration of the liquid lens of the collimating element of the structured light projector according to an embodiment of the present invention;

FIGS. 7-13 are schematic illustrations of portions of collimating elements of a structured light projector according to an embodiment of the present invention;

fig. 14 to 16 are partial schematic structural views of a structured light projector according to an embodiment of the present invention.

Description of the main element symbols:

the electronic device 1000, the housing 200, the image capturing structure 100, the structured light projector 10, the substrate assembly 11, the substrate 111, the heat dissipation hole 1111, the circuit board 112, the via hole 113, the barrel 12, the receiving cavity 121, the barrel sidewall 122, the limiting protrusion 123, the light passing hole 1231, the limiting surface 1232, the first surface 124, the second surface 125, the first stage structure 126, the second stage structure 127, the protective cover 128, the light source 13, the edge-emitting laser 131, the light emitting surface 1311, the side surface 1312, the collimating element 14, the first lens 141, the transparent substrate 1411, the upper surface 1412, the lower surface 1413, the upper sub-lens 1414, the lower sub-lens 1415, the second lens 142, the liquid lens 143, the incident cover plate 1431, the exit cover plate 1432, the inner surface 1433a, the outer surface 1433b, the end surface 1433c, the upper end surface 1433d, the lower end surface 1433e, the sealed cavity 1434, the first electrode 1435, the insulating layer 1436, the conductive, The second electrode 1439, the first lens 144, the first light incident surface 1442, the first light emitting surface 1444, the second lens 145, the second light incident surface 1452, the second light emitting surface 1454, the third lens 146, the third light incident surface 1462, the third light emitting surface 1464, the fourth lens 147, the diffractive optical element 15, the first conductive element 16, the second conductive element 17, the fixing element 18, the sealant 181, the supporting frame 182, the accommodating space 183, the connector 19, the image collector 20, the processor 30, the projection window 40, and the collecting window 50.

Detailed Description

The following further describes embodiments of the present invention with reference to the drawings. The same or similar reference numbers in the drawings identify the same or similar elements or elements having the same or similar functionality throughout.

In addition, the embodiments of the present invention described below with reference to the accompanying drawings are exemplary only for the purpose of explaining the embodiments of the present invention, and are not to be construed as limiting the present invention.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

Referring to fig. 1, an electronic device 1000 according to an embodiment of the invention includes an image capturing structure 100 and a housing 200. The electronic device 1000 may be a mobile phone, a tablet computer, a laptop computer, a game machine, a head display device, an access control system, a teller machine, etc., and the embodiment of the present invention is described by taking the electronic device 1000 as a mobile phone, it is understood that the specific form of the electronic device 1000 may be other, and is not limited herein. The image acquisition structure 100 is disposed in the housing 200 and exposed from the housing 200 to acquire a depth image, the housing 200 can provide protection such as dust prevention, water prevention, and falling prevention for the image acquisition structure 100, and a hole corresponding to the image acquisition structure 100 is formed in the housing 200, so that light passes out of the hole or penetrates into the housing 200.

Referring to fig. 2, the image acquisition architecture 100 includes a structured light projector 10, an image acquirer 20, and a processor 30. The image acquisition structure 100 may have formed thereon a projection window 40 corresponding to the structured light projector 10, and an acquisition window 50 corresponding to the image acquirer 20. The structured light projector 10 is configured to project a laser light pattern through a projection window 40 to a target space, and the image collector 20 is configured to collect the laser light pattern modulated by a target through a collection window 50. In one example, the laser light projected by the structured light projector 10 is infrared light and the image collector 20 is an infrared camera. A processor 30 is connected to both the structured light projector 10 and the image grabber 20, and the processor 30 is configured to process the laser pattern to obtain a depth image. Specifically, the processor 30 calculates the deviation value between each pixel point in the laser pattern and each corresponding pixel point in the reference pattern by using an image matching algorithm, and further obtains the depth image of the laser pattern according to the deviation value. The Image matching algorithm may be a Digital Image Correlation (DIC) algorithm. Of course, other image matching algorithms may be employed instead of the DIC algorithm. The structure of the structured light projector 10 will be described further below.

Referring to FIG. 3, the structured light projector 10 includes a substrate assembly 11, a lens barrel 12, a light source 13, a collimating element 14, and a diffractive optical element 15. The light source 13, the collimating element 14 and the diffractive optical element 15 are arranged in this order on the optical path of the light source 13, in particular, the light emitted by the light source 13 passes through the collimating element 14 and the diffractive optical element 15 in this order.

