Optical lens driving methods and driving devices, electronic equipment

Abstract

This application provides a driving method for an optical lens, which can move under the drive of one or more SMA (Surface Mount Multi-Action) wires. The method includes: acquiring a first displacement compensation signal for compensating for external shake; determining a driving signal on each of the one or more SMA wires based on the first displacement compensation signal; applying a corresponding driving signal to each SMA wire to drive the optical lens to generate a first compensation displacement; determining a second displacement compensation signal based on the first compensation displacement and the first displacement compensation signal; and re-determining and applying the driving signal to each SMA wire based on the second displacement compensation signal. This enables corresponding compensatory motion control of the optical lens when external shake occurs, thereby improving the optical image stabilization effect and avoiding image quality problems caused by shake. This application also provides a driving device for an optical lens.

Description

Technical Field

[0001] This application relates to the field of optical image stabilization, and in particular to a driving method and driving device for an optical lens, and an electronic device. Background Technology

[0002] Currently, when people take photos using smart devices such as mobile phones, the image quality is often poor due to external camera shake. External camera shake usually refers to the shaking caused by the external environment on the optical lens. Optical image stabilization (OIS) can compensate for external camera shake to improve image quality. OIS uses the movement of mechanical structures to keep the optical lens and imaging sensor in a horizontal position to ensure sharp image formation.

[0003] Current optical image stabilization solutions often suffer from poor stabilization performance and high algorithm complexity, resulting in poor overall stabilization performance and market acceptance for smart terminals. Therefore, there is a need for solutions that can effectively implement optical image stabilization. Summary of the Invention

[0004] Some embodiments of this application provide a driving method, driving device, and electronic device for an optical lens. The following describes this application from multiple aspects, and the embodiments and beneficial effects of the following aspects can be referred to each other.

[0005] In a first aspect, embodiments of this application provide a driving method for an optical lens, and a driving device for an optical lens, wherein the optical lens can move under the drive of one or more SMA metal wires. The method includes: acquiring a first displacement compensation signal for compensating for external jitter; determining a driving signal on each of the one or more SMA metal wires based on the first displacement compensation signal; applying a corresponding driving signal to each SMA metal wire to cause the one or more SMA metal wires to drive the optical lens to generate a first compensation displacement; determining a second displacement compensation signal based on the first compensation displacement and the first displacement compensation signal; and re-determining the driving signal on each SMA metal wire based on the second displacement compensation signal and applying it to the corresponding SMA metal wire.

[0006] According to the optical lens driving method provided in the first aspect of this application, corresponding optical lens compensation motion control can be performed when external shaking occurs, thereby improving the effect of optical image stabilization and avoiding quality problems of the captured image caused by external shaking.

[0007] In some embodiments, determining a drive signal on each of one or more SMA wires based on a first displacement compensation signal includes: determining a motion control signal based on the first displacement compensation signal, wherein the motion control signal is used to determine the movement of the optical lens; and determining a drive signal on each of the one or more SMA wires corresponding to the motion control signal based on a pre-established distribution relationship between the motion control signal and the drive signals on each SMA wire. By pre-establishing the distribution relationship between the motion control signal and the drive signals on each SMA wire, the response speed of obtaining the corresponding drive signal based on the motion control signal can be improved, enabling timely compensation for external jitter.

[0008] In some embodiments, applying a corresponding drive signal to each SMA wire to cause one or more SMA wires to drive the optical lens to produce a first compensation displacement includes: converting the drive signal on each SMA wire into a PWM signal; and applying the converted PWM signal to each SMA wire to cause one or more SMA wires to drive the optical lens to produce a first compensation displacement. This allows the appropriate PWM signal to be determined based on the characteristics of each SMA wire, thus better adapting to the properties of the SMA wire.

[0009] In some implementations, converting the drive signals on each SMA wire into PWM signals includes: converting the drive signals on each SMA wire into PWM signals by calibrating the reference drive value and the reference operational amplifier value. This enables the drive signals to be converted into calibrated PWM signals, avoiding inaccurate converted signals.

[0010] In some implementations, applying a converted PWM signal to each SMA wire to cause one or more SMA wires to drive the optical lens to produce a first compensating displacement includes: converting the PWM signal into a safe PWM signal using a motor protection algorithm; and applying the safe PWM signal to each SMA wire to cause one or more SMA wires to drive the optical lens to produce a first compensating displacement. This provides protection for the motor, preventing unsafe PWM signals from damaging it.

