WO2020038067A1

WO2020038067A1 - Laser projection module and control method therefor, and depth image acquisition apparatus and electronic device

Info

Publication number: WO2020038067A1
Application number: PCT/CN2019/090082
Authority: WO
Inventors: 张学勇
Original assignee: Oppo广东移动通信有限公司
Priority date: 2018-08-22
Filing date: 2019-06-05
Publication date: 2020-02-27
Also published as: CN108828562A

Abstract

A laser projection module (100) and a control method therefor, and a depth image acquisition apparatus (300) and an electronic device (800). The laser projection module (100) comprises a light source (10), a diffuser (20), and a photodetector (63). The light source (10) is used to emit laser. The diffuser (20) is used to diffuse the laser. The photodetector (63) is used to receive the laser reflected back by the diffuser (20) to form a photodetection electrical signal, and the driving current of the light source (10) is adjusted based on the photodetection electrical signal.

Description

Laser projection module and control method, depth image acquisition device and electronic device

Priority information

This application claims the priority and rights of a patent application filed with the State Intellectual Property Office of China on August 22, 2018, with a patent application number of 201810962460.0, and the entirety of which is incorporated herein by reference.

Technical field

The present application relates to the field of three-dimensional imaging technology, and in particular, to a laser projection module, a method for controlling a laser projection module, a depth image acquisition device, and an electronic device.

Background technique

Time of flight (TOF) imaging system can calculate the depth information of the measured object by calculating the time difference between the time when the laser projection module emits the optical signal and the time when the optical receiver receives the optical signal. Laser projection modules typically include a light source and a diffuser. The light from the light source is diffused by the diffuser and then casts a uniform surface light into the scene.

Summary of the Invention

Embodiments of the present application provide a laser projection module, a method for controlling the laser projection module, a depth image acquisition device, and an electronic device.

The laser projection module according to the embodiment of the present application includes a light source, a diffuser, and a light detector. The light source is used for emitting laser light. The diffuser is used to diffuse the laser light. The photodetector is configured to receive the laser light reflected by the diffuser to form a photodetection electrical signal, and a driving current of the light source is adjusted based on the photodetection electrical signal.

A method for controlling a laser projection module according to an embodiment of the present application. The laser projection module includes a light source, a diffuser, and a light detector. The light source is used to emit laser light. The diffuser is used to diffuse the laser light. The receiver is used for receiving the laser light reflected by the diffuser to form a light detection electric signal. The control method includes: acquiring the photo detection electric signal output by the photo detector; and adjusting a driving current of the light source according to the photo detection electric signal.

The depth image acquisition device according to the embodiment of the present application includes a laser projection module and a light receiver. The light receiver is configured to receive laser light emitted by the laser projection module. The laser projection module includes a light source, a diffuser, and a light detector. The light source is used for emitting laser light. The diffuser is used to diffuse the laser light. The photodetector is configured to receive the laser light reflected by the diffuser to form a photodetection electrical signal, and a driving current of the light source is adjusted based on the photodetection electrical signal.

An electronic device according to an embodiment of the present application includes a housing and a depth image acquisition device. The depth image acquisition device is disposed on the casing. The depth image acquisition device includes a laser projection module and a light receiver. The light receiver is configured to receive laser light emitted by the laser projection module. The laser projection module includes a light source, a diffuser, and a light detector. The light source is used for emitting laser light. The diffuser is used to diffuse the laser light. The photodetector is configured to receive the laser light reflected by the diffuser to form a photodetection electrical signal, and a driving current of the light source is adjusted based on the photodetection electrical signal.

Additional aspects and advantages of the present application will be given in part in the following description, part of which will become apparent from the following description, or be learned through practice of the present application.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and / or additional aspects and advantages of this application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

FIG. 1 and FIG. 2 are three-dimensional structural diagrams of an electronic device according to some embodiments of the present application.

FIG. 3 is a schematic diagram of a three-dimensional structure of a depth image acquisition device according to some embodiments of the present application.

FIG. 4 is a schematic plan view of a depth image acquisition device according to some embodiments of the present application.

FIG. 5 is a schematic cross-sectional view of the depth image acquisition device in FIG. 4 along the V-V line.

FIG. 6 is a schematic structural diagram of a laser projection module according to some embodiments of the present application.

FIG. 7 is a schematic diagram of an arrangement of photodetectors in some embodiments of the present application.

8 to 15 are schematic diagrams of arrangement of conductive electrodes in some embodiments of the present application.

16 is a cross-sectional view of a diffuser of a laser projection module according to some embodiments of the present application.

FIG. 17 is a schematic diagram of an arrangement of conductive electrodes in some embodiments of the present application.

FIG. 18 is a schematic structural diagram of a laser projection module according to some embodiments of the present application.

FIG. 19 is a schematic diagram of an arrangement of conductive electrodes in some embodiments of the present application.

20 is a cross-sectional view of a diffuser of a laser projection module according to some embodiments of the present application.

21 to 24 are schematic diagrams of the arrangement of conductive paths in some embodiments of the present application.

25 is a cross-sectional view of a diffuser of a laser projection module according to some embodiments of the present application.

26 to 29 are schematic diagrams of arrangement of conductive paths in some embodiments of the present application.

FIG. 30 is a cross-sectional view of a diffuser of a laser projection module according to some embodiments of the present application.

FIG. 31 is a schematic diagram of an arrangement of conductive paths in some embodiments of the present application.

32 is a cross-sectional view of a diffuser of a laser projection module according to some embodiments of the present application.

33 and 34 are schematic flowcharts of a method for controlling a laser projection module according to some embodiments of the present application.

detailed description

The embodiments of the present application are further described below with reference to the accompanying drawings. The same or similar reference numerals in the drawings represent the same or similar elements or elements having the same or similar functions throughout. In addition, the embodiments of the present application described below with reference to the drawings are exemplary, and are only used to explain the embodiments of the present application, and should not be construed as limiting the present application.

Please refer to FIG. 6, the present application provides a laser projection module 100. The laser projection module 100 includes a light source 10, a diffuser 20 and a light detector 63. The light source 10 is used to emit laser light. The diffuser 20 is used to diffuse laser light. The photodetector 63 is used to receive the laser light reflected by the diffuser 20 to form a photodetection electrical signal. The driving current of the light source 10 is adjusted based on the light detection electric signal.

Please refer to FIG. 6 again. In some embodiments, the laser projection module 100 further includes a rupture detection component. When the light detection electrical signal is less than a preset light detection value, the rupture detection component is used to output the rupture detection electrical signal, and the rupture detection The electrical signal is used to detect whether the diffuser 20 is broken.

Please refer to FIGS. 6 and 8 again. In some embodiments, the diffuser 20 includes an incident surface 201 and an exit surface 202 opposite to each other, and the crack detection component includes a light-transmitting conductive film 21. The light-transmitting conductive film 21 is disposed on the incident surface 201 and / or the emission surface 202. The light-transmitting conductive film 21 includes a conductive electrode 210 including an input terminal 211 and an output terminal 212, and the input terminal 211 and the output terminal 212 are connected to the processor 805 to form a conductive circuit.

Please refer to FIG. 6, FIG. 20, and FIG. 21. In some embodiments, the crack detection component includes conductive particles 220 doped in the diffuser 20. The conductive particles 220 form a conductive path 22. The conductive path 22 includes an input terminal 221 and an output terminal 222, and the input terminal 221 and the output terminal 222 are connected to the processor 805 to form a conductive circuit.

Referring to FIG. 7, in some embodiments, the light detector 63 includes a plurality of light detectors 63, and the plurality of light detectors 63 are arranged symmetrically around the light source 10.

Please refer to FIG. 6 again. In some embodiments, the laser projection module 100 further includes a lens barrel 30. The lens barrel 30 includes a lens barrel sidewall 33, which surrounds a receiving cavity 62. The side wall 33 of the lens barrel includes a first surface 31 and a second surface 32 opposite to each other. The first surface 31 is recessed toward the second surface 32 to form a mounting groove 34 communicating with the receiving cavity 62. The diffuser 20 is mounted in the mounting groove 34.

The present application also provides a method for controlling the laser projection module 100. The laser projection module 100 includes a light source 10, a diffuser 20 and a light detector 63. The light source 10 is used to emit laser light. The diffuser 20 is used to diffuse laser light. The photodetector 63 is used to receive the laser light reflected by the diffuser 20 to form a photodetection electrical signal. The control method includes: acquiring a light detection electric signal output by the light detector 63; and adjusting a driving current of the light source 10 according to the light detection electric signal.

