CN115550630B

CN115550630B - System and method for detecting lens position, voice coil motor and equipment

Info

Publication number: CN115550630B
Application number: CN202210074232.6A
Authority: CN
Inventors: 原帅; 吴鹏
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2022-01-21
Filing date: 2022-01-21
Publication date: 2023-06-13
Anticipated expiration: 2042-01-21
Also published as: CN115550630A

Abstract

The application provides a detection system for a lens position, a detection method for the lens position, a voice coil motor and electronic equipment, and relates to the technical field of terminals. The detection system comprises: the device comprises a detection module and a controller. The detection module comprises a first magnet, a second magnet, a coil and a magnetic core. The coil is located in the magnetic field formed by the first magnet and the second magnet, the relative position of the coil and the lens is fixed, the coil surrounds the outside of the magnetic core, and the position of the magnetic core is fixed. The controller controls the driving voltage of the coil to be a first voltage so that the coil and the magnetic core move relatively, when the coil is determined to reach a first position, the driving voltage of the coil is controlled to be a second voltage, the position of the lens is determined by utilizing the current of the output end of the coil, the first voltage is a direct current voltage, the second voltage is an alternating current voltage, and the effective values of the first voltage and the second voltage are the same. The scheme can reduce hardware cost, and the size of a device is not excessively increased in the direction of an optical axis and the direction perpendicular to the optical axis, so that occupied space is reduced.

Description

System and method for detecting lens position, voice coil motor and equipment

Technical Field

The application relates to the technical field of terminals, in particular to a detection system for a lens position, a detection method for the lens position, a voice coil motor and electronic equipment.

Background

In the shooting process of the electronic device, a Voice Coil Motor (VCM) is generally used to adjust the position of a lens of the camera module to realize functions such as auto-focusing. The working principle of the VCM is as follows: the electrified coil is used for being stressed to move in a magnetic field to drive the lens to move. Wherein, the relative position of the coil and the lens is fixed.

Because the coil drives the lens to move the displacement actually generated by the influence of the environment where the lens is positioned during actual shooting, the displacement possibly differs from the preset displacement, and therefore the actual position of the lens needs to be detected.

Currently, the actual position of a lens is usually determined by using a Hall sensor (Hall sensor), specifically, a Hall element of the Hall sensor is placed in a magnetic field of a VCM, a current orthogonal to the direction of the magnetic field is applied to the Hall element, displacement of a coil is determined according to the magnitude of potential difference between two ends of the Hall element, and then the lens position is obtained by using a relation that the relative positions of the coil and the lens are fixed. However, due to the fact that the cost of the Hall sensor is high, hardware cost is increased, and in order to avoid the position of the Hall sensor, more sizes of the camera module are required to be increased.

Therefore, the current method of acquiring the lens position increases the hardware cost and the space occupation.

Disclosure of Invention

In order to solve the above problems, the application provides a lens position detection system, a lens position detection method, a voice coil motor and electronic equipment, and hardware cost and occupied space are reduced.

In a first aspect, the present application provides a system for detecting a lens position, which is used for determining a position of a lens in an image capturing module. The detection device comprises: the device comprises a detection module and a controller. The detection module comprises a first magnet, a second magnet, a coil and a magnetic core. The detection module, namely the VCM, is fixed in the relative position of the coil and the lens, and the coil is positioned in a magnetic field formed by the first magnet and the second magnet, so that the coil can generate displacement in the magnetic field after being electrified, and the lens is driven to move. The coil surrounds the outside of the magnetic core, and the position of the magnetic core is fixed, namely the coil and the magnetic core relatively move after being electrified. The controller controls the driving voltage of the coil to be a first voltage, and the first voltage is a direct current voltage. When the two ends of the coil are connected with the first voltage, the coil and the magnetic core relatively move, the inductance of the coil changes, and when the controller determines that the coil reaches the first position, the driving voltage of the coil is controlled to be the second voltage, the second voltage is the alternating current voltage, and the effective values of the first voltage and the second voltage are the same. The controller then uses the current at the output of the coil to determine the position of the lens.

The first position representation is that the coil stops moving at the moment, and the second voltage is the same as the effective value of the first voltage, namely, when the driving voltage of the control coil is the second voltage, the coil does not continue to move.