[0011] In some implementations, the motor protection algorithm includes a limiting algorithm. This allows the limiting algorithm to convert unsafe PWM signals into safe PWM signals, thus preventing damage to the motor.

[0012] In some implementations, determining a second displacement compensation signal based on a first compensation displacement and a first displacement compensation signal includes: determining an error signal based on the first compensation displacement and the first displacement compensation signal; and determining the second displacement compensation signal based on the error signal. This allows subsequent displacement compensation signals to be determined based on the already occurred displacement of the optical lens, achieving closed-loop control and precisely controlling the compensation displacement of the optical lens.

[0013] In some implementations, the first displacement compensation signal used to compensate for external jitter is determined based on the angular velocity information collected by the motion sensor during external jitter. This allows the first displacement compensation signal to be acquired as the initial compensation displacement of the optical lens.

[0014] In some implementations, the first compensation displacement is obtained via a HALL module. This allows for real-time acquisition of the current position of the optical lens during compensation movement.

[0015] Secondly, embodiments of this application provide a driving device for an optical lens, comprising: a control module for acquiring a first displacement compensation signal for compensating for external shake; a drive distribution module for determining a drive signal on each of one or more SMA wires based on the first displacement compensation signal; and for applying a corresponding drive signal to each SMA wire to drive the optical lens to generate a first compensation displacement; the control module is further configured to determine a second displacement compensation signal based on the first compensation displacement and the first displacement compensation signal; and the drive distribution module is further configured to redetermine the drive signal on each SMA wire based on the second displacement compensation signal and apply it to the corresponding SMA wire. This enables corresponding compensatory motion control of the optical lens when external shake occurs, thereby improving the optical image stabilization effect and avoiding image quality problems caused by external shake.

[0016] Thirdly, embodiments of this application provide an electronic device, including: a driving device for executing the driving method of an optical lens in the first aspect and various possible embodiments thereof. This enables corresponding compensatory motion control of the optical lens when external shaking occurs, thereby improving the effect of optical image stabilization and avoiding image quality problems caused by external shaking. Attached Figure Description

[0017] Figure 1 This diagram illustrates an application scenario of a driving device for an optical lens provided according to some embodiments of this application.

[0018] Figure 2 A schematic diagram of the structure of a driving device for an optical lens provided according to some embodiments of this application is shown.

[0019] Figure 3 A flowchart illustrating a driving method for an optical lens according to some embodiments of this application is shown.

[0020] Figure 4 This diagram illustrates the trajectory of an SMA module driving an optical lens in a two-dimensional plane coordinate system, according to some embodiments of this application.

[0021] Figure 5 This document illustrates a flowchart of a method for determining the drive signal on each SMA wire based on a displacement compensation signal, according to some embodiments of this application.

[0022] Figure 6 A simplified structural schematic diagram of a four-wire SMA module provided according to some embodiments of this application is shown.

[0023] Figure 7 This diagram illustrates a block diagram of a driving device for an optical lens according to some embodiments of the present application. Detailed Implementation

[0024] The specific embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0025] Figure 1 The following illustrations depict application scenarios of an optical lens driving device provided according to some embodiments of this application. This driving device is described as an example of an optical image stabilization device.

[0026] like Figure 1 As shown, a user takes a picture using an electronic device. During the shooting process, the user holds the electronic device, points its optical lens at the object or area to be photographed, and then triggers the shutter button. The imaging sensor in the electronic device forms an image based on the light entering through the optical lens. Alternatively, the user can use a fixed method to support the electronic device for shooting, such as using a tripod. However, because electronic devices are easily shaken during shooting, such as by the user's hand tremors, this can cause blurry images and result in poor image quality.

[0027] To avoid the impact of external shaking on the quality of captured images, electronic devices can compensate for the displacement of the optical lens when external shaking is detected, so that the optical lens and imaging sensor are kept in a horizontal position to ensure clear image imaging.

[0028] This driving device can be specifically applied to wearable devices, mobile phones (such as...). Figure 1The embodiments of this application do not specifically limit the scope of electronic devices with touchscreens, such as tablet computers, laptop computers, ultra-mobile personal computers (UMPCs), handheld computers, netbooks, personal digital assistants (PDAs), and virtual reality devices.

[0029] It is understood that the optical lens driving method of this application is applicable to scenarios where optical lens driving devices perform optical image stabilization.

