Laser sensor control circuit, method and electronic device

Abstract

The present application discloses a laser sensor control circuit, method and electronic device, which belongs to the field of sensor control technology. Among them, the laser sensor control circuit includes: a laser sensor module, an electrical signal detection module, a first switch and an impedance adjustment module; the first end of the laser sensor module is connected to the power supply, the second end of the laser sensor module is connected to the impedance adjustment module through the first switch, and the electrical signal detection module is connected to the first end of the laser sensor module; the impedance adjustment module is used to adjust the impedance value of the impedance adjustment module according to the ambient temperature when the laser sensor module is in a discharge state, so that the electrical signal value of the laser sensor module at the first preset discharge time is less than the first electrical signal threshold. The embodiment of the present application can avoid abnormal discharge of the laser sensor due to changes in ambient temperature, and can improve the reliability of the laser sensor.

Description

Technical Field

[0001] The present application belongs to the field of sensor control technology, and specifically relates to a laser sensor control circuit, method and electronic device. Background Art

[0002] In the prior art, lasers are widely used in the field of distance measurement technology due to their high directivity, high monochromaticity, high brightness and other characteristics. For example, laser sensors are used to realize functions such as turning the screen on and off, preventing accidental touches, and assisting camera focus.

[0003] In the related art, the discharge speed of the laser sensor is affected by the ambient temperature, so that when the ambient temperature is low, the discharge speed of the laser sensor is easily reduced, thereby causing discharge abnormality.

[0004] As can be seen from the above, the laser sensor in the related art has the problem of abnormal discharge due to the influence of ambient temperature changes. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a laser sensor control circuit, method and electronic device, which can solve the problem of abnormal discharge of laser sensors in related technologies due to changes in ambient temperature.

[0006] In order to solve the above technical problems, this application is implemented as follows:

[0007] In a first aspect, an embodiment of the present application provides a laser sensor control circuit, including: a laser sensor module, an electrical signal detection module, a first switch and an impedance adjustment module;

[0008] The first end of the laser sensor module is connected to a power source, the second end of the laser sensor module is connected to the impedance adjustment module through the first switch, and the electrical signal detection module is connected to the first end of the laser sensor module;

[0009] When the first switch is closed and the power supply stops supplying power to the laser sensor module, the laser sensor module is in a discharging state;

[0010] The impedance adjustment module is used to adjust the impedance value of the impedance adjustment module according to the ambient temperature when the laser sensor module is in a discharge state, so that the electrical signal value of the laser sensor module during the first preset discharge time is less than the first electrical signal threshold.

[0011] In a second aspect, an embodiment of the present application provides an electronic device, comprising the laser sensor control circuit as described in the first aspect.

[0012] In a third aspect, an embodiment of the present application provides a laser sensor control method, which is applied to the electronic device as described in the second aspect, and the method includes:

[0013] Detect ambient temperature;

[0014] When the laser sensor module is in a discharging state, if the ambient temperature is less than or equal to a first temperature threshold, the impedance value of the discharge path of the laser sensor module is reduced according to the ambient temperature so that the electrical signal value of the laser sensor module during the first preset discharge time is less than the first electrical signal threshold.

[0015] In a fourth aspect, an embodiment of the present application provides a laser sensor control device, which is applied to an electronic device, wherein the electronic device includes a laser sensor, and the device includes:

[0016] A detection module, used for detecting the ambient temperature;

[0017] The impedance adjustment module is used to adjust the impedance value of the discharge path of the laser sensor module according to the ambient temperature when the laser sensor module is in a discharge state, so that the electrical signal value of the laser sensor module when discharging for a first preset time is less than a first electrical signal threshold.

[0018] In a fifth aspect, an embodiment of the present application provides an electronic device, which includes a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein the program or instruction, when executed by the processor, implements the steps of the method described in the third aspect.

[0019] In a sixth aspect, an embodiment of the present application provides a readable storage medium, on which a program or instruction is stored, and when the program or instruction is executed by a processor, the steps of the method described in the third aspect are implemented.

[0020] In a seventh aspect, an embodiment of the present application provides a chip, comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run a program or instruction to implement the method described in the third aspect.

[0021] In an embodiment of the present application, a laser sensor control circuit includes: a laser sensor module, an electrical signal detection module, a first switch and an impedance adjustment module; the first end of the laser sensor module is connected to a power source, the second end of the laser sensor module is connected to the impedance adjustment module through the first switch, and the electrical signal detection module is connected to the first end of the laser sensor module; when the first switch is closed and the power source stops supplying power to the laser sensor module, the laser sensor module is in a discharge state; the impedance adjustment module is used to adjust the impedance value of the impedance adjustment module according to the ambient temperature when the laser sensor module is in the discharge state, so that the electrical signal value of the laser sensor module at the first preset time of discharge is less than the first electrical signal threshold. In this way, when the ambient temperature changes, the discharge path impedance of the laser sensor module can be adjusted by the impedance adjustment module, so that the discharge speed of the laser sensor module is kept within a stable range, so that the electrical signal value at the first preset time of discharge of the laser sensor module is less than the first electrical signal threshold, so that the laser sensor can also work normally in a temperature change environment, that is, the reliability of the laser sensor is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a circuit diagram of a laser sensor control circuit provided in an embodiment of the present application;