Referring to fig. 3, the substrate assembly 11 includes a substrate 111 and a circuit board 112 carried on the substrate 111. The substrate 111 is used to carry the lens barrel 12, the light source 13, and the circuit board 112. The material of the substrate 111 may be plastic, such as at least one of Polyethylene Terephthalate (PET), polymethyl methacrylate (PMMA), Polycarbonate (PC), and Polyimide (PI). That is, the substrate 111 may be made of a single plastic material selected from PET, PMMA, PC, and PI. Thus, the substrate 111 is light in weight and has sufficient support strength.

The circuit board 112 may be any one of a printed circuit board, a flexible circuit board, and a rigid-flex board. The circuit board 112 may be provided with a via hole 113, the via hole 113 may be used to accommodate the light source 13, a portion of the circuit board 112 is covered by the lens barrel 12, and another portion of the circuit board 112 extends out and may be connected to a connector 19, and the connector 19 may connect the structured light projector 10 to a main board of the electronic device 1000 in fig. 1.

Referring to fig. 3, the lens barrel 12 is disposed on the substrate assembly 11 and forms a receiving cavity 121 together with the substrate assembly 11. Specifically, the lens barrel 12 may be connected to the circuit board 112 of the substrate assembly 11, and the lens barrel 12 and the circuit board 112 may be adhered by an adhesive to improve the air tightness of the accommodating chamber 121. Of course, the lens barrel 12 and the substrate assembly 11 may be connected in other specific ways, such as by a snap connection. The receiving cavity 121 may be configured to receive components such as the collimating element 14 and the diffractive optical element 15, and the receiving cavity 121 may also form a portion of the optical path of the structured light projector 10. In the embodiment of the present invention, the lens barrel 12 is in a hollow cylindrical shape, and the lens barrel 12 includes a barrel sidewall 122 and a limiting protrusion 123.

Barrel sidewall 122 surrounds receiving cavity 121, and the outer wall of barrel sidewall 122 may be formed with positioning structures and mounting structures to secure the position of structured light projector 10 when structured light projector 10 is mounted within electronic device 1000. The lens barrel 12 includes a first surface 124 and a second surface 125 opposite to each other, wherein one opening of the receiving cavity 121 is opened on the second surface 125, and the other opening is opened on the first surface 124. The second side 125 is bonded, e.g., glued, to the circuit board 112.

The limiting protrusion 123 protrudes inward from the barrel sidewall 122, and specifically, the limiting protrusion 123 protrudes inward from the barrel sidewall 122 into the receiving cavity 121. The limiting protrusion 123 may be continuous and annular, or the limiting protrusion 123 includes a plurality of limiting protrusions 123, and the plurality of limiting protrusions 123 are distributed at intervals. The limiting protrusion 123 forms a light passing hole 1231, the light passing hole 1231 may be a part of the accommodating cavity 121, and the laser passes through the light passing hole 1231 and then penetrates into the diffractive optical element 15. In the embodiment shown in fig. 3, the limiting protrusion 123 is located between the first surface 124 and the second surface 125, the receiving cavity 121 between the limiting protrusion 123 and the second surface 125 can be used for receiving the collimating element 14, and the receiving cavity 121 between the limiting protrusion 123 and the first surface 124 can be used for receiving the diffractive optical element 15. The stopper protrusion 123 includes a stopper surface 1232, and the stopper surface 1232 is combined with the diffractive optical element 15 when the diffractive optical element 15 is mounted on the stopper protrusion 123.

In some embodiments, the structured light projector 10 further includes a protective cover 128, the protective cover 128 being disposed on the first face 124. The boot 128 is attached after the diffractive optical element 15 is attached to the stopper projection 123, so that the diffractive optical element 15 can be prevented from falling off. The protective cover 128 may be made of a light-transmitting material, such as glass, PolymethylMethacrylate (PMMA), Polycarbonate (PC), Polyimide (PI), or the like. Since the light-transmitting materials such as glass, PMMA, PC, and PI have excellent light-transmitting properties, the protective cover 128 does not need to be provided with light-transmitting holes. In this way, the protective cover 128 can prevent the diffractive optical element 15 from falling off, and can prevent the diffractive optical element 15 from being exposed outside the lens barrel 12, thereby achieving water and dust prevention for the diffractive optical element 15. Of course, in other embodiments, the protective cover 128 may be provided with a light-transmitting hole opposite to the optically effective area of the diffractive optical element 15 to avoid blocking the light path of the diffractive optical element 15.