In some embodiments, the laser projection module 100 further includes a rupture detection component, and the rupture detection component is configured to output an electrical signal for rupture detection. The rupture detection electric signal is used to detect whether the diffuser 20 is ruptured. The control method, after the step of obtaining the photodetection electrical signal output by the photodetector 63, further comprises: judging whether the photodetection electrical signal is less than a preset photodetection value; and when the photodetection electrical signal is less than the preset photodetection value, obtaining a crack detection electrical signal.

In some embodiments, the step of adjusting the driving current of the light source 10 according to the light detection electric signal includes: determining whether the fracture detection electric signal is within a preset fracture detection range; and when the fracture detection electric signal is within a preset fracture detection range, The driving current of the light source 10 is increased; when the electrical signal of the fracture detection is not within a preset fracture detection range, the driving current of the light source 10 is decreased.

Referring to FIG. 3 and FIG. 6, the present application further provides a depth image acquisition device 300. The depth image acquisition device 300 includes a laser projection module 100 and a light receiver 200. The laser projection module 100 includes a light source 10, a diffuser 20 and a light detector 63. The light source 10 is used to emit laser light. The diffuser 20 is used to diffuse laser light. The photodetector 63 is used to receive the laser light reflected by the diffuser 20 to form a photodetection electrical signal. The driving current of the light source 10 is adjusted based on the light detection electric signal. The light receiver 200 is configured to receive laser light emitted by the laser projection module 100.

Please refer to FIG. 2, FIG. 3 and FIG. 6. The present application further provides an electronic device 800. The electronic device 800 includes a housing 801 and a depth image acquisition apparatus 300. The depth image acquisition device 300 is provided on the casing 801. The depth image acquisition device 300 includes: a laser projection module 100 and a light receiver 200. The laser projection module 100 includes a light source 10, a diffuser 20 and a light detector 63. The light source 10 is used to emit laser light. The diffuser 20 is used to diffuse laser light. The photodetector 63 is used to receive the laser light reflected by the diffuser 20 to form a photodetection electrical signal. The driving current of the light source 10 is adjusted based on the light detection electric signal. The light receiver 200 is configured to receive laser light emitted by the laser projection module 100.

Please refer to FIG. 1 and FIG. 2 together. The electronic device 800 according to the embodiment of the present application includes a casing 801 and a depth image acquisition device 300. The electronic device 800 may be a mobile phone, a tablet computer, a game console, a smart watch, a smart bracelet, a headset device, a drone, and the like. The embodiment of the present application uses the electronic device 800 as a mobile phone as an example for description. It can be understood that the specific form of the electronic device 800 is not limited to a mobile phone.

The housing 801 may serve as a mounting carrier for the functional elements of the electronic device 800. The housing 801 can provide protection for the functional elements from dust, drop, and water. The functional elements can be a display screen 802, a visible light camera 400, a receiver, and the like. In the embodiment of the present application, the housing 801 includes a main body 803 and a movable bracket 804. The movable bracket 804 can be moved relative to the main body 803 under the driving of a driving device. Move into the main body 803 (as shown in FIG. 1) or slide out from the main body 803 (as shown in FIG. 2). Some functional elements (such as the display 802) can be installed on the main body 803, and other functional elements (such as the depth image acquisition device 300, the visible light camera 400, and the receiver) can be installed on the movable bracket 804, and the movement of the movable bracket 804 can be driven The other functional element is retracted into or protruded from the main body 803. Of course, the embodiment shown in FIG. 1 and FIG. 2 is only an example of a specific form of the casing 801, and cannot be understood as a limitation on the casing 801 of the present application.

The depth image acquisition apparatus 300 is mounted on a casing 801. Specifically, the housing 801 may be provided with an acquisition window, and the depth image acquisition device 300 is installed in alignment with the acquisition window so that the depth image acquisition device 300 acquires depth information. In a specific embodiment of the present application, the depth image acquisition device 300 is mounted on a movable bracket 804. When the user needs to use the depth image acquisition device 300, he can trigger the movable bracket 804 to slide out from the main body 803 to drive the depth image acquisition device 300 to protrude from the main body 803; when the depth image acquisition device 300 is not needed, he can trigger The movable bracket 804 slides into the main body 803 to drive the depth image acquisition device 300 to retract into the main body. In the embodiment of the present application, the depth image acquisition device 300 is a time-of-flight (TOF) depth camera.

Please refer to FIGS. 3 to 5 together. The depth image acquisition device 300 includes a first substrate assembly 71, a spacer 72, a laser projection module 100 and a light receiver 200. The first substrate assembly 71 includes a first substrate 711 and a flexible circuit board 712 connected to each other. The spacer 72 is disposed on the first substrate 711. The laser projection module 100 is configured to project laser light outward, and the laser projection module 100 is disposed on the pad 72. The flexible circuit board 712 is bent and one end of the flexible circuit board 712 is connected to the first substrate 711 and the other end is connected to the laser projection module 100. The light receiver 200 is disposed on the first substrate 711. The light receiver 200 is configured to receive laser light reflected by a person or an object in the target space. The light receiver 200 includes a housing 741 and an optical element 742 provided on the housing 741. The housing 741 is integrally connected with the pad 72.

Specifically, the first substrate assembly 71 includes a first substrate 711 and a flexible circuit board 712. The first substrate 711 may be a printed wiring board or a flexible wiring board. The first substrate 711 may be laid with a control circuit or the like of the depth image acquisition device 300. One end of the flexible circuit board 712 may be connected to the first substrate 711, and the other end of the flexible circuit board 712 is connected to the circuit board 50 (shown in FIG. 5). The flexible circuit board 712 can be bent at a certain angle, so that the relative positions of the devices connected at both ends of the flexible circuit board 712 can be selected.

The spacer 72 is disposed on the first substrate 711. In one example, the spacer 72 is in contact with the first substrate 711 and is carried on the first substrate 711. Specifically, the spacer 72 may be combined with the first substrate 711 by means of adhesion or the like. The material of the spacer 72 may be metal, plastic, or the like. In the embodiment of the present application, a surface where the pad 72 is combined with the first substrate 711 may be a flat surface, and a surface opposite to the combined surface of the pad 72 may be a flat surface, so that the laser projection module 100 is disposed on the pad 72. It has better smoothness.

The light receiver 200 is disposed on the first substrate 711, and the contact surface between the light receiver 200 and the first substrate 711 is substantially flush with the contact surface between the pad 72 and the first substrate 711 (that is, the installation starting point of the two is at On the same plane). Specifically, the light receiver 200 includes a housing 741 and an optical element 742. The casing 741 is disposed on the first substrate 711, and the optical element 742 is disposed on the casing 741. The casing 741 may be a lens holder and a lens barrel of the light receiver 200, and the optical element 742 may be an element such as a lens disposed in the casing 741. Further, the light receiver 200 further includes a photosensitive chip (not shown), and the laser light reflected by a person or an object in the target space passes through the optical element 742 and is irradiated into the photosensitive chip, and the photosensitive chip responds to the laser. In the embodiment of the present application, the housing 741 and the cushion block 72 are integrally connected. Specifically, the housing 741 and the spacer 72 may be integrally formed; or the materials of the housing 741 and the spacer 72 are different, and the two are integrally formed by two-color injection molding or the like. The housing 741 and the spacer 72 may also be separately formed, and the two form a matching structure. When assembling the depth image acquisition device 300, one of the housing 741 and the spacer 72 may be set on the first substrate 711, and then the other One is disposed on the first substrate 711 and connected integrally.

In this way, the laser projection module 100 is disposed on the cushion block 72. The cushion block 72 can raise the height of the laser projection module 100, thereby increasing the height of the surface on which the laser projection module 100 emits laser light. The laser light is not easily blocked by the light receiver 200, so that the laser light can be completely irradiated on the measured object in the target space.

With reference to FIG. 6, the laser projection module 100 includes a light source 10, a diffuser 20, a lens barrel 30, a protective cover 40, a circuit board 50, a driver 61, and a light detector 63.

The lens barrel 30 includes a ring-shaped lens barrel sidewall 33, and the ring-shaped lens barrel sidewall 33 surrounds a receiving cavity 62. The side wall 33 of the lens barrel includes an inner surface 331 located in the receiving cavity 62 and an outer surface 332 opposite to the inner surface. The side wall 33 of the lens barrel includes a first surface 31 and a second surface 32 opposite to each other. The receiving cavity 62 penetrates the first surface 31 and the second surface 32. The first surface 31 is recessed toward the second surface 32 to form a mounting groove 34 communicating with the receiving cavity 62. The bottom surface 35 of the mounting groove 34 is located on a side of the mounting groove 34 remote from the first surface 31. The outer surface 332 of the side wall 33 of the lens barrel is circular at one end of the first surface 31, and the outer surface 332 of the side wall 33 of the lens barrel is formed with an external thread at one end of the first surface 31.

