Motor system, voltage doubling circuit, position detection method and electronic equipment

Abstract

The embodiment of the present application provides a motor system, a voltage doubling circuit, a position detection method and an electronic device, and the method is applied to the motor system. The motor system may include: a driver integrated circuit, a voltage doubling circuit and a voice coil motor VCM, wherein the driver integrated circuit, the voltage doubling circuit and the VCM may be connected in series in sequence, and the voltage doubling circuit may be used to increase the output voltage of the driver integrated circuit by multiples and output it to both ends of the coil load, thereby multiples the current flowing through the coil, and finally significantly improve the motor thrust. The position detection method may include: detecting the change of coil current by coupling the IC of the VCM coil, and then calculating the coil inductance L according to the change of coil current and the coil voltage, and determining the magnet position corresponding to the coil inductance L from the linear mapping table of the magnet position and the coil inductance L, and determining the magnet position as the lens position.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a motor system, a voltage doubling circuit, a position detection method and an electronic device. Background Art

[0002] With the development of electronic technology, mobile phones, tablet computers and other electronic devices are generally equipped with cameras. The camera lenses are getting heavier, which requires the motor to provide greater thrust. However, the internal space of mobile phones and other electronic devices is very limited, and it is difficult to increase the motor thrust by increasing the size of the motor. Summary of the invention

[0003] In a first aspect, the present application provides a motor system, such as Figure 2 As shown, the motor system may include: a driver IC, a voltage doubling circuit and a voice coil motor VCM, which are connected in sequence. The output end of the driver IC is connected to the input end of the voltage doubling circuit, and the output end of the voltage doubling circuit is connected to the VCM coil, which can be used to increase the output voltage of the driver IC by multiples and output it to both ends of the VCM coil load, thereby multiples the current flowing through the VCM coil, and ultimately significantly improve the motor thrust.

[0004] In combination with the first aspect, in some embodiments, in the motor system provided by the first aspect, the voltage doubling circuit can also be used to change the voltage polarity of the coil voltage output to both ends of the coil; when the voltage polarity of the coil voltage is the first polarity, the direction of the coil current is the first flow direction, and the VCM outputs the motor thrust in the first direction; when the voltage polarity of the coil voltage is the second polarity, the direction of the coil current is the second flow direction, and the VCM outputs the motor thrust in the second direction. In this way, the voltage doubling circuit can change the direction of the coil current, so that the motor system provided by the first aspect supports the motor to output motor thrust in two directions, and finally controls the driven component (such as the lens of the camera) to move in two directions.

[0005] In combination with the first aspect, in some embodiments, the voltage doubler circuit may be the voltage doubler circuit described in the second aspect or the third aspect.

[0006] In the second aspect, the present application provides a voltage doubling circuit, which may include: a capacitor C1, a first unidirectional conduction device, a second unidirectional conduction device and a switch S1, as well as a first input terminal, a second input terminal, a first output terminal and a second output terminal; wherein: the first end of the capacitor C1 is coupled to the first input terminal, the second end of the capacitor C1 is coupled to the first output terminal, and the second output terminal is coupled to the second input terminal; one end of the first unidirectional conduction device is coupled to the second end of the capacitor C1, and the other end is coupled to the first moving end of the switch S1; one end of the second unidirectional conduction device is also coupled to the second end of the capacitor C1, and the other end is coupled to the second moving end of the switch S1; the fixed end of the switch S1 is coupled to the second input terminal; the conduction directions of the first unidirectional conduction device and the second unidirectional conduction device are opposite.

[0007] In the second aspect, the input voltage loaded between the first input terminal and the second input terminal is an AC voltage signal. Specifically, the input voltage may be a pulse width modulation (PWM) voltage signal. The switch S1 in the voltage doubling circuit may be a single-pole double-throw switch.

[0008] The voltage doubling circuit provided in the second aspect increases the input voltage by approximately two times, and only requires one capacitor for charging and discharging, further reducing the circuit size, and can change the polarity of the output voltage. When the voltage doubling circuit is applied to a motor system, such as when the input end of the voltage doubling circuit is connected to a driver IC and the output end is connected to a VCM coil, it can change the direction of the coil current, thereby supporting the motor to output motor thrust in two directions, and ultimately controlling the driven component (such as the camera lens) to move in two directions.

[0009] In combination with the second aspect, in some embodiments, the first unidirectional conductive device may be a diode D1. One end of the first unidirectional conductive device is coupled to the second end of the capacitor C1, and the other end is coupled to the first moving end of the switch S1, specifically comprising: a cathode of the diode D1 is coupled to the second end of the capacitor C1, and an anode is coupled to the first moving end of the switch S1.

[0010] In combination with the second aspect, in some embodiments, the second unidirectional conductive device may be a diode D2. One end of the second unidirectional conductive device is also coupled to the second end of the capacitor C1, and the other end is coupled to the second movable end of the switch S1, specifically comprising: the anode of the diode D2 is also coupled to the second end of the capacitor C1, and the cathode is coupled to the second movable end of the switch S1.

[0011] The conduction voltage drop of the diode is very small, for example, the voltage drop of the silicon tube is less than or equal to 0.7V, and the voltage drop of the germanium tube is less than or equal to 0.2V. Therefore, choosing a diode as a unidirectional conduction device can further reduce the conduction voltage drop, making the output voltage of the two-stage voltage doubler circuit closer to twice the input voltage.

[0012] In combination with the second aspect, in some embodiments, the charging and discharging of the voltage doubler circuit of the second aspect may include: when the switch S1 is turned on at the first moving end, the capacitor C1 is charged in the first half cycle of the input voltage, and is discharged in the second half cycle of the input voltage, and the voltage polarity of the output voltage of the voltage doubler circuit is the first polarity when the second half cycle is discharged. The voltage polarity of the input voltage in the first half cycle is opposite to the voltage polarity of the input voltage in the second half cycle. When the switch S1 is turned on at the second moving end, the capacitor C1 is charged in the second half cycle of the input voltage, and is discharged in the first half cycle of the input voltage, and the voltage polarity of the output voltage of the voltage doubler circuit is the second polarity when the first half cycle is discharged; the second polarity is opposite to the first polarity.

[0013] Among them, the first half cycle and the second half cycle can be respectively a negative half cycle and a positive half cycle, or respectively a positive half cycle and a negative half cycle, that is, Figure 5A-5D The input voltage shown in the figure with positive top and negative bottom can be the input voltage of the positive half cycle or the input voltage of the negative half cycle.

[0014] By selectively turning on switch S1, the polarity of the output voltage of the voltage doubler circuit can be changed. When the voltage doubler circuit is applied to a motor system, such as when the input end of the voltage doubler circuit is connected to a driver IC and the output end is connected to a VCM coil, it can change the direction of the coil current, thereby supporting the motor to output motor thrust in two directions.

[0015] In combination with the second aspect, in some embodiments, the switch S1 may further include a control terminal coupled to the control unit. When the control terminal receives a first control signal, the switch S1 selects to conduct the first active terminal; when the control terminal receives a second control signal, the switch S1 selects to conduct the second active terminal.

[0016] In combination with the second aspect, in some embodiments, the two-stage voltage multiplier circuit may further include a bias resistor R1, which is connected in series between the fixed end of the switch S1 and the second output end of the driver integrated circuit. That is, the bias resistor shared by the charge and discharge circuits of the first unidirectional conduction device (such as the diode D1) and the second unidirectional conduction device (such as the diode D2) adjusts the charge and discharge time of the two charge and discharge circuits together.

[0017] In combination with the second aspect, in some embodiments, the two-stage voltage multiplier circuit may further include two bias resistors R1 and R2, wherein the bias resistor R1 is connected in series between the first unidirectional conduction device and the first moving end of the switch S1, and the bias resistor R2 is connected in series between the negative electrode of the second unidirectional conduction device and the second moving end of the switch S1. That is, the two bias resistors are respectively connected in series in the charge and discharge circuits of the first unidirectional conduction device (such as the diode D1) and the second unidirectional conduction device (such as the diode D2) to independently adjust the charge and discharge time of the two charge and discharge circuits.

[0018] In a third aspect, the present application provides a voltage doubling circuit, such as Fig. 7A As shown, the voltage doubler circuit may include n-stage voltage doubler circuits and a switch S1, where n≥2 and n is a positive integer. A switch S1 is connected in parallel to both ends of the capacitor Cn in the n-stage charge and discharge circuit in the voltage doubler circuit, and the switch S1 is used to adjust the voltage polarity of the output voltage of the voltage doubler circuit.

[0019] The n-stage voltage multiplier circuit may be a conventional n-stage voltage multiplier circuit, such as Figure 3A , Figure 3E As shown in FIG. The two ends of capacitor Cn are also the output ends of the traditional n-stage voltage multiplier circuit.

[0020] The voltage doubling circuit provided in the third aspect can control the polarity of the voltage loaded on both ends of the coil by connecting a switch S1 in series between the output end of the traditional n-stage voltage doubling circuit and the coil load, thereby changing the direction of the current flowing through the coil and ultimately changing the direction of the motor thrust.

[0021] In combination with the third aspect, in some embodiments, the switch S1 may include two fixed terminals P1 and P2, and the fixed terminals P1 and P2 are respectively coupled to the two ends of the capacitor Cn. The switch S1 also includes: a first moving terminal and a second moving terminal, wherein the first moving terminal includes a group of moving terminals T1 and T3, and the second moving terminal includes a group of moving terminals T2 and T4; when the switch S1 turns on the first moving terminal, the voltage doubler circuit outputs an output voltage of a first polarity through the first moving terminal; when the switch S1 turns on the second moving terminal, the voltage doubler circuit outputs an output voltage of a second polarity through the second moving terminal; the second polarity is opposite to the first polarity.

[0022] Among them, P1 and P2 are electrically connected to two ends of the capacitor Cn respectively, T1 and T4 are electrically connected to a first end of the coil, and T2 and T3 are electrically connected to a second end of the coil.

[0023] In conjunction with the third aspect, in some embodiments, the switch S1 may be a double-pole double-throw switch or a combination of two single-pole double-throw switches.

[0024] In combination with the third aspect, in some embodiments, the switch S1 may further include: control terminals C1 and C2. The control signal for the switch switching may be transmitted from a control unit such as a controller or an AP through the two control terminals C1 and C2.

[0025] In a fourth aspect, the present application provides a module including a voice coil motor (VCM), which may include: a voltage doubling circuit, a driver integrated circuit, wherein: the input end of the voltage doubling circuit is coupled to the output end of the driver integrated circuit, the output end of the voltage doubling circuit is coupled to the two ends of the coil of the voice coil motor, and the voltage doubling circuit is used to boost the input voltage output by the driver integrated circuit to the input end and then output it to the two ends of the coil. In addition, the voltage doubling circuit is also used to change the voltage polarity of the coil voltage output to the two ends of the coil; when the voltage polarity of the coil voltage is the first polarity, the direction of the coil current is the first flow direction, and the VCM outputs the motor thrust in the first direction; when the voltage polarity of the coil voltage is the second polarity, the direction of the coil current is the second flow direction, and the VCM outputs the motor thrust in the second direction.

[0026] In the fourth aspect, the input voltage loaded between the first input terminal and the second input terminal is an AC voltage signal. Specifically, the input voltage may be a pulse width modulation (PWM) voltage signal. The voltage doubling circuit may be the voltage doubling circuit described in the second aspect or the third aspect.

[0027] In combination with the fourth aspect, in some embodiments, the module may be a camera module, which also includes a lens; the VCM is used to output motor thrust to drive the lens to move in the direction of the optical axis, or in a plane perpendicular to the optical axis.

[0028] In combination with the fourth aspect, in some embodiments, the voltage doubling circuit can be arranged in the z-direction space of the camera module, and the z-direction is parallel to the optical axis.

[0029] In combination with the fourth aspect, in some embodiments, the module may further include an image sensor, and the voltage doubling circuit may be specifically disposed in a cavity formed by the lens and the image sensor in the z direction.

