CN108767653A - Control system and terminal of laser projector and control method of laser projector - Google Patents

Abstract

The invention discloses a control system of a laser projector. The control system includes a distance sensor, a first drive circuit, a microprocessor, and an application processor. The distance sensor is used for detecting the distance between the human eye and the laser projector. The first driving circuit is connected with the laser projector and used for driving the laser projector to project laser. The microprocessor is connected with the first driving circuit. The application processor is connected with the distance sensor and the microprocessor, the application processor is used for sending corresponding control signals to the microprocessor according to the distance between the human eyes and the laser projector, and the microprocessor controls the first driving circuit according to the control signals so that the laser projector projects laser according to preset parameters. The control system controls the parameters of the laser projector for projecting the laser according to the distance between the human eyes and the laser projector, thereby preventing the harm to the eyes of the user. In addition, the invention also discloses a terminal and a control method of the laser projector.

Description

Laser projector control system, terminal, and laser projector control method

technical field

The present invention relates to the technical field of consumer electronics, and more specifically, to a control system for a laser projector, a terminal and a control method for the laser projector.

Background technique

The mobile phone can be equipped with a laser generator, and the laser projector can project a laser with predetermined pattern information, and project the laser onto the target user in the space, and then obtain the laser pattern reflected by the target user through the imaging device, so as to further Obtain a depth image of the target user. However, improper control of the laser light projected by the laser projector is likely to cause damage to the eyes of the user.

Contents of the invention

Embodiments of the present invention provide a laser projector control system, a terminal, and a laser projector control method.

The control system of the laser projector of the embodiment of the present invention comprises:

a distance sensor, the distance sensor is used to detect the distance between human eyes and the laser projector;

a first drive circuit, the first drive circuit is connected to the laser projector, and the first drive circuit is used to drive the laser projector to project laser light;

a microprocessor connected to the first drive circuit; and

An application processor, the application processor is connected to the distance sensor, the application processor is connected to the microprocessor, and the application processor is used to calculate the distance between the human eye and the laser projector according to the distance between the human eye and the laser projector. A corresponding control signal is sent to the microprocessor, and the microprocessor controls the first driving circuit according to the control signal, so that the laser projector projects laser light with predetermined parameters.

The terminal in the embodiment of the present invention includes:

laser projectors; and

In the control system according to any one of the above embodiments, the first drive circuit is connected to the laser projector.

The laser projector in the embodiment of the present invention is connected to the first driving circuit, and the control method of the laser projector includes:

A distance sensor detects the distance between human eyes and the laser projector;

The application processor sends a corresponding control signal to the microprocessor according to the distance between the human eye and the laser projector; and

The microprocessor controls the first drive circuit according to the control signal so that the laser projector projects laser light with predetermined parameters.

The laser projector control system, terminal, and laser projector control method according to the embodiment of the present invention control the parameters of the laser projected by the laser projector according to the distance between the human eye and the laser projector, thereby preventing damage to the user's eyes.

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

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and comprehensible from the description of the embodiments in conjunction with the following drawings, wherein:

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

2 to 3 are schematic diagrams of modules of a terminal according to an embodiment of the present invention;

4 is a schematic diagram of the current parameters of the laser projected by the laser projector according to the embodiment of the present invention;

5 is a schematic diagram of the frame rate parameters of the laser projected by the laser projector according to the embodiment of the present invention;

6 is a schematic diagram of the pulse width parameters of the laser projected by the laser projector according to the embodiment of the present invention;

7 to 11 are schematic flowcharts of a control method of a laser projector according to an embodiment of the present invention;

12 is a schematic structural diagram of a laser projection assembly according to an embodiment of the present invention;

13 to 15 are partial structural schematic diagrams of a laser projector according to an embodiment of the present invention.

Detailed ways

Embodiments of the present invention will be further described below in conjunction with 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 invention described below in conjunction with the accompanying drawings are exemplary, and are only used to explain the embodiments of the present invention, and should not be construed as limiting the present invention.

In the present invention, unless otherwise clearly specified and limited, the first feature may be in direct contact with the first feature or the first and second feature may be in direct contact with the second feature through an intermediary. touch. Moreover, "above", "above" and "above" the first feature on the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "beneath" and "beneath" the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.

Referring to FIG. 1 and FIG. 2 , a terminal 100 according to an embodiment of the present invention includes a laser projector 10 , an infrared camera 20 and a control system 30 . The terminal 100 can be a mobile phone, a tablet computer, a smart watch, a smart bracelet, a smart wearable device, etc. In the embodiment of the present invention, the terminal 100 is taken as an example for illustration. It can be understood that the specific form of the terminal 100 is not limited to a mobile phone .

The laser projector 10 can project laser light to a target object, and the laser light can be infrared light, and the laser light projected by the laser projector 10 can have specific patterns such as speckles or stripes. The infrared camera 20 can collect the infrared image of the target object, or receive the laser pattern modulated by the target object. In order to obtain a clearer laser pattern, it is usually necessary to continuously emit multiple frames of laser light to the target object with a certain optical power.

The control system 30 includes a first driving circuit 31 , a second driving circuit 32 , an application processor (Application Processor) 33 and a watchdog timer 34 , a microprocessor 35 and a distance sensor 36 .

