Motor driving circuit, camera module and electronic equipment

Abstract

The invention discloses a motor driving circuit, a motor assembly, a camera module and electronic equipment, and belongs to the technical field of optical anti-vibration. A motor drive circuit comprises an acceleration circuit and an H bridge, the input end of the acceleration circuit is electrically connected with the output end of a controller, the output end of the acceleration circuit is electrically connected with the input end of the H bridge, and the output end of the H bridge is electrically connected with a motor. The acceleration circuit is used for outputting a superposed signal based on a control signal output by the controller, and the superposed signal is obtained by superposing a pulse signal and a step signal; and the H bridge is used for outputting a driving current, and the driving current has the same shape as the superposed signal in the time domain.

Description

Technical Field

[0001] The present application belongs to the field of optical technology, and specifically relates to a motor drive circuit, a camera module and an electronic device. Background Art

[0002] With the continuous upgrading of electronic products, users have an increasing demand for camera functionality. To enhance the camera experience, camera modules are often equipped with optical image stabilization (OIS). In camera modules equipped with OIS, a motor drives the lens to move perpendicular to the optical axis to compensate for camera offset caused by hand shake during shooting, maintaining image stability.

[0003] In related technologies, the OIS motor may adopt a ball motor, which uses balls to support the lens assembly. However, since the movement of the lens assembly is a friction motion, it is difficult to move, and therefore the response speed of the ball motor is relatively slow. Summary of the Invention

[0004] The present application aims to provide a motor drive circuit, a camera module and an electronic device that can speed up the response speed of the motor, thereby improving its control capability of small step motion and improving its anti-shake capability without changing the original control logic.

[0005] In a first aspect, an embodiment of the present application proposes a motor drive circuit, comprising: an acceleration circuit and an H-bridge, wherein the input end of the acceleration circuit is electrically connected to the output end of the controller, the output end of the acceleration circuit is electrically connected to the input end of the H-bridge, and the output end of the H-bridge is electrically connected to the motor; the acceleration circuit is used to output a superimposed signal based on the control signal output by the controller, wherein the superimposed signal is obtained by superimposing a pulse signal and a step signal; the H-bridge is used to output a driving current, wherein the driving current has the same shape as the superimposed signal in the time domain.

[0006] In the second aspect, an embodiment of the present application proposes a camera module, comprising: a controller, the motor drive circuit described in the first aspect above, and a motor assembly, wherein the motor assembly includes a motor and a lens, and the motor is used to drive the lens to move under the drive of a driving current, and output the position information of the lens after movement to the controller; the controller is used to output a control signal based on the position information output by the motor; and the motor drive circuit is used to output a driving current to the motor based on the control signal.

[0007] In a third aspect, an embodiment of the present application proposes an electronic device, comprising: a housing and the camera module described in the second aspect above.

[0008] In an embodiment of the present application, an acceleration circuit is added to the motor drive circuit. The acceleration circuit is used to output a superimposed signal obtained by superimposing a pulse signal and a step signal based on the control signal output by the controller. The superimposed signal outputs a driving current with the same shape as the superimposed signal in the time domain through an H-bridge, that is, a driving current with pulses, thereby accelerating the response speed of the motor and further improving its control capability of small step motion and anti-shake capability without changing the original control logic. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a current characteristic diagram of a ball motor; Figure 2 is a schematic structural diagram of a motor drive circuit provided by some embodiments of the present application; Figure 3 is a schematic structural diagram of a motor drive circuit provided by some embodiments of the present application; Figure 4 is a schematic diagram of signal conversion in some embodiments of the present application; Figure 5 is a schematic structural diagram of a motor drive circuit provided by some embodiments of the present application; Figure 6 is a schematic structural diagram of a motor drive circuit provided by some embodiments of the present application; Figure 7 is a schematic structural diagram of a motor drive circuit provided by some embodiments of the present application; Figure 8 is a circuit diagram of an acceleration circuit provided by some embodiments of the present application; Figure 9 is a circuit diagram of an acceleration circuit provided by some embodiments of the present application; Figure 10 is a schematic structural diagram of a camera module provided in some embodiments of the present application; Figure 11 It is a structural diagram of the anti-shake control system provided in some embodiments of the present application. DETAILED DESCRIPTION

[0010] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and are not to be construed as limiting the present invention. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of this application.

[0011] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly refer to one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more. Furthermore, the term "and / or" in the specification and claims refers to at least one of the connected entities, and the character " / " generally indicates an "or" relationship between the connected entities.