Referring to fig. 3, the light source 13 is disposed on the substrate assembly 11, specifically, the light source 13 may be disposed on the circuit board 112 and electrically connected to the circuit board 112, and the light source 13 may also be disposed on the substrate 111 and received in the via 113, at this time, the light source 13 may be electrically connected to the circuit board 112 by disposing a wire. The light source 13 is used for emitting Laser light, which may be infrared light, and in one example, the light source 13 may include a semiconductor substrate disposed on the substrate 111 and an emitting Laser disposed on the semiconductor substrate, which may be a Vertical Cavity Surface Emitting Laser (VCSEL). The semiconductor substrate may be provided with a single emitting laser or with an array laser composed of a plurality of emitting lasers, and specifically, the plurality of emitting lasers may be arranged on the semiconductor substrate in a regular or irregular two-dimensional pattern.

Referring to fig. 3, the diffractive optical element 15 is mounted on the limiting protrusion 123, and specifically, the diffractive optical element 15 is combined with the limiting surface 1232 to be mounted on the limiting protrusion 123. In the embodiment of the present invention, the diffractive optical element 15 has a diffractive structure formed on a surface thereof coupled to the limiting surface 1232, and the diffractive optical element 15 can project the laser beam collimated by the collimating element 14 to a laser beam pattern corresponding to the diffractive structure. The diffractive optical element 15 can be made of glass, or, as it were, of a composite plastic (e.g., PET).

With continued reference to fig. 3, the collimating element 14 is used for collimating the laser light emitted from the light source 13 and projecting the laser light onto the diffractive structure of the diffractive optical element 15. The collimating element 14 is received in the receiving cavity 121, and the collimating element 14 can be assembled into the receiving cavity 124 along a direction in which the second face 125 points toward the first face 124. The collimating element 14 includes a plurality of lenses disposed on the light emitting path of the light source 13, and each lens may have any one of an aspherical surface, a spherical surface, a fresnel surface, and a binary optical surface. The plurality of lenses includes at least one first-type lens 141, at least one second-type lens 142, and at least one liquid lens 143.

Referring to fig. 4, the first lens 141 includes a transparent substrate 1411 (for example, a substrate with a light transmittance greater than 80%). The light transmissive substrate 1411 includes opposing upper and

lower surfaces

1412 and 1413. The first-type lens 141 further includes an upper sub-lens 1414 formed on the upper surface 1412 and a lower sub-lens 1415 formed on the lower surface 1413, the upper sub-lens 1414 corresponding to the lower sub-lens 1415. The second lens 142 is made of glass. The first-class lens 141 is manufactured by forming an upper sub-lens 1414 and a lower sub-lens 1415 on a transparent substrate 1411, so that the problem that the lens generates a temperature drift phenomenon when the environmental temperature changes is solved; the second lens 142 is made of glass material, so that the problem of temperature drift of the lens is further solved.

Specifically, the first-type lens 141 may be fabricated by a WLO (wafer level optics) process. The transparent substrate 1411 may be a glass substrate, and first, UV glue is coated on the upper surface 1412 and the lower surface 1413 of the transparent substrate 1411, and then an upper sub-lens 1414 and a lower sub-lens 1415 are formed by photolithography. The upper sub-lens 1414 can be a convex lens, and the lower sub-lens 1415 can also be a convex lens (as shown in FIG. 4); alternatively, the upper sub-lens 1414 is a concave lens and the lower sub-lens 1415 is also a concave lens; alternatively, the upper sub-lens 1414 is a convex lens and the lower sub-lens 1415 is a concave lens; alternatively, the upper sub-lens 1414 is a concave lens and the lower sub-lens 1415 is a convex lens. The first lens 141, which is fabricated by WLO, can solve the problem that the collimating element 14 is deformed by heat, so that the optical effect is deteriorated (for example, speckle is increased), and the accuracy of projecting the laser pattern into the target space by the structured light projector 10 is affected.

In some embodiments, when assembling the diffractive optical element 15 and the collimating element 14, the diffractive optical element 15 or the collimating element 14 may not achieve the required mounting accuracy, and the mutual positions of the two may be shifted, for example, when there are impurity particles on the limiting surface 1232 or there are too many dots glued on the limiting surface 1232, the height of the diffractive optical element 15 that is padded up after being mounted on the limiting protrusion 123 is too high, and at the same focal length, the laser passing through the collimating element 14 may be irradiated to a certain position of the diffractive optical element 15 too intensively, so that the diffraction structure of the diffractive optical element 15 cannot be fully utilized, and the diffractive optical element 15 cannot diffract the preset laser pattern. In some embodiments, the focus of the collimating element is changed due to a temperature drift phenomenon of the collimating element 14. The liquid lens 143 according to the embodiment of the present invention can change the focal length under the action of voltage to correct the influence of the offset of the diffractive optical element 15 or the collimating element 14.