The first driving circuit 31 is connected with the laser projector 10, and the first driving circuit 31 can be used to drive the laser projector 10 to project laser light. Specifically, the first driving circuit 31 is used as a current source of the laser projector 10. If the first driving circuit 31 If it is turned off, the laser projector 10 cannot emit laser light outward. The second driving circuit 32 is connected to the first driving circuit 31, and the second driving circuit 32 can be used to supply power to the first driving circuit 31, for example, the first driving circuit 31 can be a DC/DC circuit. The first driving circuit 31 can be separately packaged into a driving chip, and the second driving circuit 32 can also be separately packaged into a driving chip, or the first driving circuit 31 and the second driving circuit 32 can be packaged together in a driving chip, and the driving chip Both can be arranged on the substrate or the circuit board of the laser projector 10 .

The application processor 33 can serve as a system of the terminal 100 , the application processor 33 can be connected with the first driving circuit 31 , and the application processor 33 can also be connected with the infrared camera 20 . The application processor 33 can also be connected to multiple electronic components of the terminal 100 and control the multiple electronic components to operate in a predetermined mode, for example, controlling the display screen of the terminal 100 to display a predetermined picture, controlling the antenna of the terminal 100 to transmit or receive Predetermined data, the visible light camera 50 of the control terminal 100 acquires a color image and processes the color image, controls the power on and off of the infrared camera 20, turns off (pwdn) the infrared camera 20 or resets (reset) the infrared camera 20, and the like.

The application processor 33 can also be used to control the operation of the first driving circuit 31 to drive the laser projector 10 to project laser light. It can be understood that when the application processor 33 fails to operate, for example, when the application processor 33 is down, the first driving circuit 31 may Just in the state of continuously driving the laser projector 10 to emit laser light, and the continuous outward emission of laser light has a high risk, which may burn the user, especially the user's eyes. Therefore, it is necessary to monitor the running state of the application processor 33, and shut down the laser projector 10 in time when the application processor 33 fails.

In order to monitor the operating state of the application processor 33, the application processor 33 sends a predetermined signal to the monitoring timer 34 at a predetermined time interval, for example, sends a clear signal to the monitoring timer 34 every 50 milliseconds, when the application processor 33 is running In the event of a failure, the application processor 33 cannot run a program that sends a predetermined signal to the watchdog timer 34, so the failure state of the application processor 33 cannot be detected due to the failure to send a predetermined signal.

Please continue to refer to Fig. 1 and Fig. 2, the watchdog timer 34 is connected with the first driving circuit 31, and the watchdog timer 34 is connected with the application processor 33, and the watchdog timer 34 is used for shutting down when a predetermined signal is not received within a predetermined period of time. The first driving circuit 31 is used to turn off the laser projector 10 . The predetermined duration can be set by the terminal 100 when it leaves the factory, or can be customized on the terminal 100 according to the user.

Specifically, in the embodiment of the present invention, the watchdog timer 34 may be in the form of a counter. After the watchdog timer 34 receives a predetermined signal, the watchdog timer 34 starts counting down from a number at a certain speed. If the application processor 33 works normally, before counting down to 0, the application processor 33 will send a predetermined signal again, and the watchdog timer 34 will reset the countdown after receiving the predetermined signal; When the counter 34 counts to 0, the watchdog timer 34 judges that the application processor 33 is malfunctioning. At this time, the watchdog timer 34 sends a signal to turn off the first driving circuit 31 so that the laser projector 10 is turned off.

In one example, the watchdog timer 34 can be set outside the application processor 33, the watchdog timer 34 can be an external timer chip, and the watchdog timer 34 can be connected with an I/O pin of the application processor 33 And receive a predetermined signal sent by the application processor 33 . The plug-in watchdog timer 34 works with higher reliability. In another example, the watchdog timer 34 can be integrated in the application processor 33 , and the function of the watchdog timer 34 can be realized by an internal timer of the application processor 33 , which can simplify the hardware circuit design of the control system 30 .

In some implementations, the watchdog timer 34 is also used to send a reset signal for restarting the application processor 33 when a predetermined signal is not received within a predetermined time period. As mentioned above, when the watchdog timer 34 does not receive a predetermined signal within a predetermined time period, the application processor 33 has failed. At this time, the watchdog timer 34 sends a reset signal to reset the application processor 33 and work normally.

Specifically, in an example, the reset signal can be directly received by the application processor 33, the reset signal has a higher level in the execution program of the application processor 33, and the application processor 33 can respond to the reset signal first and reset . In another example, the reset signal may also be sent to a reset chip attached to the application processor 33, and the reset chip responds to the reset signal to force the application processor 33 to reset.

In some embodiments, the predetermined duration is [50, 150] milliseconds. Specifically, the predetermined duration may be set to 50 milliseconds, 62 milliseconds, 75 milliseconds, 97 milliseconds, 125 milliseconds, 150 milliseconds, etc., or any duration within the above range. It can be understood that if the predetermined duration is set too short, the application processor 33 is required to send the predetermined signal too frequently, which will occupy too much processing space of the application processor 33 and cause the operation of the terminal 100 to be easily stuck. If the predetermined duration is set too long, the failure of the application processor 33 cannot be detected in time, that is, the laser projector 10 cannot be turned off in time, which is not conducive to safe use of the laser projector 10 . Setting the predetermined duration to [50, 150] milliseconds can better balance the fluency and security of the terminal 100 .

Referring to FIG. 2 , the microprocessor 35 may be a processing chip, and the microprocessor 35 is connected to the application processor 33 , the microprocessor 35 and the first driving circuit 31 , and the microprocessor 35 is connected to the infrared camera 20 .

