The present disclosure relates to the field of integrated circuit and, more specifically, to a laser diode module, a transmitter, a ranging device, and an electronic device.
In the transmitter circuits, the transmitter commonly uses in-line packaging. The use of in-line package is mainly to address the heat dissipation issues of the transmitter, or because in-line packaging is a commonly used process in the field. A laser diode will generate a relatively large amount of heat at the time of emission, and this heat needs to be dissipated to a good thermal conductor, such as a copper block. The in-line package provides a better heat dissipation structure for heat dissipation, such as its metal shell and metal pins.
Although in-line packaging is widely used, it needs further improvements. More specifically, the distributed inductance of an in-line package is relatively large, and the response to the fast pulse drive signal would be slower, which causes certain limitations on the fast narrow pulse signal drive.
Therefore, in order to improve the detection and measurement accuracy and sensitivity, the current package needs to be improved.
One aspect of the present disclosure provides a laser diode module. The laser diode module includes a substrate including a first surface and a second surface opposite to each other; a cover disposed on the first surface of the substrate, and an accommodation space being formed between the substrate and the cover; and a laser diode die disposed in the accommodation space.
In order to make the objectives, technical solutions, and advantages of the present disclosure clear, the technical solutions in the embodiments of the present disclosure will be described below with reference to the drawings. It will be appreciated that the described embodiments are some rather than all of the embodiments of the present disclosure. Other embodiments conceived by those having ordinary skills in the art on the basis of the described embodiments without inventive efforts should fall within the scope of the present disclosure.
The present disclosure may be implemented in various forms and is limited to the embodiments set forth herein. The disclosed embodiments may enable the present disclosure to be thorough and complete, and may fully convey the scope of the present disclosure to those skilled in the art.
The terms used herein are for the purpose of describing the detailed embodiments and are not intended to limit the scope of the present disclosure. The singular forms of “a”, “one”, and “the” may be intended to include plural forms unless otherwise clearly specified by the context. The terms of “composition” and/or “comprising” may be used to determine the presence of the features, integers, steps, operations, components and/or units, but may not exclude the presence or addition of one or more of other features, integers, steps, operations, components, units, and groups. The term “and/or” may include any and all combinations of the related items.
To fully understand the present disclosure, detailed structures and steps are set forth in the following descriptions to explain the technical solutions of the present disclosure. The optional embodiments of the present disclosure are described in detail below, but the present disclosure may have other embodiments in addition to the detailed description.
As described above, in transmitter circuits, the most commonly used transmitter package is the in-line package. In the in-line package structure, the laser diode is directly connected to a circuit board through a metal wire. More specifically, the distributed inductance of the in-line package is relatively large, and the response to the fast pulse drive signal will be slower, which causes limitations on the fast narrow pulse signal drive.
In the laser and laser ranging circuits, in compliance with safety regulations, the laser energy emitted each time has a certain limit. In order to improve the accuracy, the larger the laser power emitted each time the better. More emitted power means that the reflected laser intensity will be stronger, and the signal received at the receiving end will be stronger. In other words, longer distances can be measured using the same circuit and under the same optical conditions.
In order to balance the issue of emission power and safety regulations, the emitted pulse signal can be narrowed, that is, a certain amount of laser energy can be concentrated in a shorter amount of time to emit, such that both the safety regulations and the emission power requirements are satisfied. In order to narrow the pulse signal, the distributed inductance on the laser diode can be a challenge. The narrower the pulse, the greater the proportion of energy lost in the distributed inductance, which is an obstacle when increasing the emission power.
In addition, the distributed inductance on the laser diode package also has a certain stretching effect on the pulse signal. When the laser diode drive is turned on, the inductor will start to store energy. During this time, the laser diode's emission power will decrease. After the laser diode drive is turned off, this part of the inductance parameter will start to discharge, while the laser diode is still in the working state. At this time, the distributed inductance will play a role in stretching by dispersing and widening the original narrow pulse signal into a relatively wide pulse signal, which can become an obstacle when increasing the emission power.
The present disclosure provides a laser diode module. The laser diode module provided by the present disclosure will be described in detail below with reference to the accompanying drawings.
As shown in
In some embodiments, the module further includes a driver chip 309 for controlling the emission of the laser diode die, and the driver chip can be disposed in the accommodation space. In this embodiment, the driver chip 309 that controls the emission of the laser diode die and the laser diode die are directly packaged together, and both are packaged in the accommodation space formed between the substrate and the cover. By using the above setting, the inductance between the in-line laser diode and the drive circuit next to the laser diode and the distributed inductance on the line in the conventional in-line package can be eliminated. Therefore, the distributed inductance of the module can be reduced, and high-power laser emission and narrow pulse laser driving can be realized.