The circuit board 50 is disposed on the second surface 32 of the lens barrel 30 and closes one end of the receiving cavity 62. The circuit board 50 may be a flexible circuit board or a printed circuit board.

The light source 10 is carried on the circuit board 50 and received in the receiving cavity 62. The light source 10 is configured to emit laser light toward the first surface 31 (the mounting groove 34) side of the lens barrel 30. The light source 10 may be a single-point light source or a multi-point light source. When the light source 10 is a single-point light source, the light source 10 may specifically be an edge-emitting laser, for example, a distributed feedback laser (Distributed Feedback Laser, DFB), etc .; when the light source 10 is a multi-point light source, the light source 10 may specifically be vertical A cavity-surface emitter (Vertical-Cavity Surface Laser, VCSEL), or the light source 10 may also be a multi-point light source composed of multiple edge-emitting lasers. The height of the vertical cavity surface emitting laser is small, and the use of the vertical cavity surface emitter as the light source 10 is beneficial to reduce the height of the laser projection module 100, and it is convenient to integrate the laser projection module 100 into a mobile phone, etc., which has a high thickness of the fuselage. The requirements of the electronic device 800. Compared with the vertical cavity surface emitter, the temperature drift of the side-emitting laser is smaller, and the influence of the temperature on the effect of the projected laser light from the light source 10 can be reduced.

The driver 61 is carried on the circuit board 50 and is electrically connected to the light source 10. Specifically, the driver 61 may receive an input signal modulated by the processor 805, and convert the input signal into a constant current source and transmit it to the light source 10, so that the light source 10 is directed toward the first position of the lens barrel 30 under the action of the constant current source. The one side 31 emits laser light. The driver 61 of this embodiment is provided outside the lens barrel 30. In other embodiments, the driver 61 may be disposed in the lens barrel 30 and carried on the circuit board 50.

The diffuser 20 is mounted (supported) in the mounting groove 34 and abuts the mounting groove 34. The diffuser 20 is used to diffuse the laser light passing through the diffuser 20. That is, when the light source 10 emits laser light toward the first surface 31 side of the lens barrel 30, the laser light passes through the diffuser 20 and is diffused or projected outside the lens barrel 30 by the diffuser 20.

The protective cover 40 includes a top wall 41 and a protective sidewall 42 extending from one side of the top wall 41. A light through hole 401 is defined in the center of the top wall 41. The protective side wall 42 is disposed around the top wall 41 and the light through hole 401. The top wall 41 and the protection side wall 42 together form a mounting cavity 43, and the light-passing hole 401 communicates with the mounting cavity 43. The cross-section of the inner surface of the protective sidewall 42 is circular, and an inner thread is formed on the inner surface of the protective sidewall 42. The internal thread of the protective sidewall 42 is screwed with the external thread of the lens barrel 30 to mount the protective cover 40 on the lens barrel 30. The interference between the top wall 41 and the diffuser 20 causes the diffuser 40 to be sandwiched between the top wall 41 and the bottom surface 35 of the mounting groove 34.

In this way, the opening 20 is installed in the lens barrel 30, and the diffuser 20 is installed in the installation groove 34, and the protective cover 40 is installed on the lens barrel 30 to clamp the diffuser 20 between the protective cover 40 and the installation groove. Between the bottom surfaces 35 of 34, the diffuser 20 is fixed on the lens barrel 30. In this way, it is not necessary to fix the diffuser 20 to the lens barrel 30 by using glue, which can prevent the gas glue from diffusing and solidifying on the surface of the diffuser 20 after the glue is volatilized to affect the microstructure of the diffuser 20, and can avoid diffusion The diffuser 20 falls off from the lens barrel 30 when the glue of the device 20 and the lens barrel 30 decreases due to aging.

With reference to FIG. 6 again, the photodetector 63 is disposed on the circuit board 50 and is housed in the receiving cavity 62. The light transmittance of the diffuser 20 usually cannot reach 100%. Most of the laser light emitted by the light source 10 will be diffused out by the diffuser 20, but a small part of the laser light will be reflected by the diffuser 20. The light detector 63 can be used for receiving the laser light reflected by the diffuser 20. After receiving the laser light reflected from the diffuser 20, the photodetector 63 forms a photodetection electrical signal output. The depth image acquisition device 300 further includes a processor 805. The electronic device 800 also includes a processor. The processor of the electronic device 800 and the processor 805 of the depth image acquisition device 300 may be the same processor, or may be two independent processors. In a specific embodiment of the present application, the processor of the electronic device 800 and the processor of the depth image acquisition device 300 are the same processor. The processor 805 may receive the light detection electric signal output by the light detector 63 and adjust the driving current of the light source 10 according to the light detection electric signal.

Specifically, the diffuser 20 further includes a rupture detection component. The rupture detection component is configured to output a rupture detection electrical signal, and the rupture detection electrical signal is used to reflect whether the diffuser 20 is ruptured. After receiving the light detection electric signal, the processor 805 first compares the size of the light detection electric signal with the preset light detection value. If the light detection electric signal is smaller than the preset light detection value, it means that the laser light received by the light detector 63 is less. The reason for this phenomenon may be that the emitted laser light is increased due to the rupture of the diffuser 20, and the laser light reflected back to the photodetector 63 is reduced. It may also be that the reduction of the electro-optical conversion efficiency of the light source 10 causes the total amount of laser light emitted by the light source 10 to decrease, further causing reflection The laser light to the photodetector 63 is reduced. Then, when the processor 805 detects that the light detection electric signal is less than a preset light detection value, the processor 805 controls the rupture detection component to output a rupture detection electric signal. If the rupture detection electrical signal is not within the preset rupture detection range, the reason for the decrease in the laser light received by the photodetector 63 is the rupture of the diffuser 20; if the rupture detection electrical signal is within the preset rupture detection range, the diffusion is indicated The detector 20 is not broken, and the reason why the laser light received by the photodetector 63 is reduced is that the photoelectric conversion efficiency of the light source 10 becomes low. If the light detection electric signal is greater than or equal to the preset light detection value, it indicates that both the diffuser 20 and the light source 10 work normally, and the processor 805 does not perform an action at this time.

Further, if the processor 805 detects that the decrease in the laser light received by the photodetector 63 is due to the rupture of the diffuser 20, then the processor 805 should reduce the driving current of the light source 10 or directly turn off the light source 10 to avoid emission. The laser energy is too high, causing damage to the user's eyes. If the processor 805 detects that the decrease in the laser light received by the photodetector 63 is due to the low photoelectric conversion efficiency of the light source 10, the processor 805 should be appropriately adjusted higher at this time. The driving current of the light source 10 meets the current target space's demand for the light emitting power of the light source 10 and ensures the accuracy of obtaining the depth information.

In summary, the laser projection module 100, the depth image acquisition device 300, and the electronic device 800 according to the embodiments of the present application are provided with a light detector 63 on the laser projection module 100, and based on the light detection electric signal output by the light detector 63, The driving current of the light source 10 is adjusted. In this way, by autonomously adjusting the driving current of the light source 10 to ensure that the light source 10 has sufficient luminous power, it is beneficial to improve the accuracy of acquiring depth information.

Please refer to FIG. 7. In some embodiments, the number of the light detectors 63 is multiple, and the plurality of light detectors 63 are arranged symmetrically around the light source 10 in the center. In this way, the multiple photodetectors 63 can receive more laser light reflected by the diffuser 20. After the processor 805 receives a plurality of light detection electric signals, it first sums and averages the plurality of light detection electric signals to obtain an average value of the plurality of light detection electric signals, and then compares the average value of the light detection electric signals with a preset light detection. Value comparison, if the average value of the light detection electrical signal is less than the preset light detection value, further control the rupture detection component to perform the break detection of the diffuser 20; if the average value of the light detection electrical signal is greater than or equal to the preset light detection value, Then the processor 805 does nothing. The use of multiple photodetectors 63 arranged at different positions to receive the laser light reflected by the diffuser 20 can more accurately detect the amount of laser light reflected by the diffuser 20, and furthermore, the light source 10 can be more accurately detected. The actual luminous power is helpful for the processor 805 to accurately adjust the driving current.