Microprocessor 35 is connected with application processor 33 so that application processor 33 can reset microprocessor 35, wake up (wake) microprocessor 35, error correction (debug) microprocessor 35 etc., microprocessor 35 can pass The mobile industry processor interface (Mobile Industry Processor Interface, MIPI) 351 is connected with the application processor 33, specifically, the microprocessor 35 is connected with the trusted execution environment (Trusted ExecutionEnvironment, TEE) of the application processor 33 through the mobile industry processor interface 351 ) 331 to directly transmit the data in the microprocessor 35 to the trusted execution environment 331. Among them, the code and memory area in the trusted execution environment 331 are all controlled by the access control unit, and cannot be accessed by programs in the non-trusted execution environment (Rich Execution Environment, REE) 332, the trusted execution environment 331 and the non-trusted execution environment Both trusted execution environments 332 can be formed in the application processor 33 .

The microprocessor 35 can be connected with the first driving circuit 31 through the pulse width modulation interface (Pulse Width Modulation, PWM) 352, and the microprocessor 35 can be connected with the infrared camera 20 through the I2C bus (Inter-Integrated Circuit) 70, and the microprocessor 35 Clock information for collecting infrared images and laser patterns can be provided to the infrared camera 20 , and the infrared images and laser patterns collected by the infrared camera 20 can be transmitted to the microprocessor 35 through the mobile industry processor interface 351 .

In one embodiment, an infrared template and a depth template used for identity verification may be stored in the trusted execution environment 331, the infrared template may be the infrared image of the face input by the user in advance, and the depth template may be the depth image of the face input by the user in advance . The infrared template and the depth template are stored in the trusted execution environment 331, which are not easy to be tampered with or embezzled, and the security of the information in the terminal 100 is relatively high.

When the user needs to verify the identity, the microprocessor 35 controls the infrared camera 20 to collect the infrared image of the user, and after obtaining the infrared image, it is transmitted to the trusted execution environment 331 of the application processor 33, and the application processor 33 is in the trusted execution environment. In step 331, the infrared image is compared with the infrared template, and if the two match, a verification result of passing the verification of the infrared template is output. During the matching process, the infrared image and the infrared template will not be acquired, tampered with or embezzled by other programs, thereby improving the information security of the terminal 100 .

Further, the microprocessor 35 can control the first drive circuit 31 to drive the laser projector 10 to project laser light outward, and control the infrared camera 20 to collect the laser pattern modulated by the target object, and the microprocessor 35 acquires and processes the laser pattern to obtain depth image. The depth image is transmitted to the trusted execution environment 331 of the application processor 33, and the application processor 33 compares the depth image with the depth template in the trusted execution environment 331, and if the two match, then outputs the depth template verification Passed verification result. During the matching process, the depth image and the depth template will not be acquired, tampered with or embezzled by other programs, which improves the information security of the terminal 100 .

The distance sensor 36 is connected to the application processor 33 , and the distance sensor 36 is used to detect the distance between the human eye and the laser projector 10 . The distance sensor 36 may be an optical distance sensor, an infrared distance sensor, an ultrasonic distance sensor, etc. In the embodiment of the present invention, the distance sensor 36 is an infrared distance sensor as an example for description. Distance sensor 36 comprises infrared light emitting end 361 and infrared light receiving end 362, and infrared light emitting end 361 is used for emitting infrared light, and infrared light receiving end 362 is used for receiving the infrared light that infrared light emitting end 361 emits and reflects through human body, with The distance between the human eye and the laser projector 10 is detected. Specifically, the distance sensor 36 can detect the distance between the human eye and the laser projector 10 according to the intensity of the infrared light received by the infrared light receiving end 362 . When the intensity of the infrared light received by the infrared light receiving end 362 is stronger, the distance between the human eye and the laser projector 10 is closer; when the intensity of the infrared light received by the infrared light receiving end 362 is weaker, the distance between the human eye and the laser The distance between the projectors 10 is farther. The distance sensor 36 can also detect the distance between the human eye and the laser projector 10 according to the time difference between the infrared light receiving end 362 receiving the infrared light and the infrared light emitting end 361 emitting the infrared light. When the time difference is smaller, the distance between the human eye and the laser projector 10 is closer; when the time difference is larger, the distance between the human eye and the laser projector 10 is farther.

The distance sensor 36 can detect the closer the distance between the human eye and the laser projector 10 before the laser projector 10 works, and can also detect the distance between the human eye and the laser projector 10 in real time during the working process of the laser projector 10 . In this way, when the distance between the human eye and the laser projector 10 changes, it can also be detected in time, so that corresponding measures can be taken to avoid damage to the human eye.

In one embodiment, the distance sensor 36 detects the distance between the human eye and the laser projector 10 according to a predetermined cycle. For example, the distance sensor 36 detects the distance between the human eye and the laser projector 10 every 500 milliseconds, so as to be able to detect the change of the distance between the human eye and the laser projector 10 in time, and take into account the power consumption of the terminal 100 .

