Laser light source, laser light source module and depth camera

Abstract

Embodiments of the present application provide a laser light source, a laser light source module and a depth camera. The laser light source comprises: a first light emitting area comprising a plurality of rows of first light emitting holes and a first pad, the first pad being connected to the plurality of rows of first light emitting holes through a first conductive connection part; and a second light emitting area comprising a plurality of rows of second light emitting holes and a second pad, the second pad being connected to the plurality of rows of second light emitting holes through a second conductive connection part; wherein the plurality of rows of first light emitting holes and the plurality of rows of second light emitting holes are alternately arranged in sequence and are located on the same plane, the first pad and the second pad are spaced apart and located on the same plane, the first conductive connection part and the second conductive connection part cross in the thickness direction of the laser light source, and an insulating layer is arranged between the first conductive connection part and the second conductive connection part to electrically insulate the first conductive connection part and the second conductive connection part. In the laser light source, the first light emitting holes and the second light emitting holes are arranged on the same plane, so as to reduce the volume of the laser light source.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optoelectronics, and in particular to a laser light source, a laser light source module and a depth camera. BACKGROUND

[0002] TOF is one of the schemes of 3D depth camera, and TOF is the abbreviation of "time-of-flight", also known as time-of-flight ranging method. The principle is to measure the transmission time of light between the lens and the object to measure the distance, to determine how far the object is from us through these data, and to know the distance of each object in the picture, so as to realize the depth map, and finally to directly draw a stereoscopic image to achieve 3D stereoscopic depth sensing. TOF is currently divided into DTOF and iTOF.

[0003] DTOF, which stands for direct Time-of-Flight, directly measures the time of flight, as its name implies. The core components of DTOF include VCSEL, single photon avalanche diode (SPAD) and time-to-digital converter (TDC). Single Photon Avalanche Diode (SPAD) is a kind of photoelectric detection avalanche diode with single photon detection capability, which can generate current as long as there is weak light signal. The VCSEL of DTOF module emits pulsed waves to the scene, and the SPAD receives the pulsed waves reflected from the target object. Time Digital Converter (TDC) can record the flight time of each received light signal, that is, the time interval between the emitted pulse and the received pulse. DTOF will emit and receive N times of light signal within a single frame measurement time, and then make histogram statistics on the recorded N times of flight time, and the flight time t with the highest frequency is used to calculate the depth of the object to be measured.

[0004] The concept of iTOF corresponds to DTOF, and its full name is indirect Time-of-Flight, which is directly translated as indirect light flight time. Indirect means that iTOF indirectly measures the flight time of light by measuring the phase shift, rather than directly measuring the flight time of light. iTOF emits modulated infrared light signals to the scene, and the sensor receives the light signals reflected from the object to be measured in the scene, calculates the phase difference between the emitted signal and the received signal according to the cumulative charge in the exposure (integration) time, and obtains the depth of the target object.

[0005] Time-of-Flight (TOF) requires a single lamp as its light source, typically a VCSEL (Variable Cathode Laser) module. A VCSEL is a light-emitting device composed of numerous light-emitting holes; the top surface is the anode, and the bottom surface is the cathode. The device uses a common cathode connection at the cathode. The anode is connected using a gold layer, which can be segmented or continuous. Currently, segmentation involves layering the light-emitting areas, increasing the space occupied by each area and consequently increasing the size of the laser source. Summary of the Invention

[0006] This application provides a laser light source, a laser light source module, and a depth camera. The light-emitting area of ​​the laser light source adopts a partitioned but not layered design to reduce the space occupied by the light-emitting area, thereby reducing the size of the laser light source.