[0012] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0013] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0014] In related technologies, a controller can sense the movement of a device through a gyroscope (Gyro), calculate the device's motion position through a Gyro algorithm, and use a Hall sensor to feed back the motor's position information. This position information is converted into a digital signal through an analog-to-digital converter (i.e., an A / D converter, or ADC for short). This digital signal is combined with the device's motion position and outputs a control signal through a "Proportional-Integral-Derivative Controller" (PID). This control signal controls the H-bridge to generate a corresponding drive current, thereby driving the motor to move.

[0015] Although the ball motor supports the lens assembly by the balls, in fact, most of its movement is friction motion. From stationary to starting, it needs to overcome static friction, and when it continues to move, it needs to overcome dynamic friction. Usually, static friction > dynamic friction.

[0016] Figure 1 shows the current characteristics of a ball motor, where Ip is the starting current, I h The difference in current flow is caused by friction, which results in a longer time delay between the start and the end of the ball motor. With smaller movements, frequent starts and stops can lead to poor performance.

[0017] In conventional control circuits, current changes are entirely determined by the control system. The controller generates an output signal based on the feedback position signal and the target position. This output signal is then passed through a drive circuit, which can consist of an H-bridge, to generate a drive current to control the motor. However, the control system does not distinguish between start-up and continuous motion, relying entirely on feedback signals for regulation. This results in significant hysteresis, hindering the ball motor's responsiveness.

[0018] To address the above-mentioned problem, an embodiment of the present application provides a motor drive circuit, which can superimpose additional pulse current when the control current of the motor changes, thereby accelerating the response speed of the ball motor startup and improving its anti-shake capability without changing the original control logic.

[0019] Figure 2 Schematic diagram of the structure of the motor drive circuit of some embodiments of the present application is shown. Figure 2 As shown, the motor drive circuit 1020 includes an acceleration circuit 100 and an H-bridge 200. The input of the acceleration circuit 100 is electrically connected to the controller 300, the output of the acceleration circuit 200 is electrically connected to the input of the H-bridge 200, and the output of the H-bridge 200 is electrically connected to the motor 400. The acceleration circuit 100 is configured to output a superimposed signal based on a control signal output by the controller, wherein the superimposed signal is obtained by superimposing a pulse signal and a step signal. The H-bridge 200 is configured to output a drive current, wherein the drive current has the same shape as the superimposed signal in the time domain.

[0020] Through the technical solution provided by the above embodiment, an acceleration circuit is added to the motor drive circuit. The acceleration circuit is used to output a superimposed signal obtained by superimposing a pulse signal and a step signal based on the control signal output by the controller. The superimposed signal outputs a driving current with the same shape as the superimposed signal in the time domain through the H-bridge, that is, a driving current with pulses, thereby accelerating the response speed of the motor and further improving its control capability of small step motion and anti-shake capability without changing the original control logic.

[0021] Figure 3 FIG. 1 shows a schematic diagram of a motor drive circuit provided in some embodiments of the present application. Figure 3As shown, in these embodiments, the acceleration circuit 100 includes a through circuit 110, a differential circuit 120, and a superposition circuit 130, wherein the through circuit 110 and the differential circuit 120 are connected in parallel, a first connection point 1110 is electrically connected to the controller 300, and a second connection point 1120 is electrically connected to the superposition circuit 130. The first connection point 1110 is a connection point where the through circuit 110 and the differential circuit 120 are electrically connected, and the second connection point 1120 is an electrical connection point where the through circuit 110 and the differential circuit 120 are electrically connected. Another connection point connected; one end of the superposition circuit 130 is electrically connected to the second connection point 1120, and the other end of the superposition circuit 130 is electrically connected to the input end of the H-bridge 200; the direct-through circuit 110 is used to directly pass the control signal to generate a step signal; the differential circuit 120 is used to differentiate the control signal and output a pulse signal; the superposition circuit 130 is used to superimpose the step signal output by the direct-through circuit 110 and the pulse signal output by the superposition circuit 120 to generate the superposition signal.