In some embodiments, the value of the preset light detection value is determined by the driving current before being adjusted. Specifically, different driving currents correspond to different preset photodetection values. Each time the photodetection electrical signal output by the photodetector 63 should be compared with a preset photodetection value corresponding to a driving current that has not yet been adjusted. For example, if the current drive current is A1, the preset photodetection value should be B1, and the photodetection electrical signal is compared with B1; if the current drive current is A2 (A2> A1), the preset photodetection value should be B2 (B2> B1). The photodetection electrical signal is compared with B2. It can be understood that the driving current of the light source 10 may be different in different scenarios. If the driving current is large, more laser light is emitted from the light source 10, and more laser light is reflected back to the photodetector 63. If the driving current is small, less laser light is emitted from the light source 10, and laser light is reflected back to the photodetector 63. And less. Therefore, the photo-detection electric signal output by the photo-detector 63 should be compared with a preset photo-detection value corresponding to the driving current used in the current scene, in order to more accurately detect whether the actual luminous power of the light source 10 is greater than or less than the theoretical value. The power that should be transmitted further adjusts the driving current, so that the actual luminous power meets the demand for the power that should be transmitted in theory.

With reference to FIG. 6 again, the diffuser 20 includes an incident surface 201 near the light source 10 and an exit surface 202 opposite to the incident surface 201. The diffuser 20 is an optical element for diffusing the laser light emitted from the light source 10 into a plurality of light beams for emission, so that the laser light finally emitted into the target space is surface light with a substantially uniform light intensity distribution. The diffuser 20 is provided with a rupture detection element. The rupture detection element can output a rupture detection electrical signal. The processor 805 may receive a fracture detection electric signal output by the fracture detection element, and determine whether the diffuser 20 is fractured based on the fracture detection electric signal.

Specifically, referring to FIG. 6 and FIG. 8 together, the crack detection element may be a light-transmitting conductive film 21. A conductive electrode 210 is provided on the light-transmitting conductive film 21. The conductive electrode 210 includes an input terminal 211 and an output terminal 212. The input terminal 211 and the output terminal 212 are all connected to the processor 805, and the input terminal 211, the processor 805, and the output terminal 212 form a conductive loop. The light-transmitting conductive film 21 can be formed on the surface of the diffuser 20 by electroplating. The material of the light-transmitting conductive film 21 can be any one of indium tin oxide (ITO), nano-silver wire, and metal silver wire. . Indium tin oxide, nano-silver wire, and metallic silver wire all have good light transmittance and electrical conductivity, and can realize the output of the electrical signal for crack detection after being energized without blocking the light path of the diffuser 20. When the light-transmitting conductive film 21 is formed on the diffuser 20, if the diffuser 20 is in an intact state, the resistance of the light-transmitting conductive film 21 is small. In this state, the conductive electrode 210 on the light-transmitting conductive film 21 is energized. That is, when a certain amount of voltage is applied, the current output by the conductive electrode 210 obtained by the processor 805 is relatively large; if the diffuser 20 is broken, the light-transmitting conductive film 21 formed on the diffuser 20 will also be broken. The resistance value of the light-transmitting conductive film 21 at the crack position is close to infinity. In this state, the conductive electrode 210 on the light-transmitting conductive film 21 is energized, and the current output by the conductive electrode obtained by the processor 805 is small. Therefore, the processor 805 may compare the preset rupture detection range with the current rupture detection electrical signal (ie, current), where the preset rupture detection range is a value range of the current detected when the diffuser 20 is not ruptured. The value range of the current is determined by both the voltage applied to the conductive electrode 210 and the resistance of the conductive electrode 210 itself. If the rupture detection electrical signal is within the preset rupture detection range, it means that the transparent conductive film 21 is not ruptured, and it is judged that the diffuser 20 is not ruptured. If the rupture detection electrical signal is not within the preset rupture detection range, it means that the light transmission is conductive The film 21 is broken, and it is further judged that the diffuser 20 is broken. When the diffuser 20 is broken, the processor 805 can reduce the driving current of the light source 10 or directly turn off the light source 10.

Please refer to FIG. 6 again. In one embodiment, the light-transmitting conductive film 21 may be a single layer, and the single-layer light-transmitting conductive film 21 may be disposed on the incident surface 201 of the diffuser 20 (as shown in FIG. 6), or A single-layer light-transmitting conductive film 21 may also be disposed on the emission surface 202 (not shown) of the diffuser 20.

Specifically, referring to FIG. 6 and FIGS. 8 to 11 together, one conductive electrode 210 provided on the transparent conductive film 21 may be provided. The input terminal 211 and the output terminal 212 of the single conductive electrode 210 are connected to the processor 805 and form a conductive loop. Among them, there are various ways of arranging a single conductive electrode 210: for example, the connection direction of the input terminal 211 and the output terminal 212 (that is, the extending direction of the conductive electrode 210) is the length direction of the transparent conductive film 21 (as shown in FIG. 8). If the light-transmitting conductive film 21 is circular, the length direction here is the first radial direction of the light-transmitting conductive film 21, and the "length direction" of the light-transmitting conductive film 21 is interpreted the same below); or, the input terminal 211 The direction of the connection with the output terminal 212 is the width direction of the light-transmitting conductive film 21 (as shown in FIG. 9; if the light-transmitting conductive film 21 is circular, the width direction here is the first direction perpendicular to the light-transmitting conductive film 21. A radial second radial direction, the "width direction" of the light-transmitting conductive film 21 is the same; or, the direction of the connection between the input end 211 and the output end 212 is the diagonal direction of the light-transmitting conductive film 21 (such as Figures 10 and 11). Regardless of the above-mentioned arrangement of the conductive electrodes 210, the conductive electrodes 210 can span the entire light-transmitting conductive film 21, which can more accurately detect whether the light-transmitting conductive film 21 is broken, and further can accurately judge the diffuser. 20 Whether it is cracked.

Alternatively, please refer to FIG. 6 and FIG. 12 to FIG. 15 together. There may be multiple conductive electrodes 210 provided on the light-transmitting conductive film 21. The plurality of conductive electrodes 210 are disjoint from each other and are insulated from each other. Each conductive electrode 210 includes an input terminal 211 and an output terminal 212. Each input terminal 211 and each output terminal 212 are connected to the processor 805 to form a conductive loop. Thus, the input terminals 211 and output terminals 212 of the plurality of conductive electrodes 210 are respectively connected to the processor 805 to form a plurality of conductive loops. . Among them, there are various arrangements of the plurality of conductive electrodes 210: for example, the connection direction of each input terminal 211 and each output terminal 212 (that is, the extending direction of each conductive electrode 210) is the same as that of the transparent conductive film 21. In the length direction, a plurality of conductive electrodes 210 are arranged in parallel at intervals along the length direction of the light-transmitting conductive film 21 (as shown in FIG. 12); or, the direction of the line connecting each input terminal 211 and each output terminal 212 is a light-transmitting conductive film. In the width direction of 21, a plurality of conductive electrodes 210 are arranged at parallel intervals along the width direction of the light-transmitting conductive film 21 (as shown in FIG. 13); or, the direction of the line connecting each input terminal 211 and each output terminal 212 is transparent. In the diagonal direction of the conductive film 21, a plurality of conductive electrodes 210 are arranged at parallel intervals along the diagonal direction of the light-transmitting conductive film 21 (as shown in FIGS. 14 and 15). Regardless of the arrangement of the conductive electrodes 210, the multiple conductive electrodes 210 can make the entire layer of the light-transmitting conductive film 21 occupy a larger area of the diffuser 20 compared to the single conductive electrode 210. Correspondingly more rupture detection electric signals can be output. When only a single conductive electrode 210 is provided, there may be a location where the diffuser 20 ruptures is far from the position of the single conductive electrode 210, and the influence on the single conductive electrode 210 is not large. The signal is still within the preset rupture detection range, and the detection accuracy is not high. In this embodiment, the plurality of conductive electrodes 210 occupy more area of the light-transmitting conductive film 21, and correspondingly can output more electrical signals for crack detection. The processor 805 can be more accurate based on more electrical signals for crack detection. Judging whether the light-transmitting conductive film 21 is broken, and further determining whether the diffuser 20 is broken, improves the accuracy of the diffuser 20 crack detection.