[0007] This application provides a laser light source, including:

[0008] The first light-emitting area includes multiple rows of first light-emitting holes and a first pad, wherein the first pad is connected to the multiple rows of first light-emitting holes through a first conductive connection portion;

[0009] The second light-emitting area includes multiple rows of second light-emitting holes and a second pad, wherein the second pad is connected to the multiple rows of second light-emitting holes through a second conductive connection portion;

[0010] The first and second light-emitting holes are arranged in a series of alternating rows and are all located on the same plane. The first and second pads are spaced apart and located on the same plane. The first and second conductive connections intersect in the thickness direction of the laser source. An insulating layer is provided between the first and second conductive connections to make them electrically insulated.

[0011] This application embodiment also provides a laser source module, including:

[0012] The laser driver chip includes a first power supply pin and a second power supply pin;

[0013] In the aforementioned laser light source, the first pad is electrically connected to the first power supply pin, and the second pad is electrically connected to the second power supply pin.

[0014] This application also provides a depth camera, including the laser light source module described above.

[0015] The laser light source provided by the embodiment of the present application sets the multiple rows of first light emitting holes in the first light emitting area and the multiple rows of second light emitting holes in the second light emitting area in the same plane, fully utilizes the total light emitting area in the same plane light emitting area, reduces the space occupied by the light emitting area, and facilitates the reduction of the volume of the laser light source. Meanwhile, the insulation layer set between the first conductive connection part and the second conductive connection part can ensure the insulation performance between the first light emitting area and the second light emitting area. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0017] Figure 1 The structural schematic diagram of the laser light source module provided by the embodiment of the present application is shown.

[0018] Figure 2 The structural schematic diagram of the laser light source provided by the embodiment of the present application is shown.

[0019] Figure 3 The arrangement schematic diagram of the first light emitting hole and the second light emitting hole in the laser light source provided by the embodiment of the present application is shown.

[0020] Figure 4 The first setting structural schematic diagram of the insulation layer in the laser light source provided by the embodiment of the present application is shown.

[0021] Figure 5 The second setting structural schematic diagram of the insulation layer in the laser light source provided by the embodiment of the present application is shown.

[0022] Figure 6 The first circuit structural diagram corresponding to the laser light source module provided by the embodiment of the present application is shown.

[0023] Figure 7 The second circuit structural diagram corresponding to the laser light source module provided by the embodiment of the present application is shown. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0025] The embodiment of the present application provides a kind of depth camera, depth camera measures the time of light transmission between lens and object by lighting target object, judges how far this object is from us by these data, further knows the distance of each object in picture, to realize depth map, finally can directly draw out stereo image to achieve 3D stereo depth sensing. Then correspondingly, depth camera needs a lamp as light source, the depth camera in the embodiment includes laser light source module, light is emitted using the laser light source module to realize the process of lighting target object, to facilitate the realization of measurement purpose.

[0026] Reference Figure 1 , Figure 1 The structure diagram of laser light source module provided by the embodiment of the present application.

[0027] Laser light source module includes laser drive chip 10 and laser light source 20, the laser drive chip 10 includes first power supply pin 11 and second power supply pin 12;First pad in laser light source 20 is connected with first power supply pin 11 by gold wire 30, and second pad of laser light source 20 is electrically connected with second power supply pin 12 by gold wire 30.

[0028] Wherein, one first power supply pin 11 is connected with one first pad, and one second power supply pin 12 is connected with one second pad. In the embodiment, first power supply pin 11 and second power supply pin 12 are provided with one or more, and the number of first pad and second pad can also be provided with one or more.

[0029] As Figure 1 In the embodiment, first power supply pin 11 and second power supply pin 12 are provided with two, first power supply pin 11 is pin VOUT11 and pin VOUT12 respectively, and second power supply pin 12 is pin VOUT21 and pin VOUT22 respectively. Correspondingly, the number of first pad and second pad is provided with two, two first pads correspond to pad A and pad B respectively, and two second pads correspond to pad C and pad D respectively. Pad A is connected with pin VOUT11 by gold wire 30, pad B is connected with pin VOUT12 by gold wire 30, pad C is connected with pin VOUT21 by gold wire 30, and pad D is connected with pin VOUT22 by gold wire 30. Laser drive chip 10 outputs current through first power supply pin 11 and second power supply pin 12, and the output current is transmitted to laser light source 20 by gold wire 30, to drive laser light source 20 to emit laser.