By means of the scheme, the magnetic core is embedded in the coil of the VCM in the electronic equipment, detection of the lens position is achieved, the influence of the magnetic core on the size of the VCM is small, in some embodiments, the size of the VCM can be kept unchanged, the Hall sensor is avoided, hardware cost can be reduced, excessive increase of the size of a device is avoided in the direction of the optical axis and the direction perpendicular to the optical axis, and occupied space is reduced.

In one possible implementation, the controller is specifically configured to superimpose the first voltage on a preset ac voltage to obtain the second voltage.

The first voltage is direct current voltage, the second voltage is alternating current voltage, and the first voltage and the preset alternating current voltage are overlapped, so that the effective values of the first voltage and the second voltage are identical, and the coil cannot move continuously after reaching the first position.

In one possible implementation, the controller is specifically configured to determine the displacement of the coil using the current at the output of the coil, and determine the position of the lens based on the relative positions of the coil and the lens.

Because the relative position of the coil and the lens is unchanged, the coil can drive the lens to move when moving. Therefore, by determining the actual displacement of the coil and based on the relative positions of the coil and the lens, the position of the lens can be determined.

In one possible implementation, the controller is specifically configured to determine an inductance of the coil according to a current at an output end of the coil and a preset ac voltage, and determine a displacement of the coil according to a pre-calibrated correspondence between the inductance and the displacement of the coil.

Since there is a relative movement between the core and the coil, the inductance of the coil will change, and thus the coil displacement, i.e. the displacement of the relative movement between the core and the coil, can be determined by the inductance of the coil.

In one possible implementation, the controller is specifically configured to determine the displacement of the coil based on a pre-calibrated correspondence between the current and the coil displacement, and the current at the output of the coil.

The mode directly utilizes the current at the output end of the coil, so that the processing process can be simplified.

In one possible implementation manner, the controller is specifically configured to determine an inductance of the coil by using a current at an output end of the coil and a preset ac voltage, and determine a position of the lens according to a pre-calibrated correspondence between the inductance and the position of the lens.

According to the corresponding relation between the inductance and the lens position calibrated in advance, the lens position can be obtained directly according to the inductance, and the processing process can be simplified.

In one possible implementation, the controller is specifically configured to determine the position of the lens using a pre-calibrated correspondence between the current and the lens position, and the current at the output of the coil.

The mode directly utilizes the current of the coil output end, and the lens position can be directly obtained according to the current, so that the processing process can be simplified.

In one possible implementation, the controller is specifically configured to determine that the coil reaches the first position after the driving voltage of the control coil is the first voltage for a preset period of time.

The coil is determined to reach the first position according to the preset time period, the determining process is simpler, and the coil can be determined to reach the first position more simply, conveniently and efficiently.

In one possible implementation, the controller is specifically configured to determine that the coil reaches the first position when the current at the output of the coil is unchanged.

When the voltage across the coil is a constant dc voltage, the current of the coil is typically constant; cutting the magnetically induced wire when the energized coil moves in the magnetic field generates an electromotive force in a direction opposite to the voltage across the coil, and thus the current of the coil is not constant during the movement of the coil.

When the coil stops moving, the electromotive force generated by the coil cutting the magnetic induction wire disappears, so the current of the coil remains unchanged. Thus, when the current at the output of the coil is unchanged, it can be determined that the coil is stopped moving, i.e. that the coil has reached the first position.

Because unexpected movement of the coil may be caused by influence of other factors in the moving process, the method for determining that the coil stops moving can reduce occurrence of error results caused by accidental conditions, thereby improving accuracy of lens position detection.

In one possible implementation, the magnetic core in the lens position detection system has a hollow structure, so that the lens can be nested in the hollow structure of the magnetic core, thereby reducing the size of the whole camera module.

In a second aspect, the present application provides a lens position detection system, which includes a detection module and a controller.

The detection module comprises a magnetic component, a coil and a magnetic core. The detection module, namely the VCM, the coil surrounds the outside of the magnetic core, the position of the coil is fixed, and the relative positions of the magnetic component and the magnetic core are fixed, so that after the coil is electrified, the magnetic component and the coil relatively move, and the magnetic component drives the lens to move.