[0030] As mentioned earlier, in existing technologies, optical image stabilization solutions ensure image clarity through the movement of mechanical structures. However, the stabilization effect is poor and the algorithm complexity is high, which directly affects the control effect of shape memory alloy (SMA) modules in electronic devices, and thus affects the overall image stabilization effect of electronic devices.

[0031] Here, shape memory alloy refers to an alloy that exhibits the shape memory effect. The shape memory effect refers to the phenomenon that an alloy can undergo plastic deformation and be stretched at any temperature, but can recover its original shape when the temperature is changed to another temperature. In one case, the alloy can be stretched at a lower temperature and then reduced to its original shape by heating at a higher temperature. In another case, the alloy can be defined as one that elongates and then recovers when heated at a higher temperature.

[0032] To address the aforementioned problems, embodiments of this application provide a driving device and a driving method for an optical lens. In some embodiments, the driving device is the executing entity of the driving method. It is understood that in some embodiments of this application, the driving device can implement the driving control of the optical lens in the form of a chip; in other embodiments, the driving device can also implement the driving control of the optical lens in the form of a circuit. Regardless of the form, as long as the driving control of the optical lens can be achieved, it is acceptable, and embodiments of this application do not impose specific limitations on this.

[0033] The driving method for an optical lens according to an embodiment of this application includes: acquiring a displacement compensation signal for compensating for external jitter, determining a motion control signal based on the displacement compensation signal, determining a driving signal on each SMA wire based on the motion control signal, applying a corresponding driving signal on each SMA wire to cause the optical lens to generate a compensated motion, determining a new displacement compensation signal based on the position information of the optical lens after the motion, and re-determining the motion control signal based on the new displacement compensation signal.

[0034] Using the above method, the drive signal distributed to each SMA wire can be determined based on the determined motion control signal, and the movement position of the optical lens can be detected in real time. The motion control signal can be adjusted according to the position of the optical lens, thereby accurately controlling the distribution of drive signals on each SMA wire, realizing closed-loop control of optical image stabilization, and improving the image stabilization effect of SMA type modules.

[0035] The following is in conjunction with the above. Figure 1 The scene shown and combined Figure 2 This paper details the technical solution of this application.

[0036] The following scenario illustrates how the driving method of this application solves the optical image stabilization problem. When a user takes an image using an electronic device such as a mobile phone, the user's hand tremors cause the optical lens to deviate from the position where a clear image can be formed. Achieving optical image stabilization requires the optical lens to undergo compensatory displacement to return to the position where a clear image can be formed. In the driving method of this application embodiment, a displacement compensation signal is first acquired. This displacement compensation signal is determined by the electronic device using a vibration sensor such as an accelerometer to obtain the deviation position of the optical lens and based on this deviation position. This displacement compensation signal describes information related to the compensation displacement of the optical lens. Then, the distance and direction of the compensation displacement are determined based on the obtained displacement compensation signal, and a driving signal is allocated according to the distance and direction of the compensation displacement. The driving signal on each SMA metal wire is determined, and by applying the driving signal to each SMA metal wire, the SMA metal wire heats up and changes shape, thereby driving the optical lens to perform compensatory displacement. Since the optical lens compensation displacement is not a one-step process, the drive signal applied to each SMA wire can only move the optical lens a certain distance within a corresponding time period. Therefore, the current position of the optical lens is determined, and a new displacement compensation signal is determined based on the current position and the displacement compensation signal. The new displacement compensation signal describes the relevant information of the optical lens that still needs to make compensation displacement. Here, the distance and direction of the subsequent compensation displacement may change, so the drive signal on each SMA wire needs to be re-determined based on the new displacement compensation signal, so that the driving direction and driving distance of each SMA wire on the optical lens can be changed for subsequent compensation displacement. Then, the re-determined drive signal is applied to each SMA wire, which drives the optical lens to make the next compensation displacement. The above steps are repeated until the optical lens returns to a position where a clear image can be formed, thereby achieving optical image stabilization.

[0037] like Figure 2 As shown, the driving method of the optical lens in some embodiments of this application may include the following steps:

[0038] Step S1: Obtain the first displacement compensation signal used to compensate for external jitter.

[0039] It is understandable that when users take photos with electronic devices, the image quality is easily poor due to external shaking. In order to achieve optical image stabilization, the direction and displacement of external shaking can be compensated to keep the optical lens and imaging sensor on the same plane, so that the image is clear when the user takes a picture.