[0030] In conjunction with the fourth aspect, in some embodiments, the voltage doubler circuit may also be partially or fully integrated in the driver integrated circuit. In the case of partial integration, the capacitor, or the capacitor and the diode in the voltage doubler circuit are not integrated in the driver integrated circuit.

[0031] In combination with the fourth aspect, in some embodiments, the voltage doubler circuit may also be integrated in the VCM.

[0032] In a fifth aspect, the present application provides an electronic device, which may include: a first module and a control unit, wherein the first module may be the module described in the fourth aspect, and the control unit is coupled to the first module for controlling the direction of the coil current of the VCM in the first module.

[0033] In conjunction with the fifth aspect, in some embodiments, the control unit may be specifically coupled to the voltage doubling circuit in the first module;

[0034] In combination with the fifth aspect, in some embodiments, controlling the direction of the coil current of the VCM in the first module may specifically include: controlling the voltage polarity of the coil voltage output by the voltage doubling circuit to both ends of the coil, wherein when the voltage polarity of the coil voltage is a first polarity, the direction of the coil current is a first flow direction; when the voltage polarity of the coil voltage is a second polarity, the direction of the coil current is a second flow direction.

[0035] In combination with the fifth aspect, in some embodiments, the control unit may also be coupled to the first module to control the magnitude of the coil current of the VCM in the module.

[0036] In conjunction with the fifth aspect, in some embodiments, the control unit may be coupled to the driver integrated circuit in the first module. Controlling the magnitude of the coil current of the VCM in the module may specifically include: controlling one or more of the output voltage level, discharge duty cycle, and frequency of the driver integrated circuit.

[0037] In combination with the fifth aspect, in some embodiments, the first module may be a camera module.

[0038] In a sixth aspect, the present application provides an electronic device, which may include: a motor system and a control unit; wherein the motor system may be the motor system described in the first aspect, and the control unit is coupled to a voltage doubler circuit in the motor system to control the direction of the coil current of the VCM in the motor system.

[0039] In combination with the sixth aspect, in some embodiments, the control unit may also be coupled to a driver integrated circuit in the motor system to control one or more of the output voltage level, discharge duty cycle, and frequency of the driver integrated circuit.

[0040] In combination with the sixth aspect, in some embodiments, the motor system can be set in a camera module of an electronic device.

[0041] In combination with the sixth aspect, in some embodiments, the VCM in the motor system may include an autofocus VCM, and the autofocus VCM is used to drive the lens in the camera module to move in the direction of the optical axis.

[0042] In combination with the sixth aspect, in some embodiments, the VCM in the motor system may also include an optical image stabilization VCM, and the optical image stabilization VCM is used to drive the lens in the camera module to move on a plane perpendicular to the optical axis.

[0043] In a seventh aspect, the present application provides a motor control method, which can be applied to the electronic device described in the fifth aspect or the sixth aspect, wherein the motor system in the electronic device includes an autofocus VCM. The motor control method may include: the electronic device detects an operation of increasing the optical zoom ratio of the camera module, and in response thereto, switches the switch S1 in the voltage doubling circuit of the autofocus VCM to the first moving end to conduct. The electronic device detects an operation of reducing the optical zoom ratio of the camera module, and in response thereto, switches the switch S1 in the voltage doubling circuit of the autofocus VCM to the second moving end to conduct.

[0044] Among them, when the switch S1 in the voltage doubling circuit of the auto-focus VCM is switched to the first moving end and turned on, the direction of the coil current of the auto-focus VCM is the first flow direction, and the lens in the camera module moves on the optical axis in a direction away from the object being photographed; when the switch S1 in the voltage doubling circuit of the auto-focus VCM is switched to the second moving end and turned on, the direction of the coil current of the auto-focus VCM is the second flow direction, and the lens moves on the optical axis in a direction close to the object being photographed, and the second flow direction is opposite to the first flow direction.

[0045] In an eighth aspect, the present application provides a motor control method, which can be applied to the electronic device described in the fifth aspect or the sixth aspect, wherein the motor system in the electronic device includes an optical image stabilization VCM. The motor control method may include: when the camera module is turned on to capture images, the electronic device detects device jitter in a third direction, and in response thereto, the switch S1 in the voltage doubling circuit of the optical image stabilization VCM is switched to the first moving end to conduct. When the camera module is turned on to capture images, the electronic device detects device jitter in a fourth direction, and in response thereto, the switch S1 in the voltage doubling circuit of the optical image stabilization VCM is switched to the second moving end to conduct.

[0046] When the switch S1 in the voltage doubler circuit of the optical image stabilization VCM is switched to the first moving end and turned on, the direction of the coil current of the optical image stabilization VCM is the first flow direction, and the lens moves in the fourth direction on the optical axis plane; when the switch S1 in the voltage doubler circuit of the optical image stabilization VCM is switched to the second moving end and turned on, the direction of the coil current of the optical image stabilization VCM is the second flow direction, and the lens moves in the third direction on the optical axis plane. The fourth direction is the opposite direction of the third direction, and both are the optical image stabilization directions of the camera module.

[0047] The method described in the seventh aspect and the method described in the eighth aspect can be implemented in combination, that is, the electronic device can have autofocus and optical image stabilization functions, and apply the methods of the seventh aspect and the eighth aspect when autofocus and optical image stabilization occur at the same time to adjust the current direction of each VCM coil to generate motor thrust in a specified direction to achieve the autofocus and optical image stabilization goals.

[0048] In the ninth aspect, the present application provides an electronic device, which may include: a camera, a memory and a processor, the camera and the memory are coupled to the processor, the camera includes the motor system of the first aspect, the VCM in the motor system includes an autofocus VCM, and the autofocus VCM is used to drive the lens in the camera module to move in the direction of the optical axis; the memory is used to store a computer program, and when the processor executes the computer program, the electronic device executes the method described in the seventh aspect.

[0049] In combination with the ninth aspect, in some embodiments, the VCM in the motor system may also include an optical image stabilization VCM, which is used to drive the lens in the camera module to move on a plane perpendicular to the optical axis; when the processor executes the computer program, the electronic device executes the method described in the eighth aspect.

[0050] In a tenth aspect, the present application provides a position detection method, which is applied to a motor system. The motor system may include: a driving integrated circuit, a voltage doubling circuit, and a voice coil motor VCM, wherein the input end of the voltage doubling circuit is coupled to the output end of the driving integrated circuit, the output end of the voltage doubling circuit is coupled to the two ends of the coil of the voice coil motor, and the voltage doubling circuit is used to boost the input voltage output by the driving integrated circuit to the input end and then output it to the two ends of the coil; the coil of the VCM is coupled to the current detection integrated circuit IC; the VCM includes a mover carrier and a coil, the mover carrier is used to carry the driven component of the VCM, and when the coil is energized, the mover carrier is also used to drive the driven component to move in the axial direction of the coil; and there is a linear mapping relationship between the position of the mover carrier and the coil inductance within the first motor stroke;

[0051] The position detection method may include: when the coil is powered on, detecting the current change of the coil through a current detection IC. Then, the coil inductance is calculated based on the detected current change and the voltage across the coil. Based on a linear mapping relationship, the position of the mover carrier corresponding to the calculated coil inductance is determined.

[0052] In the tenth aspect, the motor system may be the motor system described in the first aspect, and the voltage doubler circuit in the motor system may be the voltage doubler circuit described in the second aspect or the third aspect.

[0053] In conjunction with the tenth aspect, in some embodiments, the coil inductance is calculated based on the detected current change and the voltage across the coil, which may specifically include: calculating the coil inductance L by the following formula: L=u*(1 / (di / dt), where u represents the voltage across the coil, and di / dt represents the current change of the coil.

[0054] In combination with the tenth aspect, in some embodiments, the position detection method may further include: when it is detected that the position of the mover carrier reaches a specified position, switching the conduction direction of the switch S1.

[0055] In combination with the tenth aspect, in some embodiments, switching the conduction direction of the switch S1 may specifically include: if the switch S1 chooses to conduct the first moving end before the position of the movable carrier reaches the specified position, the switch S1 is switched to the second moving end to conduct; if the switch S1 chooses to conduct the second moving end before the position of the movable carrier reaches the specified position, the switch S1 is switched to the first moving end to conduct.

[0056] In an eleventh aspect, the present application provides a method for calibrating a VCM of a voice coil motor, which is applied to a motor system. The motor system may include: a driving integrated circuit, a voltage doubling circuit, and a VCM, wherein the input end of the voltage doubling circuit is coupled to the output end of the driving integrated circuit, the output end of the voltage doubling circuit is coupled to both ends of the coil of the voice coil motor, and the voltage doubling circuit is used to boost the input voltage output by the driving integrated circuit to the input end and then output it to both ends of the coil; the coil of the VCM is coupled to a current detection integrated circuit IC; the VCM includes a mover carrier and a coil, the mover carrier is used to carry a driven component of the VCM, and when the coil is energized, the mover carrier is also used to drive the driven component to move in the axial direction of the coil; and there is a linear mapping relationship between the position of the mover carrier and the coil inductance within the first motor stroke;

[0057] The VCM calibration method may include: energizing the coil and detecting the coil current when the driven component moves within the motor stroke of the VCM. Then, comparing the coil current with the coil current corresponding to the coil inductance within the first motor stroke, and outputting a calibration result; the calibration result includes: the coil current is larger or smaller than the coil current corresponding to the coil inductance within the first motor stroke.

[0058] In the eleventh aspect, the motor system may be the motor system described in the first aspect, and the voltage doubler circuit in the motor system may be the voltage doubler circuit described in the second aspect or the third aspect.

[0059] In combination with the eleventh aspect, in some embodiments, the voltage doubler circuit can also be used to change the voltage polarity of the coil voltage output to the two ends of the coil; when the voltage polarity of the coil voltage is a first polarity, the direction of the coil current is a first flow direction, and the VCM outputs a motor thrust in a first direction; when the voltage polarity of the coil voltage is a second polarity, the direction of the coil current is a second flow direction, and the VCM outputs a motor thrust in a second direction.

[0060] In conjunction with the eleventh aspect, in some embodiments, the coil current corresponding to the coil inductance within the first motor stroke is calculated by the following second-order differential equation:

[0061]

[0062] Among them, u crepresents the voltage of capacitor C1; R represents the equivalent resistance of the coil; L represents the inductance of the coil, u s Indicates the input voltage of the voltage doubler circuit; Indicates the change of coil current.

[0063] In the twelfth aspect, the present application provides a computer-readable storage medium comprising instructions. When the instructions are executed on an electronic device, the electronic device executes the method described in any one of the seventh aspect, the eighth aspect, the tenth aspect, and the eleventh aspect.