[0023] Figure 2 is a circuit diagram of another laser sensor control circuit provided in an embodiment of the present application;

[0024] Figure 3 is a flowchart of another laser sensor control circuit provided in an embodiment of the present application;

[0025] Figure 4 is a flow chart of a laser sensor control method provided in an embodiment of the present application;

[0026] Figure 5 is a structural diagram of a laser sensor control device provided in an embodiment of the present application;

[0027] Figure 6 It is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0029] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0030] Laser sensors are one of the most significant scientific and technological achievements that emerged in the 1960s. Today, with the popularization and development of electronic devices, the role played by laser sensors has also increased. Lasers have the characteristics of high directivity, high monochromaticity, and high brightness, so they are often used in the field of distance measurement. Based on the characteristics of laser sensors, electronic devices have realized functions such as screen on and off, anti-mistouch, and auxiliary camera focus.

[0031] However, in practical applications, laser sensors need to be precisely controlled to prevent laser damage to human eyes. Therefore, laser sensors are usually equipped with eye protection mechanisms. Taking the eye protection mechanism of vertical-cavity surface-emitting laser (VCSEL) as an example, the core idea of ​​this eye protection mechanism is to prevent laser damage to human eyes by controlling the brightness, working time, field of view (FOV) and other parameters of VCSEL.

[0032] The working time of VCSEL includes: charging time, normal conduction working time and discharge time. In practical applications, in order to improve the working efficiency of the laser transmitter, the discharge time of VCSEL is certain. During this time, VCSEL needs to be fully discharged, and the discharge current cannot be too large to avoid burning the devices in the discharge path.

[0033] However, since VCSEL has a negative temperature characteristic, that is, when the temperature decreases, the on-resistance of VCSEL increases, so that the discharge speed of VCSEL slows down, so that a longer discharge time is required to completely discharge the VCSEL. If the time required to completely discharge the VCSEL is longer than the preset discharge time set for the VCSEL, then when the VCSEL discharges for the preset discharge time, the VCSEL is not completely discharged, so when the VCSEL is started next time, problems such as flickering caused by abnormal discharge will occur.

[0034] The laser sensor control circuit provided in the embodiment of the present application can adjust the impedance value in the discharge path of the laser sensor according to the change of the ambient temperature, so as to reduce the discharge path impedance when the temperature is low, so as to increase the discharge speed, thereby ensuring that the laser sensor can be completely discharged within the preset discharge time, so as to avoid the problem of poor reliability of the laser sensor caused by abnormal discharge; in addition, the laser sensor control circuit provided in the embodiment of the present application can also increase the discharge path impedance when the temperature is high, so as to slow down the discharge speed, thereby limiting the discharge current of the laser sensor.

[0035] The laser sensor control circuit, method, electronic device, etc. provided in the embodiments of the present application are described in detail below with reference to the accompanying drawings through specific embodiments and their application scenarios.

[0036] See also Figure 1 , is a circuit diagram of a laser sensor control circuit provided in an embodiment of the present application, such as Figure 1 As shown, the laser sensor control circuit includes: a laser sensor module 1, an electrical signal detection module 2, a first switch 3 and an impedance adjustment module 4;

[0037] The first end of the laser sensor module 1 is connected to the power supply Vc, the second end of the laser sensor module 1 is connected to the impedance adjustment module 4 through the first switch 3, and the electrical signal detection module 2 is connected to the first end of the laser sensor module 1;

[0038] When the first switch 3 is closed and the power source Vc stops supplying power to the laser sensor module 1, the laser sensor module 1 is in a discharging state;

[0039] The impedance adjustment module 4 is used to adjust the impedance value of the impedance adjustment module 4 according to the ambient temperature when the laser sensor module 1 is in a discharging state, so that the electrical signal value of the laser sensor module 1 during the first preset discharging time is less than the first electrical signal threshold.

[0040] In another optional embodiment, the first preset time may be any time when the laser sensor module 1 is in a discharge state, and the first electrical signal threshold may be the maximum discharge current that the discharge path of the laser sensor module 1 can withstand. In this way, the discharge current in the discharge path of the laser sensor module 1 is limited by adjusting the impedance value of the impedance adjustment module 4, so as to avoid the burning of the components in the discharge path of the laser sensor module 1 due to overcurrent caused by abnormal discharge.

[0041] Among them, Figure 2As shown, the laser sensor module 1 may specifically include a laser emitter 11 and a junction capacitor C connected in parallel with the laser emitter 11, and the laser sensor module 1 is charged and discharged through the junction capacitor C. In addition, the power supply Vc may be a charging pump, and when the laser sensor finishes emitting the laser, the charging pump will be turned off, and the first switch 3 will be closed, so that the laser sensor module 1 starts to discharge.

[0042] Furthermore, the electrical signal detection module 2 can detect the potential of the junction capacitor C at one end close to the power supply Vc, so as to determine whether the laser sensor module 1 is fully discharged according to the magnitude relationship between the potential and the first electrical signal threshold.