In order to ensure that the infrared light emitted by the infrared light emitting end 361 will not interfere with the laser projected by the laser projector 10, the frequency (or phase) of the infrared light emitted by the infrared light emitting end 361 can be compared with the frequency (or phase) of the laser projected by the laser projector 10 ( or phase) are different; or the wavelength of the infrared light emitted by the infrared light emitting end 361 and the wavelength of the laser light projected by the laser projector 10 may be different. For example, the wavelength of the infrared light emitted by the infrared light emitting end 361 is λ1, and the wavelength of the laser light projected by the laser projector 10 is λ2, where λ1≠λ2. Correspondingly, the infrared light receiving end 362 is used to receive infrared light with a wavelength of λ1, and the infrared camera 20 is used to receive infrared light with a wavelength of λ2.

Please refer to FIG. 3 , in some implementations, the above method of detecting the distance between the human eye and the laser projector 10 through the distance sensor 36 can be replaced by: the microprocessor 35 detects the distance between the human eye and the laser projector 10 according to the laser pattern received by the infrared camera 20 The distance from the laser projector 10. At this time, the infrared camera 20 serves as a part of the control system 30 .

Specifically, the microprocessor 35 controls the first driving circuit 31 to drive the laser projector 10 to project laser light to the target object, and controls the infrared camera 20 to collect the laser pattern modulated by the target object, and then the microprocessor 35 acquires and processes the laser pattern to The initial depth image is obtained, and the distance between the human eye and the laser projector 10 is detected according to the depth image. It can be understood that the depth image includes depth data, and the process for the microprocessor 35 to detect the distance between the human eye and the laser projector 10 according to the depth image is: convert the depth data into point cloud data with three-dimensional coordinates, and the format of the point cloud data is is (x, y, z); then the point cloud data is filtered to remove outliers and noises; then the distance between the human eye and the laser projector 10 is obtained according to the z value of the point cloud data of the filtering process. distance. In one example, the microprocessor 35 can determine the distance between the human eye and the laser projector 10 according to the minimum value among multiple z values of the point cloud data, so as to ensure that the laser light projected by the laser projection module 10 will not hurt the user. damage to the eyes. In this embodiment, the laser projector 10 projects laser light for infrared distance measurement, and the intensity of the laser light projected by the laser projector 10 can be less than the intensity of the laser light projected when the laser projector 10 works normally, so as to reduce energy consumption and ensure the distance measurement process Safe for the human eye.

In one embodiment, the laser projector 10 projects laser light to the target object according to a preset period, so as to periodically detect the distance between the human eye and the laser projector 10 . For example, the laser projector 10 projects a laser to the target object every 500 milliseconds to detect the distance between the human eye and the laser projector 10, so as to detect the change of the distance between the human eye and the laser projector 10 in time, and take into account Power consumption of the terminal 100.

In some implementations, the microprocessor 35 can also control the infrared camera 20 to collect the infrared image of the user, and detect the distance between the human eye and the laser projector 10 according to the depth image combined with the infrared image. Specifically, the microprocessor 35 can detect the key points of the human face through the infrared image to determine the two-dimensional coordinates of the human eye, and then register and align the infrared image and the depth image, and search the depth image according to the two-dimensional coordinates of the human eye. The corresponding feature points corresponding to the human eyes, and then obtain the three-dimensional coordinates of the corresponding feature points, and then obtain the distance between the human eyes and the laser projector 10 according to the three-dimensional coordinates of the corresponding feature points. Compared with the method of directly detecting the distance between the human eye and the laser projector 10 based on the depth image, this embodiment can detect the specific position of the human eye based on the infrared image, so that the distance between the human eye and the laser projector 10 can be detected more accurately. The distance between 10.

After detecting the distance between the human eye and the laser projector 10 through the above-mentioned methods, the application processor 33 sends a corresponding control signal to the microprocessor 35 according to the distance between the human eye and the laser projector 10, and the microprocessor 35 and then control the first driving circuit 31 according to the control signal, so that the laser projector 10 projects laser light with predetermined parameters.

Specifically, the parameter includes at least one of a current parameter (or a power parameter, or other parameters positively correlated with the current parameter), a frame rate parameter, and a pulse width parameter. That is to say, the microprocessor 35 controls the first drive circuit 31 according to the control signal, so that the laser projector 10 projects laser light with predetermined current parameters; or projects laser light with predetermined frame rate parameters; or projects laser light with predetermined pulse width parameters Projecting laser light; or projecting laser light with predetermined current parameters and predetermined frame rate parameters; or projecting laser light with predetermined current parameters and predetermined pulse width parameters; or projecting laser light with predetermined frame rate parameters and predetermined pulse width parameters; or Laser light is projected with predetermined current parameters, predetermined frame rate parameters, and predetermined pulse width parameters.

In order to prevent the laser projected by the laser projector 10 from causing damage to the human eye, when the distance between the human eye and the laser projector 10 is smaller, the predetermined current parameter is smaller; the predetermined frame rate parameter is smaller; the predetermined pulse width parameter smaller. For example, assuming that the distance between the human eye and the laser projector 10 is d, when the distance d≥20cm, the laser projector 10 can project laser light with the current parameter I0, frame rate parameter F0, and pulse width parameter P0 during normal operation; When the distance 10≤d<20cm, the laser projector 10 projects laser light with the current parameter I1, the frame rate parameter F1, and the pulse width parameter P1; when the distance d<10cm, the laser projector 10 uses the current parameter I2 and the frame rate parameter F2 , The pulse width parameter P2 projects the laser light, wherein, I2<I1<I0, F2<F1<F0, P2<P1<P0.