[0064] In the thirteenth aspect, the present application provides a computer program product comprising instructions, which, when the computer program product is run on an electronic device, enables the electronic device to execute the method described in any one of the seventh aspect, the eighth aspect, the tenth aspect, and the eleventh aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 A typical motor system is shown;

[0066] Figure 2 The motor system provided by the embodiment of the present application is shown;

[0067] Figure 3A A conventional two-stage voltage doubling circuit is shown;

[0068] Figure 3B The conventional two-stage voltage doubling circuit is shown with one capacitor charging;

[0069] Figure 3C The double capacitance charging of the conventional two-stage voltage doubling circuit is shown;

[0070] Figure 3D The double capacitance discharge of the conventional two-stage voltage doubling circuit is shown;

[0071] Figure 3E A conventional n (n≥3) level voltage multiplier circuit is shown;

[0072] Figure 4A The two-stage voltage doubling circuit provided in the embodiment of the present application is shown;

[0073] Figure 4B Shows Figure 4A The voltage doubler circuit shown is applied to a motor system;

[0074] Figure 5A Shows Figure 4A The capacitor of the two-stage voltage doubling circuit shown is charged, and at this time, the switch S1 selectively turns on D1;

[0075] Figure 5B Shows Figure 4AThe input voltage of the two-stage voltage doubler circuit shown is superimposed on the discharge of one-time capacitor, at which time the switch S1 selectively turns on D1;

[0076] Figure 5C Shows Figure 4A The capacitor of the two-stage voltage doubling circuit shown is charged, and at this time, the switch S1 selectively turns on D2;

[0077] Figure 5D Shows Figure 4A The input voltage of the two-stage voltage doubler circuit shown is superimposed on the discharge of one-time capacitance, at which time the switch S1 selectively turns on D2;

[0078] Fig. 6A Another two-stage voltage doubling circuit provided in an embodiment of the present application is shown;

[0079] Figure 6B Another two-stage voltage doubling circuit provided in an embodiment of the present application is shown;

[0080] Fig. 7A An n (n≥2) level voltage doubling circuit provided in an embodiment of the present application is shown;

[0081] Figure 7B Shows Fig. 7A The structure of the switch S1 in the n-stage voltage multiplier circuit shown;

[0082] Figure 8 Shows Figure 4B The waveform timing curves of the voltage of capacitor C1 and the coil current in the circuit shown;

[0083] Fig. 9 Comparison of coil current I under several input configurations coil Timing curve;

[0084] Fig. 10A An example of an integration method of a voltage doubling circuit in an application module is shown;

[0085] Fig. 10B Another integration method of the voltage doubling circuit in the application module is shown by way of example;

[0086] Fig. 10C Another integration method of the voltage doubling circuit in the application module is exemplified;

[0087] Fig.11 The relative positions of the VCM coil and the magnet are shown as an example;

[0088] Fig. 12A The example shows that the coil inductance does not change substantially when the magnet moves relative to the coil on the x-axis;

[0089] Fig. 12BThe example shows that the coil inductance fluctuates significantly when the magnet moves relative to the coil on the z-axis;

[0090] Fig.13 The coil current corresponding to the actual stroke of the motor is shown as an example;

[0091] Fig.14 Another motor system provided by an embodiment of the present application is shown;

[0092] Fig.15 An electronic device according to an embodiment of the present application is exemplarily shown;

[0093] Fig.16 Several motor thrust directions of the camera are shown;

[0094] Fig.17 A motor control method provided by an embodiment of the present application is shown. DETAILED DESCRIPTION

[0095] The terms used in the following embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0096] The motor is an important component of the camera, used to move the lens to change the focal length. Depending on whether it is used for anti-shake, the motor can be divided into a motor used only for auto focus (AF) and a motor with optical image stabilization (OIS) function (also known as "optical image stabilization"). The motor drives the lens to move in the direction of the optical axis to achieve zoom, and the motor drives the lens to move in the plane perpendicular to the optical axis to achieve anti-shake.

[0097] The voice coil motor (VCM) uses the Lorentz force between the energized coil and the magnet to drive the lens to achieve focus or anti-shake function. The motor and the motor driver IC connected to it constitute the most basic motor drive system. The driver IC can output current to the motor to drive the motor to work, thereby driving the lens to move. Generally, the driver IC uses a linear current or pulse width modulated current that is not higher than the supply voltage to drive the motor.

[0098] A typical motor driving solution is that the driver IC outputs a linear current to drive the VCM to drive the lens to move. Linear current refers to a current that changes continuously and linearly. Figure 1 As shown, the driverIC is connected to the power management circuit (PMC) and receives the power provided by the PMC (the voltage is shown as V DD); driverIC can also pass the bus (such as I 2 C bus) to the application processor (AP), receiving control signals from the AP to control the current of the VCM coil. After the linear current passes through the coil, it generates a magnetic field that attracts or repels the magnet, causing the motor to re-enter the force balance position to drive the motor to move.

[0099] Another typical motor driving solution is that a driver IC outputs a pulse width modulation (PWM) current to drive an SMA motor. The current flows through the SMA, causing the SMA to heat up and expand and contract, thereby pushing the lens to move.

[0100] However, in the scheme of using linear current to drive VCM, when the input voltage (such as driverIC output voltage) remains unchanged, the maximum coil current is: I = U in / R z , where U in Represents input voltage, R Z Indicates coil impedance. Therefore, referring to the calculation formula of Lorentz force F = B*L*I, it can be seen that increasing the motor thrust requires increasing the number of coil turns or increasing the size of the magnet, but this will lead to an increase in the size of the motor. In this formula, F represents the Lorentz force, B represents the magnetic flux density (magnetic induction intensity), L represents the length of the wire in the magnetic field, and I represents the current in the coil.

[0101] The embodiment of the present application introduces a voltage doubling circuit to increase the VCM coil current, which can increase the motor driving force without increasing the size of the camera module and avoid the above-mentioned problems.

[0102] Figure 2 A motor system provided by an embodiment of the present application is shown. Figure 2 As shown, the motor system may include: a driver IC, a voltage doubling circuit and a VCM, which are connected in sequence. The output end of the driver IC is connected to the input end of the voltage doubling circuit, and the output end of the voltage doubling circuit is connected to the VCM coil, which can be used to increase the output voltage of the driver IC by multiples and output it to both ends of the VCM coil load, thereby multiples the current flowing through the VCM coil, and ultimately significantly improve the motor thrust.

[0103] The voltage doubling circuit provided in the embodiments of the present application will be described in detail from multiple aspects below.

[0104] Voltage doubler circuit

[0105] The voltage doubling circuit mentioned in this article may include a two-stage voltage doubling circuit, a three-stage voltage doubling circuit, or even a multi-stage voltage doubling circuit.

[0106] Figure 3A-3D A conventional two-stage voltage doubling circuit and its function are shown.

[0107] like Figure 3A As shown in the figure, the two-stage voltage doubling circuit can be composed of two diodes D1 and D2, and two capacitors C1 and C2. Among them, the diode D1 and the capacitor C1 constitute a one-time charging circuit; the capacitor C1, the diode D2 and the capacitor C2 constitute a two-time charging circuit; the capacitor C2 and the coil load constitute a two-time discharging circuit. In addition, the two-stage voltage doubling circuit uses the two ends of the capacitor C2 as the output end. The coil is actually a series connection of an inductor and a resistor. In the figure, "R Z " can represent the equivalent load of the coil. The input voltage U in It can be an AC signal, specifically a PWM voltage signal. It is not limited to a PWM voltage signal, and the input voltage can also be other AC voltage signals. One cycle includes a positive half cycle and a negative half cycle.

[0108] like Figure 3B As shown in the figure, when the input voltage signal is in the negative half cycle, diode D1 is turned on and diode D2 is turned off. At this time, capacitor C1 is charged, and the voltage polarity is positive on the right and negative on the left. Soon after, the capacitor voltage is charged to be close to the input voltage, thus achieving "one-time capacitor charging". Figure 3C As shown in the figure, when the input voltage signal switches to the positive half cycle, diode D2 is turned on and diode D1 is turned off. At this time, the voltage on capacitor C1 is superimposed on the input voltage to charge capacitor C2. The voltage polarity of capacitor C2 is positive at the top and negative at the bottom, and its peak voltage can reach twice the peak value of the input voltage to achieve "double capacitor charging". Figure 3D As shown in the figure, when the input voltage signal switches to the negative half cycle again, the capacitor C2 discharges to the coil load. Since the capacitor voltage of C2 is approximately twice the input voltage, the current flowing through the coil when C2 discharges is approximately 2*I, so as to achieve "double capacitor discharge". Where I represents the coil current when the voltage doubling circuit is not used under the same input voltage, I=U in / R z. .

[0109] After that, when the input voltage signal reaches the next positive half cycle and negative half cycle, the voltage doubler circuit repeats Figure 3C , Figure 3D The charging and discharging process shown in the figure repeatedly realizes the double capacitance charging function and the double capacitance discharging function.

[0110] Figure 3E A conventional n-stage voltage multiplier circuit is shown, where n≥3.

[0111] like Figure 3EAs shown, the n-level voltage doubling circuit can be composed of n diodes D1, D2, D3...Dn, and n capacitors C1, C2, C3...Cn, including n charging circuits. Among them, the diode D1 and the capacitor C1 constitute a one-fold charging circuit; the capacitor C1, the diode D2 and the capacitor C2 constitute a two-fold charging circuit; the capacitor C1, the diode D3 and the capacitor C3 constitute a three-fold charging circuit; the capacitor C1, the diode Dn and the capacitor Cn constitute an n-fold charging circuit; the capacitor Cn and the coil load constitute an n-fold discharge circuit. In addition, the two-stage voltage doubling circuit uses the two ends of the capacitor Cn as the output end. In theory, if the path transmission loss such as the diode conduction voltage drop is ignored, the output voltage is n times the input voltage.

[0112] Improvement of two-stage voltage doubler circuit

[0113] The embodiment of the present application provides a two-stage voltage doubling circuit, which further reduces the circuit size and can change the polarity voltage of the output voltage. When the voltage doubling circuit is applied to a motor system, such as when the input end of the voltage doubling circuit is connected to a driver IC and the output end is connected to a VCM coil, it can change the direction of the coil current, thereby supporting the motor to output motor thrust in two directions, and ultimately controlling the driven component (such as the lens of a camera) to move in two directions.

[0114] like Figure 4A As shown, the secondary voltage doubler circuit 11 may include a capacitor C1, a diode D1, a diode D2, and a switch S1, input terminals 08A, 08B, and output terminals 09A, 09B. The switch S1 may be a single-pole double-throw switch, including a fixed terminal P1 and two moving terminals T1, T2, which may be used to switch between conducting D1 and conducting D2. Among them, one end of the capacitor C1 is coupled to the input terminal 08A, and the other end is coupled to the output terminal 09A. Of the two ends of the capacitor C1, the end coupled to the input terminal 08A may be referred to as the first end of the capacitor C1, and the other end coupled to the output terminal 09A may be referred to as the second end of the capacitor C1. The cathode of the diode D1 is coupled to the second end of the capacitor C1, and the anode is coupled to the active end T1 of the switch S1; the anode of the diode D2 is also coupled to the second end of the capacitor C1, and the cathode is coupled to the active end T2 of the switch S1; the fixed end P1 of the switch S1 is coupled to the input end 08B; and the input end 08B is also coupled to the output end 09B.

[0115] In the voltage doubler circuit 11, C1 and D1 form a charge-discharge circuit, and C1 and D2 also form a charge-discharge circuit. The two charge-discharge circuits share the same capacitor C1, so that the improved two-stage voltage doubler circuit 11 does not need two capacitors, which can further reduce the circuit size.

[0116] In the voltage doubling circuit 11, the two charge and discharge circuits do not work at the same time, and the switch S1 can be used to select which charge and discharge circuit to work. Specifically, the switch S1 can also include two control terminals C1 and C2 to receive control signals from control units such as AP or controllers. Whether the switch S1 selectively turns on D1 or D2 (i.e., which charge and discharge circuit is selected to work) can be controlled by a control signal input to the control terminal. The control signal can be generated due to the user's zoom action. For example, the action of increasing the zoom ratio will trigger the control unit such as AP to generate a control signal to select to turn on D1, thereby driving the lens to move in the first direction. For another example, the action of reducing the zoom ratio will trigger the control unit such as AP to generate a control signal to select to turn on D2, thereby driving the lens to move in the second direction. The first direction can be, for example, a direction close to the object being photographed, and the second direction can be, for example, a direction away from the object being photographed.

[0117] The diodes D1 and D2 are only an example of a unidirectional conduction device, and the voltage doubler circuit 11 may also use other types of unidirectional conduction devices. In the voltage doubler circuit 11, the diodes D1 and D2 may be replaced by two unidirectional conduction devices with opposite conduction directions. Herein, the unidirectional conduction device may be a unidirectional conduction device or a unidirectional conduction circuit that forms a small conduction voltage drop (less than 1V).

[0118] like Figure 4B As shown, the secondary voltage doubling circuit 11 provided in the embodiment of the present application can be connected between the driver IC and the coil 13, and can be used to increase the output voltage of the driver IC (i.e., the input voltage U in ) is further output to both ends of the coil load after being increased. Specifically, one input end of the voltage doubler circuit 11 is coupled to the output end 10A of the driver IC, and the other input end is coupled to the output end 10B of the driver IC; one output end of the voltage doubler circuit 11 is coupled to one end of the coil 13, and the other output end is coupled to the other end of the coil 13.