[0040] Here, the first displacement compensation signal is used to compensate for external shaking. The external shaking-related signal can be a displacement-related signal generated by the shaking of the optical lens. In order to achieve optical image stabilization, the first displacement compensation signal can be inverted, for example, the direction of the displacement-related signal can be inverted to determine the direction of the first displacement compensation signal.

[0041] It is understood that the first displacement compensation signal can be a distance signal, such as a displacement value in micrometers, or a meaningless scalar such as code. This application does not specifically limit this.

[0042] Step S2: Determine the driving signal on each SMA metal wire in one or more SMA metal wires based on the first displacement compensation signal.

[0043] It can be understood that there can be one or more SMA wires that drive the movement of the optical lens. By applying corresponding driving signals to each SMA wire, the optical lens can be driven to move in different directions by the deformation of the SMA wire.

[0044] Here, the driving signals determined by different first displacement compensation signals are also different on each SMA wire, and there is a corresponding relationship between the first displacement compensation signal and the driving signal on each SMA wire.

[0045] In some embodiments, the drive signal on each SMA wire corresponding to the displacement compensation signal can be determined based on a pre-established distribution relationship between the displacement compensation signal and the drive signal on each SMA wire. By pre-establishing the distribution relationship, the corresponding drive signal on each SMA wire can be directly determined after receiving a specific displacement compensation signal, which can improve the compensation response speed to external jitter.

[0046] S3: Apply a corresponding driving signal to each SMA wire to drive the optical lens to produce a first compensation displacement.

[0047] Here, after determining the driving signal distributed on each SMA wire according to the first displacement compensation signal, a corresponding driving signal is applied to each SMA wire, so that each SMA wire undergoes a corresponding deformation according to the applied driving signal, thereby driving the optical lens connected to the SMA wire to produce a corresponding first compensation displacement.

[0048] It is understood that the driving signal applied to each SMA wire has a corresponding time period. During this time period, each SMA wire undergoes a corresponding deformation, which drives the optical lens to produce a corresponding first compensation displacement.

[0049] Additionally, it can be understood that some SMA wires have a drive signal of 0, in which case the SMA wire does not deform. SMA wires with a drive signal of non-zero heat up and deform due to the applied drive signal. The different deformations of multiple SMA wires can drive the optical lens to move in different directions.

[0050] Figure 3 This diagram illustrates the trajectory of an optical lens moving in a two-dimensional plane coordinate system. (For example...) Figure 3 As shown, by applying different driving signals to the four SMA metal wires, the optical lens can be compensated for displacement in different directions of the X-axis or Y-axis.

[0051] S4: Determine the second displacement compensation signal based on the first compensation displacement and the first displacement compensation signal.

[0052] It is understandable that after the optical lens generates the first compensation displacement, the relative distance between the current position of the optical lens and the target position that can be clearly imaged changes. However, the first displacement compensation signal still describes the relative distance between the previous position of the optical lens and the target position that can be clearly imaged. Therefore, the first displacement compensation signal needs to be adjusted to determine the second displacement compensation signal used to describe the relative distance between the current position of the optical lens and the target position that can be clearly imaged.

[0053] S5: Based on the second displacement compensation signal, redetermine the driving signal on each SMA wire and apply it to the corresponding SMA wire.

[0054] Here, after determining the second displacement compensation signal, the second displacement compensation signal is used as input, and the driving signal on each SMA wire is determined again according to the second displacement compensation signal and applied to the corresponding SMA wire, that is, the process of steps S2 to S5 is executed again.

[0055] The above process is repeated until the final displacement compensation signal is 0. A displacement compensation signal of 0 indicates that the optical lens has returned to a position where clear imaging is possible, thereby solving the problem of unclear imaging caused by external shaking and achieving optical image stabilization.

[0056] Using the above method, the drive signal allocated to each SMA wire can be determined based on the acquired displacement compensation signal. By applying the corresponding drive signal to each SMA wire, the optical lens can generate a compensation displacement. A new displacement compensation signal is determined based on the compensation displacement and the displacement compensation signal. Then, the drive signal on each SMA wire is re-determined based on the new displacement compensation signal. This allows for precise control of the drive signal allocation on each SMA wire, achieving closed-loop control of optical image stabilization and improving the image stabilization effect of the optical lens.