As shown in FIGS. 16 and 17, in one embodiment, the light-transmitting conductive film 21 is a single-layer bridge structure. The light-transmitting conductive film 21 with a single-layer bridge structure may be disposed on the incident surface 201 or the exit surface 202 of the diffuser 20. Specifically, the light-transmitting conductive film 21 includes a plurality of conductive electrodes 210. The plurality of conductive electrodes 210 include a plurality of first conductive electrodes 213 disposed in parallel and insulated from each other, a plurality of second conductive electrodes 214 disposed in parallel and insulated from each other, and a plurality of bridge conductive electrodes 215. The plurality of first conductive electrodes 213 and the plurality of second conductive electrodes 214 are criss-crossed. Each of the first conductive electrodes 213 is continuous and uninterrupted, and each of the second conductive electrodes 214 is disconnected at the intersection with the corresponding plurality of first conductive electrodes 213 and is not conductive with the plurality of first conductive electrodes 213. Each bridge conductive electrode 215 conducts a break of the corresponding second conductive electrode 214. An insulator 216 is provided at the staggered position of the bridge conductive electrode 215 and the first conductive electrode 213. The insulator 216 can be produced by a silk screen or a yellow light process. The two ends of each first conductive electrode 213 are connected to the processor 805 to form a conductive loop, and the two ends of each second conductive electrode 214 are connected to the processor 805 to form a conductive loop. Thus, a plurality of first conductive electrodes The two ends of the electrode 213 are respectively connected to the processor 805 to form a plurality of conductive loops, and the two ends of the plurality of second conductive electrodes 214 are respectively connected to the processor 805 to form a plurality of conductive loops. The plurality of first conductive electrodes 213 and the plurality of second conductive electrodes 214 mean that the plurality of first conductive electrodes 213 and the plurality of second conductive electrodes 214 are vertically staggered with each other, that is, the plurality of first conductive electrodes 213 and the plurality of The included angle of the second conductive electrode 214 is 90 degrees. Of course, in other implementation manners, the plurality of first conductive electrodes 213 and the plurality of second conductive electrodes 214 may be criss-crossed, and the plurality of first conductive electrodes 213 and the plurality of second conductive electrodes 214 may be staggered with each other. When in use, the processor 805 can simultaneously energize the plurality of first conductive electrodes 213 and the plurality of second conductive electrodes 214 to obtain multiple crack detection electrical signals; or, the processor 805 can sequentially energize the plurality of first conductive electrodes 213 and The plurality of second conductive electrodes 214 are energized to obtain a plurality of crack detection electrical signals. Subsequently, the processor 805 judges whether the light-transmitting conductive film 21 is broken or not, and further determines whether the diffuser 20 is broken or not according to the break detection electric signal. Combining with 17, for example, when it is detected that the electrical signal of the rupture detection output by the first conductive electrode 213 with the number ① is not within the preset rupture detection range, the electrical signal of the rupture detection output by the second conductive electrode 214 with the number ③ is not within the preset range. When the crack detection range is set, it is explained that the transparent conductive film 21 is broken at the intersection A of the first conductive electrode 213 with the number ① and the second conductive electrode 214 with the number ③, and the diffuser 20 and the transparent conductive film 21 are broken. The position corresponding to the rupture position is also ruptured. In this way, through the single-layer bridging structure of the light-transmitting conductive film 21, it is possible to more accurately detect whether the diffuser 20 is broken and the specific position where the diffuser 20 is broken.

As shown in FIGS. 18 and 19, in one embodiment, the light-transmitting conductive film 21 may also have a multilayer structure. Specifically, the light-transmitting conductive film 21 includes a first light-transmitting conductive film 217 and a second light-transmitting conductive film 218. The first light-transmitting conductive film 217 is disposed on the incident surface 201 of the diffuser 20, and the second light-transmitting conductive film 218 is disposed on the exit surface 202 of the diffuser 20. The first light-transmitting conductive film 217 is provided with a plurality of first conductive electrodes 2171 disposed in parallel and insulated from each other, and the second light-transmissive conductive film 218 is provided with a plurality of second conductive electrodes 2181 disposed in parallel and insulated from each other. The projections of the plurality of first conductive electrodes 2171 on the exit surface 202 and the plurality of second conductive electrodes 2181 are criss-crossed. The two ends of each first conductive electrode 2171 are connected to the processor 805 to form a conductive loop, and the two ends of each second conductive electrode 2181 are connected to the processor 805 to form a conductive loop. Thus, a plurality of first conductive electrodes 2171 The two ends of each are respectively connected to the processor 805 to form a plurality of conductive loops, and the two ends of the plurality of second conductive electrodes 2181 are respectively connected to the processor 805 to form a plurality of conductive loops. The plurality of first conductive electrodes 2171 and the plurality of second conductive electrodes 2181 are criss-crossed, which means that the plurality of first conductive electrodes 2171 and the plurality of second conductive electrodes 2181 are vertically staggered with each other, that is, the plurality of first conductive electrodes 2171 and the plurality of The included angle of the second conductive electrode 2181 is 90 degrees. Of course, in other embodiments, the plurality of first conductive electrodes 2171 and the plurality of second conductive electrodes 2181 may be criss-crossed, and the plurality of first conductive electrodes 2171 and the plurality of second conductive electrodes 2181 may be staggered with each other. In use, the processor 805 can simultaneously power on the plurality of first conductive electrodes 2171 and the plurality of second conductive electrodes 2181 to obtain multiple crack detection electrical signals; or, the processor 805 can sequentially turn on the plurality of first conductive electrodes 2171 and The plurality of second conductive electrodes 2181 are energized to obtain a plurality of crack detection electrical signals. Subsequently, the processor 805 judges whether the light-transmitting conductive film 21 is broken or not, and further determines whether the diffuser 20 is broken or not according to the break detection electric signal. Specifically, if the rupture detection electric signal output by any one of the first conductive electrodes 2171 is not within the preset rupture detection range, it indicates that the first transparent conductive film 217 is ruptured, and the diffuser 20 is further considered to be ruptured; The fracture detection electric signal output by the conductive electrode 2181 is not within the preset fracture detection range, it indicates that the second light-transmitting conductive film 218 is fractured, and the diffuser 20 is further considered to be fractured. If the first conductive electrode 2171 is ruptured and the rupture detection electrical signal output by the second conductive electrode 2181 is not within the preset rupture detection range, for example, the first conductive electrode 2171 with the number ① and the second conductive electrode 2181 with the number ③ If none of the output electrical signals are within the preset fracture detection range, it means that the staggered position of the first conductive electrode 2171 with the number ① and the second conductive electrode 2181 with the number ③ is broken. In this way, the processor 805 can accurately detect whether the diffuser 20 is broken and the specific position of the diffuser 20 according to the burst detection electrical signals output by the plurality of first conductive electrodes 2171 and the plurality of second conductive electrodes 2181.

Referring to FIG. 20, in some embodiments, the rupture detection element may be conductive particles 220 doped in the diffuser 20. The conductive particles 220 may form a conductive path 22. When the diffuser 20 is in an intact state, the adjacent conductive particles 220 are bonded. At this time, the resistance of the entire conductive path 22 is small. In this state, the conductive path 22 is energized, that is, a certain amount of voltage is applied. At this time, the current output by the conductive path 22 obtained by the processor 805 is relatively large. When the diffuser 20 is broken, the junction between the conductive particles 220 doped in the diffuser 20 is disconnected. At this time, the resistance value of the entire conductive path 22 is close to infinity. In this state, the conductive path 22 is energized. The current output by the conductive path 22 obtained by the processor 805 is small. Therefore, the processor 805 may compare the preset rupture detection range with the current rupture detection electrical signal (ie, current), where the preset rupture detection range is a value range of the current detected when the diffuser 20 is not ruptured. The value range of the current is determined by both the voltage applied to the conductive path 22 and the resistance of the conductive path 22 itself. If the rupture detection electrical signal is within the preset rupture detection range, the conductive path 22 is not disconnected, and it is determined that the diffuser 20 is not ruptured. If the rupture detection electrical signal is not within the preset rupture detection range, the conductive path 22 is disconnected. On, it is judged that the diffuser 20 is broken. When the diffuser 20 is broken, the processor 805 can reduce the driving current of the light source 10 or directly turn off the light source 10.