The controller is used for controlling the driving voltage of the control coil to be a first voltage so as to enable the magnetic component and the coil to move relatively, when the magnetic component is determined to reach the first position, the driving voltage of the control coil is a second voltage, the position of the lens is determined by utilizing the current of the output end of the coil, the first voltage is a direct current voltage, the second voltage is an alternating current voltage, and the effective values of the first voltage and the second voltage are the same. The controller then uses the current at the output of the coil to determine the position of the lens.

The first position representation is that the magnetic component stops moving at the moment, and the second voltage is the same as the effective value of the first voltage, namely, when the driving voltage of the control coil is the second voltage, the magnetic component does not continue to move.

In one possible implementation, the controller is specifically configured to determine the displacement of the magnetic component using the current at the output of the coil, and determine the position of the lens based on the relative positions of the magnetic component and the lens.

Because the relative position of the magnetic component and the lens is unchanged, the magnetic component can drive the lens to move when moving. Therefore, by determining the actual displacement of the magnetic member and based on the relative positions of the magnetic member and the lens, the position of the lens can be determined.

In one possible implementation, the controller is specifically configured to determine the inductance of the coil according to the current at the output end of the coil and a preset ac voltage, and determine the displacement of the magnetic component according to a pre-calibrated correspondence between the inductance and the displacement of the magnetic component.

Because the coil is fixed, the relative positions of the magnetic component and the magnetic core are fixed, and the magnetic component and the coil relatively move after the coil is electrified, and then the magnetic component drives the lens to move. The inductance of the coil may change due to the relative movement between the core and the coil, so that the displacement of the magnetic component may be determined by the inductance of the coil.

In one possible implementation, the controller is specifically configured to determine the displacement of the magnetic component based on a pre-calibrated correspondence between the current and the displacement of the magnetic component, and the current at the output of the coil.

In one possible implementation, the controller is specifically configured to determine that the magnetic component reaches the first position after the driving voltage of the control coil is the first voltage for a preset period of time.

In one possible implementation, the controller is specifically configured to determine that the magnetic component reaches the first position when the current at the output of the coil is unchanged.

When the voltage across the coil is a constant dc voltage, the current of the coil is typically a constant current; when a magnetic field is generated around the energized coil, the magnetic member moves in the magnetic field. Since the position of the coil is fixed, a relative motion is generated between the coil and the magnetic member, so that the energized coil cuts the magnetic induction line in the magnetic field generated by the magnetic member, and the coil cuts the magnetic induction line to generate electromotive force. Therefore, during the movement of the magnetic component, the coil cuts the electromotive force generated by the magnetic induction wire, so that the current passing through the coil is variable.

When the magnetic member stops moving, the electromotive force generated by the coil cutting the magnetic induction wire disappears, and thus the current of the coil is not changed any more. Thus, when the current at the output of the coil is unchanged, it can be determined that the magnetic component stops moving, i.e. that the magnetic component reaches the first position.

Since the magnetic component may be influenced by other factors to generate unexpected movement during the movement, the above manner of determining that the magnetic component stops moving can reduce the occurrence of erroneous results due to occasional situations.

In one possible implementation, the coil in the lens position detection system surrounds the outside of the magnetic component to reduce the size of the detection module, i.e., the VCM.

In a third aspect, the present application provides a voice coil motor.

The voice coil motor includes a first magnet, a second magnet, a coil, and a core. The coil is arranged in a magnetic field formed by the first magnet and the second magnet, the coil surrounds the outside of the magnetic core, and the position of the magnetic core is fixed. The coil is used for generating displacement corresponding to the external driving voltage when the external driving voltage is externally connected.

By adopting the voice coil motor provided by the application, the camera lens can be driven to move by moving the electrified coil in the magnetic field formed by the first magnet and the second magnet, so that the adjustment and the determination of the position of the camera lens are realized; in addition, the Hall sensor is not utilized when the lens position is determined, so that the hardware cost can be reduced, and the occupied space can be reduced.

In a fourth aspect, the present application provides a voice coil motor.