In some embodiments, in the module, the laser diode die can be placed as close to the driver chip as possible. The smaller the distance between the laser diode die and the driving chip, the more effective the distributed inductance can be reduced. By using this setting, the loss of the distributed inductance of the emitting module can be reduced, such that it is easier to realize high-power laser emission. Further, the reduction of the distributed inductance also makes the narrow pulse laser driving possible.
In some embodiments, the laser diode die 305 and the driver chip 309 may be directly mounted on the first surface of the substrate. In the present disclosure, the conventional in-line package can be improved by mounting to reduce the distributed inductance on the package in-line pins and further reduce the distributed inductance on the line, which is easier to realize high-power laser emission and narrow pulse laser driving.
In some embodiments, it is also possible to directly mount the laser diode die 305 on the first surface of the substrate, and simultaneously mount the driver chip 309 directly on the second surface of the substrate. Although the laser diode die 305 and the driver chip 309 are not disposed on the same surface, the distance between the laser diode die 305 and the driver chip 309 may be sufficiently close. Therefore, the inductance between the in-line laser diode and the drive circuit next to the laser diode and the distributed inductance on the line in conventional in-line package can be eliminated. Thereby reducing the distributed inductance of the packaged module, and realizing high-power laser emission and narrow pulse laser driving.
Of course, as a modification of this embodiment, the laser diode die may also be directly mounted on the first surface of the substrate. At the same time, a part of the driver chip may be mounted on the first surface, and another part of the driver chip may be mounted on the second surface. By using this setting, the area of the substrate can be further reduced, the second surface can be used more effectively, and the degree of integration of the packaged module can be further improved.
In a specific embodiment of the present disclosure, the packaged module may further include a switch chip, and the switch chip may also be disposed in the accommodation space. The switch chip may include a switch circuit, and the switch circuit can be used to control the laser diode die to emit laser light under the drive of the drive circuit.
In some embodiments, the laser diode die 305 may be a bare die, that is, a small piece of circuited “die” cut from a wafer, which can be mounted on the substrate 301 by means of die bond. Die bond may refers to the process of bonding the chip to a designed area of the substrate through glue, generally a conductive glue or an insulating glue, to form a thermal path or an electrical path to provide conditions for the subsequent wire bonding. In this embodiment, the laser diode die 305 is mounted on the substrate 301 through a silver paste or other soldering materials (e.g., a conductive glue) 307.
In some embodiments, the substrate 301 may be various types of substrates, such as a PCB substrate, a ceramic substrate, etc. The structure and material of the substrate will be described in further detail in the following descriptions.
In some embodiments, the cover is not limited to a certain structure. The cover may be at least partially provided with a light-transmitting area, and the emitted light of the laser diode die may be emitted through the light-transmitting area.
In one embodiment of the present disclosure, as shown in
In another embodiment of the present disclosure, as shown in
In this embodiment, the light-transmitting area in the cover body may be disposed on the top surface or the side surface of the cover body, and the top surface may be disposed opposite to the first surface. More specifically, the top surface may be disposed parallel to the first surface, and the side surface may be disposed perpendicular to the first surface. The emitted light of the laser diode die can emit through the light-transmitting area. For example, the emitted light of the laser diode die can emit through the light-transmitting area in a direction perpendicular or parallel to the first surface. Alternatively, the emitted light of the laser diode die can emit through the light-transmitting area within a certain angle range in a direction substantially perpendicular or parallel to the first surface. The angle range is not limited to a numerical range, and can be adjusted as needed.
In some embodiments, the emitted light of the laser diode die can emit directly through the light-transmitting area; or the emitted light of the laser diode die can be reflected by a reflector and then emitted through the light-transmitting area.
For example, when the emission direction of the emitted light of the laser diode die is perpendicular to the light-transmitting area in the cover, the emitted light of the laser diode die may directly emit through the light-transmitting area. When the emission direction of the emitted light of the laser diode is parallel to the light-transmitting area in the cover, a reflector may be provided, and the light emitted from the laser diode die may be reflected by the reflector and then emitted through the light-transmitting area. Based on the above description, there are several implementation methods.
In the first implementation method, as shown in
In the second implementation method, as shown in
In the third implementation method, as shown in
In order to better make the emitted light of the laser diode die directly face the light-transmitting area, a heat sink or a support structure may be disposed on the substrate to adjust the height of the laser diode die.
In the fourth implementation method, the light-transmitting area may be disposed on the side surface of the cover and disposed in parallel with the first surface. The laser diode die may be vertically disposed, and the emitted light of the laser diode die may be parallel to the light-transmitting area. At this time, a reflector needs to be disposed in the accommodation space formed by the substrate and the cover, for example, the reflector may be disposed on the top surface of the cover. The angle between the crystal plane of the reflector and the horizontal direction may be at 45°. The light emitted in the vertical direction can be changed into a reflected light in the horizontal direction by the reflector, in order to be reflected out through the light-transmitting area.
It should be noted that the above embodiments are merely examples. The technical solutions of the present disclosure may also include modifications of the embodiments described above and other achievable embodiments, which are not limited to the examples, and will not be listed here.