[0119] Herein, coupling includes direct electrical connection and indirect electrical connection with a conductive device (such as a resistor) or a conductive circuit in series.

[0120] Charging and discharging of the improved two-stage voltage doubler circuit

[0121] Figure 4A The input voltage of the voltage doubler circuit shown can be a PWM voltage signal. It is not limited to a PWM voltage signal, and the input voltage can also be other AC voltage signals. One cycle includes two half cycles, and the voltage polarities of the input voltages in these two half cycles are opposite.

[0122] Figure 5A-Figure 5B Shows Figure 4A A charging and discharging circuit of the voltage doubler shown in FIG. Figure 5A-Figure 5BIn the embodiment, switch S1 selectively turns on D1.

[0123] like Figure 5A As shown, when the input voltage signal is in the first half cycle, the voltage polarities of the input terminals 08A and 08B are negative and positive respectively, and the capacitor C1 is charged, with the voltage polarity being positive on the right and negative on the left, and soon after, the capacitor voltage is charged to be close to the input voltage. In this article, this charging process can be referred to as "one-time capacitor charging".

[0124] like Figure 5B As shown, when the input voltage signal switches to the second half cycle, the voltage polarities of the input terminals 08A and 08B are positive and negative respectively, D1 is not conducting, capacitor C1 is discharged, and the voltage on capacitor C1 is superimposed on the input voltage to form an output voltage, and the polarity of the output voltage is the first polarity (positive on top and negative on bottom as shown in the figure), which supplies power to the coil, and the current flowing through the coil is approximately 2*I. In this article, this discharge process can be referred to as "discharge with one-fold capacitance superimposed on input voltage".

[0125] For the explanation of I, please refer to the previous text and will not be repeated here. Figure 5B In the embodiment, the direction of the coil current is from the first end of the coil 13 to the second end of the coil 13. The first end of the coil 13 is an end coupled to the output end 09A, and the second end of the coil 13 is an end coupled to the output end 09B.

[0126] When the input voltage signal reaches the next cycle, the voltage doubler circuit 11 repeats Figure 5A The charging process shown Figure 5B The discharge process is shown.

[0127] Unlike the traditional two-stage voltage doubling circuit, the two-stage voltage doubling circuit provided in the embodiment of the present application can achieve an approximate doubling of the VCM supply voltage in one half cycle of the power supply, without taking as long as one cycle. The two-stage voltage doubling circuit provided in the embodiment of the present application only requires one capacitor C1, not two capacitors, which can save size.

[0128] Figure 5C-5D Shows Figure 4A Another charging and discharging method of the voltage doubler circuit shown in FIG. Figure 5C-5D In the embodiment, switch S1 selectively turns on D2.

[0129] like Figure 5C As shown, when the input voltage signal is in the second half cycle, the voltage polarities of the input terminals 08A and 08B are positive and negative respectively, the capacitor C1 is charged, the voltage polarity is positive on the left and negative on the right, and soon it is charged until the capacitor voltage is close to the input voltage, completing the "one-fold capacitor charging".

[0130] like Figure 5DAs shown, when the input voltage signal is switched to the first half cycle, the voltage polarities of the input terminals 08A and 08B are negative and positive respectively, D2 is not conducting, capacitor C1 is discharged, and the voltage on capacitor C1 is superimposed on the input voltage to form an output voltage. The polarity of the output voltage is the second polarity (negative on the top and positive on the bottom as shown in the figure), which supplies power to the coil. The current flowing through the coil is approximately 2*I, completing the "one times capacitance superimposed on input voltage discharge".

[0131] Figure 5D In the embodiment, the direction of the coil current is from the second end of the coil 13 to the first end of the coil 13.

[0132] When the input voltage signal reaches the next positive half cycle and negative half cycle, the voltage doubler circuit 11 repeats Figure 5C The charging process shown Figure 5D The discharge process is shown.

[0133] In addition, according to the right-hand screw rule, when current flows through the coil, the coil can generate an attractive force or a repulsive force relative to its matching magnet, thereby driving the lens or other components to be driven to move. Figure 5B The coil current and Figure 5D The coil currents shown in the figure have opposite directions, so they will generate two opposite driving forces, which can drive the lens to move in these two directions.

[0134] The first half cycle and the second half cycle can be respectively the negative half cycle and the positive half cycle, or respectively the positive half cycle and the negative half cycle. That is, the input voltage with positive top and negative bottom shown in the figure can be the input voltage of the positive half cycle or the input voltage of the negative half cycle.

[0135] Derivation of approximate double pressure

[0136] With reference to the charging and discharging process of the voltage doubling circuit 11 described above, the following derivation can be performed.

[0137] When capacitor C1 is charging: U C1 =U in -U D1 / D2 ;

[0138] When capacitor C1 is discharged: U coil =U in +U C1 ;

[0139] Therefore, U coil =2*U in -U D1 / D2 ≈2*U in .

[0140] Among them, U coil Indicates coil voltage, U C1 Represents the capacitance voltage of capacitor C1, U inIndicates input voltage, U D1 / D2 Indicates the voltage drop of diode D1 or D2. Its value is generally very small. For example, the voltage drop of silicon tube is less than or equal to 0.7V, and the voltage drop of germanium tube is less than or equal to 0.2V. When switch S1 selects to turn on D1, U D1 / D2 is the voltage drop across D1; ​​when switch S1 selects to turn on D2, U D1 / D2 is the voltage drop across D2.

[0141] Assume U in is 3V, U D1 / D2 is equal to 0.7V, then U coil It's U in 1.7 to 1.8 times of U in twice as much.

[0142] Adding bias resistors

[0143] Furthermore, a resistor can be connected in series in the charge-discharge circuit to adjust the charge-discharge time of the capacitor C1. Because the time constant of the charge-discharge circuit is τ=R*C, where R represents the circuit resistance, including the power supply internal resistance, the diode conduction resistance, and the transmission line resistance, further connecting resistors of different sizes in series can change the charge-discharge time constant of the circuit.

[0144] like Fig. 6A As shown, the two-stage voltage doubler circuit 11 may also include a bias resistor R1, which may be connected in series between the fixed end P1 of the switch S1 and the output end 10B of the driver IC, that is, it constitutes a bias resistor shared by the charge and discharge circuits of the diodes D1 and D2, and adjusts the charge and discharge time of the two charge and discharge circuits together. That is, the fixed end P1 of the switch S1 in the voltage doubler circuit 11 is not directly coupled to the output end 10B of the driver IC, but is indirectly coupled to the output end 10B of the driver IC through the series-connected bias resistor R1.

[0145] like Figure 6B As shown, the secondary voltage doubler circuit 11 may also include two bias resistors R1 and R2, which may be connected in series in the charge and discharge circuits of the diodes D1 and D2, respectively, to independently adjust the charge and discharge time of the charge and discharge circuits of D1 or D2. Specifically, the bias resistor R1 may be connected in series between the positive electrode of the diode D1 and the moving end T1 of the switch S1, and the bias resistor R2 may be connected in series between the negative electrode of the diode D2 and the moving end T2 of the switch S1. That is, the positive electrode of the diode D1 in the voltage doubler circuit 11 is not directly coupled to the moving end T1 of the switch S1, and the negative electrode of the diode D2 is not directly coupled to the moving end T2 of the switch S1.

[0146] More voltage doubler circuits

[0147] Fig. 7AFIG. 2 shows an n-level voltage multiplication circuit provided in an embodiment of the present application, where n≥2. Fig. 7A As shown, the n-stage voltage multiplier circuit can be composed of a traditional n-stage voltage multiplier circuit (including a traditional two-stage voltage multiplier circuit) and a switch S1. The switch S1 is electrically connected between the output end of the traditional n-stage voltage multiplier circuit and the coil load, and can be used to control the polarity of the voltage loaded on both ends of the coil to change the direction of the current flowing through the coil, thereby changing the direction of the motor thrust.

[0148] like Figure 7B As shown, the switch S1 may be a double-pole double-throw switch or a combination of two single-pole double-throw switches, and may include: two fixed terminals P1 and P2, four moving terminals T1, T2, T3, and T4, and two control terminals C1 and C2. Among them, P1 and P2 are electrically connected to the two ends of the capacitor Cn, respectively, T1 and T4 are electrically connected to the first end of the coil, and T2 and T3 are electrically connected to the second end of the coil.

[0149] When the voltage polarity of the output end of the n-stage voltage doubler circuit (i.e., the two ends of the capacitor Cn) is positive at the top and negative at the bottom, the switch can be controlled to switch so that P1 to T1 is turned on, P1 to T2 is turned off, P2 to T3 is turned on, and P2 to T4 is turned off, thereby controlling the voltage polarity of the coil to be positive at the top and negative at the bottom, and the direction of the coil current is to flow from the first end of the coil to the second end. When the voltage polarity of the output end of the n-stage voltage doubler circuit is positive at the top and negative at the bottom, the switch can be controlled to switch so that P1 to T2 is turned on, P1 to T1 is turned off, P2 to T4 is turned on, and P2 to T3 is turned off, thereby controlling the voltage polarity of the coil to be positive at the bottom and negative at the top, and the direction of the coil current is to flow from the second end of the coil to the first end. In this way, the direction of the coil current can be adjusted by the selective conduction capability of S1, thereby controlling the direction of the motor thrust.

[0150] Similarly, when the voltage polarity of the output end of the n-stage voltage multiplier circuit is negative at the top and positive at the bottom, the direction of the coil current can also be adjusted through the selective conduction capability of S1, thereby controlling the direction of the motor thrust.

[0151] The control signal of the switch switching can be transmitted from a control unit such as a controller or AP through two control terminals C1 and C2.

[0152] In addition, in order to independently control the time constant τ of each charging circuit, a bias resistor can be connected in series in each charging circuit, such as Fig. 7A R1, R2, R3...Rn.

[0153] Control the motor thrust

[0154] exist Figure 4B In the circuit shown, capacitor C1 is an inertial device in the electromagnetic field, and the voltage across it will not change suddenly. The coil is actually a series connection of an inductor and a resistor, and the inductor is also an inertial device in the electromagnetic field, and its current will not change suddenly.

[0155] Below Figure 5A-Figure 5B Taking the embodiment (switch S1 selectively turns on D1) as an example, how to increase or decrease the motor thrust is discussed.

[0156] Figure 8 Shows Figure 4B The capacitance voltage U of capacitor C1 in the circuit shown C1 , coil current I coil The timing curve of .

[0157] like Figure 8 As shown, when the input voltage signal (U in ) In the negative half cycle, capacitor C1 is charged, and the capacitor voltage rises rapidly and then stabilizes. In the steady state, the capacitor voltage is approximately twice the input voltage (2*U in ); at this time, the coil current is almost zero. When the input voltage signal switches to the positive half cycle, the capacitor C1 discharges, and the capacitor voltage decreases rapidly and then stabilizes, close to 0V; at this time, at the beginning of the discharge, the coil current does not change suddenly, but gradually rises from zero until it reaches a steady state. In the steady state, the coil current tends to be stable, close to direct current, and its value is approximately 2*I. For the explanation of I, please refer to the previous article and will not be repeated here. Generally, the coil current reaches a steady state after 5 τ, τ is the time constant of the charge and discharge circuit, τ=R circuit *C1. Here, R circuit is the resistance of the charge and discharge circuit, and its value can be determined as: R circuit = power supply internal resistance + on-resistance of switch S1 + on-resistance of diode D1 / D2.

[0158] Input voltage U in It can be a PWM signal, whose discharge duty cycle and frequency affect the coil current I coil In addition, the input voltage U in The level will affect the coil current I coil These factors will ultimately affect the size of the average motor thrust during the cycle.

[0159] By introducing the voltage doubling circuit, the motor thrust is nearly doubled, which can significantly increase the acceleration of the lens movement and improve the efficiency of moving the lens to the target position, even if the motor does not output thrust when the capacitor is charged. in The frequency is very high, generally 10KHz, 20KHz, or even higher, which also makes the output of motor thrust very intensive in a short period of time, such as 20,000 times of high thrust output in 1 second, which makes the focusing or anti-shake smooth and the user experience is good.