Specifically, referring to fig. 3 and 5, in some embodiments, the liquid lens 143 includes an entrance cover plate 1431, an exit cover plate 1432, a sealing body 1433, a first electrode 1435, an insulating layer 1436, a conductive liquid 1437, an insulating liquid 1438, and a second electrode 1439. The laser light is incident from the incident cover plate 1431 to enter the liquid lens 143, and exits from the liquid lens 143 after passing through the conductive liquid 1437, the insulating liquid 1438, and the exit cover plate 1432 in order.

The incident cover plate 1431 may be transparent, the incident cover plate 1431 may be made of glass or resin, the incident cover plate 1431 may be a flat plate to make the liquid lens 143 simple in structure and easy to manufacture, and the incident cover plate 1431 may also be a convex lens, such as a plano-convex lens, to improve the collimation capability of the liquid lens 143 for the laser light. Similarly, the exit cover plate 1432 may be transparent, the exit cover plate 1432 may be made of glass or resin, and the exit cover plate 1432 may be a flat plate or a plano-convex lens. In other embodiments, the entrance cover plate 1431 and the exit cover plate 1432 may also be concave lenses. Mounting structures may be formed on the outer sidewalls of the entrance cover 1431 and the exit cover 1432, and when the liquid lens 143 is mounted in the barrel 12, the mounting structures may cooperate with the structures in the barrel sidewall 122 to securely mount the liquid lens 143 in the barrel 12, in one example, the outer sidewalls of the entrance cover 1431 and the exit cover 1432 may be formed with external threads, and the inner wall of the barrel sidewall 122 may be formed with internal threads, so that the liquid lens 143 may be screwed into the barrel 12 and the external threads cooperate with the internal threads.

The sealing body 1433, the first electrode 1435, the insulating layer 1436, the conducting liquid 1437, the insulating liquid 1438 and the second electrode 1439 may all be arranged between the entrance cover plate 1431 and the exit cover plate 1432. The sealing body 1433 may be annular, and the sealing body 1433, the entrance cover plate 1431, and the exit cover plate 1432 collectively enclose a sealing cavity 1434. The location of the sealed cavity 1434 may be aligned with the location of the light source 13, the light passing hole 1321, and the shape of the sealed cavity 1434 may be cylindrical, truncated cone, or other shapes. The sealing body 1433 includes an inner surface 1433a, an outer surface 1433b, and an end surface 1433c, the inner surface 1433a is located within the sealing cavity 1434, the inner surface 1433a is opposite to the outer surface 1433b, the outer surface 1433b may be flush with the outer sidewalls of the entrance cover plate 1431 and the exit cover plate 1432, and may be used to bond with the inner wall of the barrel sidewall 122. The end face 1433c connects the inner surface 1433a and the outer surface 1433b, the end face 1433c includes an upper end face 1433d and a lower end face 1433e, the upper end face 1433d is opposite to the lower end face 1433e, in the embodiment of the present invention, the lower end face 1433e is close to the incident cover plate 1431, and the upper end face 1433d is close to the exit cover plate 1432.

The conductive liquid 1437 and the insulating liquid 1438 are contained in the sealed cavity 1434, in the embodiment of the present invention, the conductive liquid 1437 and the insulating liquid 1438 fill the sealed cavity 1434, and the conductive liquid 1437 and the insulating liquid 1438 are not soluble and wettable with each other, so that an interface S1 between the conductive liquid 1437 and the insulating liquid 1438 is formed. In an embodiment of the invention, the conducting liquid 1437 is located at a side close to the entrance cover plate 1431 and the insulating liquid 1438 is located at a side close to the exit cover plate 1432. The conductive liquid 1437 and the insulating liquid 1438 are both transparent liquids. The density of the conductive liquid 1437 and the insulating liquid 1438 should be substantially the same so that the interface S1 is not affected by gravity. The conductive liquid 1437 may be a conductive aqueous solution, such as saline, sodium sulfate solution, and the insulating liquid 1438 may be a non-polar liquid, such as a silicone solution, bromododecane solution, or the like.