In some embodiments, the packaged module may further include a first heat sink 304 and a second heat sink 306 respectively and oppositely disposed on the first surface and the second surface of the laser diode die. The first surface and the second surface of the laser diode die may be surfaces other than the exist surface of the laser diode die. The first sink 304 and the second heat sink 306 may also play a good role in heat dissipation to dissipate the heat on the laser diode die. Through this setting, the heat of the laser diode die can be dissipated as soon as possible to avoid burning the laser diode die, which further improves the reliability of the packaged module.
The structure of the laser diode die is shown in
In some other embodiments, as shown in
In some other embodiments, any one of the first heat sink and the second heat sink can also be retained. For example, as shown in
In some embodiments, the first heat sink and the second heat sink may include metal or metalized material.
The metal material may include common metals, such as copper, and the metalized material may include a semiconductor material coated with a metal on the surface, such as a silicon plate coated with aluminum.
In one embodiment of the present disclosure, both the first heat sink and the second heat sink may be made of copper material to achieve better heat dissipation effect.
In some embodiments, the first heat sink and the first electrode may be glued by a conductive adhesive; and the second heat sink and the second electrode may also be glued by a conductive adhesive.
The conductive adhesive may include materials such as a conductive glue, a silver paste, or a solder paste, but the present disclosure is not limited thereto.
In the embodiment of the present disclosure, the first heat sink and the second heat sink can be disposed on the first electrode and the second electrode, and glued with a conductive material, such that the electrical connection points of the two electrodes of the laser diode can be connected to the two metal heat sinks. The metal heat sinks not only play the role of connection, but also play the role of heat dissipation, which can simplify the preparation process and reduce the process cost.
In some embodiments, the laser diode die, the first heat sink, and the second heat sink may all have a cuboid structure. The first heat sink and the second heat sink may be respectively disposed on the first surface and the second surface of the laser diode die perpendicular to the exit surface.
The shape of the laser diode die may be a cylindrical structure. For example, it can be a cuboid, and it can be a polyhedron, a cylindrical shape, and other suitable shapes, which will not be listed here. The exit surface of the laser diode die may be disposed on the side wall at one end of the cylindrical structure of the laser diode die.
In some embodiments, the laser diode die may have a cuboid structure, the first surface and the second surface may be the upper and lower surfaces of the cuboid structure, and the exit surface of the laser diode die may refer to the side surface of one end of the cuboid structure. As shown in
It should be noted that the exit surface may also be the side surface at the right end of the laser diode die, and may also be the front and back of the laser diode die, and is not limited to the above example.
In some embodiments, the first heat sink and the second heat sink may each include a first end and a second end opposite to each other, and the end surface of at least one of the first end of the first heat sink and the first end of the second heat sink may be lower than the exit surface.
For example, the end surface of the second heat sink 306 may be retracted by a certain distance from the exit surface of the laser diode die, in order to reduce the light shielding rate of the laser diode die, such that the emitted light of the laser diode die may be better emitted. The end surface of the laser diode die exit surface of the first heat sink may protrude for a certain distance to facilitate cutting. In addition, increasing the volume of the second heat since can also improve the heat dissipation efficiency.
More specifically, as shown in
In some embodiments, as shown in
In some embodiments, the bottom surface of the laser diode die opposite to the exit surface may be suspended between the first heat sink and the second heat sink, and may have a predetermined distance from the first surface of the substrate.
In some embodiments, the second end 35 of the first heat sink 304 and the second end 37 of the second heat sink 306 may be attached to the first surface of the substrate through a soldering material 37.
The soldering material 37 may be a glue made of conductive material, such as a silver paste or a solder paste, but the present disclosure is not limited thereto.
A preparation method of the laser diode die will be described below with reference to
A method for preparing the laser diode die may include providing a whole piece of the first heat sink 304, mounting the whole of the first heat sink 304 on a packaging fixture, and mounting the laser diode die 305. As shown in
In some embodiments, another method for preparing the laser diode die may include providing a whole piece of the first heat sink 304, mounting the whole of the first heat sink 304 on a packaging fixture, and mounting the laser diode die 305. Every two laser diode dies may be a group as a repeating unit. The repeating unit may be used to form an array of rows and columns on the first heat sink. As shown in
For the materials of the first heat sink and the second heat sink, as well as the bonding methods of the first heat sink, the second heat sink, and the laser diode, reference may be made to the previous description, and will not be further described here.
In this embodiment, a plurality of dummy dies may be disposed between the first heat sink and the second heat sink on the outside of three other sides of the laser diode die except the exit surface. Since the height of the second heat sink 306 is lower than the height of the laser diode die, the end surface of the second heat sink 306 may be retracted a certain distance from the exit surface of the laser diode die. Therefore, the bonding area between the second heat sink 306 and the laser diode die may be relatively small, and may be separated during the cutting process. By using the dummy dies, the separation may be prevented.