To sum up, in the terminal 100 according to the embodiment of the present invention, the control system 30 controls the parameters of the laser projected by the laser projector 10 according to the distance between the human eye and the laser projector 10, specifically the distance between the human eye and the laser projector 10 When the distance is small, the current parameters, frame rate parameters and pulse width parameters of the laser projected by the laser projector 10 are reduced, so as to prevent damage to the user's eyes.

Please refer to FIG. 4 , in some implementations, the parameters of the laser projected by the laser projector 10 include current parameters. The application processor 33 is configured to send a first control signal to the microprocessor 35 when the distance between the human eye and the laser projector 10 is greater than a predetermined distance. The microprocessor 35 controls the first driving circuit 31 according to the first control signal, so that the laser projector 10 projects laser light with the first current parameter (as shown in FIG. 4( a )). The application processor 33 is configured to send a second control signal to the microprocessor 35 when the distance between the human eye and the laser projector 10 is less than or equal to a predetermined distance. The microprocessor 35 controls the first driving circuit 31 according to the second control signal, so that the laser projector 10 projects laser light with the second current parameter (as shown in FIG. 4( b ), wherein the second current parameter is smaller than the first current parameter parameter. It can be understood that the predetermined distance can be understood as a safe distance for the human eye. When the distance between the human eye and the laser projector 10 is greater than the predetermined distance, as long as the diffractive optical elements and collimation elements of the laser projector 10 do not break, fall off, etc. In this case, the laser projector 10 can maintain the current parameter (ie, the first current parameter) during normal operation to project laser light. And when the distance between the human eye and the laser projector 10 is less than or equal to the predetermined distance, the distance between the human eye and the laser projector 10 is too short, and the laser projector 10 needs to reduce the current parameter to ensure the safety of the human eye.

Please refer to FIG. 5 , in some implementations, the parameters of laser projection by the laser projector 10 include frame rate parameters. The application processor 33 is configured to send a first control signal to the microprocessor 35 when the distance between the human eye and the laser projector 10 is greater than a predetermined distance. The microprocessor 35 controls the first driving circuit 31 according to the first control signal, so that the laser projector 10 projects laser light with the first frame rate parameter (as shown in FIG. 5( a )). The application processor 33 is configured to send a second control signal to the microprocessor 35 when the distance between the human eye and the laser projector 10 is less than or equal to a predetermined distance. The microprocessor 35 controls the first driving circuit 31 according to the second control signal, so that the laser projector 10 projects laser light with the second frame rate parameter (as shown in FIG. 5( a)), wherein the second frame rate parameter is smaller than the first A frame rate parameter. It can be understood that the predetermined distance can be understood as a safe distance for the human eye. When the distance between the human eye and the laser projector 10 is greater than the predetermined distance, as long as the diffractive optical elements and collimation elements of the laser projector 10 do not break, fall off, etc. In this case, the laser projector 10 can maintain the frame rate parameter (ie, the first frame rate parameter) during normal operation to project laser light. And when the distance between the human eye and the laser projector 10 is less than or equal to the predetermined distance, the distance between the human eye and the laser projector 10 is too short, and the laser projector 10 needs to reduce the frame rate parameter to ensure human eye safety.

Please refer to FIG. 6 , in some implementations, the parameters of the laser projected by the laser projector 10 include a pulse width parameter. The application processor 33 is configured to send a first control signal to the microprocessor 35 when the distance between the human eye and the laser projector 10 is greater than a predetermined distance. The microprocessor 35 controls the first driving circuit 31 according to the first control signal, so that the laser projector 10 projects laser light with the first pulse width parameter (as shown in FIG. 6( a )). The application processor 33 is configured to send a second control signal to the microprocessor 35 when the distance between the human eye and the laser projector 10 is less than or equal to a predetermined distance. The microprocessor 35 controls the first driving circuit 31 according to the second control signal, so that the laser projector 10 projects laser light with the second pulse width parameter (as shown in FIG. 6( a)), wherein the second pulse width parameter is smaller than the first pulse width parameter A pulse width parameter. It can be understood that the predetermined distance can be understood as a safe distance for the human eye. When the distance between the human eye and the laser projector 10 is greater than the predetermined distance, as long as the diffractive optical elements and collimation elements of the laser projector 10 do not break, fall off, etc. In this case, the laser projector 10 can maintain the pulse width parameter (ie, the first pulse width parameter) during normal operation to project laser light. And when the distance between the human eye and the laser projector 10 is less than or equal to the predetermined distance, the distance between the human eye and the laser projector 10 is too short, and the laser projector 10 needs to reduce the pulse width parameter to ensure the safety of human eyes.

Referring to Fig. 2 and Fig. 7, the laser projector 10 according to the embodiment of the present invention is connected to the first driving circuit 31, and the control method of the laser projector 10 includes:

10: the distance sensor 36 detects the distance between the human eye and the laser projector 10;

20: The application processor 33 sends a corresponding control signal to the microprocessor 35 according to the distance between the human eye and the laser projector 10; and

30: The microprocessor 35 controls the first driving circuit 31 according to the control signal so that the laser projector 10 projects laser light with predetermined parameters.

The control method in the embodiment of the present invention controls the parameters of the laser beam projected by the laser projector 10 according to the distance between the human eye and the laser projector 10. Specifically, when the distance between the human eye and the laser projector 10 is small, the 10 Project the current parameters, frame rate parameters and pulse width parameters of the laser, so as to prevent harm to the user's eyes. For implementation details of the control method, reference may be made to the above specific description of the terminal 100 , and details are not repeated here.