[0043] In addition, the above-mentioned impedance adjustment module 4 may include: electronic components with adjustable impedance values ​​and temperature sensing units, for example: the impedance adjustment module 4 includes a temperature detection sensor and an adjustable resistor, or the impedance adjustment module 4 includes a thermistor, or the impedance adjustment module 4 includes a temperature detection sensor and a transistor with variable on-impedance, etc., which is not specifically limited here.

[0044] In addition, the above-mentioned adjusting the impedance value of the impedance adjustment module 4 according to the ambient temperature so that the electrical signal value of the laser sensor module 1 at the first preset discharge time is less than the first electrical signal threshold value may include: when the ambient temperature of the laser sensor module 1 is low, by reducing the discharge path impedance of the laser sensor module 1, the discharge speed of the laser sensor module 1 is increased to compensate for the influence of the ambient temperature on the discharge speed of the laser sensor module 1, so that the laser sensor module 1 can be completely discharged at the first preset discharge time, thereby avoiding the human eye protection mechanism from being triggered and causing the laser sensor module 1 to stop working.

[0045] In other words, in this embodiment, when the laser sensor module 1 discharges for the first preset time, if the electrical signal detection module 2 detects that the electrical signal value of the laser sensor module 1 is greater than or equal to the first electrical signal threshold, the laser sensor module 1 stops working (i.e., triggers the human eye protection mechanism).

[0046] In practical applications, it is assumed that the above-mentioned laser sensor module 1 is a VCSEL. At this time, if the VCSEL is not fully discharged within the first preset time, it will cause the VCSEL to flicker when the VCSEL is started next time, which may easily cause damage to the human eye. Therefore, in order to avoid damage to the human eye due to incomplete discharge of the VCSEL, a human eye protection mechanism is introduced during the VCSEL discharge process to determine whether the VCSEL is fully discharged when the VCSEL discharges for the first preset time. If it is not fully discharged, the human eye protection mechanism is triggered to control the failure of the laser emitter. In this embodiment, the impedance value of the impedance adjustment module 4 can be adjusted to appropriately increase the discharge speed of the laser sensor module 1, thereby avoiding abnormal discharge speed of the laser sensor module 1 caused by the ambient temperature, thereby erroneously triggering the human eye protection mechanism.

[0047] In an optional implementation, the first preset time represents the discharge duration set by the laser sensor module 1, and the first electrical signal threshold may be a triggering threshold of the human eye protection mechanism. Specifically, the human eye protection mechanism specifies a fixed discharge duration (i.e., the first preset time). In implementation, if the judgment result of the human eye protection mechanism is that the laser sensor module 1 is not fully discharged when it discharges for the first preset time (i.e., the electrical signal value of the laser sensor module 1 is greater than or equal to the first electrical signal threshold), the human eye protection mechanism will trigger the laser emitter to stop working, i.e., causing the laser emitter to fail.

[0048] That is to say, the above-mentioned method of adjusting the impedance value of the impedance adjustment module 4 according to the ambient temperature so that the electrical signal value of the laser sensor module 1 during the first preset discharge time is less than the first electrical signal threshold value may also include: when the ambient temperature of the laser sensor module 1 is high, by increasing the discharge path impedance of the laser sensor module 1, the discharge speed of the laser sensor module 1 is reduced to avoid the ambient temperature being too high so that the discharge speed of the laser sensor module 1 is too fast and an overcurrent is generated.

[0049] In this way, when the laser transmitter is needed to be used later, the laser transmitter cannot be started normally, which seriously affects the function of the laser transmitter.

[0050] The first preset time and the first electrical signal threshold can be set according to the device properties of the laser sensor module 1 and the requirements of the application scenario, and are not specifically limited here.

[0051] In an embodiment of the present application, a laser sensor control circuit includes: a laser sensor module, an electrical signal detection module, a first switch and an impedance adjustment module; the first end of the laser sensor module is connected to a power source, the second end of the laser sensor module is connected to the impedance adjustment module through the first switch, and the electrical signal detection module is connected to the first end of the laser sensor module; when the first switch is closed and the power source stops supplying power to the laser sensor module, the laser sensor module is in a discharge state; the impedance adjustment module is used to adjust the impedance value of the impedance adjustment module according to the ambient temperature when the laser sensor module is in the discharge state, so that the electrical signal value of the laser sensor module at the first preset time of discharge is less than the first electrical signal threshold. In this way, when the ambient temperature changes, the discharge path impedance of the laser sensor module can be adjusted by the impedance adjustment module, so that the discharge speed of the laser sensor module is kept within a stable range, so that the electrical signal value at the first preset time of discharge of the laser sensor module is less than the first electrical signal threshold, so that the laser sensor can also work normally in a temperature change environment, that is, the reliability of the laser sensor is improved.

[0052] As an optional implementation, the impedance adjustment module 4 is specifically used for:

[0053] When the laser sensor module 1 is in a discharging state and the ambient temperature is less than or equal to a first temperature threshold, the impedance value of the impedance adjustment module 4 is reduced according to the ambient temperature, so that the electrical signal value of the laser sensor module 1 during the first preset discharging time is less than the first electrical signal threshold;

[0054] and / or,

[0055] When the laser sensor module 1 is in a discharging state and the ambient temperature is greater than or equal to the second temperature threshold, the impedance value of the impedance adjustment module 4 is increased according to the ambient temperature so that the discharge current of the laser sensor module 1 is less than or equal to the preset current.