The first electrode 1435 is formed on the inner surface 1433a, the insulating layer 1436 is formed on a side of the first electrode 1435 opposite to the inner surface 1433a, the insulating layer 1436 separates the first electrode 1435 from the conductive liquid 1437 and the insulating liquid 1438, so that the first electrode 1435 is not conductive to the conductive liquid 1437, and the first electrode 1435 is not conductive to the insulating liquid 1438, and the first electrode 1435 may be a sheet or a laminated electrode, and the material of the electrode may be gold, platinum, indium tin oxide, or the like. The insulating layer 1436 has an insulating property and also has a hydrophobic property, and neither the conductive liquid 1437 nor the insulating liquid 1438 adheres to the surface of the insulating layer 1436. The second electrode 1439 is electrically connected to the conductive liquid 1437, and the second electrode 1439 is insulated from the first electrode 1435, and the second electrode 1439 may be formed on the end surface 1433 c.

As shown in fig. 5, in the liquid lens 143 in a natural state, an interface S1 between the conductive liquid 1437 and the insulating liquid 1438 is a natural curved surface caused by surface tension. When the first electrode 1435 and the second electrode 1439 are respectively connected to the positive electrode and the negative electrode of the dc power supply, according to the electrowetting effect, the contact angle between the conductive liquid 1437 and the insulating layer 1436 changes, so that the shape and the curvature of the interface S1 between the conductive liquid 1437 and the insulating liquid 1438 change (for example, become the interface S2), wherein the curvature of the interface S1 has a quantitative relationship with the magnitude of the voltage difference between the first electrode 1435 and the second electrode 1439. Therefore, the shape and curvature of the interface S1 can be controlled by controlling the magnitude of the voltage difference between the first electrode 1435 and the second electrode 1439, so as to change the focal length of the liquid lens 143, i.e., change the magnitude of the laser collimation effect of the liquid lens 143.

In summary, in the electronic device 1000 according to the embodiment of the invention, when the relative position between the liquid lens 143 and the diffractive optical element 15 is changed, a certain voltage is applied to the liquid lens 143 to change the focal length of the liquid lens 143, so that the laser light is projected onto the predetermined range of the diffractive optical element 15, and the structured light projector 10 emits a predetermined laser pattern.

Referring to fig. 5, in some embodiments, the first electrode 1435 is further formed on the end surface 1433c and exposed from the outer surface 1433b, and the second electrode 1439 is exposed from the outer surface 1433 b. First and

second electrodes

1435 and 1439 are each exposed from outer surface 1433b to facilitate interfacing first and

second electrodes

1435 and 1439 with an external power source. In one example, referring to fig. 3, a first conductive element 16 and a second conductive element 17 are disposed on an inner wall of the barrel sidewall 122, the first conductive element 16 is used for electrically connecting the first electrode 1435 and the substrate assembly 11, and the second conductive element 17 is used for electrically connecting the second electrode 1439 and the substrate assembly 11.

One end of the first conductive element 16 and the second conductive element 17 may be electrically connected to the circuit board 112 of the substrate assembly 11, and the other end may be a ring-shaped electrode disposed on the inner wall of the barrel sidewall 122, the first electrode 1435 and the second electrode 1439 have a height difference at the position where the outer surface 1433b is exposed, when the liquid lens 143 is installed in the barrel 12, the first electrode 1435 is in contact with the first conductive element 16, and the second electrode 1439 is in contact with the second conductive element 17. By controlling the voltages applied to the first conductive element 16 and the second conductive element 17, the voltage difference between the first electrode 1435 and the second electrode 1439 can be controlled, so as to adjust the focal length of the liquid lens 143.

Referring to fig. 5 and 6, in some embodiments, a first electrode 1435 is formed on the upper end surface 1433d and/or the lower end surface 1433e, and an insulating layer 1436 separates the first electrode 1435 from the second electrode 1439. Specifically, the first electrode 1435 may be formed only on the inner surface 1433a and the upper end face 1433 d; or the first electrode 1435 is formed only on the inner surface 1433a and the lower end surface 1433 e; at this time, the second electrode 1439 may be formed on the same end face 1433c as the first electrode 1435, or may be formed on an end face 1433c opposite to the first electrode 1435. Of course, as shown in fig. 6, the first electrode 1435 may be formed on the inner surface 1433a, the upper end surface 1433d and the lower end surface 1433e at the same time, the first electrode 1435 may be exposed from two positions of the outer surface 1433b, and the first conductive element 16 and the first electrode 1435 may have at least two contact points, so as to improve the reliability of the contact between the first conductive element 16 and the first electrode 1435.