[0160] In this article, discharge duty cycle refers to the proportion of capacitor discharge time to the PWM period within a PWM period. Figure 5A-Figure 5B In the embodiment, the switch S1 turns on D1, and the capacitor C1 discharges in the positive half cycle of the input voltage, so the discharge duty cycle is the ratio of the positive half cycle time of the PWM waveform to the PWM period. Figure 5C-5D In the embodiment, switch S1 selectively turns on D2, and capacitor C1 discharges in the negative half cycle of the input voltage. Therefore, the discharge duty cycle is the ratio of the negative half cycle time of the PWM waveform to the PWM period.

[0161] Fig. 9 Comparison of coil current I under several input configurations coil Timing curve. Among them, Fig. 9 (a) shows the coil current I at 3V, 50% discharge duty cycle, and 20KHz frequency. coil ; Fig. 9 (b) shows the coil current I at 3V, 80% discharge duty cycle, and 20KHz frequency. coil ; Fig. 9 (c) shows the coil current I at 3V, 50% discharge duty cycle, and 10KHz frequency. coil ; Fig. 9 (d) shows the coil current I at 6V, 50% discharge duty cycle, and 20KHz frequency. coil .

[0162] It can be seen that the input voltage U in The larger the discharge duty cycle, the greater the coil current I coil The longer the time in steady state, the longer the input voltage U in The smaller the frequency, the longer the period, and the coil current I coil The longer the time in steady state, the longer the input voltage U in The larger the current I coil The bigger.

[0163] In the embodiment of the present application, the input voltage U in The level, frequency and discharge duty cycle of the coil current I coil The current waveform is adjusted to adjust the average motor thrust within the cycle, and ultimately control the motor to push the lens to the target position.

[0164] Specifically, the motor thrust can be increased by one or more of the following: increasing U in level, reduce U in frequency, increase U in For example, when the discharge duty cycle and frequency remain unchanged, increasing U in For another example, when the frequency and the level remain unchanged, the discharge duty cycle is increased. For another example, when the level and the discharge duty cycle remain unchanged, the frequency is reduced.

[0165] The discharge duty cycle can be increased by referring to the time constant τ, so that the discharge duration in the PWM cycle after the discharge duty cycle is increased is much greater than the time constant τ, for example, at least greater than 5*τ, so as to extend the coil current I as much as possible. coil During the steady-state time, the steady-state current is large (such as the designed 1.8*I), which can increase the motor thrust.

[0166] Specifically, the motor thrust can be reduced by one or more of the following: reducing U in level, increase U in frequency, reduce U in For example, when the discharge duty cycle and frequency remain unchanged, reducing U in For another example, when the frequency and the level remain unchanged, the discharge duty cycle is reduced. For another example, when the level and the discharge duty cycle remain unchanged, the frequency is increased.

[0167] Similarly, the time constant τ can also be used to reduce the discharge duty cycle. For example, after reducing the discharge duty cycle, the discharge duration in the PWM cycle is less than the time constant τ, making the coil current I coil In the transient state or even in the early stage of the transient state, the transient current is small (generally less than 65% of the steady-state current), which can reduce the motor thrust.

[0168] Integration method of voltage doubler circuit

[0169] The voltage doubling circuit introduced in the embodiment of the present application can be integrated into an application module (such as a camera module, a button module, etc.), or even integrated into a VCM. The voltage doubling circuit can also be partially or fully integrated into a driver IC.

[0170] The following is combined with Figure 1 1. Explanation.

[0171] Fig. 10A Figure 2 shows an integrated method of voltage doubling circuit. Fig. 10A As shown, the voltage doubling circuit can be integrated into the IC to form a new driver IC that can multiply the VCM power supply. The new driver IC has the capabilities of the voltage doubling circuit provided in the embodiments of the present application, namely: 1. It can approximately multiply and output the input voltage, significantly improving the external power supply capacity; 2. It can change the voltage polarity of the output voltage, support adjustment of the VCM coil current direction, and thus control the direction of the motor thrust.

[0172] exist Fig. 10A In this integrated manner, the output end of the new driver IC is coupled to both ends of the VCM coil to power the VCM.

[0173] The voltage doubler circuit may also be only partially integrated in the IC, and the rest may be integrated in the application module (such as a camera module, a key module, etc.). Partial integration in the IC may mean that the switches and other logic devices in the voltage doubler circuit are integrated in the driver IC, while one or more of the remaining capacitor C1, diode D1 and diode D2 are arranged outside the IC due to their relatively large size.

[0174] Fig. 10B Another integration method of voltage doubling circuit is shown. Fig. 10B As shown, the voltage doubling circuit can be integrated into an application module (such as a camera module, a button module, etc.). For example, a voltage doubling circuit welding pad is etched on a flexible printed circuit board (FPCB) part or a metal part built into the camera module. The voltage doubling circuit can be set in a size-insensitive position of the application module, such as in the z-direction space of the module, to avoid increasing the size of the application module. Here, the z-direction of the module refers to the direction of the optical axis. In particular, in the z-direction, the lens cannot be infinitely close to the image sensor, and the two need to maintain a certain distance, which forms a cavity. The voltage doubling circuit can be set in the cavity, taking care not to block the light exposure, and can be specifically attached to the wall of the cavity.

[0175] Fig. 10C Another integration method of voltage doubling circuit is shown. Fig. 10C As shown, the voltage doubler circuit can be integrated in the VCM. For example, a voltage doubler circuit soldering pad is etched on a part of a flexible printed circuit board (FPCB) or a metal part built into the VCM. The location of the voltage doubler circuit can be determined according to the internal design of the VCM, and it only needs to not conflict with the mover carrier, magnet, coil and other components.

[0176] Lens shift position detection

[0177] The moving carrier that carries the lens can have a magnet, which can attract or repel the energized coil, thereby pushing the lens to move. In this case, the coil is stationary and the magnet is moving, and the position of the magnet relative to the coil can be used to indicate the position of the lens. Of course, the magnet can also be relatively stationary, and the coil and the lens move together. In this case, the position of the coil relative to the magnet can indicate the position of the lens. The following example is used to illustrate the situation where the magnet moves and the coil is stationary.

[0178] Fig.11The side view (cross-section view) briefly shows the relative position of the coil and the magnet. The coil is composed of a series of turns wound around the z-axis, and the current flows as shown by the arrows in the figure. The z-axis is parallel to the axis of the coil, and the z-axis direction can also be called the axis direction of the coil. When the coil is energized, the z-axis also points to the south pole (S) or north pole (N) of the coil, depending on how the coil is wound. The movement of the magnet relative to the coil may affect the inductance of the coil. Fig. 12A As shown in Figure 1, when the magnet moves in the x-axis direction or in the opposite direction, the inductance L of the coil does not change substantially. Fig. 12B As shown, when the magnet moves in the z-axis direction or the opposite direction, the inductance L of the coil will fluctuate significantly. In the embodiment of the present application, the VCM is used to drive the movement of the lens, etc. in the z-axis direction or the opposite direction.

[0179] Moreover, through repeated experiments, it is found that when the magnet moves in the z-axis direction, the magnet position and the inductance L of the coil are approximately linearly related in a certain section (which can be called the first motor stroke), such as Fig. 12B The position of the middle magnet is in the motor stroke from -1.40 mm to -0.80 mm. This approximately linear segment can be found through simulation. During simulation, fixed parameters such as the number of coil turns, magnetic permeability of the magnet, capacitance and resistance of the LCR circuit can be input to simulate the movement of the magnet in a larger stroke range to find this approximately linear segment.

[0180] The approximately linear segment of the magnet position and the coil inductance L can be recorded into a linear mapping table. In this way, under the condition of determining the coil inductance L, the magnet position can be estimated, so as to understand whether the driven components such as the lens have moved to the specified position.

[0181] The coil's volt-ampere characteristic can be expressed by the following formula: u = L*di / dt, where u represents the coil voltage, L represents the coil inductance, and di / dt represents the rate of change of the coil current. The change in coil current can be detected by a current detection IC coupled to the coil. The coil voltage u, i.e., the output voltage of the aforementioned voltage doubler circuit, is a fixed value, and its value can be approximated to the input voltage U when the capacitor C is discharged. in twice or more, and can be estimated as n*U in , n represents the number of stages of the voltage doubler circuit.

[0182] Therefore, on the premise of determining the coil voltage u and the coil current change di / dt, the electronic device or the control unit of the current detection IC coupled in the electronic device (such as AP) can calculate the inductance L by the above formula, L=u*(1 / (di / dt)). Then, based on the linear mapping relationship between the magnet position and the coil inductance L, the electronic device or the control unit of the current detection IC coupled in the electronic device (such as AP) can determine the magnet position (i.e., the lens position) corresponding to the calculated inductance L. Specifically, the magnet position corresponding to the calculated inductance L can be found from the linear mapping table used to record the linear mapping relationship between the magnet position and the coil inductance L.

[0183] Motor calibration

[0184] The travel covered by the magnet position in the approximately linear section between the magnet position and the coil inductance L may deviate greatly from the actual motor travel. Fig. 12B As shown, this approximately linear segment covers the motor travel from -1.40 mm to -0.80 mm, while Fig.13 As shown, the actual motor travel is -1.0 mm to 1.0 mm. The minus sign "-" can represent movement in the opposite direction along the z-axis.

[0185] To this end, the motor calibration must be performed first to make the actual motor stroke fall within the approximate linear segment as much as possible. The calibration method includes:

[0186] The coil is energized, and the coil current (which may be referred to as the coil current corresponding to the actual motor stroke) is detected when the lens moves within the actual motor stroke, and the coil current is recorded, such as Fig.13 The power supply of the coil can refer to the above-mentioned embodiment and will not be described in detail here.

[0187] Determine whether the coil current corresponding to the actual motor stroke is larger or smaller than the coil current corresponding to the coil inductance L in the aforementioned approximate linear segment (magnet position-coil inductance L), and output the calibration result. If the calibration result indicates that the coil current corresponding to the actual motor stroke is smaller, the charging time can be increased and the discharge time can be shortened to increase the coil current; if the calibration result indicates that the coil current corresponding to the actual motor stroke is larger, the charging time can be shortened and the discharge time can be increased to reduce the discharge current. In this way, the actual motor stroke can be adjusted to the approximate linear segment as much as possible.

[0188] The motor calibration method can be implemented by a calibration device. The calibration device can be an electronic device that integrates the motor to be calibrated and the motor system, or it can be an independent device that couples the motor to be calibrated and the motor system. The calibration program that implements the calibration method can be installed on the calibration device.

[0189] When the capacitor is discharged, the coil current corresponding to the coil inductance L in the approximate linear segment of the magnet position-coil inductance L can be calculated by the following second-order differential equation:

[0190]

[0191] Among them, u c represents the capacitor voltage; R represents the equivalent resistance of the coil; L represents the coil inductance, u s represents the input voltage of the LCR circuit, that is, the input voltage U of the voltage doubler circuit in the above embodiment. in ; It can represent the change of coil current. Therefore, in R, C, u s If the inductance L of the coil is known, the corresponding coil current can be calculated based on the coil inductance L in the approximate linear segment.

[0192] In the motor system provided in the embodiment of the present application, Figure 4B As shown in the example, the time constant τ1 of capacitor C1 discharge = equivalent resistance of coil * C1, and the time constant τ2 of capacitor C1 charging = (power supply internal resistance + switch S1 on resistance + diode D1 / D2 on resistance + bias resistor R1 / R2) * C1. The equivalent resistance of the coil is generally 20-30Ω, which is much larger than the power supply internal resistance of 1-2Ω, the switch S1 on resistance of 1Ω, and the diode on resistance of mΩ.

[0193] like Fig.14 As shown in the figure, when the motor design is completed, the equivalent resistance R3 of the coil is fixed. A resistor R4 is connected in parallel at both ends of the coil. By adjusting R4, the equivalent resistance of the coil can be adjusted, thereby changing the discharge time constant τ and adjusting the size of the coil current during discharge, so that the adjusted coil current and the coil current corresponding to the coil inductance L in the approximate linear segment (magnet position-coil inductance L) are more overlapped, so that the actual formation of the motor falls on the approximate linear segment as much as possible.