[0056] The first temperature threshold can be set according to the device properties of the laser sensor module 1 and the requirements of the application scenario, for example, the first temperature threshold is 0° C. or −10° C.

[0057] In implementation, making the discharge current of the laser sensor module 1 less than or equal to the preset current can be understood as preventing overcurrent from occurring in the discharge path of the laser sensor module 1 and damaging the components in the discharge path. In implementation, the second temperature threshold and the preset current can be determined based on the temperature characteristics of the laser sensor module 1 and the current parameters of each component in the discharge path of the laser sensor module 1, and are not specifically limited here.

[0058] In addition, in practical applications, when the ambient temperature is too high, if the discharge path impedance of the laser sensor module 1 remains unchanged, the discharge speed of the laser sensor module 1 will increase. In other words, the higher the temperature, the greater the discharge current of the laser sensor module 1.

[0059] In implementation, the second temperature threshold may be greater than the first temperature threshold. In this case, when the ambient temperature is between the first temperature threshold and the second temperature threshold, the impedance adjustment module 4 may not work to maintain the discharge path impedance of the laser sensor module 1 unchanged.

[0060] Of course, the second temperature threshold may also be equal to the first temperature threshold. In this case, the impedance value of the impedance adjustment module 4 will change only when the ambient temperature remains unchanged and when the ambient temperature changes, thereby compensating for the change in the on-resistance of the laser sensor module 1 caused by the change in ambient temperature.

[0061] In this embodiment, the impedance value of the impedance adjustment module 4 is increased according to the ambient temperature so that the discharge current of the laser sensor module 1 is less than or equal to the preset current. It can be understood that when the ambient temperature of the laser sensor module 1 is high, the discharge speed of the laser sensor module 1 is slowed down by increasing the discharge path impedance of the laser sensor module 1 to avoid the discharge current of the laser sensor module 1 exceeding the standard due to the influence of the ambient temperature. This can ensure that the laser sensor module 1 can be fully discharged during the first preset discharge time, and can also ensure that the laser sensor module 1 does not generate excessive discharge current, thereby improving the safety and reliability of the discharge path.

[0062] Optional, such as Figure 2 As shown, the impedance adjustment module 4 includes: an adjustable resistance unit 41, a temperature sensing unit 42 and an electrical signal adjustment unit 43;

[0063] The first end of the adjustable resistance unit 41 is connected to the second end of the laser sensor module 1 through the first switch 3, the second end of the adjustable resistance unit 41 is grounded, the control end of the adjustable resistance unit 41 is connected to the output end of the electric signal adjustment unit 43, and the input end of the electric signal adjustment unit 43 is connected to the temperature sensing unit 42;

[0064] The temperature sensing unit 42 is used to detect the ambient temperature and output a first signal to the input end of the electrical signal adjustment unit 43 according to the ambient temperature;

[0065] The electrical signal adjustment unit 43 outputs a second signal to the control end of the adjustable resistance unit 41 according to the received first signal;

[0066] The adjustable resistance unit 41 adjusts the impedance value according to the received second signal to adjust the discharge speed of the laser sensor module 1 .

[0067] In implementation, the first signal and the second signal may be analog signals or digital signals. For ease of description, the following embodiments are only described by taking the first signal and the second signal as voltage signals as an example, and no specific limitation is made herein.

[0068] In addition, the impedance value of the adjustable resistance unit 41 can be adjusted according to different second signals received. For example, assuming that the second signal is a voltage signal, the greater the value of the voltage signal, the greater the impedance value of the adjustable resistance unit 41 can be.

[0069] In application, the temperature sensing unit 42 can output a first signal corresponding to the ambient temperature to the electrical signal adjustment unit 43 according to different ambient temperatures, so that the electrical signal adjustment unit 43 can output a second signal matching the ambient temperature according to the first signal, thereby adjusting the impedance value of the adjustable resistance unit 41 to an impedance value matching the ambient temperature, and the impedance value of the adjustable resistance unit 41 is positively correlated with the ambient temperature, that is, the lower the ambient temperature, the smaller the impedance value of the adjustable resistance unit 41, thereby reducing the impedance value of the adjustable resistance unit 41 when the temperature is less than the first temperature threshold, thereby reducing the discharge path impedance of the laser sensor module 1 and improving the discharge speed of the laser sensor module 1.

[0070] Optional, such as Figure 2 As shown, the adjustable resistance unit 41 is an NMOS tube, the temperature sensing unit 42 includes: a thermistor NTC, a first power supply VDD and a first resistor R1, and the electrical signal adjustment unit 43 includes: an error amplifier EA;

[0071] The control end of the adjustable resistance unit 41 is the gate of the NMOS tube, and the first end and the second end of the adjustable resistance unit 41 are the source and the drain of the NMOS tube respectively;

[0072] The output end of the electric signal adjustment unit 43 is the output end of the error amplifier EA, the input end of the electric signal adjustment unit 43 is the input end of the error amplifier EA, and the error amplifier EA also includes a first reference voltage end Vref;

[0073] A first end of the thermistor NTC is connected to a first power supply VDD, a second end of the thermistor NTC is grounded via a first resistor R1, and an input end of the error amplifier EA is connected to the second end of the thermistor NTC;

[0074] The thermistor NTC is a negative temperature coefficient thermistor, and the on-resistance of the NMOS tube is negatively correlated with the impedance value of the thermistor NTC.