[0030] It should be noted that the current carrying capacity of a single gold wire 30 is limited, and generally, in order to increase the current carrying capacity, a plurality of gold wires 30 can be arranged between each pad and the corresponding pin for connection, as Figure 1 Three gold wires 30 can be used for connection in the embodiment.

[0031] In some embodiments, the first power supply pin 11 has a first distance from the first pad, the second power supply pin 12 has a second distance from the second pad, and the first distance and the second distance are equal. That is, the distance between the pad A and the pin VOUT11 is equal to the distance between the pad C and the pin VOUT21. Similarly, the distance between the pad B and the pin VOUT12 is equal to the distance between the pad D and the pin VOUT22. In this embodiment, the power supply pin in the laser drive chip 10 is arranged close to the position where the corresponding pad is located. When connecting the pad and the power supply pin with gold wires, the gold wire 30 can be selected to be connected between the pad and the pin in the vicinity, and the gold wire 30 does not need to cross each other, nor does the gold wire 30 need to be connected across the area, thereby facilitating the wire bonding equipment to bond the wires.

[0032] Reference Figure 2 , Figure 2 A structure schematic diagram of a laser light source 20 provided by an embodiment of the present application is shown in FIG. 1.

[0033] The laser light source 20 includes a first light emitting area and a second light emitting area. The first light emitting area includes a plurality of rows of first light emitting holes 211 and a first pad 212, and the first pad 212 is connected to the plurality of rows of first light emitting holes 211 through a first conductive connection part. The second light emitting area includes a plurality of rows of second light emitting holes 221 and a second pad 222, and the second pad 222 is connected to the plurality of rows of second light emitting holes 221 through a second conductive connection part. The laser light source 20 in this embodiment can be regarded as being composed of a plurality of vertical cavity surface emitting lasers, wherein the first light emitting area corresponds to one vertical cavity surface emitting laser, and the second light emitting area corresponds to another vertical cavity surface emitting laser. Each vertical cavity surface emitting laser includes a plurality of rows of light emitting holes, and each light emitting hole can emit a beam of laser. During packaging, the cathode of each vertical cavity surface emitting laser is connected using a bottom-sinking common cathode, the anode is connected using an independent gold layer, and the first pad 212 and the second pad 222 correspond to the anodes of the single vertical cavity surface emitting lasers, respectively.

[0034] In this embodiment, the plurality of rows of first light emitting holes 211 and the plurality of rows of second light emitting holes 221 are arranged alternately and are located in the same plane, and the first pad 212 and the second pad 222 are spaced apart and located in the same plane. In this way, the plurality of rows of first light emitting holes 211 in the first light emitting area and the plurality of rows of second light emitting holes 221 in the second light emitting area are both arranged in the same plane, so as to fully utilize the total light emitting area in the same plane light emitting area, so as to reduce the space occupied by the light emitting area, thereby facilitating the reduction of the volume of the laser light source.

[0035] It should be noted that the first pad 212, the second pad 222, the plurality of rows of first light emitting holes 211 and the plurality of rows of second light emitting holes 221 in the embodiments of the present application can also be located in the same plane. In the embodiments, the first pad 212 and the second pad 222 are arranged side by side along the arrangement direction of the plurality of rows of first light emitting holes 211 and the plurality of rows of second light emitting holes 221. By arranging the first pad 212 and the second pad 222 side by side on the same side, the gold wire 30 can be directly connected to the corresponding pin in proximity, without the need to cross other pads to be connected to the corresponding pin. Figure 1

[0036] It should be noted that the first light emitting region and the second light emitting region in the embodiments of the present application correspond to a group of light emitting regions in which the first pad 212 and the second pad 222 are arranged side by side on the same side. Then according to the needs, the laser light source 20 can include a plurality of groups of light emitting regions, which can be arranged oppositely or on the same side.