The voice coil motor includes a magnetic member, a coil, and a core. The coil surrounds the outside of the magnetic core, and the position of the coil is fixed; the relative positions of the magnetic component and the magnetic core are fixed; the magnetic component is used for generating movement corresponding to the external driving voltage when the coil is externally connected with the driving voltage.

By adopting the voice coil motor provided by the application, the magnetic component moves corresponding to the external driving voltage when the coil is externally connected with the driving voltage, so that the magnetic component can drive the lens to move, and the adjustment and the determination of the position of the lens are realized; in addition, the Hall sensor is not utilized when the lens position is determined, so that the hardware cost can be reduced, and the occupied space can be reduced.

In a fifth aspect, the present application provides a method for detecting a lens position, where the method is applied to a detection module. The detection module comprises a first magnet, a second magnet, a coil and a magnetic core. The detection module is VCM.

The coil is located in the magnetic field formed by the first magnet and the second magnet, the relative position of the coil and the lens is fixed, the coil surrounds the outside of the magnetic core, and the position of the magnetic core is fixed. The method comprises the following steps: controlling the driving voltage of the coil to be a first voltage so as to enable the coil and the magnetic core to move relatively, wherein the first voltage is a direct current voltage; when the coil is determined to reach the first position, controlling the driving voltage of the coil to be a second voltage, wherein the second voltage is an alternating voltage, and the effective value of the first voltage is the same as that of the second voltage; the position of the lens is determined by the current at the output of the coil.

In one possible implementation manner, the driving voltage of the control coil is a second voltage, which specifically includes:

and superposing the first voltage and a preset alternating voltage to obtain a second voltage.

In one possible implementation, determining the position of the lens by using the current at the output end of the coil specifically includes:

Determining the displacement of the coil by using the current of the output end of the coil; and determining the position of the lens according to the relative positions of the coil and the lens.

In one possible implementation, determining the displacement of the coil using the current at the output of the coil specifically includes:

determining the inductance of the coil according to the current of the output end of the coil and the preset alternating voltage; and determining the displacement of the coil according to the corresponding relation between the inductance and the coil displacement calibrated in advance.

and determining the displacement of the coil according to the corresponding relation between the pre-calibrated current and the coil displacement and the current of the output end of the coil.

determining the inductance of the coil by using the current of the output end of the coil and the preset alternating voltage; and determining the position of the lens according to the corresponding relation between the pre-calibrated inductor and the position of the lens.

and determining the position of the lens by utilizing the corresponding relation between the pre-calibrated current and the position of the lens and the current of the output end of the coil.

In a sixth aspect, the present application provides a method for detecting a lens position, which is applied to a detection module, where the detection module includes a magnetic component, a coil, and a magnetic core; the coil surrounds the outside of the magnetic core, and the position of the coil is fixed; the relative positions of the magnetic component and the magnetic core are fixed, and the method comprises the following steps:

controlling the driving voltage of the control coil to be a first voltage so as to enable the magnetic component and the coil to move relatively, wherein the first voltage is a direct current voltage; when the magnetic component is determined to reach the first position, the driving voltage of the control coil is a second voltage, the second voltage is an alternating voltage, and the effective value of the first voltage is the same as that of the second voltage; the position of the lens is determined by the current at the output of the coil.

Determining the displacement of the magnetic component by using the current at the output end of the coil; and determining the position of the lens according to the relative positions of the magnetic component and the lens.

In one possible implementation, the determining the displacement of the magnetic component using the current at the output of the coil comprises:

determining the inductance of the coil according to the current of the output end of the coil and the preset alternating voltage; and determining the displacement of the magnetic component according to the corresponding relation between the inductance and the displacement of the magnetic component, which are calibrated in advance.

And determining the displacement of the magnetic component according to the corresponding relation between the pre-calibrated current and the displacement of the magnetic component and the current of the output end of the coil.

In a seventh aspect, the present application provides an electronic device. The electronic device comprises a detection system for the position of the lens as described above. The electronic device also includes a lens. The detection system of the lens position of any one of the above is applied to determining the position of the lens module in the electronic device.