[0075] In a specific implementation, considering that the thermistor NTC is a negative temperature coefficient thermistor, the lower the ambient temperature is, the greater the resistance of the thermistor NTC is, so that the difference between the voltage received at the input end of the error amplifier EA and the reference voltage on the first reference voltage end Vref is greater, driving the voltage value output from the output end of the error amplifier EA to be greater, so as to reduce the on-resistance of the NMOS tube, thereby improving the discharge speed of the laser sensor module 1.

[0076] In implementation, the first resistor R1 is used as a voltage divider resistor of the thermistor NTC, and the voltage received by the input end of the error amplifier EA is the voltage on the first resistor R1. During operation, the voltage value on the first resistor R1 can be calculated by the following formula:

[0077]

[0078] Among them, V R1 Represents the voltage value on the first resistor R1; V VDD represents the voltage value provided by the first power supply VDD; the resistance value of the first resistor R1 is represented as R1; R NTC Indicates the resistance value of the thermistor NTC.

[0079] As can be seen from the above, in this embodiment, when V VDD When the value of R1 is constant, R NTC The larger the value of V R1 The smaller the value of, the smaller the voltage received by the input terminal of the error amplifier EA. The resistance value of the thermistor NTC is negatively correlated with the ambient temperature. The lower the ambient temperature, the lower the resistance value of R NTC The larger the value of V R1 The smaller the value is, the greater the difference between the voltage received by the input terminal of the error amplifier EA and the reference voltage on the first reference voltage terminal Vref is, and the greater the voltage value output from the output terminal of the error amplifier EA is. In this way, the voltage difference between the gate and the source of the NMOS tube is greater, so that the on-resistance of the NMOS tube is smaller, that is, the discharge path impedance of the laser sensor module 1 is smaller, so that the discharge speed of the laser sensor module 1 is accelerated.

[0080] It should be noted that, in implementation, the adjustable resistor unit 41 may also be an adjustable resistor, the temperature sensing unit 42 may also be a temperature detection sensor, and the electrical signal adjustment unit 43 may also include an amplifier or a comparator, etc., to convert the temperature signal detected by the temperature detection sensor into a control signal for adjusting the impedance value of the adjustable resistor to an impedance value corresponding to the temperature signal, such as Figure 2In the illustrated embodiment, the adjustable resistance unit 41 is only an NMOS tube, the temperature sensing unit 42 includes: a thermistor NTC, a first power supply VDD and a first resistor R1, and the electrical signal adjustment unit 43 includes: an error amplifier EA as an example for illustration, which does not constitute a specific limitation herein.

[0081] Optional, such as Figure 2 As shown, the laser sensor control circuit also includes: a second power supply (such as Figure 2 In the embodiment shown, the second power supply VDD connected to the second end of the first switch 3 and the control module 5, the second power supply VDD is used to provide a preset voltage;

[0082] The first switch 3 includes a first end, a second end, a third end and a control end, the first end of the first switch 3 is connected to the second end of the laser sensor module 1, the second end of the first switch 3 is connected to the second power supply VDD, the third end of the first switch 3 is connected to the impedance adjustment module 4, and the control module 5 is connected to the control end of the first switch;

[0083] Among them, when the laser sensor module 1 enters the discharge state, the control module 5 controls the first end of the first switch 3 to be connected with the second end of the first switch for a second preset time, and then controls the first end of the first switch 3 to be connected with the third end of the first switch for a third preset time, and the first preset time is equal to the sum of the second preset time and the third preset time.

[0084] The control module 5 may be a processor in an electronic device, or a microcontroller unit (MCU) in a laser sensor, which is not specifically limited here.

[0085] In implementation, the voltage value of the preset voltage provided by the second power supply VDD is greater than 0. Thus, compared with the method of connecting the second end of the laser sensor module 1 to the ground end, the voltage difference in the discharge path of the laser sensor module 1 can be reduced. When the laser sensor module 1 has a higher potential during normal operation, the discharge speed of the laser sensor module 1 can be slowed down by first discharging to the second power supply VDD with a preset voltage, that is, limiting the discharge current to prevent the discharge current from being too large and damaging the components in the discharge path. Then, after the laser sensor module 1 discharges the second power supply VDD for a second preset time, the potential of the laser sensor module 1 decreases. At this time, the first end of the first switch 3 is connected to the third end of the first switch, so that when the laser sensor module 1 discharges to the ground end, the discharge current will not exceed the standard due to the lower potential of the laser sensor module 1.

[0086] In addition, if Figure 2As shown, a second resistor R2 is further provided between the first end of the first switch 3 and the second end of the laser sensor module 1, so that when the first end of the first switch 3 is connected with the second end of the first switch 3, the discharge current is limited by the second resistor R2; in addition, when the first end of the first switch 3 is connected with the third end of the first switch 3, the discharge current is limited by the second resistor R2 and the NMOS tube.