[0037] In the embodiments, two groups of opposite light emitting regions are arranged, and the plurality of rows of first light emitting holes 211 and the plurality of rows of second light emitting holes 221 in one group of light emitting regions are arranged alternately and located in the same plane. In the two groups of light emitting regions, the plurality of rows of light emitting holes in the four regions are arranged periodically and located in the same plane. Compared with the layered arrangement of the light emitting holes and the corresponding pads, the total light emitting area in the same plane can be fully utilized, the space occupied by the light emitting holes is reduced, and then the volume of the laser light source 20 is reduced.

[0038] In the embodiments, two groups of opposite light emitting regions are arranged, and the plurality of rows of first light emitting holes 211 and the plurality of rows of second light emitting holes 221 in one group of light emitting regions are arranged alternately and located in the same plane. In the two groups of light emitting regions, the plurality of rows of light emitting holes in the four regions are arranged periodically and located in the same plane. Compared with the layered arrangement of the light emitting holes and the corresponding pads, the total light emitting area in the same plane can be fully utilized, the space occupied by the light emitting holes is reduced, and then the volume of the laser light source 20 is reduced. Figure 2

[0039] ​​Each row of the first light emitting holes 211 in the embodiment corresponds to a connection of a pad, each row of the second light emitting holes 221 corresponds to a connection of a pad, and the first light emitting holes 211 or the second light emitting holes 221 belonging to the same light emitting area are connected to the same pad. Specifically, the multiple rows of the first light emitting holes 211 in the embodiment can share the first pad 212, and the multiple rows of the second light emitting holes 221 can share the second pad 222. The first pad 212 and the second pad 222 are connected to the corresponding peripheral power supply circuit through gold wires. The peripheral power supply circuit in the embodiment corresponds to the laser driving chip 10, and the first pad 212 and the second pad 222 are connected to the corresponding power supply pins in the laser driving chip 10 through gold wires. Compared with the prior art in which one row of light emitting holes corresponds to one pad, the wiring path of each row of light emitting holes can be increased in the embodiment, the gold wires can be connected between the pad and the pin, and the gold wires do not cross each other, so as to reduce the impedance. That is, the laser driving chip 10 charges and discharges the vertical cavity surface laser emitter at a faster speed, so that the change speed of light emission of each vertical cavity surface laser emitter can be faster.

[0040] In some embodiments, with reference to Figure 3 , Figure 3 The arrangement schematic diagram of the first light emitting hole and the second light emitting hole provided in the embodiment of the application is shown.

[0041] The edge of the first light emitting hole 211 is a straight line or a curve, and the edge of the first light emitting hole 211 faces the adjacent second light emitting hole 221; the edge of the second light emitting hole 221 is a straight line or a curve, and the edge of the second light emitting hole 221 faces the adjacent first light emitting hole 211. The edge of the first light emitting hole 211 is matched with the edge of the second light emitting hole 221. In the embodiment, the area boundary of the first light emitting hole 211 and the second light emitting hole 221 is set as an irregular boundary, so as to fully utilize the area of the same plane when multiple rows of light emitting holes in multiple groups of light emitting areas are periodically arranged, and more light emitting holes can be arranged under the condition of a total light emitting area.

[0042] In some embodiments, with reference to Figure 4 , Figure 4 The first structure schematic diagram of the insulating layer provided in the embodiment of the application is shown.