Referring to Fig. 3 and Fig. 8, above-mentioned step 10 can be replaced by step 11, step 12 and step 13, that is to say, the control method of laser projector 10 can comprise:

11: The first drive circuit 31 drives the laser projector 10 to project laser light to the target object;

12: The infrared camera 20 receives the laser pattern modulated by the target object;

13: The microprocessor 35 processes the laser pattern to obtain the distance between the human eye and the laser projector 10;

20: The application processor 33 sends a corresponding control signal to the microprocessor 35 according to the distance between the human eye and the laser projector 10; and

30: The microprocessor 35 controls the first driving circuit 31 according to the control signal so that the laser projector 10 projects laser light with predetermined parameters.

Please refer to FIG. 9 , in some embodiments, the step of the application processor 33 sending a corresponding control signal to the microprocessor 35 according to the distance between the human eye and the laser projector 10 (that is, step 20) includes:

21: The application processor 33 sends a first control signal to the microprocessor 35 when the distance between the human eye and the laser projector 10 is greater than a predetermined distance; and

22: The application processor 33 sends a second control signal to the microprocessor 35 when the distance between the human eye and the laser projector 10 is less than or equal to a predetermined distance.

Please refer to FIG. 10 and FIG. 11 , in some embodiments, the parameters include current parameters, and the microprocessor 35 controls the first drive circuit 31 according to the control signal so that the laser projector 10 projects the laser with predetermined parameters (ie step 30 )include:

31: the microprocessor 35 controls the first drive circuit 31 according to the first control signal, so that the laser projector 10 projects laser light with the first current parameter; and

32: The microprocessor 35 controls the first driving circuit 31 according to the second control signal, so that the laser projector 10 projects laser light with a second current parameter, wherein the second current parameter is smaller than the first current parameter.

In some embodiments, the parameters include a frame rate parameter, and the microprocessor 35 controls the first driving circuit 31 according to the control signal so that the laser projector 10 projects laser light with predetermined parameters (ie, step 50) includes:

33: the microprocessor 35 controls the first drive circuit 31 according to the first control signal, so that the laser projector 10 projects laser light with the first frame rate parameter; and

34: The microprocessor 35 controls the first driving circuit 31 according to the second control signal, so that the laser projector 10 projects laser light at a second frame rate parameter, wherein the second frame rate parameter is smaller than the first frame rate parameter

In some embodiments, the parameters include a pulse width parameter, and the microprocessor 35 controls the first drive circuit 31 according to the control signal so that the laser projector 10 projects laser light with predetermined parameters (ie step 50) includes:

35: the microprocessor 35 controls the first drive circuit 31 according to the first control signal, so that the laser projector 10 projects laser light with the first pulse width parameter; and

36: The microprocessor 35 controls the first driving circuit 31 according to the second control signal, so that the laser projector 10 projects laser light with a second pulse width parameter, wherein the second pulse width parameter is smaller than the first pulse width parameter.

Referring to FIG. 12 , the embodiment of the present invention also provides a laser projection assembly 60 , which includes a laser projector 10 , a first drive circuit 31 , a second drive circuit 32 and a watchdog timer 34 . At this time, the first driving circuit 31 , the second driving circuit 32 and the watchdog timer 34 can all be integrated into the substrate assembly 11 of the laser projector 10 .

Referring to FIG. 12 , in some embodiments, the laser projector 10 includes a substrate assembly 11 , a lens barrel 12 , a light source 13 , a collimator 14 , a diffractive optical element (DOE) 15 , and a protective cover 16 .

The substrate assembly 11 includes a substrate 111 and a circuit board 112 . The circuit board 112 is arranged on the substrate 111, and the circuit board 112 is used to connect the light source 13 and the main board of the terminal 100. The circuit board 112 can be a rigid board, a flexible board or a combination of rigid and flexible boards. In the embodiment shown in FIG. 12 , a through hole 1121 is opened on the circuit board 112 , and the light source 13 is fixed on the substrate 111 and electrically connected to the circuit board 112 . Heat dissipation holes 1111 may be provided on the substrate 111, and the heat generated by the light source 13 or the circuit board 112 may be dissipated through the heat dissipation holes 1111. The heat dissipation holes 1111 may also be filled with thermal conductive glue to further improve the heat dissipation performance of the substrate assembly 11.

The lens barrel 12 is fixedly connected with the substrate assembly 11, the lens barrel 12 is formed with a receiving cavity 121, the lens barrel 12 includes a top wall 122 and an annular peripheral wall 124 extending from the top wall 122, the peripheral wall 124 is arranged on the substrate assembly 11, and the top wall 122 A light hole 1212 communicating with the receiving cavity 121 is defined. The peripheral wall 124 may be connected to the circuit board 112 by glue.

The protective cover 16 is disposed on the top wall 122 . The protective cover 16 includes a baffle 162 defining a light exit hole 160 and an annular sidewall 164 extending from the baffle 162 .

Both the light source 13 and the collimating element 14 are disposed in the housing cavity 121 , the diffractive optical element 15 is installed on the lens barrel 12 , and the collimating element 14 and the diffractive optical element 15 are sequentially disposed on the light emitting path of the light source 13 . The collimating element 14 collimates the laser light emitted by the light source 13 , and the laser light passes through the collimating element 14 and then passes through the diffractive optical element 15 to form a laser pattern.