[0087] It should be noted that if Figure 2 In the illustrated embodiment, the impedance adjustment module 4 is only set between the third end of the first switch 3 and the ground end as an example. In implementation, the impedance adjustment module 4 can also be set between the second end of the first switch 3 and the second power supply VDD, or between the third end of the first switch 3 and the ground end, and between the second end of the first switch 3 and the second power supply VDD. It is only necessary to ensure that the discharge current of the laser sensor module 1 within the second preset time and the discharge current within the third preset time will not exceed the safety current of each device in its discharge path.

[0088] In addition, in this embodiment, the control module 5 controls the switch state of the first switch 3. However, in practical applications, the first switch 3 can also adjust the switch state automatically according to the value of the electrical signal thereon. The control method of the first switch 3 is not specifically limited here.

[0089] Optional, such as Figure 2 As shown, the electric signal detection module 2 includes: a control module 5, a comparator CA and a second switch 21;

[0090] The input end of the comparator CA is connected to the first end of the laser sensor module 1 through the second switch 21, the electrical signal value of the reference signal end Vs of the comparator CA is equal to the first electrical signal threshold, the output end of the comparator CA is connected to the control module 5, and the control end of the second switch 21 is connected to the control module 5;

[0091] Among them, when the laser sensor module 1 enters the discharge state for the first preset time, the control module 5 controls the second switch 21 to close, so that the comparator CA compares the size between the electrical signal value of the first end of the laser sensor module 1 and the first electrical signal threshold, so that when the electrical signal value of the first end of the laser sensor module 1 is greater than or equal to the first electrical signal threshold, a third signal is output to the control module 5, so that the control module 5 controls the laser sensor module 1 to stop working based on the received third signal.

[0092] Among them, the control module 5 controls the laser sensor module 1 to stop working based on the received third signal, which can be understood as the human eye protection mechanism being triggered.

[0093] In addition, during operation, the comparator CA can compare the voltage value received at its input terminal with the voltage value at the reference signal terminal Vs, and output a corresponding control signal to the control module 5 according to the comparison result. For example, when the voltage value received at the input terminal of the comparator CA is less than the voltage value at the reference signal terminal Vs, the fourth signal is output so that the control module 5 determines that the laser sensor module 1 is fully discharged based on the received fourth signal, thereby controlling the laser sensor module 1 to work normally.

[0094] It should be noted that if Figure 2 In the illustrated embodiment, the control module in the electrical signal detection module 2 and the control module 5 for controlling the switch state of the first switch 3 are taken as the same control module for illustration. In practice, the two may also be different control modules, which will not be elaborated in detail here.

[0095] In this embodiment, the on and off of the second switch 21 is controlled so that the electrical signal detection module 2 only works when the laser sensor module 1 enters the discharge state for the first preset time, thereby avoiding that when the laser sensor module 1 just enters the discharge state, the input end of the electrical signal detection module 2 will receive a higher voltage value, thereby erroneously triggering the human eye protection mechanism.

[0096] The following is Figure 2 Taking the laser sensor control circuit shown in FIG. 1 as an example, the working process and working principle of the laser sensor control circuit provided in the embodiment of the present application are specifically described:

[0097] like Figure 3 As shown in the figure, when the ambient temperature rises, the on-resistance of VCSEL will become smaller, causing the discharge speed to accelerate. At this time, the resistance of NTC resistor will decrease, increasing the negative input voltage of the error amplifier, driving the negative output voltage of the difference amplifier to decrease, and reducing the voltage difference between the gate and source of NMOS tube, thereby increasing the on-resistance of NMOS tube, that is, increasing the impedance of discharge path to reduce the discharge speed, thus compensating for the faster discharge speed caused by the ambient temperature affecting the on-resistance of VCSEL.

[0098] Correspondingly, when the ambient temperature drops, the on-resistance of the VCSEL will increase, causing the discharge speed to slow down. At this time, the resistance of the NTC resistor will increase, reducing the negative input voltage of the error amplifier, driving the negative output voltage of the difference amplifier to increase, and increasing the voltage difference between the gate and source of the NMOS tube, thereby reducing the on-resistance of the NMOS tube, that is, reducing the impedance of the discharge path to increase the discharge speed, thus compensating for the slow discharge speed caused by the ambient temperature affecting the on-resistance of the VCSEL.

[0099] As can be seen from the above, no matter how the ambient temperature changes, the impedance adjustment function of the impedance adjustment module 4 can make the discharge speed of the laser sensor module 1 consistent. In other words, no matter how the ambient temperature changes, it can ensure that the laser sensor module 1 will not be affected by the ambient temperature and trigger the human eye protection mechanism by mistake, and it can also limit the discharge current of the laser sensor module 1 to avoid excessive discharge current and damage to the laser sensor. In this way, it can not only maintain the original function of the human eye protection mechanism, but also avoid the problem of false triggering of the human eye protection mechanism due to changes in ambient temperature, causing the laser sensor to fail.

[0100] The present application also provides an electronic device, including: Figure 1 or Figure 2 The laser sensor control circuit provided in the illustrated embodiment.

[0101] In practice, the electronic device can use the above laser sensor control circuit to realize functions such as screen on / off control, anti-false touch control, and auxiliary camera focus. In this way, the electronic device provided by the embodiment of the present application can avoid the problem that the above functions such as screen on / off control, anti-false touch control, and auxiliary camera focus fail or cause device damage due to changes in ambient temperature, thereby improving the performance and reliability of the electronic device.