[0022] In these embodiments, the acceleration circuit 100 includes three parts, namely, a through circuit 110, a differential circuit 120, and a superposition circuit 130. Figure 4 As shown, the direct circuit 110 directly passes the control signal 10 output by the controller to generate a step signal 20. The direct circuit 110 can amplify or reduce the control signal 10, and therefore, it can also be called the proportional portion. The differential circuit 120 differentiates the control signal 10 output by the controller to form a pulse signal 30. The differential circuit 120 differentiates the control signal 10, and therefore, it can also be called the differential portion. The superposition circuit 130 superimposes the step signal 20 generated by the direct circuit 110 with the pulse signal 30 generated by the differential circuit 120 to generate a superposition signal 40. Because the superposition signal contains pulses, it can also be called a pulsed step signal. The superposition signal 40 outputs a driving current through the H-bridge. This driving current has the same shape as the superposition signal 40 in the time domain, that is, it is a pulsed current. This can increase the starting current of the motor, reduce the delay from the ball motor's quiescence to startup, and thus improve the ball motor's response speed.

[0023] In some embodiments, as Figure 5As shown, the through circuit 110 may include a first resistor 111, and the differential circuit 120 may include a first capacitor 121. It should be noted that, although this embodiment is described by taking the example that the through circuit 110 may include the first resistor 111 and the differential circuit 120 may include the first capacitor 121, the present invention is not limited thereto. In practical applications, the through circuit 110 may also include other forms of components, such as multiple resistors connected in parallel or in series, as long as this part of the circuit can realize the control signal 10 output by the through controller, and the differential circuit 120 may also include other forms of components, such as multiple capacitors connected in parallel or in series, as long as this part of the circuit can realize the differentiation of the control signal 10 output by the controller to generate the pulse signal 30.

[0024] Figure 6 FIG. 1 shows a schematic diagram of a motor drive circuit provided in some embodiments of the present application. Figure 6 As shown, in these embodiments, the superposition circuit 130 may include: a second resistor 131 and an inverse proportional amplifier 132 connected in parallel, wherein the second resistor 131 is connected in series between the second connection point 1120 and the H-bridge 200; a negative input terminal of the inverse proportional amplifier 132 is electrically connected to the second connection point 1120, a positive input terminal of the inverse proportional amplifier 132 is grounded, and an output terminal of the inverse proportional amplifier 132 is electrically connected to an input terminal of the H-bridge 200.

[0025] In these embodiments, the step signal 20 output by the through circuit 110 and the pulse signal 30 output by the differential circuit 120 are superimposed through the second resistor 131, and the reverse proportional amplifier 132 keeps the voltage of the positive and negative input terminals at 0 to achieve signal reversal.

[0026] In some optional embodiments, the second resistor 131 may be a resistor with adjustable resistance, and the first capacitor 121 may be a capacitor with adjustable capacitance. In these embodiments, the resistance R2 of the second resistor 131 and the capacitance C1 of the first capacitor 121 are adjustable, so that the pulse width of the superimposed signal can be adjusted by adjusting the resistance R2 of the second resistor 131 and the capacitance C1 of the first capacitor 121. , where the pulse width of the superimposed signal is The resistance R2 of the second resistor 131 and the capacitance C1 of the first capacitor 121 have the following relationship: (1) Therefore, in the above embodiment, the required width, based on the required width, adjusting the resistance R2 of the second resistor 131 and the capacitance C1 of the first capacitor 121, so as to obtain a pulse width that meets the requirements and further improve the performance of the motor.

[0027] Figure 7 FIG. 1 shows a schematic diagram of a motor drive circuit provided in some embodiments of the present application. Figure 9 As shown, in these embodiments, the superposition circuit 130 may include: a third resistor 133, a non-inverting proportional amplifier 134, a fourth resistor 135, and a fifth resistor 136, wherein one end of the third resistor 133 is electrically connected to the second connection point 1120, and the other end of the third resistor 133 is grounded; a positive input end of the non-inverting proportional amplifier 134 is electrically connected to the second connection point 1120, a negative input end of the non-inverting proportional amplifier 134 is grounded via the fifth resistor 136, and an output end of the non-inverting proportional amplifier 134 is electrically connected to the input end of the H-bridge 200; one end of the fourth resistor 135 is electrically connected to the third connection point 1130, and the other end of the fourth resistor 135 is electrically connected to the fourth connection point 1140. The third connection point 1130 is the connection point between the non-inverting proportional amplifier 134 and the fifth resistor 136. The fourth connection point 1140 is electrically connected to the connection point between the output end of the non-inverting proportional amplifier 134 and the input end of the H-bridge 200.

[0028] In the above embodiment, the step signal 20 output by the through circuit 110 and the pulse signal 30 output by the differential circuit 120 are superimposed through the third resistor 133, the in-phase proportional amplifier 134 maintains the positive direction of the signal, and the ratio of the signal is adjusted through the fourth resistor 135 and the fifth resistor 136.