Referring to fig. 3 and 7, in some embodiments, the plurality of lenses may include a first lens 144, a second lens 145, and a third lens 146. The first lens 144, the second lens 145, and the third lens 146 are coaxially disposed in order on the light emitting path of the light source 13. The first lens 144 includes a first light incident surface 1442 and a first light emitting surface 1444 opposite to each other. The first light incident surface 1442 is a surface of the first lens 144 close to the light source 13, and the first light emitting surface 1444 is a surface of the first lens 144 close to the diffractive optical element 15. The second lens 145 includes a second light incident surface 1452 and a second light emitting surface 1454 opposite to each other. The second light incident surface 1452 is a surface of the second lens 145 close to the light source 13, and the second light emitting surface 1454 is a surface of the second lens 145 close to the diffractive optical element 15. The third lens 146 includes a third light incident surface 1462 and a third light emitting surface 1466 opposite to each other. The third light incident surface 1462 is a surface of the third lens 146 close to the light source 13, and the third light emitting surface 1466 is a surface of the third lens 146 close to the diffractive optical element 15. The first light incident surface 1442 is a concave surface, the vertex of the first light emitting surface 1444 is abutted against the vertex of the second light incident surface 1452, the second light emitting surface 1454 is a convex surface, and the vertex of the second light emitting surface 1454 is abutted against the vertex of the third light incident surface 1462. Further, the first light emitting surface 1444 and the second light incident surface 1452 may be convex surfaces. Thus, the vertex of the first light emitting surface 1444 is convenient to collide with the vertex of the second light incident surface 1452.

In the collimating element 14 shown in fig. 7, the first lens 144 is a first-type lens 141 (note that, the light incident surface of the first-type lens 141 is the surface of the lower sub-lens 1415 close to the light source 13, the light emergent surface of the first-type lens 141 is the surface of the upper sub-lens 1414 close to the diffractive optical element 15, and the same applies below), the second lens 145 is a second-type lens 142, and the third lens 146 is a liquid lens 143. Of course, in other examples, the positions of the first lens 144, the second lens 145 and the third lens 146 may be adjusted according to needs, and are not limited in detail herein.

In some embodiments, the number of the plurality of lenses may also be adjusted according to requirements, for example, the plurality of lenses may also be four lenses, five lenses, six lenses, etc., and the types of the lenses may also be set according to requirements, so long as the plurality of lenses includes at least one first-type lens 141, at least one second-type lens 142, and at least one liquid lens 143. Referring to fig. 8, in an embodiment, the plurality of lenses includes a first lens 144, a second lens 145, a third lens 146 and a fourth lens 147, the first lens 144 is a first lens 141, the second lens 145 is a second lens 142, the third lens 146 is a liquid lens 143, and the fourth lens 147 is the first lens 141.

In some embodiments, the collimating element 14 comprises a plurality of lenses. The plurality of lenses are sequentially disposed on the light emission path of the light source 13, and the optical axis of at least one lens is shifted from the optical axes of the other lenses. At this time, the structure of the lens barrel 20 may be one or more sections, each section being used for mounting a corresponding lens.