Specifically, as shown in FIGS. 20 to 24, in one embodiment, the diffuser 20 is doped with a plurality of conductive particles 220, and the plurality of conductive particles 220 form a conductive path 22. The conductive path 22 includes an input terminal 221 and an output terminal 222. The input terminal 221 and the output terminal 222 are connected to the processor 805. The input terminal 221, the processor 805, and the output terminal 222 form a conductive loop. There are various ways to arrange the conductive paths 22: for example, the extending direction of the conductive paths 22 is the length direction of the diffuser 20 (as shown in FIG. 21; if the diffuser 20 is circular, the length direction here is The first radial direction of the diffuser 20 is the same as the "length direction" of the diffuser 20; or, the extending direction of the conductive path 22 is the width direction of the diffuser 20 (as shown in FIG. 22; if the diffuser 20 is circular Shape, then the width direction here is perpendicular to the first radial direction of the diffuser 20 and the second radial direction, and the “width direction” of the diffuser 20 is the same below); or, the extending direction of the conductive path 22 is the diffuser 20 Diagonal direction (as shown in Figures 23 and 24). Regardless of the above-mentioned arrangement of the conductive paths 22, the conductive paths 22 can span the entire diffuser 20, and it can be more accurately detected whether the diffuser 20 is broken.

As shown in FIGS. 25 to 29, in one embodiment, the diffuser 20 is doped with a plurality of conductive particles 220, and the plurality of conductive particles 220 form a plurality of conductive paths 22. The plurality of conductive paths 22 are disjoint from each other and are insulated from each other. Each conductive path 22 includes an input terminal 221 and an output terminal 222. Each input terminal 221 and each output terminal 222 are connected to the processor 805 to form a conductive circuit. Thus, the input terminals 221 and output terminals 222 of the plurality of conductive paths 22 are respectively connected to the processor 805 to form a plurality of conductive circuits. . Among them, there are various arrangements of the plurality of conductive paths 22: for example, the extension direction of each conductive path 22 is the length direction of the diffuser 20 (as shown in FIG. 26), and the plurality of conductive paths 22 are arranged along the diffuser 20 The longitudinal direction is arranged at parallel intervals. Since the diffuser 20 has a certain thickness, after the plurality of conductive paths 22 are arranged at parallel intervals along the longitudinal direction of the diffuser 20, it can also be arranged at stacked intervals along the thickness direction of the diffuser 20 ( (As shown in FIG. 25); or, the extending direction of each conductive path 22 is the width direction of the diffuser 20 (as shown in FIG. 27), and a plurality of conductive paths 22 are arranged at parallel intervals along the width direction of the diffuser 20, due to the diffusion The diffuser 20 has a certain thickness. Therefore, after a plurality of conductive paths 22 are arranged in parallel and spaced apart along the width direction of the diffuser 20, they can also be arranged in a stacked interval along the thickness direction of the diffuser 20 (not shown); or The extending direction of the conductive path 22 is the diagonal direction of the incident surface 201 (shown in FIG. 6) of the diffuser 20 (as shown in FIGS. 28 and 29). Since the diffuser 20 has a certain thickness, a plurality of conductive paths 22 at the diffuser 20 After the diagonal directions of the incident surface 201 are arranged at parallel intervals, they can also be arranged in a stacking interval along the thickness direction of the diffuser 20 (not shown); or, the extension direction of each conductive path 22 is the incident surface of the diffuser 20 201 and a diagonal direction (not shown) of the exit surface 202 (shown in FIG. 6), and a plurality of conductive paths 22 are disposed at parallel intervals along the diagonal direction of the incident surface 201 and the exit surface 202 of the diffuser 20; or, The extension direction of each conductive path 22 is arranged at parallel intervals in the thickness direction of the diffuser 20 (not shown). Since the diffuser 20 has a certain width, multiple conductive paths are arranged in parallel at intervals in the thickness direction of the diffuser 20 Later, it can also be arranged at a stacking interval along the width direction of the diffuser 20 (not shown). No matter which of the conductive paths 22 is arranged in the manner described above, compared with a single conductive path 22, a plurality of conductive paths 22 can occupy more volume of the diffuser 20, and accordingly can output more rupture detection. electric signal. When only a single conductive path 22 is provided, there may be a location where the diffuser 20 ruptures is far from the position of the single conductive path 22, and the influence on the single conductive path 22 is not large. The rupture detection voltage output by the single conductive path 22 The signal is still within the preset rupture detection range, and the detection accuracy is not high. In this embodiment, the multiple conductive paths 22 occupy more volume of the diffuser 20 and correspondingly output more electric signals for rupture detection. The processor 805 can more accurately judge based on the more electric signals for rupture detection. Whether the diffuser 20 is ruptured improves the accuracy of the diffuser 20 rupture detection.

As shown in FIGS. 30 and 31, in one embodiment, the diffuser 20 is doped with a plurality of conductive particles 220, and the plurality of conductive particles 220 form a plurality of conductive paths 22. The plurality of conductive paths 22 include a plurality of first conductive paths 223 and a plurality of second conductive paths 224. A plurality of first conductive paths 223 are arranged in parallel and spaced apart from each other, and a plurality of second conductive paths 224 are arranged in parallel and spaced apart from each other. The plurality of first conductive paths 223 and the plurality of second conductive paths 224 are criss-crossed in space. The two ends of each first conductive path 223 are connected to the processor 805 to form a conductive loop, and the two ends of each second conductive path 224 are connected to the processor 805 to form a conductive loop. Thus, a plurality of first conductive paths 223 The two ends of each are respectively connected to the processor 805 to form a plurality of conductive loops, and the two ends of the plurality of second conductive paths 224 are respectively connected to the processor 805 to form a plurality of conductive loops. Wherein, the plurality of first conductive paths 223 and the plurality of second conductive paths 224 are spatially criss-crossed, which means that the plurality of first conductive paths 223 and the plurality of second conductive paths 224 are vertically staggered with each other in space, that is, a plurality of An included angle between the first conductive path 223 and the plurality of second conductive paths 224 is 90 degrees. At this time, the extending direction of the plurality of first conductive paths 223 may be the length direction of the diffuser 20, and the extending direction of the plurality of second conductive paths 224 is the width direction of the diffuser 20; or, the plurality of first conductive paths 223 The direction of extension of the diffuser 20 is the length direction of the diffuser 20, and the direction of extension of the plurality of second conductive paths 224 is the thickness direction of the diffuser 20; or, the direction of extension of the plurality of first conductive paths 223 may be the width direction of the diffuser 20 The extending direction of the plurality of second conductive paths 224 is the thickness direction of the diffuser 20. Of course, in other embodiments, the plurality of first conductive paths 223 and the plurality of second conductive paths 224 are spatially criss-crossed. The plurality of first conductive paths 223 and the plurality of second conductive paths 224 may be staggered with each other. When in use, the processor 805 can simultaneously power on the plurality of first conductive paths 223 and the plurality of second conductive paths 224 to obtain multiple crack detection electrical signals; or, the processor 805 can sequentially apply power to the plurality of first conductive paths 223 and The plurality of second conductive paths 224 are energized to obtain a plurality of crack detection electrical signals. Subsequently, the processor 805 determines whether the diffuser 20 is ruptured based on the rupture detection electric signal. Please refer to FIG. 30. For example, when it is detected that the electrical signal for the rupture detection output by the first conductive path 223 with the number ② is not within the preset rupture detection range, and the electrical signal with the rupture detection output from the second conductive path 224 with the number ④ When neither is within the preset rupture detection range, it is explained that the intersection C of the first conductive path 223 with the number ② and the second conductive path 224 with the number ④ is broken, and the position corresponding to the diffuser 20 is also broken. In this way, by arranging the first conductive paths 223 and the second conductive paths 224 in a crisscross pattern, it is possible to more accurately detect whether the diffuser 20 is broken and the specific position of the diffuser 20 is broken.

Referring to FIG. 32, since the diffuser 20 has a certain width and thickness, a plurality of first conductive paths 223 and a plurality of second conductive paths 224 are spatially criss-crossed to form a pair of mutually-intersecting conductive path pairs 225. It is also possible to form a plurality of pairs of the aforementioned conductive path pairs 225 in the width direction or the thickness direction of the diffuser 20. Similarly, the processor 805 may determine whether the diffuser 20 is ruptured and a specific position of the diffuser 20 based on a plurality of rupture detection electrical signals. When only one pair of conductive path pairs 225 is provided, there may be a location where the diffuser 20 ruptures is far from the position of a single pair of conductive path pairs 225, and the effect of a single pair of conductive path pairs 225 is not significant. The single pair In the case where the plurality of first conductive paths 223 and the plurality of second conductive paths 224 in the conductive path pair 225 output rupture detection electrical signals within a preset rupture detection range, the detection accuracy is not high. Multiple pairs of conductive path pairs 225 can occupy more volume of the diffuser 20 and can output more electrical signals for rupture detection. The processor 805 can more accurately determine whether the diffuser 20 ruptures based on more electrical signals for rupture detection The specific position of the diffuser 20 rupture improves the accuracy of the diffuser 20 rupture detection.