[0029] In some optional embodiments, the third resistor 133 may be a resistor with adjustable resistance, and the first capacitor 121 may also be a capacitor with adjustable capacitance. Similar to the above embodiment, the pulse width of the step signal with pulses can be achieved by adjusting the resistance of the third resistor 133 and the capacitance of the first capacitor 121. adjustments.

[0030] Among them, the pulse width of the superimposed signal The resistance R3 of the third resistor 133 and the capacitance C1 of the first capacitor 121 have the following relationship: (2) Therefore, in the above embodiment, the required width, based on the required width, adjusting the resistance R3 of the third resistor 133 and the capacitance C1 of the first capacitor 121, so as to obtain a pulse width that meets the requirements and further improve the performance of the motor.

[0031] Figure 8 FIG. 1 shows a schematic diagram of an acceleration circuit 100 in a motor drive circuit according to an exemplary embodiment of the present application. Figure 8 As shown, in this embodiment, the acceleration circuit 100 primarily comprises resistor R1, capacitor C1, resistor R2, and operational amplifier U1. R1 directly passes the step signal, while C1 differentiates the input signal to form a pulse signal. Both signals simultaneously pass through R2, achieving signal superposition and accelerating motor startup. Operational amplifier U1 acts as an inverting adder, with the voltages at its positive and negative input terminals being zero.

[0032] In some optional embodiments of the present application, Figure 8 In the acceleration circuit shown, the resistance value of resistor R2 is adjustable, and the capacitance value of capacitor C1 is adjustable, so that the width of the pulse signal can be adjusted in real time to achieve more precise control requirements. The resistance value of resistor R2 and the capacitance value of capacitor C1 satisfy the above formula (1), so the required length.

[0033] Figure 9 FIG. 1 is a schematic diagram showing an acceleration circuit 100 in a motor driving circuit in another exemplary embodiment of the present application. Figure 9 As shown, in this embodiment, the acceleration circuit 100 primarily comprises resistor R3, capacitor C2, resistors R4, R5, and R6, and an operational amplifier U2. R3 directly passes the step signal, while C2 differentiates the input signal to form a pulse signal. Both signals simultaneously pass through R4, achieving signal superposition and accelerating motor startup. Operational amplifier U2 acts as a non-inverting adder, while resistors R5 and R6 adjust the signal ratio.

[0034] In some optional embodiments, Figure 9 In the acceleration circuit shown, the resistance value of resistor R4 is adjustable, and the capacitance value of capacitor C2 is adjustable, so that the width of the pulse signal can be adjusted in real time to achieve more precise control requirements. The width Tp of the pulse signal, the resistance value R3 of resistor R4, and the capacitance value C2 of capacitor C2 satisfy the following formula: (3) Therefore, the required Tp length can be determined according to the specific characteristics of the control object.

[0035] According to some embodiments of the present application, a camera module is also provided.

[0036] Figure 10 The structure diagram of the camera module provided by some embodiments of the present application is shown in FIG. Figure 10As shown, the camera module includes: a controller 1010, a motor driving circuit 1020, and a motor assembly 1030, wherein the motor assembly 1030 includes a motor 1031 and a lens 1032, and the motor 1031 is used to drive the lens 1032 to move under the drive current, and output the position information of the lens 1032 after movement to the controller 1010; the controller 1010 is used to output a control signal based on the position information output by the motor 1031; the motor driving circuit 1020 can be the motor driving circuit in any of the above embodiments, and is used to output a driving current to the motor 1031 based on the control signal.

[0037] Through the above-mentioned camera module, since the motor driving circuit 1020 can output a pulsed driving current, the response speed of the motor 1031 can be accelerated, and the control capability of the small step motion can be improved without changing the original control logic, thereby improving the anti-shake capability.

[0038] Figure 11 The following is a schematic diagram showing the structure of an anti-shake control system in some embodiments of the present application. In the anti-shake control system, the complete process of motor control includes the following steps: In step 1, the controller 2 receives the target position information of the control signal 1 and calculates the driving current (step signal) required for the next step based on the current position information fed back by the Hall 11 built into the motor assembly 12.

[0039] Step 2: The acceleration circuit 3 receives the step signal from the controller 2 and converts it into a step signal with pulses.