For example: referring to fig. 9 to 13, the collimating element 14 includes a first lens 144, a second lens 145 and a third lens 146, wherein: the first lens 144 is a first lens 141, the second lens 145 is a second lens 142, and the third lens 146 is a liquid lens 143; alternatively, the first lens 144 is the second lens 142, the second lens 145 is the first lens 141, and the third lens 146 is the liquid lens 143; alternatively, the first lens 144 is a liquid lens 143, the second lens 145 is a first lens 141, and the third lens 146 is a second lens 142, but the types of the first lens 144, the second lens 145, and the third lens 146 may be other combinations, which are not listed here. The first lens 144, the second lens 145, and the third lens 146 are sequentially disposed on the light emitting optical path of the light source 13. The optical axis of the second lens 145 is shifted from the optical axis of the first lens 144, the optical axis of the first lens 144 coincides with the optical axis of the third lens 146 (as shown in fig. 9), further, the optical axis of the second lens 145 may be parallel to the optical axis of the first lens 144, at this time, the structure of the lens barrel 12 may be a two-stage structure, the first stage structure 126 is used for installing the first lens 144, the second stage structure 127 is used for installing the third lens 146, the first stage structure 126 is obliquely connected to the second stage structure 127, and the second lens 145 is installed at the connection position of the first stage structure 126 and the second stage structure 127, so that the plurality of lenses form a bent structure to increase the optical path, thereby reducing the overall height of the structured light projector 10, the inner walls of the first stage structure 126 and the second stage structure 127 are coated with a reflective coating for reflecting light, so that the light emitted by the light source 13 can sequentially pass through the first light incident surface 1442, A first light emitting surface 1444, a second light emitting surface 1452, a second light emitting surface 1454, a third light emitting surface 1462, and a third light emitting surface 1464; of course, in other embodiments, the first stage structure 126 and the second stage structure 127 may also be reflective elements independent from the lens barrel 12, the reflective elements are disposed on the lens barrel 12, the reflective elements are prisms or mirrors, and the like, and the reflective elements are used for reflecting light to change the direction of the light path; alternatively, the optical axis of the first lens 144 is offset from the optical axis of the second lens 145, the optical axis of the second lens 145 coincides with the optical axis of the third lens 146 (as shown in fig. 10), and further, the optical axis of the first lens 144 may be parallel to the optical axis of the second lens 145; alternatively, the optical axis of the third lens 146 may be offset from the optical axis of the first lens 144, the optical axis of the first lens 144 may coincide with the optical axis of the second lens 145 (as shown in fig. 11), and the optical axis of the third lens 146 may be parallel to the optical axis of the first lens 144; alternatively, the optical axis of the second lens 145 is shifted from the optical axis of the first lens 144, the optical axis of the third lens 146 is shifted from the optical axis of the first lens 144, the optical axis of the second lens 145 and the optical axis of the third lens 146 are located on the same side of the optical axis of the first lens 144 (as shown in fig. 12), further, the optical axis of the first lens 144 may be parallel to the optical axis of the second lens 145, the optical axis of the first lens 144 is parallel to the optical axis of the third lens 146, and the optical axis of the second lens 145 is parallel to the optical axis of the third lens 146; alternatively, the optical axis of the second lens 145 is offset from the optical axis of the first lens 144, the optical axis of the third lens 146 is offset from the optical axis of the first lens 144, the optical axis of the second lens 145 and the optical axis of the third lens 146 are located on opposite sides of the optical axis of the first lens 144 (as shown in fig. 13), further, the optical axis of the first lens 144 may be parallel to the optical axis of the second lens 145, the optical axis of the first lens 144 may be parallel to the optical axis of the third lens 146, and the optical axis of the second lens 145 may be parallel to the optical axis of the third lens 146.

In some embodiments, the optical axis of the second lens 145 is offset from the optical axis of the first lens 144, the optical axis of the third lens 146 is offset from the optical axis of the first lens 144, and the optical axis of the second lens 145 and the optical axis of the third lens 146 are located on opposite sides of the optical axis of the first lens 144. Thus, the multiple lenses form a bending structure, which is beneficial to increase the optical path, increase the focal length, and reduce the height of the structured light projector 10.

It should be noted that, in the structured light projector 10 shown in fig. 10 to 13, the structure of the lens barrel 12 is the same as or similar to the structure of the lens barrel 12 shown in fig. 9, and the structure of the lens barrel 12 can be a one-stage or multi-stage structure, which is not described herein again.

Referring to fig. 3 and 14, in some embodiments, the light source 13 includes an edge-emitting Laser (EEL) 131, and specifically, the edge-emitting Laser 131 may be a distributed feedback Laser (DFB). The side emitting laser 131 is columnar as a whole, and a light emitting surface 1311 is formed on one end surface of the side emitting laser 131 away from the substrate assembly 11, and laser light is emitted from the light emitting surface 1311, with the light emitting surface 1311 facing the liquid lens 143. The edge-emitting laser 131 is adopted as a light source, on one hand, the temperature drift of the edge-emitting laser 131 is smaller than that of a VCSEL array, and on the other hand, the edge-emitting laser 131 is of a single-point light-emitting structure, so that an array structure does not need to be designed, the manufacturing is simple, and the light source cost of the structured light projector 10 is lower.

Referring to fig. 14 and 15, in some embodiments, the structured light projector 10 further includes a fastener 18, the fastener 18 being used to secure the edge-emitting laser 131 to the substrate assembly 11. When the laser of the distributed feedback laser propagates, the gain of power is obtained through the feedback of the grating structure. To improve the power of the distributed feedback laser, the injection current needs to be increased and/or the length of the distributed feedback laser needs to be increased, which may increase the power consumption of the distributed feedback laser and cause serious heat generation. When the light emitting surface 1311 of the edge-emitting laser 131 faces the collimating element 14, the edge-emitting laser 131 is vertically placed, and because the edge-emitting laser 131 is of a slender strip structure, the edge-emitting laser 131 is prone to falling, shifting or shaking accidents, and therefore the edge-emitting laser 131 can be fixed by arranging the fixing member 18, and the edge-emitting laser 131 is prevented from falling, shifting or shaking accidents.