For example, a plurality of dummy dies with the same thickness as the laser diode die may be disposed between the first heat sink and the second heat sink below the bottom end of the laser diode die to improve the structural strength, thereby ensuring that the first heat sink or the second heat sink will not be separated from the laser diode die during the cutting process.
In some embodiments, the dummy dies may be made of glass or other insulators, but the material is not limited thereto.
In addition, other devices may be disposed on the substrate. As shown in
The laser diode module of the present disclosure can reduce the distributed inductance existing in the conventional direct-insertion packaging method and improve the intensity of the laser emission. In addition, the ranging device implemented based on the packaged module based on the embodiment of the present disclosure can increase the transmission power and quickly respond to the fast pulse drive signal, thereby improving the reliability and accuracy, reducing the production cost and complexity, and improving the production efficiency.
Another embodiment of the present disclosure will be further described below with reference to
As shown in
In some embodiments, the packaged module may further include a driver chip for controlling the emission of the laser diode die, and the driver chip may be mounted on the carrier.
In this embodiment, the driver chip 309 that controls the emission of the laser diode die and the laser diode die are both mounted on the carrier 410. By using this setting, the inductance between the in-line laser diode and the driving circuit adjacent to the laser diode in the conventional in-line package can be eliminated, including the distributed inductance on the line. As such, the distributed inductance of the packaged module can be reduced, and high-power emission and narrow pulse lase driving can be realized.
In some embodiments, the packaged module may further include a third heat sink 404. As shown in
In some embodiments, the material of the third heat sink may include a metal material or a metalized material. The metal material may include copper, and the metalized material may include a metalized ceramic plate or a metalized silicon plate.
Further, the laser diode die may include a first electrode and a second electrode disposed opposite to each other, and the structure may be the same as that of the previous embodiment, as shown in
As shown in
The carrier can be mounted on the substrate through SMT. The specific mounting method can be the commonly used method in the field, such as using a solder paste to mount the substrate through SMT, which will not be described in detail here.
In some embodiments, the second surface of the substrate may be mounted on a circuit board.
In some embodiments, in one embodiment of the present disclosure, the method for preparing a packaging module including the carrier may include the following processes.
(a) mounting a SMT IC 409 on the vertical carrier 410 through SMT.
(b) mounting the third heat sink 404 (e.g., a copper heat sink) on the vertical carrier in a die bond manner.
(c) mounting the laser diode die 405 on the vertical carrier 410 with conductive glue in a die bond manner, for example, mounting the first electrode of the laser diode die on the vertical carrier 410.
(d) connecting the second electrode of the laser diode die 405 to the vertical carrier using a wire (e.g., a gold wire) through die bond.
(e) placing the vertical carrier SMT on the substrate 401 and ensure that the exit surface of the laser diode die 405 is facing a package window.
(f) parallel to the processes (a) to (e) above, producing the cover body 402 with a window (such as a U-shaped metal shell), cutting the light-transmitting plate 403 (such as glass), and bonding the light-transmitting plate 403 from the inside of the cover body 402 to the window.
(g) bonding the cover body 402 with the light-transmitting plate 403 on the substrate through SMT.
(h) marking, cutting, and testing.
It should be noted that the method described above is merely an example and the present disclosure is not limited to this method. Those skilled in the art can choose other commonly used methods for packaging, which will not be described in detail here.
In some embodiments, the carrier may include a metalized ceramic board. In one embodiment of the present disclosure, the carrier may be an aluminum nitride ceramic plate. At this time, the carrier 410 may also function as a heat sink. As shown in
In some other embodiments, the carrier may include a metalized silicon plate. The metalized silicon plate may include a metal film 411 formed on the surface of a partial area of the silicon plate for electrical connection. At this time, the carrier 410 may also function as a heat sink. As shown in
As described in the previous embodiments, the laser dies can be directly mounted on the substrate and the laser dies can be mounted on the carrier and then mounted on the substrate. The combination of the packaging method, the substrate, and the cover in the previous embodiments will be described below with reference to the accompanying drawings. It should be noted that the combination of the packaging method, the substrate, and the cover is not limited to the listed example, and modifications of the example are also included in the protection scope of the appended claims.
The packaging method of the present disclosure will be further described below with reference to the accompanying drawings. The packaging method in the present disclosure may include the following processes.
1. Forming a laser diode and a driver chip on the first surface of the substrate and mounting the second surface of the substrate on the circuit board, as shown in
The method of forming the laser diode and the driver chip on the first surface of the substrate may include directly mounting the laser diode and the driver chip on the first surface of the substrate, or mounting the laser diode and the driver chip on the first surface of the substrate through the carrier described in the previous embodiments.
2. Forming the laser diode and the driver chip on the first surface of the substrate, and mounting the first surface of the substrate on the circuit board, as shown in
In this embodiment, the first surface including the laser diode and the driver chip may be mounted on the circuit board. In order to ensure that the emitted light of the laser diode can be emitted normally during the packaging process, the shape of the substrate and cover need to be improved, such that the side where the laser diode and the driver chip are formed may be used for packaging.