[0040] In step 3, drive circuit 4 receives the pulsed step signal converted by acceleration circuit 3 and controls the H-bridge composed of four transistors 5, 6, 7, and 8 to output a drive current with the same shape as the pulsed step signal in the time domain. Transistors 5 and 7 have one end connected to ground via DC 13, while transistors 6 and 8 have one end connected directly to ground.

[0041] In step 4, a driving current flows through the coil 9 built into the motor assembly 12, generating a magnetic field to drive the lens 10 to move.

[0042] In step 5, the built-in hall 11 of the motor assembly 12 detects the movement of the lens 10 and outputs the position information to the controller 2 for the next round of calculation.

[0043] According to some embodiments of the present application, an electronic device is also provided, which may include a housing and the above-mentioned camera module.

[0044] Other components of the electronic device according to the embodiment of the present invention, such as a processor and a display screen, and operations are known to those skilled in the art and will not be described in detail here.

[0045] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0046] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A motor drive circuit, characterized in that: include: Speed-up circuit and H-bridge; The input end of the acceleration circuit is electrically connected to the controller, the output end of the acceleration circuit is electrically connected to the input end of the H-bridge, and the output end of the H-bridge is electrically connected to the motor; The acceleration circuit is used to output a superposition signal based on the control signal output by the controller, wherein the superposition signal is obtained by superposition of a pulse signal and a step signal; The H-bridge is used to output a driving current, wherein the driving current has the same shape as the superimposed signal in the time domain.

2. The driving circuit according to claim 1, wherein: The acceleration circuit includes a direct circuit, a differential circuit and a superposition circuit; wherein, The through circuit is connected in parallel with the differential circuit, a first connection point is electrically connected to the controller, and a second connection point is electrically connected to the superposition circuit, the first connection point is a connection point where the through circuit and the differential circuit are electrically connected, and the second connection point is another connection point where the through circuit and the differential circuit are electrically connected; One end of the superimposed circuit is electrically connected to the second connection point, and the other end of the superimposed circuit is electrically connected to the input end of the H-bridge; The pass-through circuit is used to pass the control signal directly to generate a step signal; The differentiator circuit is used to differentiate the control signal and output a pulse signal; The superimposition circuit is configured to superimpose the step signal output from the through circuit and the pulse signal output from the superimposition circuit to generate the superimposed signal.

3. The driving circuit according to claim 2, wherein: The through circuit includes a first resistor, and the differential circuit includes a first capacitor.

4. The driving circuit according to claim 2 or 3, characterized in that: The superposition circuit includes: a second resistor and an inverse proportional amplifier connected in parallel; The second resistor is connected in series between the second connection point and the H-bridge; The negative input terminal of the inverse proportional amplifier is electrically connected to the second connection point, the positive input terminal of the inverse proportional amplifier is grounded, and the output terminal of the inverse proportional amplifier is electrically connected to the input terminal of the H-bridge.

5. The driving circuit according to claim 4, wherein: The second resistor is a resistor with adjustable resistance.

6. The driving circuit according to claim 2 or 3, characterized in that: The superposition circuit includes: a third resistor, a non-inverting proportional amplifier, a fourth resistor and a fifth resistor; One end of the third resistor is electrically connected to the second connection point, and the other end of the third resistor is grounded; The positive input terminal of the non-inverting proportional amplifier is electrically connected to the second connection point, the negative input terminal of the non-inverting proportional amplifier is grounded via the fifth resistor, and the output terminal of the non-inverting proportional amplifier is electrically connected to the input terminal of the H-bridge; One end of the fourth resistor is electrically connected to the third connection point, and the other end of the fourth resistor is electrically connected to the fourth connection point. The third connection point is the connection point between the non-inverting proportional amplifier and the fifth resistor, and the fourth connection point is the connection point between the output end of the non-inverting proportional amplifier and the input end of the H-bridge.

7. The driving circuit according to claim 6, wherein: The third resistor is a resistor with adjustable resistance.

8. The driving circuit according to claim 3, wherein: The first capacitor is a capacitor with an adjustable capacitance value.

9. A camera module, characterized in that: include: A controller, a motor drive circuit, or a motor assembly according to any one of claims 1 to 8, wherein: The motor assembly includes a motor and a lens, wherein the motor is used to drive the lens to move under the drive current and output the position information of the lens after movement to the controller; The controller is configured to output a control signal based on the position information output by the motor; The motor driving circuit is configured to output a driving current to the motor based on the control signal.

10. An electronic device, characterized in that: It comprises a housing and the camera module according to claim 10.

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