[0057] Figure 4 The diagram illustrates the structure of an electronic device provided in some embodiments of this application. For example... Figure 4 As shown, the electronic device includes a drive unit 100, which includes a control module and a drive distribution module. The electronic device also includes an SMA module and a HALL module. The control module is connected to the drive distribution module, the drive distribution module is connected to both the control module and the SMA module, the SMA module is connected to both the HALL module and the drive distribution module, and the HALL module is connected to both the SMA module and the control module.

[0058] The control module is used to receive displacement compensation signals and calculate the magnitude of the real-time feed control signal, i.e., the motion control signal, required by the SMA module based on the displacement compensation signals. The motion control signal is used to determine the direction of motion and displacement of the optical lens.

[0059] The drive distribution module is used to distribute motion control signals to multiple SMA wires. Here, the drive distribution module determines which drive signals to assign to different SMA wires based on the motion control signals; some SMA wires may have drive signals assigned, while others may not. By assigning different drive signals to different SMA wires, the SMA wires undergo different deformations, thereby causing the optical lens, pulled by multiple SMA wires, to move in different directions.

[0060] The SMA module includes multiple SMA metal wires and a motor. It receives drive signals distributed to each SMA metal wire by the drive distribution module and applies the drive signals to the corresponding SMA metal wires. The deformation of the SMA metal wires drives the motor to move the optical lens.

[0061] The HALL module is used to detect the current position of the optical lens in real time and provide the detected position information to the control module, which then adjusts the motion control signal based on the position information.

[0062] Here, the control module determines a new displacement compensation signal based on the displacement compensation signal and the received real-time position information of the optical lens, and then re-determines a new motion control signal based on the new displacement compensation signal. This enables the drive distribution module to determine the drive signal distributed to each SMA wire based on the new motion control signal, thus forming a closed-loop scheme that can control the movement of the optical lens in real time and achieve precise optical image stabilization.

[0063] The optical lens drive device 100 is presented in the form of a chip. In some other embodiments, the optical lens drive device 100 may also take other forms, such as circuits, without being specifically limited here, as long as it can realize the motion control of the optical lens.

[0064] In some embodiments of this application, the entity executing the optical lens driving method may be an optical lens driving device, which may be included in an electronic device.

[0065] Figure 5 The following describes a process for determining the drive signal on each SMA wire based on a displacement compensation signal according to some other embodiments of this application. This process may include the following steps:

[0066] Step S51: Determine the motion control signal based on the displacement compensation signal.

[0067] Here, motion control signals are used to determine the direction of motion of the optical lens.

[0068] Here, the driving device for the optical lens includes a control module and a drive distribution module. The motion control signal is generated by the control module based on the displacement compensation signal. The control module can be implemented as a controller, which determines the output motion control signal based on the input displacement compensation signal. In some embodiments, the control module is implemented as a closed-loop controller, capable of generating an output signal based on the input signal and adjusting the input signal based on feedback from the output signal.

[0069] It is understood that the control module includes, but is not limited to, classic closed-loop controllers such as PID controllers, PI controllers, PD controllers, ADRC controllers, and sliding diaphragm controllers. The embodiments of this application do not specifically limit the type of controller used in the control module.

[0070] The following explanation uses a PID controller as an example of a closed-loop controller. The motion control signal generated by the PID controller can include two types: pid_x and pid_y. pid_x can have three values: pid_x>0, pid_x=0, and pid_x<0. Similarly, pid_y can also have three values. By combining pid_x and pid_y, the motion direction of the optical lens can be controlled.

[0071] In some embodiments, the control module calculates the magnitude of the real-time feed control signal required for each SMA wire based on the displacement compensation signal, determines the real-time feed control signal as the motion control signal, and sends the generated motion control signal to the drive distribution module.

[0072] Step S52: Determine the driving signal on each SMA wire based on the motion control signal.

[0073] Here, the drive distribution module receives motion control signals from the control module and determines the drive signals on each SMA wire based on the motion control signals.

[0074] In some embodiments, the drive distribution module determines the drive signal on each SMA wire corresponding to the motion control signal based on a pre-established distribution relationship between the motion control signal and the drive signal on each SMA wire. By pre-establishing the distribution relationship, the drive distribution module can directly determine the corresponding drive signal on each SMA wire after receiving a specific motion control signal, thereby improving the compensation response speed to external jitter.