More specifically, in one embodiment of the present disclosure, as shown in
As an implementation manner, as shown in
The first sub-substrate 601, the second sub-substrate 602, and the third sub-substrate 603 may be formed separately or all at once through an injection molding process, and is not limited to a specific manner. In addition, the substrate having the groove structure can be formed in similar manner.
A hole exposing an area where the device is formed on the substrate, especially the area where the laser diode die is positioned, may be disposed on the circuit board 606 to ensure that the light emitted by the laser diode die can be emitted normally.
3. Forming the laser diode die and the driver chip on the first surface of the substrate and mounting the first surface of the substrate on a circuit board, while mounting the second surface of the substrate on another circuit board.
More specifically, in one embodiment of the present disclosure, as shown in
As an implementation manner, as shown in
4. Forming the laser diode on the first surface of the substrate, and at least a part of the driving chips is disposed on the second surface of the substrate. Subsequently, mounting the second surface of the substrate on the circuit board, as shown in
More specifically, a part of the driving chips may be attached to the first surface and another part of the driving chips may be mounted on the second surface. Alternatively, all driving chips may be completely mounted on the second surface of the substrate, as shown in
In some embodiments, the substrate includes the first sub-substrate 601, and the second sub-substrate 602 may be formed on both the first surface and the second surface of the first sub-substrate. The first sub-substrate 601 may have a flat plate structure. The second sub-substrate 602 may have a ring structure, and a first hole may be formed on the second sub-substrate to expose a part of the first sub-substrate for forming devices. Subsequently, the cover 607 may be disposed on the second sub-substrate 602, which can be disposed on the second sub-substrate 602 on the first surface or the second sub-substrate 602 on the second surface.
As an implementation manner, as shown in
In some embodiments, a plurality of first pins 605 are disposed at the edge of the second sub-substrate 602 on the second surface of the first sub-substrate, and is connected to the circuit board through the plurality of first pins 605 (not shown in
As another implementation manner, a plurality of first pins 605 are disposed at the edge of the second sub-substrate 602 on the second surface of the first sub-substrate. After the plurality of first pins 605 are connected to the circuit board (not shown
A hole exposing an area where the device is formed on the substrate, especially the area where the laser diode die is positioned, may be disposed on the circuit board to ensure that the light emitted by the laser diode die can be emitted normally.
It should be noted that the packing method described above is merely an example, and the packaging method of the present disclosure is not limited to the above example. Various modifications of the above example can also be applied to the present disclosure. For example, the number of sub-substrates formed on the first surface and/or the second surface, the size of the sub-substrates, the shape of the holes, etc. can all be selected based on actual needs. In another example, the number of substrates formed on the surface and the second surface and the size of the sub-substrates may be the same, and the shapes of the grooves formed on the first surface and the second surface may be completely symmetrical. As an alternative embodiment, the number of substrates formed on the first surface and the second surface and the size of the sub-substrates may not be the same, and they can be designed based on actual needs, which will not be listed here.
Examples of substrate and cover are described below.
The substrates described in the present disclosure may be selected as printed circuit board (PCB) substrates, ceramic substrates, pre-mold substrates, etc.
The PCB is made of different components and a variety of complex process technologies, etc. The structure of the PCB may include a single-layer structure, a double-layer structure, and a multi-layer structure, and the production methods of different layer structures are different.
In some embodiments, the PCB may be mainly composed of pads, via, mounting holes, wires, components, connectors, filling, electrical boundaries, etc.
Further, the common layer structures of PCBs include three types, namely the single-layer PCB, the double-layer PCB, and the multi-layer PCB. The specific structures will be described in detail below.
In the single-layer PCB, one side of the circuit board includes copper, while the other side of the circuit board does not include copper. Generally, components are disposed on the side without copper, and the side with copper is mainly used for wiring and welding.
In the double-layer PCB, both sides of the circuit board include copper. Generally, one side of the double-layer PCB is called the top layer, and the other side is called the bottom layer. The top layer is generally used as a component disposing surface, and the bottom is used as a components welding surface.
In the multi-layer PCB, the circuit board includes multiple working layers. In addition to the top and bottom layers, the circuit board also includes several intermediate layers. Generally, the intermediate layer can be used as a wire layer, signal layer, power layer, ground layer, etc. The layers are insulated from each other, and the connection between the layers is generally achieved through holes.
The PCB may include many types of working layers, such as signal layer, protective layer, silk screen layer, internal layer, etc., which will not be described in detail here.