The light source 13 may be a vertical cavity surface emitting laser (Vertical Cavity Surface Emitting Laser, VCSEL) or an edge-emitting laser (edge-emitting laser, EEL). In the embodiment shown in FIG. 12 , the light source 13 is an edge-emitting laser, specifically , the light source 13 may be a distributed feedback laser (Distributed Feedback Laser, DFB). The light source 13 is used for emitting laser light into the receiving cavity 121 . Please refer to FIG. 13 , the light source 13 has a cylindrical shape as a whole, and an end surface of the light source 13 away from the substrate assembly 11 forms a light-emitting surface 131 , from which the laser light is emitted, and the light-emitting surface 131 faces the collimator 14 . The light source 13 is fixed on the substrate assembly 11 , specifically, the light source 13 can be bonded to the substrate assembly 11 through the sealant 17 , for example, the surface of the light source 13 opposite to the light-emitting surface 131 is bonded to the substrate assembly 11 . Please combine Figure 12 and Figure 14, the side 132 of the light source 13 can also be bonded on the substrate assembly 11, and the sealing glue 17 can wrap the surrounding side 132, or only a certain surface of the side 132 can be bonded to the substrate assembly 11 or Junction certain surfaces and the substrate assembly 11 . At this time, the sealing glue 17 can be a heat-conducting glue, so as to conduct the heat generated by the light source 13 to the substrate assembly 11 .

Please refer to FIG. 12 , the diffractive optical element 15 is carried on the top wall 122 and accommodated in the protective cover 16 . Two opposite sides of the diffractive optical element 15 are in contact with the protective cover 16 and the top wall 122 respectively. The baffle 162 includes an opposing surface 1622 close to the light hole 1212 . The diffractive optical element 15 is in contact with the opposing surface 1622 .

Specifically, the diffractive optical element 15 includes a diffractive incident surface 152 and a diffractive output surface 154 opposite to each other. The diffractive optical element 15 is carried on the top wall 122 , the diffractive outgoing surface 154 collides with the surface of the baffle 162 close to the light hole 1212 (the conflicting surface 1622 ), and the diffractive incident surface 152 collides with the top wall 122 . The light through hole 1212 is aligned with the receiving cavity 121 , and the light output through hole 160 is aligned with the light through hole 1212 . The top wall 122 , the annular side wall 164 and the baffle 162 are in contact with the diffractive optical element 15 , thereby preventing the diffractive optical element 15 from falling out of the protective cover 16 along the light emitting direction. In some embodiments, the protective cover 16 is attached to the top wall 122 by glue.

The light source 13 of the above-mentioned laser projector 10 adopts a side-emitting laser. On the one hand, the temperature drift of the side-emitting laser is smaller than that of the VCSEL array; The cost of the light source of the laser projector 10 is relatively low.

When the laser light of the distributed feedback laser is propagating, the power gain is obtained through the feedback of the grating structure. To increase the power of the distributed feedback laser, it is necessary to increase the injection current and/or increase the length of the distributed feedback laser, because increasing the injection current will increase the power consumption of the distributed feedback laser and cause serious heating problems, so , in order to ensure that the distributed feedback laser can work normally, it is necessary to increase the length of the distributed feedback laser, resulting in the distributed feedback laser generally having a slender strip structure. When the light-emitting surface 131 of the side-emitting laser is facing the collimation element 14, the side-emitting laser is placed vertically. Since the side-emitting laser is in a slender structure, the side-emitting laser is prone to accidents such as falling, shifting or shaking. Therefore, by setting The sealant 17 can fix the side-emitting laser to prevent accidents such as dropping, displacement or shaking of the side-emitting laser.

Please refer to FIG. 12 and FIG. 15 , in some embodiments, the light source 13 can also be fixed on the substrate assembly 11 in a fixing manner as shown in FIG. 15 . Specifically, the laser projector 10 includes a plurality of support blocks 18, the support blocks 18 can be fixed on the substrate assembly 11, and the plurality of support blocks 18 surround the light source 13 together, and the light source 13 can be directly installed on the plurality of support blocks 18 during installation. between. In one example, a plurality of supporting blocks 18 jointly clamp the light source 13 to further prevent the light source 13 from shaking.

In some embodiments, the protective cover 16 can be omitted, and the diffractive optical element 15 can be arranged in the receiving cavity 121 at this time, the diffractive exit surface 154 of the diffractive optical element 15 can be against the top wall 122, and the laser light passes through the diffractive optical element 15 Then pass through the light hole 1212. In this way, the diffractive optical element 15 is less likely to fall off.

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

In the description of this specification, references to the terms "certain embodiments," "one embodiment," "some embodiments," "exemplary embodiments," "examples," "specific examples," or "some examples" To describe means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of said features. In the description of the present invention, "plurality" means at least two, such as two, three, unless otherwise specifically defined.

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

Claims (14)

1. a kind of control system of laser projecting apparatus, which is characterized in that the control system includes：

Range sensor, the range sensor is for detecting the distance between human eye and the laser projecting apparatus；

First driving circuit, first driving circuit are connect with the laser projecting apparatus, and first driving circuit is for driving The dynamic laser projecting apparatus projects laser；

Microprocessor, the microprocessor are connect with first driving circuit；With

Application processor, the application processor and the range sensor, the application processor and the microprocessor are equal Connection, the application processor are used for according to the corresponding control letter of the distance between the human eye and laser projecting apparatus transmission Number to the microprocessor, the microprocessor controls first driving circuit according to the control signal, so that described sharp Light projector projects laser with predefined parameter.