[0075] The following explanation uses an SMA module consisting of four SMA metal wires and a motor as an example. Figure 6 A simplified structural diagram of a four-wire SMA module is shown in some embodiments of this application. For example... Figure 6 As shown, the four-wire SMA module includes four SMA metal wires, SMA#0, SMA#1, SMA#2, and SMA#3, and a motor (not shown). The motor is connected to the optical lens, and the movement of the motor drives the corresponding movement of the optical lens. The optical lens is represented by a circle in the figure.

[0076] Here, the X and Y axes on the diagonal are taken as the vector axes of the Cartesian coordinate system of the motor in the SMA module. The motion of the motor in the two-dimensional plane composed of the X and Y axes is subdivided into positive half-axis motion and negative half-axis motion, which can be simplified using Xp, Xn, Yp, and Yn, where Xp represents motion in the positive direction of the X axis, Xn represents motion in the negative direction of the X axis, Yp represents motion in the positive direction of the Y axis, and Yn represents motion in the negative direction of the Y axis.

[0077] The motor's movement in the two-dimensional plane is driven by the contraction of different SMA (Surface Mount MA) wires. This contraction is achieved by heating the SMA wires. Applying a drive signal to the SMA wires causes them to heat up, which in turn causes them to contract, driving the motor's movement in different directions. Here, the drive signal provides the power required to heat the SMA wires. Under a fixed heating power, the SMA wires heat up and contract, creating a pulling force that drives the optical lens's movement. Simultaneously, this force stretches the opposing SMA wires. While pulling the optical lens, it also stretches the opposing SMA wires. When the optical lens needs to move in the opposite direction, only the opposing SMA wires need to be heated. For example, applying a drive signal to SMA wires SMA#0 and SMA#3 causes them to heat up and contract, resulting in the optical lens moving in the positive X-axis direction. If the optical lens is to move in the negative X-axis direction, a drive signal is applied to SMA#1 and SMA#2, causing them to heat up and contract to pull the optical lens.

[0078] It can be understood that the relative motion of the motor on the X and Y axes is driven by applying drive signals to two different SMA metal wires. Specifically, Xp corresponds to applying drive signals to metal wires SMA#0 and SMA#3, Xn corresponds to applying drive signals to metal wires SMA#1 and SMA#2, Yp corresponds to applying drive signals to metal wires SMA#0 and SMA#1, and Yn corresponds to applying drive signals to metal wires SMA#2 and SMA#3.

[0079] Similarly, the entire motion of the motor in the first, second, third, and fourth quadrants of a two-dimensional plane coordinate system can be achieved through motion control signals. In some embodiments, the distribution relationship between the motion control signals and each SMA wire is shown in Table 1 below.

[0080] Table 1. Relationship between motion control signals and metal wire distribution.

[0081]

[0082] The following explanation uses the motion control signal with serial number No.7 as an example.

[0083] In the motion control signal with serial number No.7, pid_x>0 and pid_y<0, it indicates that it is desired for the motor to drive the optical lens to move in the composite direction formed by the positive direction of the X-axis and the negative direction of the Y-axis, that is, to move towards the fourth quadrant. At this time, the corresponding values ​​of Xp and Yn are 1, and the corresponding values ​​of Xn and Yp are 0.

[0084] In some embodiments, the values ​​of the four SMA wires can be determined by the movement directions of any two motors on the X and Y axes. For example, the value of wire sma#0 is determined by Xn and Yn, the value of wire sma#1 is determined by Xp and Yn, the value of wire sma#2 is determined by Xp and Yp, and the value of wire sma#3 is determined by Xn and Yp. Therefore, the values ​​of wires sma#0, sma#1, and sma#2 are 1, and the value of sma#3 is 0.

[0085] Here, a value of 0 for the SMA wire indicates that no drive signal is applied to the SMA wire, while a value of 1 indicates that a drive signal is applied to the SMA wire. Therefore, after receiving the motion control signal with serial number No.7, the drive distribution module determines to apply drive signals to wires sma#0, sma#1, and sma#2, and not to apply a drive signal to wire sma#3.

[0086] The relationships in Table 1 can be described using matrix operations as follows:

[0087]

[0088] The aforementioned drive allocation matrix can effectively cover all motor movements in the positive and negative X and Y axes, as well as in the composite directions of the first, second, third, and fourth quadrants.

[0089] The following describes, using mathematical formulas, how the drive distribution module distributes the motion control signal obtained from the PID closed-loop controller to the four SMA metal wires.