In addition, the substrate described in the present disclosure can also be a ceramic substrate. Ceramic substrate may be referred to a special process board in which copper foil is directly bonded to alumina (Al2O3) or aluminum nitride (AlN) ceramic substrate surface (single-sided or double-sided) at high temperature. The formed ultra-thin composite substrate has excellent electrical insulation properties, high thermal conductivity, excellent solderability and high adhesion strength. In addition, the substrate can be etched into various pattern a like a PCB board, and has a great current-carrying capacity.
Further, as shown in
The preparation method of the pre-mold substrate can be formed through a conventional injection process, planer excavation, and mold embossing, which will not be described in detail here.
The injection material of the pre-mold substrate can be a conventional material, such as a thermally conductive plastic material, etc. but is not limited to a certain type of material. The shape of the pre-mold substrate is limited to the injection frame and is not limited to a certain type of injection frame.
In one embodiment, a PCB substrate 7014 is first disposed in the injection molding frame on the substrate, and then an annular groove structure 7015 is formed on the PCB substrate 7014 by injection molding, as shown in
Alternatively, the injection molded wires and the pins 703 can be disposed in the injection frame, and then injection mold the injection frame to obtain the structure as shown in
The shape of the substrate may be a plate. As shown in
In some embodiments, as shown in
In some embodiments, the shape can also be as shown in
In some embodiments, as shown in
In this embodiment, the cover 702 includes a U-shaped cover body 7021 with a window, and a light-transmitting plate 7022 disposed on the window. The emitted light of the laser diode die can be emitted through the light-transmitting plate.
In some embodiments, the light-transmitting plate 7022 may be made of commonly used light-transmitting materials, such as glass. The glass needs to have high passability to the wavelength of the laser light emitted by the laser diode die.
In some embodiments, as shown in
For example, in a specific embodiment of the present disclosure, the outer cover is a metal shell with a glass window, and the substrate is a PCB substrate, as shown in
In view of the above, the material and shape of the substrate and the material and shape of the cover can be combined arbitrarily without contradicting each other to obtain a variety of implementations in which the substrate and the cover can be combined. Of course, the material and shape of the substrate and the material and shape of the cover are not limited to the above examples, and may also be variations of the above examples and other examples commonly used in the art.
As shown in
As shown in
In some embodiments, the light emitter 811 may be a laser diode. For the wavelength of the light emitted by the light emitter 811, in one example, light with a wavelength between 895 nanometers and 915 nanometers can be selected. For example, light with a wavelength of 905 nanometers may be selected. In another example, light with a wavelength between 1540 nanometers and 1560 nanometers can be selected. For example, light with a wavelength of 1550 nanometers may be selected. In other examples, other suitable wavelengths of lights may also be selected based on the application scenarios and various needs.
In some embodiments, the light beam expanding unit 812 may be implemented by a one-stage or multi-stage beam expansion system. The light beam expansion process can be reflective or transmissive, or a combination of the two. In one example, a holographic filter may be used to obtain a large-angle beam composed of multiple sub-beams.
In another example, a laser diode array may also be used to form multiple light beams with laser diodes to obtained lasers similar to the beam expansion (as the VCSEL laser array described above).
In yet another example, a two-dimensional angle adjustable micro-electromechanical system (MEMS) lens may also be used to reflect the emitted light. By using the MEMS micro-mirror to constantly change the angle between the mirror surface and the light beam, the angle of the reflected light is constantly changing, thereby diverging into a two-dimensional angle to cover the entire surface of the object to be measured.
The ranging device can be used to sense external environment information, such as distance information, angle information, reflection intensity information, speed information, etc. of targets in the environment. More specifically, the ranging device provided in the embodiment of the present disclosure can be applied to a mobile platform, and the ranging device can be mounted on a platform body of the mobile platform. A mobile platform with the ranging device can measure the external environment, such as measuring the distance between the mobile platform and obstacles for obstacle avoidance and other purposes, and external environment for two-dimensional or three-dimensional mapping. In some embodiments, the mobile platform may include at least one of an unmanned aerial vehicle (UAV), a car, and a remote control car. When the ranging device is applied to an UAV, the platform body may be the body of the UAV. When the ranging device is applied to a car, the platform body may be the body of the car. When the ranging device is applied to a remote control car, the platform body may be the body of the remote control car.
Since the light emitted by the light emitter 810 can cover at least a part of the surface or even the entire surface of the object to be measured, correspondingly, the light reflected after reaching the surface of the object, and the reflected light reaching the reflected light receiving device 820 is not a single point, but is distributed in an array.
The reflected light receiving device 820 may include photoelectric sensing unit array 821 and a lens 822. After the light reflected from the surface of the object to be measured reaches the lens 822, based on the principle of lens imaging, it can reach the corresponding photoelectric sensing unit in the photoelectric sensing unit array 821, and then be received by the photoelectric sensing unit, causing the photoelectric response of the photoelectric sensing unit.