In this way, the conductive path 22 is formed by doping the conductive particles 220 in the diffuser, and the break detection of the diffuser 20 can also be realized by using the electrical signal of the break detection output by the conductive path 22. Compared with the arrangement of the transmissive conductive film 21 as the detection element, the way in which the conductive particles 220 are doped in the diffuser 20 to form the conductive path 22 as the detection element can reduce the thickness of the laser projection module 100, which is further beneficial to reducing the depth image The thickness of the acquisition device 300 is beneficial for integrating the depth image acquisition device 300 into an electronic device 800, such as a mobile phone, which requires a high thickness of the fuselage.

Please refer to FIG. 2 to FIG. 5 together. In some embodiments, the side where the cushion block 72 is combined with the first substrate 711 is provided with a receiving cavity 723. The depth image acquisition apparatus 300 further includes an electronic component 77 provided on the first substrate 711. The electronic component 77 is housed in the receiving cavity 723. The electronic component 77 may be an element such as a capacitor, an inductor, a transistor, or a resistor. The electronic component 77 may be electrically connected to a control line laid on the first substrate 711 and used for or controlling the operation of the laser projection module 100 or the light receiver 200. The electronic component 77 is housed in the receiving cavity 723, and the space in the pad 72 is used reasonably. It is not necessary to increase the width of the first substrate 711 to set the electronic component 77, which is beneficial to reducing the overall size of the depth image acquisition device 300. The number of the receiving cavities 723 may be one or more, and the receiving cavities 723 may be spaced apart from each other. When mounting the pad 72, the receiving cavity 723 and the electronic component 77 may be aligned and the pad 72 may be disposed on the first substrate 711.

Please continue to refer to FIG. 2 to FIG. 5. In some embodiments, the cushion block 72 is provided with an escape through hole 724 connected to at least one receiving cavity 723, and at least one electronic component 77 extends into the escape through hole 724. It can be understood that when the electronic component 77 needs to be accommodated in the avoiding through hole, the height of the electronic component 77 is required to be not higher than the height of the receiving cavity 723. For electronic components having a height higher than the receiving cavity 723, an avoiding through hole 724 corresponding to the receiving cavity 723 may be provided, and the electronic component 77 may partially extend into the avoiding through hole 724 so as not to increase the height of the cushion 72. Arranges the electronic component 77.

Please also refer to FIGS. 2 to 5. In some embodiments, the first substrate assembly 711 further includes a reinforcing plate 713, and the reinforcing plate 713 is coupled to a side of the first substrate 711 opposite to the pad 72. The reinforcing plate 713 may cover one side of the first substrate 711, and the reinforcing plate 713 may be used to increase the strength of the first substrate 711 and prevent deformation of the first substrate 711. In addition, the reinforcing plate 713 may be made of a conductive material, such as a metal or an alloy. When the depth image acquisition device 300 is installed on the electronic device 800, the reinforcing plate 713 and the housing 801 may be electrically connected to make the reinforcing plate 713. Grounding and effectively reducing the interference of the static electricity of external components on the depth image acquisition device 300.

Please refer to FIG. 2 to FIG. 5 again. In other embodiments, the depth image acquisition device 300 further includes a connector 76 connected to the first substrate assembly 71 and used to electrically communicate with electronic components external to the depth image acquisition device 300. Sexual connection.

Please refer to FIG. 6, FIG. 33 and FIG. 34 together. The present application further provides a control method of the laser projection module 100. The laser projection module 100 is the laser projection module 100 according to any one of the above embodiments. Control methods include:

01: Obtaining the light detection electric signal output by the light detector 63; and

03: Adjust the driving current of the light source 10 according to the light detection electric signal.

The control method after step 01 further includes:

021: determine whether the light detection electric signal is less than a preset light detection value; and

022: Obtain a fracture detection electrical signal when the light detection electrical signal is less than a preset light detection value.

Step 03: Adjusting the driving current of the light source 10 according to the light detection electric signal includes:

031: Determine whether the electrical signal for rupture detection is within a preset rupture detection range;

032: increase the driving current of the light source 10 when the electrical signal of the fracture detection is within the preset fracture detection range;

033: When the fracture detection electric signal is not within the preset fracture detection range, the driving current of the light source 10 is reduced.

With reference to FIG. 6 and FIG. 8, step 01, step 021, step 022, step 03, step 031, step 032, and step 033 can all be implemented by the processor 805. That is to say, the processor 805 may be configured to obtain a photodetection electrical signal output by the photodetector 63 and adjust a driving current of the light source 10 according to the photodetection electrical signal. Further, the processor 805 may be further configured to determine whether the light detection electrical signal is less than a preset light detection value, and when the light detection electrical signal is less than a preset light detection value, obtain a fracture detection electrical signal, and determine whether the fracture detection electrical signal is within a preset Within the rupture detection range, when the rupture detection electrical signal is within the preset rupture detection range, the drive current of the light source 10 is increased, and when the rupture detection electrical signal is not within the preset rupture detection range, the drive current of the light source 10 is decreased. .

It can be understood that the light transmittance of the diffuser 20 usually cannot reach 100%. Most of the laser light emitted by the light source 10 will be diffused out by the diffuser 20, but a small part of the laser light will be reflected by the diffuser 20. The light detector 63 can be used for receiving the laser light reflected by the diffuser 20. After receiving the laser light reflected from the diffuser 20, the photodetector 63 forms a photodetection electrical signal output. When the driving current is constant, the processor 805 receives the photodetection electrical signal output by the photodetector 63, and compares the magnitude of the photodetection electrical signal with a preset photodetection value. If the photodetection electrical signal is less than the preset photodetection value, It indicates that the laser light received by the photodetector 63 is less. The reason for this phenomenon may be that the emitted laser light is increased due to the rupture of the diffuser 20, the laser light reflected back to the photodetector 63 is reduced, or the electro-optical conversion efficiency of the light source 10 is reduced The total amount of laser light emitted from the light source 10 is reduced, which further reduces the amount of laser light reflected to the photodetector 63. Then, when the processor 805 detects that the light detection electric signal is less than a preset light detection value, the processor 805 controls the rupture detection component to output a rupture detection electric signal. If the rupture detection electrical signal is not within the preset rupture detection range, the reason for the decrease in the laser light received by the photodetector 63 is the rupture of the diffuser 20; if the rupture detection electrical signal is within the preset rupture detection range, the diffusion is indicated The detector 20 is not broken, and the reason why the laser light received by the photodetector 63 is reduced is that the photoelectric conversion efficiency of the light source 10 becomes low. If the light detection electric signal is greater than or equal to the preset light detection value, it indicates that both the diffuser 20 and the light source 10 work normally, and the processor 805 does not perform an action at this time.

Further, if the processor 805 detects that the decrease in the laser light received by the photodetector 63 is due to the rupture of the diffuser 20, then the processor 805 should reduce the driving current of the light source 10 or directly turn off the light source 10 to avoid emission The laser energy is too high, causing damage to the user's eyes. If the processor 805 detects that the decrease in the laser light received by the photodetector 63 is due to the low photoelectric conversion efficiency of the light source 10, the processor 805 should be appropriately adjusted higher at this time. The driving current of the light source 10 meets the current target space's demand for the light emitting power of the light source 10 and ensures the accuracy of obtaining the depth information.

The control method of the laser projection module 100 according to the embodiment of the present application adjusts the driving current of the light source 10 based on the light detection electric signal output by the light detector 63. In this way, by autonomously adjusting the driving current of the light source 10 to ensure that the light source 10 has sufficient luminous power, it is beneficial to improve the accuracy of acquiring depth information.

Please refer to FIG. 6 and FIG. 7. In some embodiments, there are a plurality of light detectors 63 and are arranged symmetrically around the light source 10. At this time, the processor 805 can receive a plurality of light detection electrical signals. After the processor 805 receives a plurality of light detection electric signals, it first sums and averages the plurality of light detection electric signals to obtain an average value of the plurality of light detection electric signals, and then compares the average value of the light detection electric signals with a preset light detection. Value comparison, if the average value of the light detection electrical signal is less than the preset light detection value, further control the rupture detection component to perform the break detection of the diffuser 20; if the average value of the light detection electrical signal is greater than or equal to the preset light detection value, Then the processor 805 does nothing. The use of multiple photodetectors 63 arranged at different positions to receive the laser light reflected by the diffuser 20 can more accurately detect the amount of laser light reflected by the diffuser 20, and furthermore, the light source 10 can be more accurately detected. The actual luminous power is helpful for the processor 805 to accurately adjust the driving current.