[0090]

[0091] Among them, pid_xp, pid_xn, pid_yp and pid_yp are temporary variables used to obtain part of the motion control signal output by the PID closed-loop controller, and the pid_out() function is used to output the motion control signal of the PID closed-loop controller on the X-axis or Y-axis.

[0092] Applying the above formula (2) to the calculation rules of formula (1), we can obtain:

[0093]

[0094] The sma array corresponds to the drive signals assigned to the four SMA metal wires.

[0095] Furthermore, the control module and drive distribution module can redetermine the drive signals on each SMA wire based on the new displacement compensation signal. Here, the control module takes the new displacement compensation signal as input, redetermines the motion control signal based on it, and then provides the redetermined motion control signal to the drive distribution module for allocation, thus determining the drive signal on each SMA wire. For example, the error signal can be used as the new displacement compensation signal input to the control module, which then calculates the corresponding motion control signal according to the corresponding control law calculation formula.

[0096] In addition, in some other embodiments of this application, the first displacement compensation signal for compensating for external jitter is determined by an electronic device. The electronic device can use a gyroscope to detect external jitter. The gyroscope can detect the direction and speed of movement of external jitter in real time. The signal detected by the gyroscope usually includes an angular velocity signal.

[0097] In other embodiments of this application, the electronic device can determine a first displacement compensation signal based on the angular velocity signal of the gyroscope. The electronic device receives the angular velocity signal detected by the gyroscope in real time and calculates the corresponding displacement signal based on the angular velocity signal. This displacement signal is the displacement that the optical image stabilization needs to cancel. The electronic device can reverse the direction of this displacement signal to determine the corresponding displacement compensation signal.

[0098] In other embodiments of this application, the allocated drive signal can be converted into a pulse width modulation (PWM) signal based on the characteristics of the SMA wire, and the converted PWM signal can be applied to the corresponding SMA wire to cause the optical lens to generate a compensating displacement. Here, the PWM signal is obtained by modulating the width of a series of pulses to obtain the required waveform (including shape and amplitude), and then digitally encoding the analog signal level.

[0099] In other embodiments of this application, the drive signal can be converted into a PWM signal by calibrating the reference drive value and the reference operational amplifier value. For example, the PWM duty cycle signal can be calculated using the following formula:

[0100] PWM duty cycle = sma[n] * reference op-amp value + reference drive value (4)

[0101] Wherein, sma is the SMA metal wire array in formula (3), and n takes the value of 0 to 3.

[0102] The methods for determining the reference operational amplifier value and the reference drive value are disclosed in relevant patents and will not be repeated here.

[0103] In other embodiments of this application, the PWM duty cycle signal is converted into a safe PWM signal using a motor protection algorithm, and then the safe PWM signal is applied to the corresponding SMA wire to compensate for the displacement of the optical lens. Here, to avoid damage to the motor due to improper driving, the duty cycle signal after the drive signal conversion is not directly applied to the motor, but is converted by the motor protection algorithm to obtain a motor-safe PWM signal, which is then used.

[0104] In other embodiments of this application, the motor protection algorithm includes a limiting algorithm, which limits the amplitude of the PWM duty cycle signal to a safe range for the motor. The PWM duty cycle signal after limiting can be assigned to a hardware register. Driving the motor with the PWM duty cycle signal after limiting can avoid damaging the motor.

[0105] In other embodiments of this application, the displacement information generated by the compensation displacement of the optical lens can be obtained through the HALL module of the electronic device. Here, the HALL module senses the real-time position of the compensation displacement of the optical lens to obtain the real-time displacement information of the optical lens. The Hall effect is an electromagnetic effect discovered by the American scholar Hall in 1879, and it can be widely used in the position movement measurement of precision instruments.

[0106] In other embodiments of this application, the driving device of the optical lens receives displacement information provided by the HALL module, and then combines the displacement information with the current displacement compensation signal to determine a new displacement compensation signal. Here, since the optical lens has undergone compensation displacement, the displacement compensation distance required for optical image stabilization has changed, so it is necessary to redetermine the displacement compensation signal in order to precisely control the compensation displacement of the optical lens.

[0107] In some other embodiments of this application, the driving device of the optical lens subtracts the obtained displacement information from the current displacement compensation signal to obtain an error signal, and then uses the error signal as a new displacement compensation signal.