Since the light being emitted to the photoelectric sensing unit receiving the reflected light, the light emitter 811 and the photoelectric sensing unit array 821 are controlled by a clock control module (e.g., a clock control module 830 shown in
In addition, since the photoelectric sensing unit is not a single point but a part of the photoelectric sensing unit array 821, the distance information of all points in the field of view of the entire ranging device can be obtained through data processing by a data processing module (e.g., a data processing module 840 shown in
Based on the foregoing structure and working principle of the laser diode module based on the embodiments of the present disclosure and the structure and working principle of the ranging device based on the embodiment of the present disclosure, those skilled in the art can understand the structure and working principle of the electronic device based on the embodiment of the present disclosure. For the sake of brevity, the structure and working principle of the electronic device will not be repeated here.
With the development of science and technology, detection and measurement technology is applied in various fields. Lidar is a perception system for the environment, which can acquire the three-dimensional information of the environment, and is no longer confined to the plane perception of the environment such as cameras. The principle is to actively transmit laser pulse signals to the outside, detect the reflected pulse signals, determine the distance of the measured object based on the time difference between the emission and reception, and combine the emission angle information of the light pulse to reconstruct and obtain the three-dimensional depth information.
The present disclosure provides a detection device, which can be used to measure the distance from the detection object to the detection device, and the orientation of the detection object relative to the detection device. In one embodiment, the detection device may include a radar, such as a Lidar. The detection device can detect distance between the detection device and the detection object by measuring the time of light propagation between the device and the detection object, that is, the time-of-flight (TOF).
A coaxial optical path can be used in the detection device, that is, the light beam emitted by the detection device and the reflected light beam may share at least a part of the optical path in the detection device. Alternatively, the detection device may also adopt an off-axis optical path, that is, the light beam emitted by the detection device and the reflected light beam may be respectively transmitted along different optical paths in the detection device.
As shown in
The detection device 100 may further include a scanning module 102. The scanning module 102 may be placed on the exit light path of the optical transceiver 110. Further, the scanning module 102 may be used to change the emission direction of a collimated light beam 119 emitted by the collimating element 104 to project to the external environment, and project the returned light to the collimating element 104. The returned light may be collected on the detector 105 via the collimating element 104.
In some embodiments, the scanning module 102 may include one or more optical elements, for example, a lens, a mirror, a prism, a grating, an optical phased array, or any combination of the foregoing optical elements. In some embodiments, multiple optical elements of the scanning module 102 may be rotated around a common axis 109, and each rotating optical element may be used to continuously change the direction of the incident beam. In some embodiments, the multiple optical elements of the scanning module 102 may rotate at different rotation speeds. In some other embodiments, the multiple optical elements of the scanning module 102 may rotate at substantially the same rotation speed.
In some embodiments, the multiple optical elements of the scanning module 102 may also rotate around different axes, or vibration in the same direction, or vibration in different directions, which is not limited here.
In some embodiments, the scanning module 102 may include a first optical element 114 and a driver 116 connected to the first optical element 114. The driver 116 can be used to drive the first optical element 114 around the rotation axis 109, such that the first optical element 114 may change the direction of the collimated light beam 119. The first optical element 114 may project the collimated light beam 119 to different directions. In some embodiments, the angle between the direction of the collimated light beam 119 changed by the first optical element and the rotation axis 109 may change with the rotation of the first optical element 114. In some embodiments, the first optical element 114 may include a pair of opposite non-parallel surfaces through which the collimated light beam 119 passes. In some embodiments, the first optical element 114 may include a wedge-angle prism to collimate the collimated light beam 119 for refracting. In some embodiments, the first optical element 114 may be coated with an anti-reflection coating, and the thickness of the anti-reflection coating may be equal to the wavelength of the light beam emitted by the light source 103, which can increase the intensity of the emitted light beam.
In the embodiment shown in
In some embodiments, the second optical element 115 may include a pair of opposite non-parallel surfaces through which the light beam passes. In some embodiments, the second optical element 115 may include a wedge-angle prism. In some embodiments, the second optical element 115 may be coated with an anti-reflection coating, which can increase the intensity of the emitted light beam.
The rotation of the scanning module 102 can project light to different directions, such as directions 111 ad 113, thereby scanning the space around the detection device 100. When the light 111 projected by the scanning module 102 hits the detection object 101, a part of the light may be reflected by the detection object 101 to the detection device 100 in a direction opposite to the projected light 111. The scanning module 102 can receive a returned light 112 reflected by the detection object 101, and project the returned light 112 to the collimating element 104.
The collimating element 104 may converge at least a part of the returned light 112 reflected by the detection object 101. In some embodiments, an anti-reflection coating may be coated on the collimating element 104 to increase the intensity of the emitted light beam. The detector 105 and the light source 103 may be disposed on the same side of the collimating element 104, and the detector 105 may be used to covert at least a part of the returned light passing through the collimating element 104 into an electrical signal. In some embodiments, the detector 105 may include an avalanche photodiode. The avalanche photodiode is a highly sensitive semiconductor device that can convert optical signals into electrical signals using the photocurrent effect.