By means of the scheme, the magnetic core is nested in the coil of the VCM in the electronic device, detection of the lens position is achieved, the influence of the magnetic core on the size of the VCM is small, in some embodiments, the size of the VCM can be kept unchanged, the Hall sensor is avoided, hardware cost can be reduced, excessive increase of the size of the device is avoided in the direction of the optical axis and the direction perpendicular to the optical axis, occupied space is reduced, and therefore occupied space of a lens module in the electronic device is enabled.

Drawings

Fig. 1A is a schematic structural diagram of an electronic device according to an embodiment of the present application;

FIG. 1B is an exploded view of FIG. 1A;

fig. 1C is a schematic structural diagram of a camera module provided in an embodiment of the present application;

FIG. 1D is an exploded view of FIG. 1C;

FIG. 1E is a schematic diagram of the operating principle of a voice coil motor;

fig. 1F is a schematic structural diagram of a voice coil motor and lens assembly according to an embodiment of the present disclosure;

fig. 2A is a schematic structural diagram of a lens position detection system according to an embodiment of the present application;

fig. 2B is a schematic structural diagram of another lens position detection system according to an embodiment of the present disclosure;

FIG. 2C is a schematic diagram of the driving voltage of the coil and the current at the output end of the coil according to the embodiment of the present application;

Fig. 3A is a schematic structural diagram of a lens position detection system according to another embodiment of the present disclosure;

FIG. 3B is a schematic cross-sectional view of a voice coil motor assembly according to an embodiment of the present disclosure;

FIG. 3C is an exploded view of FIG. 3B;

fig. 3D is a graph of correspondence between inductance and actual displacement of a coil according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of a lens position detection system according to another embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of a voice coil motor according to an embodiment of the present disclosure;

fig. 6 is a flowchart of a method for detecting a lens position according to an embodiment of the present application;

fig. 7 is a flowchart of a method for detecting a lens position according to another embodiment of the present disclosure;

fig. 8 is a flowchart of a method for detecting a lens position according to another embodiment of the present disclosure;

fig. 9 is a flowchart of a method for detecting a lens position according to another embodiment of the present disclosure;

fig. 10 is a flowchart of a calibration method for the correspondence between inductance and actual displacement of a coil according to an embodiment of the present application;

FIG. 11 is a flowchart of a method for detecting a lens position according to another embodiment of the present disclosure;

FIG. 12 is a flowchart of a calibration method for the correspondence between current and lens position according to an embodiment of the present disclosure;

Fig. 13 is a schematic structural diagram of a lens position detection system according to another embodiment of the present disclosure;

fig. 14 is a schematic structural diagram of a voice coil motor according to another embodiment of the present disclosure;

fig. 15 is a flowchart of a method for detecting a lens position according to another embodiment of the present disclosure;

fig. 16 is a flowchart of a method for detecting a lens position according to another embodiment of the present disclosure;

FIG. 17 is a flowchart of a method for detecting a lens position according to another embodiment of the present disclosure;

fig. 18 is a flowchart of a method for detecting a lens position according to another embodiment of the present disclosure;

fig. 19 is a flowchart of a method for detecting a lens position according to another embodiment of the present disclosure;

fig. 20 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

In order to facilitate a clearer understanding of the technical solutions provided in the present application by those skilled in the art, the following description will first be given with terms in the embodiments of the present application.

The terminology used in the description section of the present application is for the purpose of describing particular embodiments of the present application only and is not intended to be limiting of the present application.

The words "first," "second," and the like in the description herein are used for descriptive purposes only and are not to be interpreted as indicating or implying a relative importance or implicitly indicating the number of technical features indicated.

In the present application, unless explicitly specified and limited otherwise, the term "coupled" is to be construed broadly, and for example, "coupled" may be either fixedly coupled, detachably coupled, or integrally formed; may be directly connected or indirectly connected through an intermediate medium.

With the continuous progress of technology, the shooting function has gradually become a basic equipment of mobile terminals such as mobile phones, tablet computers, notebook computers, personal digital assistants (Personal Digital Assistant, PDA), smart wearable devices, point of Sales (POS), and the like.

Referring to fig. 1A and fig. 1B, fig. 1A is a schematic structural diagram of an electronic device according to an embodiment of the present application; fig. 1B is an exploded view of fig. 1A.