[0194] Specifically, if the calibration result indicates that the coil current corresponding to the actual stroke of the motor is too small, a smaller R4 can be selected to make the discharge resistance smaller, shorten the discharge time, and thus increase the coil current during discharge; if the calibration result indicates that the coil current corresponding to the actual stroke of the motor is too large, a larger R4 can be selected to make the discharge resistance larger, increase the discharge time, and thus reduce the coil current during discharge.

[0195] If the calibration result indicates that the coil current corresponding to the actual motor stroke is too small, you can also select a larger bias resistor R1 / R2 to increase the charging time; if the calibration result indicates that the coil current corresponding to the actual motor stroke is too large, you can also select a smaller bias resistor R1 / R2 to shorten the charging time.

[0196] against Figure 4B The motor system shown, if the lens movement and lens position detection have been completed, such as detecting that the lens has reached the specified position, can control the switch S1 in the secondary voltage doubling circuit to switch to the other moving end to transfer the remaining electrical energy on the capacitor C1 to the negative electrode of the power supply, so as to prevent the remaining electrical energy from causing the lens to continue to move and affecting the lens position accuracy control.

[0197] Specifically, in Figure 5A-Figure 5B In the embodiment, the switch S1 conducts the first moving end T1, and the current direction of the coil is the first flow direction when the coil is energized. Based on this, if it is detected that the lens has moved to the specified position, the control switch S1 is switched to the second moving end T2 to conduct, so that the unreleased electrical energy on C1 will be transmitted to the negative electrode of the power supply through the diode D2 and the switch S1.

[0198] Specifically, in Figure 5C-5D In the embodiment, the switch S1 conducts the second moving end T2, and the current direction of the coil is the second flow direction when the coil is energized. Based on this, if it is detected that the lens has moved to the specified position, the control switch S1 is switched to the first moving end T1 to conduct, so that the unreleased electrical energy on C1 will be transmitted to the negative electrode of the power supply through the switch S1 and the diode D1.

[0199] Fig.15 An electronic device 100 provided in an embodiment of the present application is shown.

[0200] like Fig.15 As shown, the electronic device 100 may include: a processor 110, a memory 120, a motor system 130, a power management module 140, a camera 150, a button 160, and a display screen 170. Among them:

[0201] The processor 110 may include an application processor (AP), an image signal processor (ISP). The processor 110 may also include a modem processor, a graphics processing unit (GPU), a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU). Different processing units may be independent devices or integrated into one or more processors.

[0202] The processor 110 may include one or more interfaces. The interface may include an integrated circuit (IC). 2C) interface, inter-integrated circuit sound, I 2 S) interface, pulse code modulation (PCM) interface, universal asynchronous receiver / transmitter (UART) interface, mobile industry processor interface (MIPI), general-purpose input / output (GPIO) interface, subscriber identity module (SIM) interface, and / or universal serial bus (USB) interface, etc.

[0203] I 2 The I C interface is a bidirectional synchronous serial bus that includes a serial data line (SDA) and a serial clock line (SCL). The processor 110 may include multiple I 2 C bus. The processor 110 can be connected to the 2 The C bus couples the memory 120, the power management module 140, the camera 150, the button 160, the display screen 170, etc.

[0204] For example, the processor 110 may 2 The C bus is coupled to the camera 150 to control the driver IC in the camera 150 to adjust the voltage signal output to VCM (the aforementioned input voltage U in , which is a PWM voltage signal), the level, discharge duty cycle, and frequency, thereby adjusting the current of the VCM coil and ultimately adjusting the motor thrust. For another example, the processor 110 may use I 2 The C bus is coupled to the camera 150 to control the controller in the camera 150 to output a switch selection signal, thereby adjusting the current direction of the VCM coil to generate a motor thrust in a specified direction.

[0205] I 2 The S interface can be used for audio communication. The processor 110 can include multiple groups of I 2 The processor 110 can use I 2 The S bus is coupled to the audio module in the electronic device 100 to realize communication between the processor 110 and the audio module. The audio module can be connected to the I 2The S interface transmits audio signals to the wireless communication module in the electronic device 100, thereby realizing the function of answering calls through a Bluetooth headset.

[0206] The PCM interface can also be used for audio communication, sampling, quantizing and encoding analog signals. The audio module and the wireless communication module can be coupled through the PCM bus interface. The audio module can also transmit audio signals to the wireless communication module through the PCM interface to realize the function of answering calls through Bluetooth headsets.

[0207] The UART interface is a universal serial data bus that converts the data to be transmitted between serial communication and parallel communication. The UART interface is usually used to connect the processor 110 with the wireless communication module. For example, the processor 110 communicates with the Bluetooth module in the wireless communication module through the UART interface to implement the Bluetooth function.

[0208] The MIPI interface can be used to connect the processor 110 with peripheral devices such as a display screen and a camera 150. The MIPI interface includes a camera serial interface (CSI), a display serial interface (DSI), and the like.

[0209] The GPIO interface can be configured by software. The GPIO interface can be configured as a control signal or a data signal. The GPIO interface can be used to connect the processor 110 with the camera 150, a display screen, a wireless communication module, an audio module, and various sensors. The GPIO interface can also be configured as I 2 C interface, I 2 S interface, UART interface, MIPI interface, etc.

[0210] The USB interface may include: Mini USB interface, Micro USB interface, USB Type C interface, etc. The USB interface may be used to connect a charger to charge the electronic device 100, or may be used to transmit data between the electronic device 100 and a peripheral device. The interface may also be used to connect other electronic devices, such as AR devices, etc.

[0211] The memory 120 may include one or more random access memories (RAM) and one or more non-volatile memories (NVM). The random access memory can be directly read and written by the processor 110, and can be used to store executable programs (such as machine instructions) of the operating system or other running programs, and can also be used to store user and application data. The non-volatile memory can also store executable programs and store user and application data, etc., and can be loaded into the random access memory in advance for direct reading and writing by the processor 110.

[0212] The processor 110 may also be provided with a memory for storing instructions and data. The memory in the processor 110 is a high-speed cache memory. The memory may store instructions or data that the processor 110 has just used or cyclically used. If the processor 110 needs to use the instruction or data again, it may be directly called from the memory. This avoids repeated access, reduces the waiting time of the processor 110, and thus improves the efficiency of the electronic device 100.

[0213] The motor system 130 may include a driver IC, a voltage doubling circuit, and a VCM.

[0214] Among them, the voltage doubler circuit can be the aforementioned Figure 4A , Figure 7A-7B The voltage doubling circuit described in the embodiment supports the VCM to output motor thrust in two directions. Figure 4A The two-stage voltage doubling circuit shown is composed of only one capacitor and a diode, unlike the traditional two-stage voltage doubling circuit which requires two capacitors. Therefore, the motor thrust is increased exponentially while the design size of the motor system is saved.

[0215] The input end of the driver IC is connected to the power management module 140, and the output end is connected to the voltage doubler circuit. The output voltage of the driver IC is the input voltage U of the voltage doubler circuit. in In the embodiment of the present application, the output voltage of the driver IC is multiplied by the voltage doubling circuit in the VCM, and then loaded to both ends of the VCM coil, thereby multiplying the VCM coil current and significantly improving the motor thrust. The output voltage signal of the driver IC can be a PWM signal. Adjusting the level, discharge duty cycle, and frequency of the output voltage signal of the driver IC can change the VCM coil current, thereby changing the motor thrust. Specifically, the driver IC can be controlled by I 2 The C bus communicates with the processor 110 (such as AP), receives the power supply adjustment signal, and then changes the level, discharge duty cycle, and frequency of its output voltage signal accordingly.

[0216] The motor system 130 may also be coupled to a controller, specifically, the gate switch S1 in the VCM voltage doubler circuit may be coupled to the controller. The controller may be used to control the selective conduction of the switch S1 in the voltage doubler circuit, thereby adjusting the current direction of the VCM coil and generating a motor thrust in a specified direction. The controller may be integrated into the processor 110, or may be integrated into other components, such as the camera 150, or may be independently provided on a printed circuit board.

[0217] The motor system 130 can be applied to one or some components of the electronic device 100, such as the camera 150, the button 160, and the display screen 170. The dotted arrows in the figure represent a hardware-implemented dependency, that is, the camera 150, the button 160, and the display screen 170 can be implemented by relying on the motor system 130.

[0218] When the motor system 130 is applied to the camera 150, the VCM generates mechanical force to drive the lens to move so as to change the zoom ratio; when the motor system 130 is applied to the button 160, the VCM generates mechanical force to drive the rebound mechanism in the button to rebound; when the motor system 130 is applied to the display screen 170 (specifically a touch screen), the VCM generates mechanical force to form force feedback to simulate force tactile sensation.

[0219] The following description will be made by taking the application of the motor system 130 to the camera 150 as an example.

[0220] The camera 150 may include: a lens, an AF VCM, an OIS VCM, a photosensitive sensor, and a controller. The camera 150 may also include: a driver IC (not shown) connected to each VCM. The driver IC and the controller may be arranged on a flexible printed circuit board (FPCB). The FPCB may also be responsible for connecting some components in the camera 150 to the processor 110, for example, transmitting the raw data output by the photosensitive sensor to the processor 110 (specifically, the ISP).

[0221] When taking a photo, the shutter of the camera 150 is opened, and light enters and shines on the photosensitive sensor. The photosensitive sensor converts the light signal into an electrical signal, and then further converts the electrical signal into a digital signal through analog digital convert (ADC) to pass it to the ISP for processing. The ISP can perform the following processing on the output data of the photosensitive sensor: auto exposure control (AEC), auto gain control (AGC), auto white balance (AWB), color correction, removal of bad pixels, etc. The ISP can also be integrated into the camera 150.

[0222] AF VCM and OIS VCM can integrate the improved voltage doubling circuit described in the above embodiments, which can multiply the coil voltage, increase the coil current, and ultimately multiply the motor thrust. AF VCM can be used to drive the lens to move in the direction of the optical axis. OIS VCM can be used to drive the lens to move in the plane perpendicular to the optical axis.

[0223] Generally, such as Fig.16 As shown, OIS requires jitter compensation in at least four directions in the plane perpendicular to the optical axis: x1, x2, y1, and y2. In the figure, z1 and z2 represent the direction of the optical axis. As mentioned above, a VCM provided in an embodiment of the present application can generate motor thrust in both directions. To this end, the OIS VCM may include at least two VCMs, one VCM for generating motor thrust in the two directions of x1 and x2, and the other VMC for generating motor thrust in the two directions of y1 and y2.

[0224] The controller can be used to control the selective conduction of the switch S1 in the voltage doubler circuit, thereby adjusting the current direction of the VCM coil and generating the motor thrust in a specified direction. 2 The C bus communicates with the processor 110 (such as AP), receives autofocus instructions and optical image stabilization instructions, and then outputs switch selection signals to the control terminals C1 and C2 of the switch S1 in the voltage doubling circuit accordingly, adjusts the current direction of the VCM coil to generate motor thrust in the specified direction, and completes the autofocus and optical image stabilization goals.

[0225] The camera 150 may have only one controller for controlling the coil current direction of multiple VCMs, and thus controlling the motor thrust direction of the multiple VCMs. That is, the one controller may be electrically connected to the switch S1 in the multiple VCM voltage doubling circuits, specifically connected to the control terminals C1 and C2 of the switch S1. Of course, the camera 150 may also have multiple controllers, one controller for each VCM, to independently control the motor thrust direction of each VCM.

[0226] In the camera 150, the driver ICs can be provided for the AF VCM and the OIS VCM respectively to independently power the AF VCM and the OIS VCM. The driver ICs of the AF VCM and the OIS VCM can be provided through I 2 The C bus communicates with the processor 110 (such as AP), receives the power supply adjustment signal of AFVCM and OIS VCM, and then adapts to change the level, discharge duty cycle and frequency of the output voltage signal of each driver IC, thereby changing the motor thrust.