[0108] Figure 7 This diagram illustrates a block diagram of a driving device for an optical lens according to some embodiments of the present application. The driving device 100 for the optical lens includes a control module 110 and a drive distribution module 120.

[0109] The control module 110 is used to acquire a first displacement compensation signal for compensating for external jitter;

[0110] The drive distribution module 120 is used to determine the drive signal on each of the one or more SMA wires according to the first displacement compensation signal; and to apply the corresponding drive signal on each SMA wire so that the one or more SMA wires drive the optical lens to generate the first compensation displacement.

[0111] The control module is also used to determine the second displacement compensation signal based on the first compensation displacement and the first displacement compensation signal;

[0112] The drive distribution module is also used to redetermine the drive signal on each SMA wire according to the second displacement compensation signal and apply it to each SMA wire.

[0113] According to the optical lens driving method and optical lens driving device provided in this application, the optical lens can be compensated and driven accordingly when the user experiences external shaking, thereby improving the optical image stabilization effect and avoiding image quality problems caused by external shaking.

Claims

1. A driving method of an optical lens, characterized by, The optical lens can be driven to move by one or more SMA wires, and the method comprises: acquiring a first displacement compensation signal for compensating external jitter; determining a driving signal on each SMA wire in the one or more SMA wires according to the first displacement compensation signal; applying the corresponding driving signal on each SMA wire to drive the one or more SMA wires to generate a first compensation displacement of the optical lens; determining a second displacement compensation signal according to the first compensation displacement and the first displacement compensation signal; redetermining and applying the driving signal on each SMA wire according to the second displacement compensation signal; wherein the determining of the second displacement compensation signal according to the first compensation displacement and the first displacement compensation signal comprises: determining an error signal according to the first compensation displacement and the first displacement compensation signal; determining a second displacement compensation signal according to the error signal.

2. The method of claim 1, wherein, The determining of the driving signal on each SMA wire in the one or more SMA wires according to the first displacement compensation signal comprises: determining a motion control signal according to the first displacement compensation signal, wherein the motion control signal is used to determine the motion of the optical lens; determining the driving signal on each SMA wire in the one or more SMA wires corresponding to the motion control signal according to a pre-established allocation relationship between the motion control signal and the driving signal on each SMA wire.

3. The method of claim 1, wherein, The applying of the corresponding driving signal on each SMA wire to drive the one or more SMA wires to generate a first compensation displacement of the optical lens comprises: converting the driving signal on each SMA wire into a PWM signal; applying the converted PWM signal on each SMA wire to drive the one or more SMA wires to generate a first compensation displacement of the optical lens.

4. The method of claim 3, wherein, The converting of the driving signal on each SMA wire into a PWM signal comprises: converting the driving signal on each SMA wire into a PWM signal by a calibration reference driving value and a reference operational amplifier value.

5. The method of claim 3, wherein, The applying of the converted PWM signal on each SMA wire to drive the one or more SMA wires to generate a first compensation displacement of the optical lens comprises: converting the PWM signal into a safe PWM signal by a motor protection algorithm; applying the safe PWM signal on each SMA wire to drive the one or more SMA wires to generate a first compensation displacement of the optical lens.

6. The method of claim 5, wherein, The motor protection algorithm comprises a limiting algorithm.

7. The method of claim 1, wherein, The first displacement compensation signal for compensating external jitter is determined according to angular velocity information collected by a motion sensor when the external jitter occurs.

8. The method of claim 1, wherein, The first compensation displacement is obtained by a HALL module.

9. A driving device of an optical lens, characterized in that, comprises: a control module configured to acquire a first displacement compensation signal for compensating external jitter; a driving allocation module configured to determine a driving signal on each SMA wire in the one or more SMA wires according to the first displacement compensation signal; and for applying corresponding driving signals on each SMA wire to drive the one or more SMA wires to generate a first compensation displacement of the optical lens; the control module is further configured to determine a second displacement compensation signal according to the first compensation displacement and the first displacement compensation signal; the driving distribution module is further configured to re-determine the driving signals on each SMA wire according to the second displacement compensation signal and apply the driving signals on corresponding SMA wires; wherein the determining the second displacement compensation signal according to the first compensation displacement and the first displacement compensation signal comprises: determining an error signal according to the first compensation displacement and the first displacement compensation signal; determining the second displacement compensation signal according to the error signal.

10. An electronic device, comprising: comprises: a driving device configured to perform the driving method of the optical lens according to any one of claims 1-8.

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