Specifically, referring to fig. 14 and 15, in some embodiments, the fixing member 18 includes an encapsulant 181, and the encapsulant 181 is disposed between the edge-emitting laser 131 and the substrate assembly 11. More specifically, in the example shown in fig. 14, the side emitting laser 131 is bonded to the substrate assembly 11 on the side opposite to the light emitting surface 1311. In the example shown in fig. 15, the side surface 1312 of the edge-emitting laser 131 may be bonded to the substrate assembly 11, and the side surface 1312 around the side surface may be covered with the sealant 181, or only one of the side surfaces 1312 may be bonded to the substrate assembly 11, or some of the side surfaces may be bonded to the substrate assembly 11. Further, the encapsulant 181 may be a heat conductive adhesive to conduct heat generated by the operation of the light source 13 to the substrate assembly 11. In order to improve the heat dissipation efficiency, the substrate 111 may further be formed with a heat dissipation hole 1111, heat generated by the operation of the light source 13 or the circuit board 112 may be dissipated through the heat dissipation hole 1111, and the heat dissipation hole 1111 may be filled with a thermal conductive adhesive to further improve the heat dissipation performance of the substrate assembly 11.

Referring to fig. 16, in some embodiments, the fixing member 18 includes at least two elastic supporting frames 182 disposed on the substrate assembly 11, the at least two supporting frames 182 together form an accommodating space 183, the accommodating space 183 is used for accommodating the edge-emitting laser 131, and the at least two supporting frames 182 are used for supporting the edge-emitting laser 131 to further prevent the edge-emitting laser 131 from shaking.

In some embodiments, the substrate 111 can be omitted and the light source 13 can be directly mounted on the circuit board 112 to reduce the overall thickness of the structured light projector 10.

In the description of the specification, reference to the terms "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the 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.

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 at least one of the feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, unless specifically limited otherwise.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and those skilled in the art can make changes, modifications, substitutions and alterations to the above embodiments within the scope of the present invention, which is defined by the claims and their equivalents.

Claims

1. A structured light projector, comprising:

a substrate assembly;

the light source is arranged on the substrate assembly and used for emitting laser to the accommodating cavity, and the light source comprises an edge-emitting laser;

the fixing piece comprises at least two elastic support frames arranged on the base plate component, the at least two support frames jointly form an accommodating space, the accommodating space is used for accommodating the edge-emitting laser, and the at least two support frames are used for supporting the edge-emitting laser;

a diffractive optical element mounted on the barrel, the diffractive optical element for diffracting the laser light collimated by the collimating element to form a laser light pattern; when the collimating element or the diffractive optical element is deflected, the liquid lens can correct the focal length of the diffractive optical element or the collimating element under the action of a voltage.

2. The structured light projector of claim 1 wherein a plurality of the lenses are coaxially disposed in sequence in a light emitting path of the light source.

3. The structured light projector of claim 1 wherein a plurality of the lenses are sequentially disposed in an emission light path of the light source, an optical axis of at least one of the lenses being offset relative to optical axes of the other lenses.

4. The structured light projector of claim 1 wherein the liquid lens comprises:

an incident cover plate;

an exit cover plate;

the annular sealing body is positioned between the incident cover plate and the emergent cover plate, the sealing body, the incident cover plate and the emergent cover plate jointly form a sealing cavity, and the sealing body comprises an inner surface positioned in the sealing cavity;

a first electrode formed on the inner surface;

an insulating layer formed on a side of the first electrode opposite the inner surface;

the conducting liquid and the insulating liquid which are mutually insoluble are contained in the sealed cavity; and

a second electrode electrically connected to the conductive liquid and insulated from the first electrode.

5. The structured light projector of claim 4 wherein the seal includes an outer surface opposite the inner surface and an end surface connecting the inner surface and the outer surface, the first electrode further formed on the end surface and exposed from the outer surface, the second electrode exposed from the outer surface.

6. The structured light projector of claim 5 wherein the end face comprises opposing upper and lower end faces, the first electrode being formed on the upper and/or lower end face, the insulating layer separating the first and second electrodes.

7. The structured light projector of claim 4 wherein an inner wall of the barrel sidewall is provided with a first conductive element connecting the first electrode and the substrate assembly and a second conductive element connecting the second electrode and the substrate assembly.

8. The structured light projector of claim 4 wherein the entrance cover plate is a flat plate or a convex lens; and/or the exit cover plate is a flat plate or a convex lens.

9. An image acquisition structure, comprising:

the structured light projector of any one of claims 1 to 8;

10. An electronic device, comprising:

a housing; and

the image capturing structure of claim 9, disposed within and exposed from the housing to capture a depth image.