[0227] The button 160 may be a power button, a volume button, etc. The motor system 130 may be applied to the button 160 to drive the rebound mechanism to rebound, provide significant rebound force, and improve the user's button experience.

[0228] The display screen 170 can be used to display images, videos, etc. The display screen 170 can be a touch screen with a touch panel, and the motor system 130 can be applied to the display screen 170 to generate vibration prompts (such as vibration prompts for incoming calls, alarms, etc.) or provide touch force feedback to the user.

[0229] The power management module 140 can be used to connect the battery, charging management module and processor 110 in the electronic device 100. The power management module 140 receives input from the battery and / or charging management module to power the processor 110, the memory 120, the camera 150, the display screen, the wireless communication module, etc. Specifically, the power management module 140 can be connected to the driver IC that matches each VCM in the camera 150 to control the power supply to the camera through the driver IC. The power management module 140 can also be used to monitor parameters such as battery capacity, battery cycle number, battery health status (leakage, impedance), etc. The power management module 140 can also be set in the processor 110. The power management module 140 can also be integrated with the charging management module.

[0230] The electronic device 100 may also include: a wireless communication module. The wireless communication module may provide wireless communication solutions including wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), nearfield communication technology (NFC), infrared technology (IR), etc., which are applied to the electronic device 100. The wireless communication module may also provide wireless communication solutions including 2G / 3G / 4G / 5G, etc., which are applied to the electronic device 100. The wireless communication module receives electromagnetic waves via an antenna, modulates and filters the electromagnetic wave signals, and sends the processed signals to the processor 110. The wireless communication module may also receive the signal to be sent from the processor 110, modulate the frequency of the signal, amplify it, and convert it into electromagnetic waves for radiation through the antenna.

[0231] The electronic device 100 may further include: an audio module, a speaker, a receiver, a microphone, and an earphone interface.

[0232] Among them, the electronic device can realize audio functions through an audio module, a speaker, a receiver, a microphone, a headphone interface, and an application processor (AP). For example, music playback, recording, etc. The audio module is used to convert digital audio information into an analog audio signal output, and is also used to convert analog audio input into a digital audio signal. The audio module can also be used to encode and decode audio signals. The audio module can be set in the processor 110, or some functional modules of the audio module can be set in the processor 110. The speaker, also known as a "speaker", is used to convert audio electrical signals into sound signals. The electronic device can listen to music or listen to hands-free calls through the speaker. The receiver, also known as a "handset", is used to convert audio electrical signals into sound signals. When the electronic device answers a call or voice message, the voice can be answered by placing the receiver close to the human ear. The microphone, also known as a "microphone" or a "microphone", is used to convert sound signals into electrical signals. When making a call or sending a voice message, the user can make a sound by approaching the microphone with the human mouth to input the sound signal into the microphone. The headphone interface is used to connect wired headphones. The headphone jack may be a USB interface, or a 3.5 mm open mobile terminal platform (OMTP) standard interface, or a cellular telecommunications industry association of the USA (CTIA) standard interface.

[0233] The electronic device 100 may further include sensors, such as a gyroscope, an accelerometer, a pressure sensor, a distance sensor, a proximity light sensor, an ambient light sensor, etc. Among them, the gyroscope and the accelerometer are very necessary for OIS.

[0234] Fig.15 The illustrated structure does not constitute a specific limitation on the electronic device, and the electronic device may include more or fewer components than shown in the figure, or combine some components, or separate some components, or arrange the components differently. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0235] In addition, based on the above Figure 4B , Figure 7A-7B The motor system described in the embodiment is applied to the camera 150 . The embodiment of the present application also provides a motor control method to control the motor to output motor thrust in a specified direction.

[0236] like Fig.17 As shown, the method may include:

[0237] S11 , the electronic device 100 detects an operation of increasing the optical zoom ratio of the camera 150 .

[0238] S12, the electronic device 100 switches the switch S1 in the AF VCM voltage doubling circuit in the camera 150 to the first active end to be turned on.

[0239] When the switch S1 is turned to the first moving end to be turned on, the direction of the AF VCM coil current is from the first end of the coil to the second end of the coil. At this time, the lens of the camera 150 moves away from the object being photographed on the optical axis.

[0240] S13, the electronic device detects an operation of reducing the optical zoom ratio of the camera 150.

[0241] S14, the electronic device 100 switches the switch S1 in the AF VCM voltage doubling circuit in the camera 150 to the second active end to be turned on.

[0242] When the switch S1 is turned to the second moving end to be turned on, the direction of the AF VCM coil current is from the second end of the coil to the first end of the coil. At this time, the lens of the camera 150 moves on the optical axis toward the direction of the object being photographed.

[0243] In the AF VCM voltage doubler circuit, Figure 4A-4B In the case described in the embodiment, the first moving end may refer to the moving end T1, and the second moving end may refer to the moving end T2. Figure 7A-7B In the case described in the embodiment, the first moving end may refer to a group of moving ends T1 and T3, and the second moving end may refer to a group of moving ends T2 and T4.

[0244] Furthermore, the method may also include:

[0245] S15, when the camera 150 is turned on to capture images, the electronic device 100 detects device shaking in a third direction.

[0246] The third direction may be an OIS direction of the camera 150. Herein, the OIS direction refers to the direction in which the OIS VCM provides jitter compensation. Fig.16 The four directions represented by x1, y1, x2, and y2 provide jitter compensation, and these four directions are OIS directions. Of course, the OIS VCM can also provide jitter compensation in more (such as 8) directions, that is, have more OIS directions. This embodiment is described by taking the camera 150 having four OIS directions as an example.

[0247] S16, the electronic device 100 switches the switch S1 in the OIS VCM voltage doubling circuit in the camera 150 to the first active end to be turned on.

[0248] When the switch S1 is turned on to the first moving end, the direction of the OIS VCM coil current flows from the first end of the coil to the second end of the coil. At this time, the lens of the camera 150 moves in the fourth direction on the optical axis plane. The fourth direction is the opposite direction of the third direction and is also another OIS direction of the camera 150. The third direction and the fourth direction can be respectively Fig.16 x1, x2, or y1, y2 in .

[0249] S17, when the camera 150 is turned on to capture images, the electronic device 100 detects device shaking in a fourth direction.

[0250] S18, the electronic device 100 switches the switch S1 in the OIS VCM voltage doubling circuit in the camera 150 to the second active end to be turned on.

[0251] When the switch S1 is turned on to the second moving end, the direction of the current of the OIS VCM coil is from the second end of the coil to the first end of the coil. At this time, the lens of the camera 150 moves in the third direction on the optical axis plane.

[0252] An actual device jitter may not be simply a device jitter in a certain OIS direction. In this case, the actual device jitter can be decomposed into two device jitters in two mutually perpendicular OIS directions, for example Fig.16 After performing this decomposition, anti-shake compensation is performed on the device jitter in a single OIS direction.

[0253] In the above method, the execution order of S11-S12, S13-S14, S15-S16, and S17-S18 is not particularly limited. S13-S14 can be executed before S11-S12, such as when the user first reduces the zoom ratio and then increases the zoom ratio. S17-S18 can also be executed before S15-S16. S15-S16 and S17-S18 can be executed before S11-S12 and S13-S14, such as when the device shakes before the user adjusts the focus. S15-S16 and S17-S18 can also be executed simultaneously with S11-S12 and S13-S14, such as when the device shakes when the user adjusts the focus.

[0254] The VCM control method provided by the embodiment of the present application is further described below based on the internal architecture of the electronic device 100.

[0255] S21, after detecting an operation of increasing the optical zoom ratio of the camera 150 through an input device such as a touch screen, the AP may send a first automatic focus instruction to a controller in the camera 150, wherein the instruction may indicate a direction for the lens to move away from the object being photographed.

[0256] S22, the controller outputs a first control signal to the control end of the switch S1 in the AF VCM voltage doubling circuit.

[0257] S23, in response to the first control signal, the switch S1 in the AF VCM voltage doubler circuit is switched to the first active end to be turned on. The first control signal may be a level signal.

[0258] S24, after detecting the operation of reducing the optical zoom ratio of the camera 150 through an input device such as a touch screen, the AP may send a second automatic focus instruction to the controller in the camera 150, which may indicate the direction of the lens movement to move closer to the object being photographed.

[0259] S25, the controller outputs a second control signal to the control end of the switch S1 in the AF VCM voltage doubling circuit.

[0260] S26, in response to the second control signal, the switch S1 in the AF VCM voltage doubler circuit is switched to the second active end to be turned on. The second control signal may be a level signal.

[0261] In addition, when device shaking is detected, the AP may also send an OIS command to the OIS VCM 1 or OIS VCM 2, and the OIS command may indicate the anti-shake compensation direction.

[0262] S27, after detecting device shaking in the x1 direction through input devices such as a gyroscope and an accelerometer, the AP may send an OIS instruction to the controller in the camera 150, and the OIS instruction may indicate that the anti-shake compensation direction is: the x2 direction.

[0263] S28 , the controller outputs a first control signal to the control terminal of the switch S1 in the voltage doubling circuit of the OIS VCM 1 .

[0264] S29, in response to the first control signal, the switch S1 in the voltage doubler circuit of the OIS VCM 1 is switched to the first active end and turned on.

[0265] S30, after detecting device shaking in the x2 direction through input devices such as a gyroscope and an accelerometer, the AP may send an OIS instruction to the controller in the camera 150, and the OIS instruction may indicate that the anti-shake compensation direction is: the x1 direction.

[0266] S31 , the controller outputs a second control signal to the control terminal of the switch S1 in the voltage doubling circuit of the OIS VCM 1 .

[0267] S32, in response to the second control signal, the switch S1 in the voltage doubler circuit of the OIS VCM 1 is switched to the second active end to be turned on.

[0268] By controlling the conduction of the switch S1 in the voltage doubling circuit of the OIS VCM 1, the OIS VCM 1 can be controlled to push the lens to move in the anti-shake compensation direction, thereby achieving anti-shake compensation.

[0269] Similarly, after detecting device shaking in the y1 or y2 direction through input devices such as a gyroscope and an accelerometer, the AP can also send an OIS instruction to the controller in the camera 150 and indicate the direction of anti-shake compensation; the controller can control the conduction of the switch S1 in the voltage doubling circuit of the OIS VCM 2 according to the OIS instruction to control the OIS VCM 2 to push the lens to move in the anti-shake compensation direction to achieve anti-shake compensation.

[0270] Each step in the above method embodiment provided by the present application can be completed by an integrated logic circuit of hardware in a processor or by instructions in the form of software. The method steps disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware processor, or by a combination of hardware and software modules in a processor.

[0271] The present application also provides an electronic device, which may include: a memory and a processor, wherein the memory may be used to store a computer program; and the processor may be used to call the computer program in the memory so that the electronic device executes the method in any one of the above embodiments.

[0272] The present application also provides a chip system, which includes at least one processor for implementing the functions involved in the method executed by the electronic device in any of the above embodiments.

[0273] In one possible design, the chip system also includes a memory, which is used to store program instructions and data, and the memory is located inside or outside the processor.

[0274] The chip system may be composed of the chip, or may include the chip and other discrete devices.

[0275] Optionally, the processor in the chip system may be one or more. The processor may be implemented by hardware or by software. When implemented by hardware, the processor may be a logic circuit, an integrated circuit, etc. When implemented by software, the processor may be a general-purpose processor implemented by reading software code stored in a memory.

[0276] Optionally, the memory in the chip system may also be one or more. The memory may be integrated with the processor or may be separately arranged with the processor, which is not limited in the embodiments of the present application. Exemplarily, the memory may be a non-transient processor, such as a read-only memory ROM, which may be integrated with the processor on the same chip or may be arranged on different chips respectively. The embodiments of the present application do not specifically limit the type of memory and the arrangement of the memory and the processor.

[0277] Exemplarily, the chip system can be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD) or other integrated chips.

[0278] The present application also provides a computer program product, which includes: a computer program (also referred to as code, or instruction), which enables a computer to execute the method executed by the electronic device in any of the above embodiments when the computer program is executed.