[0043] The first pad, the second pad, the plurality of rows of first light emitting holes and the plurality of rows of second light emitting holes are located in the same plane in the embodiment. The first conductive connection part 213 is located in the same plane as the first pad, the second pad, the plurality of rows of first light emitting holes and the plurality of rows of second light emitting holes. The insulating layer 40 is arranged on the first conductive connection part 213, and the second conductive connection part 223 is arranged on the side of the insulating layer 40 away from the first conductive connection part 213. In the embodiment, the first pad, the first conductive connection part 213 and the plurality of rows of first light emitting holes are in one-way communication. Similarly, the second pad, the second conductive connection part 223 and the plurality of rows of second light emitting holes are also in one-way communication. The first pad, the first conductive connection part 213 and the plurality of rows of first light emitting holes and the plurality of rows of light emitting holes and the second pad are all in the same plane, and the second conductive connection part 223 connects the second pad and the plurality of rows of second light emitting holes across the plane. As can be seen from the cross-sectional view of the laser light source 20 in the thickness direction, as shown in Figure 3 ,

[0044] In some embodiments, referring to Figure 5 , Figure 5 , a second structure of the insulating layer 40 provided in the embodiment of the application is shown.

[0045] The first pad, the second pad, the plurality of rows of first light emitting holes and the plurality of rows of second light emitting holes are located in the same plane in the embodiment. The first pad, the second pad, the plurality of rows of first light emitting holes and the plurality of rows of second light emitting holes are located in the same plane. The first conductive connection part 213 and the second conductive connection part 223 are arranged on opposite sides of the insulating layer 40. In the embodiment, the first pad, the plurality of rows of first light emitting holes, the plurality of rows of second light emitting holes and the second pad are located in one plane, and the first conductive connection part 213 and the second conductive connection part 223 are located in two other planes. As can be seen from the cross-sectional view of the laser light source 20 in the thickness direction, as shown in Figure 4 ,

[0046] Referring to Figure 6 , Figure 6 , a first circuit diagram corresponding to the laser light source 20 provided in the embodiment of the application is shown.

[0047] In this embodiment, two groups of light emitting regions are set (i.e., four vertical cavity surface lasers D1, D2, D3 and D4 are set), and the principle of the circuit diagram corresponding to the laser light source 20 is described. In this embodiment, the anodes of the four vertical cavity surface lasers are connected to four power supply pins, respectively, and the four power supply pins are VOUT11, VOUT12, VOUT21 and VOUT22, respectively. The cathodes of the four vertical cavity surface lasers are commonly connected to a pin LDOUT, and the laser driving chip 10 is connected to the power supply end. Four corresponding switches are provided in the laser driving chip 10, and the four switches are connected to the four power supply pins one by one. By controlling the conduction or disconnection of the four switches, the purpose of controlling which vertical cavity surface laser emits light is achieved.

[0048] The luminance of the four vertical cavity surface lasers changes with the change of the supply voltage, and the luminance changes little with the change of the circuit. Therefore, the supply voltage provided by the power supply end is a fixed voltage, i.e., LDVCC is a constant. The laser driving chip 10 can control the luminance by detecting the current flowing through the vertical cavity surface laser, adjusting the impedance of the pin LDOUT to the ground end GNC, and then adjusting the size of the current. The laser driving chip 10 can control the vertical cavity surface laser to switch quickly through the pin LDOUT.

[0049] In some embodiments, reference is made to Figure 7 , Figure 7 A second circuit diagram corresponding to the laser light source 20 provided in the embodiments of the present application is provided.

[0050] The circuit diagram in the embodiments of the present application is different from the first circuit diagram in that the power supply of the vertical cavity surface laser is directly provided by the power supply chip 50. The anode of the vertical cavity surface laser is connected to the power supply chip 50, and the power supply chip 50 provides a fixed supply voltage LDVCC for the vertical cavity surface laser. The cathode of the vertical cavity surface laser is connected to the pin LDOUT of the laser driving chip 10, and the laser driving chip 10 controls the vertical cavity surface laser to switch quickly through the pin LDOUT.

[0051] In the description of the present application, it should be understood that terms such as "first", "second" and the like are only used to distinguish similar objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated.