In some embodiments, the value of the preset light detection value is determined by the driving current before being adjusted. Specifically, different driving currents correspond to different preset photodetection values, and each time the photodetection electrical signal output by the photodetector 63 should be compared with a preset photodetection value corresponding to the current unadjusted drive current. For example, if the current drive current is A1, the preset photodetection value should be B1, and the photodetection electrical signal is compared with B1; if the current drive current is A2 (A2> A1), the preset photodetection value should be B2 (B2> B1). The photodetection electrical signal is compared with B2. It can be understood that the driving current of the light source 10 may be different in different scenarios. If the driving current is large, more laser light is emitted from the light source 10, and more laser light is reflected back to the photo detector 63. If the driving current is small, less laser light is emitted from the light source 10, and laser light is reflected back to the photo detector 63 And less. Therefore, the photo-detection electric signal output by the photo-detector 63 should be compared with a preset photo-detection value corresponding to the driving current used in the current scene, in order to more accurately detect whether the actual luminous power of the light source 10 is greater than or less than the theoretical value. The power that should be transmitted further adjusts the driving current, so that the actual luminous power meets the demand for the power that should be transmitted in theory.

In the description of this specification, reference is made to the terms "certain embodiments", "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" The description means that a specific feature, structure, material, or characteristic described in combination with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same implementation or example. Moreover, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more implementations or examples.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as “first” and “second” may explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "plurality" is at least two, for example, two, three, unless specifically defined otherwise.

Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present application. Those skilled in the art may, within the scope of the present application, understand the above. The embodiments are subject to change, modification, replacement, and modification, and the scope of the present application is defined by the claims and their equivalents.

Claims

A laser projection module, characterized in that the laser projection module includes:

A light source for emitting laser light;

A diffuser for diffusing the laser light; and

A light detector configured to receive laser light reflected by the diffuser to form a light detection electric signal, and a driving current of the light source is adjusted based on the light detection electric signal.
The laser projection module according to claim 1, wherein the laser projection module further comprises a rupture detection component, and the rupture detection component is used when the light detection electrical signal is less than a preset light detection value. A rupture detection electric signal is output, and the rupture detection electric signal is used to detect whether the diffuser is ruptured.
The laser projection module according to claim 2, wherein the diffuser includes opposite incident surfaces and outgoing surfaces, and the rupture detection component includes a light-transmitting conductive film, and the light-transmitting conductive film is disposed at On the incident surface and / or the exit surface, the transparent conductive film includes a conductive electrode, the conductive electrode includes an input terminal and an output terminal, and the input terminal and the output terminal are connected to a processor to form a conductive circuit. .
The laser projection module according to claim 2, wherein the fracture detection component comprises conductive particles doped in the diffuser, the conductive particles forming a conductive path, and the conductive path includes an input terminal and An output terminal, the input terminal and the output terminal are connected to a processor to form a conductive loop.
The laser projection module according to claim 1, wherein the light detector comprises a plurality of light detectors, and the plurality of light detectors are arranged symmetrically around the light source.
The laser projection module according to claim 1, wherein the laser projection module further comprises a lens barrel, the lens barrel includes a sidewall of the lens barrel, and the sidewall of the lens barrel surrounds a receiving cavity, The side wall of the lens barrel includes a first surface and a second surface opposite to each other. The first surface is recessed toward the second surface to form a mounting groove communicating with the receiving cavity. The diffuser is installed in the mounting groove. .
A method for controlling a laser projection module, characterized in that the laser projection module includes a light source, a diffuser, and a light detector, the light source is used to emit laser light, the diffuser is used to diffuse the laser light, and the light The detector is configured to receive laser light reflected by the diffuser to form a light detection electrical signal; the control method includes:

Acquiring the light detection electric signal output by the light detector; and

A driving current of the light source is adjusted according to the light detection electric signal.
The control method according to claim 7, wherein the laser projection module further comprises a rupture detection component, the rupture detection component is configured to output an electrical signal for rupture detection, and the electrical signal for rupture detection is used to detect all Whether the diffuser is broken; after the step of obtaining the photo-detection electrical signal output by the photo-detector, the control method further includes:

Determining whether the light detection electric signal is less than a preset light detection value; and

When the light detection electric signal is smaller than the preset light detection value, the fracture detection electric signal is acquired.
The control method according to claim 8, wherein the step of adjusting the driving current of the light source according to the light detection electric signal comprises:

Judging whether the rupture detection electric signal is within a preset rupture detection range;

Increasing the drive current of the light source when the burst detection electrical signal is within the preset burst detection range;

When the burst detection electric signal is not within the preset burst detection range, the driving current of the light source is reduced.
A depth image acquisition device, comprising:

Laser projection module, the laser projection module includes:

A light source for emitting laser light;

A diffuser for diffusing the laser light; and

A light detector configured to receive laser light reflected by the diffuser to form a light detection electric signal, and a driving current of the light source is adjusted based on the light detection electric signal; and

A light receiver for receiving laser light emitted by the laser projection module.
The depth image acquisition device according to claim 10, wherein the laser projection module further comprises a rupture detection component, and the rupture detection component is used when the light detection electrical signal is less than a preset light detection value. A rupture detection electric signal is output, and the rupture detection electric signal is used to detect whether the diffuser is ruptured.
The depth image acquisition device according to claim 11, wherein the diffuser includes an incident surface and an exit surface opposite to each other, and the crack detection component includes a light-transmitting conductive film, and the light-transmitting conductive film is disposed at On the incident surface and / or the exit surface, the transparent conductive film includes a conductive electrode, the conductive electrode includes an input terminal and an output terminal, and the input terminal and the output terminal are connected to a processor to form a conductive circuit. .
The depth image acquisition device according to claim 11, wherein the fracture detection component includes conductive particles doped in the diffuser, the conductive particles forming a conductive path, and the conductive path includes an input terminal and An output terminal, the input terminal and the output terminal are connected to a processor to form a conductive loop.
The depth image acquisition device according to claim 10, wherein the light detector comprises a plurality of light detectors, and the plurality of light detectors are arranged symmetrically around the light source.
The depth image acquisition device according to claim 10, wherein the laser projection module further comprises a lens barrel, the lens barrel includes a sidewall of the lens barrel, and the sidewall of the lens barrel surrounds a receiving cavity, The side wall of the lens barrel includes a first surface and a second surface opposite to each other. The first surface is recessed toward the second surface to form a mounting groove communicating with the receiving cavity. The diffuser is installed in the mounting groove. .
An electronic device, comprising:

Shell; and

A depth image acquisition device, which is disposed on the casing;

The depth image acquisition device includes:

Laser projection module, the laser projection module includes:

A light source for emitting laser light;

A diffuser for diffusing the laser light; and

A light detector configured to receive laser light reflected by the diffuser to form a light detection electric signal, and a driving current of the light source is adjusted based on the light detection electric signal; and

A light receiver for receiving laser light emitted by the laser projection module.
The electronic device according to claim 16, wherein the laser projection module further comprises a rupture detection component, and the rupture detection component is configured to output a rupture when the light detection electrical signal is less than a preset light detection value. An electrical signal is detected, and the rupture detection electrical signal is used to detect whether the diffuser is ruptured.
The electronic device according to claim 17, wherein the diffuser comprises an incident surface and an exit surface opposite to each other, and the rupture detection component comprises a light-transmitting conductive film, and the light-transmitting conductive film is disposed on the incidence Surface and / or the exit surface, the light-transmitting conductive film includes a conductive electrode, the conductive electrode includes an input terminal and an output terminal, and the input terminal and the output terminal are connected to a processor to form a conductive circuit.
The electronic device according to claim 17, wherein the crack detection component comprises conductive particles doped in the diffuser, the conductive particles forming a conductive path, and the conductive path includes an input terminal and an output terminal The input terminal and the output terminal are connected to a processor to form a conductive loop.
The electronic device according to claim 16, wherein the light detector comprises a plurality of light detectors, and the plurality of light detectors are arranged symmetrically around the light source.
The electronic device according to claim 16, wherein the laser projection module further comprises a lens barrel, the lens barrel includes a sidewall of the lens barrel, the sidewall of the lens barrel surrounds a receiving cavity, and the lens barrel The side wall includes a first surface and a second surface opposite to each other. The first surface is recessed toward the second surface to form a mounting groove communicating with the receiving cavity. The diffuser is installed in the mounting groove.