[0279] The present application also provides a computer-readable storage medium, which stores a computer program (also referred to as code or instruction). When the computer program is executed, the computer executes the method executed by the electronic device in any of the above embodiments.

[0280] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the process or function according to the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that the computer can access or a data storage device such as a server or a data center that includes one or more available media integrations. Available media can be magnetic media, (e.g., floppy disk, hard disk, tape), optical media (e.g., DVD), or semiconductor media (e.g., solid-state drive Solid State Disk), etc.

[0281] Those skilled in the art can understand that to implement all or part of the processes in the above-mentioned embodiments, the processes can be completed by computer programs to instruct related hardware, and the programs can be stored in computer-readable storage media. When the programs are executed, they can include the processes of the above-mentioned method embodiments. The aforementioned storage media include: ROM or random access memory RAM, magnetic disk or optical disk and other media that can store program codes.

[0282] In short, the above are only embodiments of the technical solution of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made according to the disclosure of the present invention shall be included in the protection scope of the present invention.

Claims

1. A position detection method, applied to a motor system, characterized in that: The motor system includes: a driving integrated circuit, a voltage doubling circuit, and a voice coil motor VCM, wherein the input end of the voltage doubling circuit is coupled to the output end of the driving integrated circuit, the output end of the voltage doubling circuit is coupled to the two ends of the coil of the voice coil motor, and the voltage doubling circuit is used to boost the input voltage output by the driving integrated circuit to the input end and then output it to the two ends of the coil; the coil of the VCM is coupled to the current detection integrated circuit IC; the VCM includes a mover carrier and a coil, the mover carrier is used to carry the driven component of the VCM, and when the coil is energized, the mover carrier is also used to drive the driven component to move in the axial direction of the coil; and there is a linear mapping relationship between the position of the mover carrier and the coil inductance within the first motor stroke; The method comprises: When the coil is energized, the current change of the coil is detected by the current detection IC; Calculating the coil inductance based on the detected current change and the voltage across the coil; Based on the linear mapping relationship, determining the position of the mover carrier corresponding to the calculated coil inductance; The voltage doubling circuit is a two-stage voltage doubling circuit, and the two-stage voltage doubling circuit includes: a capacitor C1, a diode D1, a diode D2 and a switch S1, wherein: the first end of the capacitor C1 is coupled to the first output end of the driving integrated circuit, the second end of the capacitor C1 is coupled to the first end of the coil, and the second end of the coil is coupled to the second output end of the driving integrated circuit; the cathode of the diode D1 is coupled to the second end of the capacitor C1, and the anode is coupled to the first moving end of the switch S1; the anode of the diode D2 is also coupled to the second end of the capacitor C1, and the cathode is coupled to the second moving end of the switch S1; the fixed end of the switch S1 is coupled to the second output end of the driving integrated circuit.

2. The method according to claim 1, characterized in that The step of calculating the coil inductance according to the detected current change and the voltage across the coil specifically includes: The coil inductance L is calculated by the following formula: L=u*(1 / (di / dt)), wherein u represents the voltage across the coil, and di / dt represents the current change of the coil.

3. The method according to claim 2, characterized in that The voltage doubling circuit is also used to change the voltage polarity of the coil voltage output to the two ends of the coil; when the voltage polarity of the coil voltage is a first polarity, the direction of the coil current is a first flow direction, and the VCM outputs a motor thrust in a first direction; when the voltage polarity of the coil voltage is a second polarity, the direction of the coil current is a second flow direction, and the VCM outputs a motor thrust in a second direction.

4. The method according to claim 3, characterized in that The first flow direction is from the first end of the coil to the second end of the coil, and the second flow direction is from the second end of the coil to the first end of the coil; When the switch S1 selects to conduct the first moving end, the voltage polarity of the coil voltage is the first polarity, specifically including: when the switch S1 conducts the first moving end, the capacitor C1 is charged in the first half cycle of the input voltage, the capacitor C1 is discharged in the second half cycle of the input voltage, and the voltage polarity of the coil voltage is the first polarity when the second half cycle is discharged; the voltage polarity of the input voltage in the first half cycle is opposite to the voltage polarity of the input voltage in the second half cycle; When the switch S1 selects to turn on the second moving end, the voltage polarity of the coil voltage is the second polarity, specifically including: when the switch S1 turns on the second moving end, the capacitor C1 is charged in the second half cycle of the input voltage, and the capacitor C1 is discharged in the first half cycle of the input voltage, and the voltage polarity of the coil voltage when discharging in the first half cycle is the second polarity; the second polarity is opposite to the first polarity.

5. The method according to claim 4, characterized in that The switch S1 is a single-pole double-throw switch.

6. The method according to claim 5, characterized in that Also includes: Detecting that the position of the mover carrier reaches a specified position; The conduction direction of the switch S1 is switched.

7. The method according to claim 6, characterized in that The switching of the conduction direction of the switch S1 specifically includes: If the switch S1 selects to conduct the first moving end before the position of the moving carrier reaches the specified position, the switch S1 is switched to conduct the second moving end; If the switch S1 selects to conduct the second moving end before the position of the moving carrier reaches the specified position, the switch S1 is switched to conduct the first moving end.

8. The method according to any one of claims 1 to 7, characterized in that The two-stage voltage multiplier circuit further includes a bias resistor R1, which is connected in series between the fixed end of the switch S1 and the second output end of the driving integrated circuit.

9. The method according to any one of claims 1 to 7, characterized in that The two-stage voltage multiplier circuit also includes two bias resistors R1 and R2, wherein the bias resistor R1 is connected in series between the positive electrode of the diode D1 and the first moving end of the switch S1, and the bias resistor R2 is connected in series between the negative electrode of the diode D2 and the second moving end of the switch S1.

10. The method according to claim 8, characterized in that The input voltage is an AC voltage signal; the input voltage includes a pulse width modulation (PWM) voltage signal.

11. The method according to claim 9, characterized in that The input voltage is an AC voltage signal; the input voltage includes a pulse width modulation (PWM) voltage signal.

12. An electronic device, characterized in that: include: A motor system, a memory and a processor, wherein the motor system and the memory are coupled to the processor, and the motor system comprises: a driving integrated circuit, a voltage doubling circuit, and a voice coil motor (VCM), wherein the input end of the voltage doubling circuit is coupled to the output end of the driving integrated circuit, and the output end of the voltage doubling circuit is coupled to both ends of the coil of the voice coil motor, and the voltage doubling circuit is used to boost the input voltage output by the driving integrated circuit to the input end and then output it to both ends of the coil; the coil of the VCM is coupled to a current detection integrated circuit (IC); the VCM comprises a mover carrier and a coil, wherein the mover carrier is used to carry a driven component of the VCM, and when the coil is energized, the mover carrier is also used to drive the driven component to move in the axial direction of the coil; and there is a linear mapping relationship between the position of the mover carrier and the coil inductance within the first motor stroke; The memory is used to store a computer program, and when the processor executes the computer program, the electronic device executes the method according to any one of claims 1 to 11.

13. A method for calibrating a voice coil motor VCM, applied to a motor system, characterized in that: The motor system includes: a driving integrated circuit, a voltage doubling circuit, and a VCM, wherein the input end of the voltage doubling circuit is coupled to the output end of the driving integrated circuit, the output end of the voltage doubling circuit is coupled to the two ends of the coil of the voice coil motor, and the voltage doubling circuit is used to boost the input voltage output by the driving integrated circuit to the input end and then output it to the two ends of the coil; the coil of the VCM is coupled to the current detection integrated circuit IC; the VCM includes a mover carrier and a coil, the mover carrier is used to carry the driven component of the VCM, and when the coil is energized, the mover carrier is also used to drive the driven component to move in the axial direction of the coil; and there is a linear mapping relationship between the position of the mover carrier and the coil inductance within the first motor stroke; The method comprises: energizing the coil and detecting coil current when the driven component moves within the motor stroke of the VCM; Comparing the coil current with the coil current corresponding to the coil inductance within the first motor stroke, and outputting a calibration result; the calibration result includes: the coil current is larger or smaller than the coil current corresponding to the coil inductance within the first motor stroke; The voltage doubling circuit is a two-stage voltage doubling circuit, and the two-stage voltage doubling circuit includes: a capacitor C1, a diode D1, a diode D2 and a switch S1, wherein: the first end of the capacitor C1 is coupled to the first output end of the driving integrated circuit, the second end of the capacitor C1 is coupled to the first end of the coil, and the second end of the coil is coupled to the second output end of the driving integrated circuit; the cathode of the diode D1 is coupled to the second end of the capacitor C1, and the anode is coupled to the first moving end of the switch S1; the anode of the diode D2 is also coupled to the second end of the capacitor C1, and the cathode is coupled to the second moving end of the switch S1; the fixed end of the switch S1 is coupled to the second output end of the driving integrated circuit.

14. The method according to claim 13, characterized in that The voltage doubling circuit is also used to change the voltage polarity of the coil voltage output to the two ends of the coil; when the voltage polarity of the coil voltage is a first polarity, the direction of the coil current is a first flow direction, and the VCM outputs a motor thrust in a first direction; when the voltage polarity of the coil voltage is a second polarity, the direction of the coil current is a second flow direction, and the VCM outputs a motor thrust in a second direction.

15. The method according to claim 14, characterized in that The coil current corresponding to the coil inductance in the first motor stroke is calculated by the following second-order differential equation: Among them, u c represents the voltage of capacitor C1; R represents the equivalent resistance of the coil; L represents the inductance of the coil, u s represents the input voltage of the voltage doubling circuit; Indicates the change of coil current.

16. The method according to claim 15, characterized in that The first flow direction is from the first end of the coil to the second end of the coil, and the second flow direction is from the second end of the coil to the first end of the coil; When the switch S1 selects to conduct the first moving end, the voltage polarity of the coil voltage is the first polarity, specifically including: when the switch S1 conducts the first moving end, the capacitor C1 is charged in the first half cycle of the input voltage, the capacitor C1 is discharged in the second half cycle of the input voltage, and the voltage polarity of the coil voltage is the first polarity when the second half cycle is discharged; the voltage polarity of the input voltage in the first half cycle is opposite to the voltage polarity of the input voltage in the second half cycle; When the switch S1 selects to turn on the second moving end, the voltage polarity of the coil voltage is the second polarity, specifically including: when the switch S1 turns on the second moving end, the capacitor C1 is charged in the second half cycle of the input voltage, and the capacitor C1 is discharged in the first half cycle of the input voltage, and the voltage polarity of the coil voltage when discharging in the first half cycle is the second polarity; the second polarity is opposite to the first polarity.

17. The method according to any one of claims 13 to 16, characterized in that The two-stage voltage multiplier circuit further includes a bias resistor R1, which is connected in series between the fixed end of the switch S1 and the second output end of the driving integrated circuit.

18. The method according to any one of claims 13 to 16, characterized in that The two-stage voltage multiplier circuit also includes two bias resistors R1 and R2, wherein the bias resistor R1 is connected in series between the positive electrode of the diode D1 and the first moving end of the switch S1, and the bias resistor R2 is connected in series between the negative electrode of the diode D2 and the second moving end of the switch S1.

19. An electronic device, characterized in that: include: A motor system, a memory and a processor, wherein the motor system and the memory are coupled to the processor, and the motor system comprises: a driving integrated circuit, a voltage doubling circuit, and a voice coil motor (VCM), wherein the input end of the voltage doubling circuit is coupled to the output end of the driving integrated circuit, and the output end of the voltage doubling circuit is coupled to both ends of the coil of the voice coil motor, and the voltage doubling circuit is used to boost the input voltage output by the driving integrated circuit to the input end and then output it to both ends of the coil; the coil of the VCM is coupled to a current detection integrated circuit (IC); the VCM comprises a mover carrier and a coil, wherein the mover carrier is used to carry a driven component of the VCM, and when the coil is energized, the mover carrier is also used to drive the driven component to move in the axial direction of the coil; and there is a linear mapping relationship between the position of the mover carrier and the coil inductance within the first motor stroke; The memory is used to store a computer program, and when the processor executes the computer program, the electronic device executes the method according to any one of claims 13 to 18.

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