[0102] See also Figure 4 , is a flow chart of a laser sensor control method provided in an embodiment of the present application, and the laser sensor control method is applied to an electronic device having a laser sensor, such as Figure 4 As shown, the laser sensor control method may include the following steps:

[0103] Step 401: Detect the ambient temperature.

[0104] Step 402: When the laser sensor module is in a discharging state, adjust the impedance value of the discharge path of the laser sensor module according to the ambient temperature so that the electrical signal value of the laser sensor module during the first preset discharge time is less than a first electrical signal threshold.

[0105] In implementation, the electronic device may be the one provided in the previous embodiment of the present application including: Figure 1 or Figure 2 Electronics of the laser sensor control circuit in the illustrated embodiment.

[0106] In addition, the first temperature threshold, the first preset time and the first electrical signal threshold are Figure 1 or Figure 2 The first temperature threshold, the first preset time and the first electrical signal threshold in the illustrated embodiment have the same meaning and are not described in detail herein.

[0107] Optionally, when the laser sensor module is in a discharging state, adjusting the impedance value of the discharge path of the laser sensor module according to the ambient temperature so that the electrical signal value of the laser sensor module when discharging for a first preset time is less than a first electrical signal threshold value includes:

[0108] When the laser sensor module is in a discharging state and the ambient temperature is less than or equal to a first temperature threshold, the impedance value of the discharge path of the laser sensor module is reduced according to the ambient temperature, so that the electrical signal value of the laser sensor module during the first preset discharge time is less than the first electrical signal threshold;

[0109] and / or,

[0110] When the laser sensor module is in a discharging state and the ambient temperature is greater than or equal to a second temperature threshold, the impedance value of the discharge path of the laser sensor module is increased according to the ambient temperature so that the discharge current of the laser sensor module is less than or equal to a preset current.

[0111] The laser sensor control method provided in the embodiment of the present application includes the following steps: Figure 1 The laser sensor control circuit shown in or 2 can perform various steps and can obtain the same Figure 1 Or the same beneficial effects as the laser sensor control circuit shown in 2, to avoid repetition, they will not be repeated here.

[0112] See also Figure 5 , is a structural diagram of a laser sensor control device provided in an embodiment of the present application, the laser sensor control device can be applied to an electronic device, and the electronic device includes a laser sensor, such as Figure 5 As shown, the laser sensor control device 500 includes:

[0113] Detection module 501, used to detect ambient temperature;

[0114] The impedance adjustment module 502 is used to adjust the impedance value of the discharge path of the laser sensor module according to the ambient temperature when the laser sensor module is in a discharge state, so that the electrical signal value of the laser sensor module during the first preset discharge time is less than the first electrical signal threshold.

[0115] Optionally, the impedance adjustment module 502 is specifically used for:

[0116] When the laser sensor module is in a discharging state and the ambient temperature is less than or equal to a first temperature threshold, the impedance value of the discharge path of the laser sensor module is reduced according to the ambient temperature, so that the electrical signal value of the laser sensor module during the first preset discharge time is less than the first electrical signal threshold;

[0117] and / or,

[0118] When the laser sensor module is in a discharging state and the ambient temperature is greater than or equal to a second temperature threshold, the impedance value of the discharge path of the laser sensor module is increased according to the ambient temperature so that the discharge current of the laser sensor module is less than or equal to a preset current.

[0119] The laser sensor control device 500 provided in the embodiment of the present application can perform the following operations: Figure 4 The various steps in the method embodiment shown can achieve the same beneficial effects, and will not be described again here to avoid repetition.

[0120] Optional, such as Figure 6 As shown, an embodiment of the present application further provides an electronic device 600, including a processor 601, a memory 602, and a program or instruction stored in the memory 602 and executable on the processor 601. When the program or instruction is executed by the processor 601, each process of the above-mentioned laser sensor control method embodiment is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be described here.

[0121] It should be noted that the electronic devices in the embodiments of the present application include the mobile electronic devices and non-mobile electronic devices mentioned above.