As shown in fig. 1A and 1B, an electronic device will be described by taking a mobile phone as an example. It should be understood that the electronic device of this embodiment includes, but is not limited to, a mobile phone, and the electronic device may also be a mobile terminal such as a tablet computer, a notebook computer, a PDA, a smart wearable device, or a POS. The embodiment of the application does not limit the specific type of the electronic equipment.

As shown in fig. 1A, the electronic apparatus may include an image pickup module 1, a housing 2, a display panel 3, and a circuit board 4.

The shell 2 encloses the back and the side of establishing at electronic equipment, and display panel 3 installs on shell 2, and display panel 3 and shell 2 enclose into electronic equipment's accommodation space jointly, and camera module 1 and circuit board 4 are all installed in this accommodation space.

In addition, a microphone, a loudspeaker, a battery or other devices can be arranged in the accommodating space.

Fig. 1A and 1B show the camera module 1 in the top, near-edge region of the housing 2. It is understood that the position of the image pickup module 1 is not limited to the position shown in fig. 1A.

As shown in fig. 1B, in some embodiments, the housing 2 may include a rear cover 21 and a middle frame 22, where the rear cover 21 is provided with a light hole 211, the camera module 1 may be disposed on the middle frame 22, and the camera module 1 collects external ambient light through the light hole 211 on the rear cover 21.

The light sensing surface of the camera module 1 and the light hole 211 are oppositely arranged, external ambient light passes through the light hole 211 and irradiates the light sensing surface, the light sensing surface is used for collecting external ambient light, and the camera module 1 is used for converting optical signals into electric signals so as to achieve the shooting function.

Fig. 1B shows that one camera module 1 is provided in the electronic device, and it should be noted that, in practical application, the number of camera modules 1 is not limited to one, and the number of camera modules 1 may be two or more.

When the number of the camera modules 1 is plural, the plural camera modules 1 may be arranged arbitrarily in the X-Y plane. For example, the plurality of camera modules 1 are arranged in the X-axis direction, or the plurality of camera modules 1 are arranged in the Y-axis direction.

In addition, the image capturing module 1 includes, but is not limited to, an Auto Focus (AF) module, a wide-angle image capturing module 1, a telephoto image capturing module 1, a color image capturing module 1, or a black-and-white image capturing module 1. The camera module 1 in the electronic device may include any one of the camera modules 1 described above, or may include two or more of the camera modules 1 described above.

When the number of the camera modules 1 is two or more, the two or more camera modules 1 may be integrated into one camera module.

As shown in fig. 1B, the camera module 1 may be electrically connected to the circuit board 4. The circuit board 4 is, for example, a motherboard in an electronic device, and the camera module 1 may be electrically connected to the motherboard through an electrical connector.

For example, the camera module 1 is provided with a female socket of an electrical connector, the main board is provided with a male socket of the electrical connector, and the electrical connection between the camera module 1 and the main board is realized by plugging the female socket into the male socket. The main board is provided with a processor, for example, and the processor controls the camera module 1 to shoot images. When a user inputs a shooting instruction, the processor receives the shooting instruction and controls the image pickup module 1 to shoot a shooting object according to the shooting instruction.

Referring to fig. 1C and fig. 1D, fig. 1C is a schematic structural diagram of an image capturing module according to an embodiment of the present application; fig. 1D is an exploded view of fig. 1C.

Fig. 1C shows the structure of the image pickup module 1 in fig. 1B.

As shown in fig. 1C, the image pickup module 1 of the present embodiment includes a housing 11, a lens 12, and a sensor assembly 15.

The focusing assembly and the driving means are not shown in fig. 1C and 1D.

Specifically, as shown in fig. 1D, the housing 11 may include an outer frame 111 and a bottom plate 112, and the outer frame 111 and the bottom plate 112 together enclose an accommodating space of the housing 11. By providing the detachable chassis 112, the lens 12, the image sensor assembly 15, and other devices of the image pickup module 1 are facilitated to be mounted in the housing 11.