[0052] The laser light source, the laser light source module and the depth camera provided by the embodiments of the present application are described in detail. The principles and implementation manners of the present application are described by applying specific examples, and the above description of the embodiments is only used to help understand the present application. Meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges will be changed, and the above description of the specification should not be understood as the limitation of the present application.

Claims

1. A laser light source, characterized by, For electrically connecting with a laser driving chip, the laser driving chip includes a first power supply pin and a second power supply pin, the second power supply pin includes a first part and a second part, the first part and the first power supply pin extend in a first direction, and the first part is spaced apart from the first power supply pin on a side of the first power supply pin away from the laser light source in a second direction, the second part is connected with the first part by bending and extends in the second direction towards the laser light source; the laser light source includes: A first light emitting area includes a plurality of rows of first light emitting holes and a first pad, the first pad is connected with the plurality of rows of first light emitting holes through a first conductive connection part; A second light emitting area includes a plurality of rows of second light emitting holes and a second pad, the second pad is connected with the plurality of rows of second light emitting holes through a second conductive connection part; Wherein, the plurality of rows of first light emitting holes and the plurality of rows of second light emitting holes are arranged alternately and are located in the same plane, the first pad and the second pad are arranged in the first direction and are located in the same plane with the first power supply pin and the second power supply pin, the first pad is used for connecting with the first power supply pin, and the second pad is used for connecting with the second power supply pin; the first conductive connection part and the second conductive connection part cross in the thickness direction of the laser light source, and an insulating layer is arranged between the first conductive connection part and the second conductive connection part to electrically insulate the first conductive connection part and the second conductive connection part.

2. The laser light source according to claim 1, characterized by, The first pad, the second pad, the plurality of rows of first light emitting holes and the plurality of rows of second light emitting holes are located in the same plane.

3. The laser light source according to claim 2, characterized by, The first conductive connection part, the first pad, the second pad, the plurality of rows of first light emitting holes and the plurality of rows of second light emitting holes are located in the same plane, the insulating layer is arranged on the first conductive connection part, and the second conductive connection part is arranged on a side of the insulating layer away from the first conductive connection part.

4. The laser light source according to claim 2, characterized by, The insulating layer, the first pad, the second pad, the plurality of rows of first light emitting holes and the plurality of rows of second light emitting holes are located in the same plane, and the first conductive connection part and the second conductive connection part are arranged on opposite sides of the insulating layer.

5. The laser light source according to any one of claims 1 to 4, characterized by, The first pad and the second pad are arranged side by side along the arrangement direction of the plurality of rows of first light emitting holes and the plurality of rows of second light emitting holes.

6. The laser light source according to claim 5, characterized by The edge of the first light emitting hole is a straight line or a curve, and the edge of the first light emitting hole is directed towards the adjacent second light emitting hole; the edge of the second light emitting hole is a straight line or a curve, and the edge of the second light emitting hole is directed towards the adjacent first light emitting hole.

7. The laser light source according to claim 6, characterized by The edge of the first light emitting hole is matched with the edge of the second light emitting hole.

8. A laser light source module, characterized by comprising: The laser light source includes: A laser driving chip includes a first power supply pin and a second power supply pin; The laser light source of any one of claims 1-7, the first pad in the laser light source is electrically connected with the first power supply pin, and the second pad is electrically connected with the second power supply pin; The laser light source of any one of claims 1-7, the first pad in the laser light source is electrically connected with the first power supply pin, and the second pad is electrically connected with the second power supply pin; The second power supply pin comprises a first part and a second part, the first part and the first power supply pin extend in a first direction, and the first part is arranged at a side of the first power supply pin away from the laser light source in a second direction, and the second part is bently connected with the first part and extends in the second direction towards the laser light source.

9. The laser source module of claim 8, wherein, The first pad is connected with the first power supply pin through a gold wire, and the second pad is connected with the second power supply pin through a gold wire.

10. A depth camera, comprising: The laser light source module comprises the laser light source module as claimed in claim 8 or 9.

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