[0122] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, each process of the above-mentioned laser sensor control method embodiment is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0123] The processor is a processor in the electronic device described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0124] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned laser sensor control method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0125] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0126] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0127] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for a terminal (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0128] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A laser sensor control circuit, characterized in that: include: A laser sensor module, an electrical signal detection module, a first switch and an impedance adjustment module; The first end of the laser sensor module is connected to a power source, the second end of the laser sensor module is connected to the impedance adjustment module through the first switch, and the electrical signal detection module is connected to the first end of the laser sensor module; When the first switch is closed and the power supply stops supplying power to the laser sensor module, the laser sensor module is in a discharging state; The impedance adjustment module is used to adjust the impedance value of the impedance adjustment module according to the ambient temperature when the laser sensor module is in a discharge state, so that the electrical signal value of the laser sensor module during the first preset discharge time is less than the first electrical signal threshold; The impedance adjustment module includes: an adjustable resistance unit, a temperature sensing unit and an electrical signal adjustment unit; The first end of the adjustable resistance unit is connected to the second end of the laser sensor module through the first switch, the second end of the adjustable resistance unit is grounded, the control end of the adjustable resistance unit is connected to the output end of the electrical signal adjustment unit, and the input end of the electrical signal adjustment unit is connected to the temperature sensing unit; The temperature sensing unit is used to detect the ambient temperature and output a first signal to the input end of the electrical signal adjustment unit according to the ambient temperature; The electrical signal adjustment unit outputs a second signal to the control end of the adjustable resistance unit according to the received first signal; The adjustable resistance unit adjusts the impedance value according to the received second signal to adjust the discharge speed of the laser sensor module; The adjustable resistance unit is an NMOS tube, the temperature sensing unit includes: a thermistor, a first power supply and a first resistor, and the electrical signal adjustment unit includes: an error amplifier; The control end of the adjustable resistance unit is the gate of the NMOS tube, and the first end and the second end of the adjustable resistance unit are the source and the drain of the NMOS tube respectively; The output end of the electrical signal adjustment unit is the output end of the error amplifier, the input end of the electrical signal adjustment unit is the input end of the error amplifier, and the error amplifier further includes a first reference voltage end; The first end of the thermistor is connected to the first power supply, the second end of the thermistor is grounded through the first resistor, and the input end of the error amplifier is connected to the second end of the thermistor; The thermistor is a negative temperature coefficient thermistor, and the on-resistance of the NMOS tube is negatively correlated with the impedance value of the thermistor.

2. The circuit according to claim 1, characterized in that The impedance adjustment module is specifically used for: When the laser sensor module is in a discharging state and the ambient temperature is less than or equal to a first temperature threshold, the impedance value of the impedance adjustment module is reduced according to the ambient temperature, so that the electrical signal value of the laser sensor module during the first preset discharging time is less than the first electrical signal threshold; and / or, When the laser sensor module is in a discharging state and the ambient temperature is greater than or equal to a second temperature threshold, the impedance value of the impedance adjustment module is increased according to the ambient temperature so that the discharge current of the laser sensor module is less than or equal to a preset current.

3. The circuit according to claim 1, characterized in that Also includes: A second power supply and control module, wherein the second power supply is used to provide a preset voltage; The first switch includes a first end, a second end, a third end and a control end, the first end of the first switch is connected to the second end of the laser sensor module, the second end of the first switch is connected to the second power supply, the third end of the first switch is connected to the impedance adjustment module, and the control module is connected to the control end of the first switch; Wherein, when the laser sensor module enters the discharge state, the control module controls the first end of the first switch to be connected with the second end of the first switch for a second preset time, and then controls the first end of the first switch to be connected with the third end of the first switch for a third preset time, and the first preset time is equal to the sum of the second preset time and the third preset time.

4. The circuit according to claim 1, characterized in that The electrical signal detection module includes: a control module, a comparator and a second switch; The input end of the comparator is connected to the first end of the laser sensor module through the second switch, the electrical signal value of the reference signal end of the comparator is equal to the first electrical signal threshold, the output end of the comparator is connected to the control module, and the control end of the second switch is connected to the control module; Among them, when the laser sensor module enters the discharge state for a first preset time, the control module controls the second switch to close, so that the comparator compares the size between the electrical signal value of the first end of the laser sensor module and the first electrical signal threshold, so that when the electrical signal value of the first end of the laser sensor module is greater than or equal to the first electrical signal threshold, the control module outputs a third signal to the control module, so that the control module controls the laser sensor module to stop working based on the received third signal.

5. An electronic device, characterized in that: The method comprises the laser sensor control circuit as claimed in any one of claims 1 to 4.

6. A laser sensor control method, characterized in that: Applied to the electronic device as claimed in claim 5, the electronic device includes a laser sensor, and the method includes: Detect ambient temperature; When the laser sensor module is in a discharging state, the impedance value of the discharge path of the laser sensor module is adjusted according to the ambient temperature so that the electrical signal value of the laser sensor module during the first preset discharging time is less than the first electrical signal threshold.

7. The method according to claim 6, characterized in that When the laser sensor module is in a discharging state, adjusting the impedance value of the discharge path of the laser sensor module according to the ambient temperature so that the electrical signal value of the laser sensor module when discharging for a first preset time is less than a first electrical signal threshold value includes: When the laser sensor module is in a discharging state and the ambient temperature is less than or equal to a first temperature threshold, the impedance value of the discharge path of the laser sensor module is reduced according to the ambient temperature, so that the electrical signal value of the laser sensor module during the first preset discharge time is less than the first electrical signal threshold; and / or, When the laser sensor module is in a discharging state and the ambient temperature is greater than or equal to a second temperature threshold, the impedance value of the discharge path of the laser sensor module is increased according to the ambient temperature so that the discharge current of the laser sensor module is less than or equal to a preset current.

8. A laser sensor control device, characterized in that: Applied to the electronic device as claimed in claim 5, the electronic device comprises a laser sensor, and the device comprises: A detection module, used for detecting the ambient temperature; The impedance adjustment module is used to adjust the impedance value of the discharge path of the laser sensor module according to the ambient temperature when the laser sensor module is in a discharge state, so that the electrical signal value of the laser sensor module when discharging for a first preset time is less than a first electrical signal threshold.

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