In some embodiments, the detection device may include a measuring circuit, such as a TOF unit 107, which can be used to measure TOF to measure the distance of the detection object 101. For example, the TOF unit 107 can calculate the distance by using the formula t=2D/c, where D may be the distance between the detection device and the detection object, c may be the speed of light, and t may be the total time it takes for light to project from the detection device to the detection object and return form the detection object to the detection device. The detection device 100 can determine the time t based on the time different between the light emitted by the light source 103 and the returned light received by the detector 105, and then the distance D can be determined. The detection device 100 can also detect the position of the detection object 101 relative to the detection device 100. The distance and orientation detected by the detection device 100 can be used for remote sensing, obstacle avoidance, surveying and mapping, modeling, navigation, and the like,
In some embodiments, the light source may include a laser diode through which nanosecond laser light can be emitted. For example, the laser pulse emitted by the light source 103 may last 10 ns, and the pulse duration of the returned light detected by the detector 105 may be the same as the duration of the emitted laser pulse. Further, the laser pulse receiving time can be determined. For example, the laser pulse receiving time can be determined by detecting the rising edge time and/or the falling edge time of the electrical signal pulse. In some embodiments, the electrical signal can be amplified in multiple stages. As such, the detection device 100 can calculate the TOF using the pulse receiving time information and the pulse sending time information, thereby determining the distance between the detection object 101 and the detection device 100.
Although the exemplary embodiments have been described herein with reference to the drawings, and it should be understood that the above-described exemplary embodiments are merely exemplary, and are not intended to limit the scope of the present disclosure. Those skilled in the art may make various changes and modifications therein without departing from the scope and spirit of the present disclosure. All these changes and modifications are intended to be included within the scope of the present disclosure as claimed in the appended claims.
Those of ordinary skill in the art may appreciate that various units or steps described in the embodiments of the present disclosure may be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed by hardware or software depends on specific applications and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each particular application. However, such implementation should be included within the scope of the present disclosure.
In the embodiments of the present disclosure, the disclosed device and method may be implemented in other manners. For example, the device embodiments are merely illustrative. For example, the division of the units is only a logic function division. Other divisions may be possible in actual implementation. For example, a plurality of units or components may be combined or integrated to a different system. Some features may be omitted or may not be executed.
Many details are discussed in the specification provided herein. However, it should be understood that the embodiments of the disclosure can be implemented without these specific details. In some examples, the well-known methods, structures, and technologies are not shown in detail so as to avoid an unclear understanding of the description.
Similarly, it should be understood that, in order to simplify the disclosure and to facilitate the understanding of one or more of various aspects thereof, in the above description of the exemplary embodiments of the disclosure, various features of the disclosure may sometimes be grouped together into a single embodiment, accompanying figure or description thereof. However, the method of this disclosure should not be constructed as follows: the disclosure for which the protection is sought claims more features than those explicitly disclosed in each of claims. More specifically, as reflected in the following claims, the inventive aspect is in that the features therein are less than all features of a single embodiment as disclosed above. Therefore, claims following specific embodiments are definitely incorporated into the specific embodiments, wherein each of claims can be considered as a separate embodiment of the disclosure.
It should be understood by those skilled in the art that except for features that are mutually exclusive, various combinations can be used to combine all the features disclosed in specification (including claims, abstract and accompanying figures) and all the processes or units of any methods or devices as disclosed herein. Unless otherwise definitely stated, each of features disclosed in specification (including claims, abstract and accompanying figures) may be taken place with an alternative feature having same, equivalent, or similar purpose.
In addition, it should be understood by those skilled in the art, although some embodiments as discussed herein comprise some features included in other embodiment rather than other feature, combination of features in different embodiment means that the combination is within a scope of the disclosure and forms the different embodiment. For example, in the claims, any one of the embodiments for which the protection is sought can be used in any combination manner.
Various modules of the present disclosure may be implemented by hardware, software running in one or more processors, or a combination of them. For persons having ordinary skills in the art, some or all of the functions of the modules of the present disclosure may be implemented by a microprocessor or a digital signal processor (DSP). The present disclosure may also be implemented as a device or a program running in a device (e.g., a computer program and a product with computer programs) that perform a part, or all of the methods described herein. Such kind of programs may be stored on a computer readable medium, or may be in a form of one or more signals. Such signals may be downloaded from an Internet website, provided on a carrier signal, or provided in any other forms.
The foregoing descriptions are merely some implementation manners of the present disclosure, but the scope of the present disclosure is not limited thereto. Without departing from the spirit and principles of the present disclosure, any modifications, equivalent substitutions, and improvements, etc. shall fall within the scope of the present disclosure. Thus, the scope of invention should be determined by the appended claims.
This application is a continuation of International Application No. PCT/CN2018/085125, filed on Apr. 28, 2018, the entire content of which is incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/CN2018/085125 | Apr 2018 | US |
Child | 16949405 | US |