2. control system according to claim 1, which is characterized in that the parameter includes current parameters, frame per second parameter, arteries and veins At least one of wide parameter.

3. control system according to claim 1, which is characterized in that the parameter includes current parameters；

The application processor is used to send when being more than preset distance at a distance from the human eye is between the laser projecting apparatus First control signal is to the microprocessor, and the microprocessor is according to first control signal control the first driving electricity Road, so that the laser projecting apparatus projects laser with the first current parameters；

The application processor is used to be less than or equal at a distance from the human eye is between the laser projecting apparatus described predetermined Apart from when send second control signal to the microprocessor, described in the microprocessor is controlled according to the second control signal First driving circuit, so that the laser projecting apparatus projects laser with the second current parameters, wherein second current parameters are small In first current parameters.

4. control system according to claim 1, which is characterized in that the parameter includes frame per second parameter；

The application processor is used to send when being more than preset distance at a distance from the human eye is between the laser projecting apparatus First control signal is to the microprocessor, and the microprocessor is according to first control signal control the first driving electricity Road, so that the laser projecting apparatus projects laser with the first frame per second parameter；

The application processor is used to be less than or equal at a distance from the human eye is between the laser projecting apparatus described predetermined Apart from when send second control signal to the microprocessor, described in the microprocessor is controlled according to the second control signal First driving circuit, so that the laser projecting apparatus projects laser with the second frame per second parameter, wherein the second frame per second parameter is small In the first frame per second parameter.

5. control system according to claim 1, which is characterized in that the parameter includes width parameter；

The application processor is used to send when being more than preset distance at a distance from the human eye is between the laser projecting apparatus First control signal is to the microprocessor, and the microprocessor is according to first control signal control the first driving electricity Road, so that the laser projecting apparatus projects laser with the first width parameter；

The application processor is used to be less than or equal at a distance from the human eye is between the laser projecting apparatus described predetermined Apart from when send second control signal to the microprocessor, described in the microprocessor is controlled according to the second control signal First driving circuit, so that the laser projecting apparatus projects laser with the second width parameter, wherein second width parameter is small In first width parameter.

6. control system according to claim 1, which is characterized in that the range sensor detects institute according to predetermined period State the distance between human eye and the laser projecting apparatus.

7. control system according to claim 1, which is characterized in that the control system further includes：

Second driving circuit, second driving circuit connect with first driving circuit and are used for the first driving electricity Road powers.

8. a kind of terminal, which is characterized in that the terminal includes：

Laser projecting apparatus；With

Control system described in claim 1 to 7 any one, first driving circuit are connect with the laser projecting apparatus.

9. terminal according to claim 8, which is characterized in that the laser projecting apparatus can be projected to target object to swash Light, the terminal further include：

Infrared camera, the infrared camera can be received by the modulated laser pattern of the target object.

10. a kind of control method of laser projecting apparatus, which is characterized in that the laser projecting apparatus is connect with the first driving circuit, The control method includes：

Range sensor detects the distance between human eye and the laser projecting apparatus；

Application processor is according to the corresponding control signal of the distance between the human eye and laser projecting apparatus transmission to micro- place Manage device；With

The microprocessor controls first driving circuit so that the laser projecting apparatus is with predetermined according to the control signal Parameter projects laser.

11. control method according to claim 10, which is characterized in that the application processor is according to the human eye and institute It states the distance between laser projecting apparatus and sends corresponding control signal to the step of microprocessor and include：

The application processor sends first when being more than preset distance at a distance from the human eye is between the laser projecting apparatus Signal is controlled to the microprocessor；With

The application processor is less than or equal to the preset distance at a distance from the human eye is between the laser projecting apparatus When send second control signal to the microprocessor.

12. control method according to claim 11, which is characterized in that the parameter includes current parameters, micro- place It manages device and first driving circuit is controlled so that the laser projecting apparatus projects laser with predefined parameter according to the control signal The step of include：

The microprocessor controls first driving circuit according to the first control signal so that the laser projecting apparatus with First current parameters project laser；With

The microprocessor controls first driving circuit according to the second control signal so that the laser projecting apparatus with Second current parameters project laser, wherein second current parameters are less than first current parameters.

13. control method according to claim 11, which is characterized in that the parameter includes frame per second parameter, micro- place It manages device and first driving circuit is controlled so that the laser projecting apparatus projects laser with predefined parameter according to the control signal The step of include：

The microprocessor controls first driving circuit according to the first control signal so that the laser projecting apparatus with First frame per second parameter projects laser；With

The microprocessor controls first driving circuit according to the second control signal so that the laser projecting apparatus with Second frame per second parameter projects laser, wherein the second frame per second parameter is less than the first frame per second parameter.

14. control method according to claim 11, which is characterized in that the parameter includes width parameter, micro- place It manages device and first driving circuit is controlled so that the laser projecting apparatus projects laser with predefined parameter according to the control signal The step of include：

The microprocessor controls first driving circuit according to the first control signal so that the laser projecting apparatus with First width parameter projects laser；With

The microprocessor controls first driving circuit according to the second control signal so that the laser projecting apparatus with Second width parameter projects laser, wherein second width parameter is less than first width parameter.