A side surface of the outer frame 111 facing away from the bottom plate 112 is provided with a mounting hole 1111, the lens 12 is mounted in the housing 11, and a portion of the lens 12 is exposed outside the housing 11 through the mounting hole 1111. The light incident side of the lens 12 is located outside the housing 11, and the light emergent side of the lens 12 is located inside the housing 11. For example, the light incident side of the lens 12 corresponds to the light transmitting hole 211 on the rear cover of the electronic device. The external ambient light enters the lens 12 from the light entrance side of the lens 12 through the light transmission hole 211, the lens 12 is formed by, for example, one or a plurality of laminated lenses, the optical axis of the lens 12 passes through the center of the lens, the lens condenses the incident light, and the condensed light exits from the light exit side of the lens 12.

The image sensor assembly 15 is located on the light exit path of the lens 12, for example, the image sensor assembly 15 is located on the light exit side of the lens 12, and the optical axis of the lens 12 passes through the center of the image sensor assembly 15. The light emitted from the lens 12 enters the image sensor assembly 15, and the emitted light signal is converted into an electric signal through the photoelectric conversion function of the image sensor assembly 15, so as to realize the imaging function of the camera module 1.

With continued reference to fig. 1D, the image sensor assembly 15 may be located at the bottom of the housing 11, i.e., the image sensor assembly 15 is disposed proximate to the floor 112. For example, the image sensor assembly 15 may be secured to the base plate 112, with the image sensor assembly 15 being supported and positioned by the base plate 112. In particular, the image sensor assembly 15 may include an image sensor 151 and an electrical connection 152.

The image sensor 151 is located on the light-emitting side of the lens 12, for example, the optical axis of the lens 12 passes through the center of the image sensor 151. The light emitted from the lens 12 is irradiated to the image sensor 151, and the image sensor 151 photoelectrically converts the emitted light signal into an electric signal to realize the imaging function of the imaging module 1.

The electrical connector 152 is used to electrically connect the image sensor 151 to an external circuit, and further, control the image sensing operation through the external circuit. Specifically, one end of the electrical connector 152 is connected to the image sensor 151, and the other end of the electrical connector 152 is connected to an external circuit, for example, the other end of the electrical connector 152 is connected to the circuit board 4 in the electronic device. When a user shoots, a processor on the circuit board 4 controls the image sensor 151 to operate.

Since the image sensor assembly 15 of the present embodiment may be fixed in the housing 11, the back surface of the image sensor 151 is fixed to the base 112 by taking the case where the image sensor assembly 15 is fixed to the base 112 as an example. Since the image sensor 151 does not need to be moved, electrical connection of the image sensor 151 and an external circuit may be achieved using a flexible electrical connector, or the image sensor 151 and the external circuit may be connected using an electrical connector 152 having superior strength and rigidity, for example, the image sensor 151 and the external circuit may be connected using a printed circuit board 4 (Printed Circuit Board, PCB).

The image sensor 151 generates heat during operation, and the heat is collected on the image sensor 151, which affects the performance of the image sensor 151, and when severe, the image sensor 151 cannot work normally, so that heat dissipation of the image sensor 151 is required. Accordingly, as shown in fig. 1D, a space may be provided between the heat radiation surface of the image sensor 151 (the surface of the image sensor 151 facing the bottom plate 112) and the bottom plate 112, and the space may be filled with the heat conductive liquid 16, and the heat radiation of the image sensor 151 is performed by the heat conductive liquid 16. Through the heat conduction effect of the heat conduction liquid 16, the heat dissipation efficiency of the image sensor 151 can be improved, the heat dissipation effect of the image sensor 151 is improved, and further the working performance of the image sensor 151 is ensured.

The annular sealing plate 17 may be attached to the bottom plate 112 of the housing 11, and the heat conductive liquid 16 may be located in a region surrounded by the annular sealing plate 17. The heat conductive liquid 16 is a flowable liquid, and the annular seal plate 17 is provided on the bottom plate 112 of the housing 11, so that the heat conductive liquid 16 is confined in the area surrounded by the annular seal plate 17. The area surrounded by the annular sealing plate 17 may correspond to a heat radiation surface of the image sensor 151.

A gap may be formed between the annular sealing plate 17 and the heat dissipation surface of the image sensor 151, so as to ensure that the heat conduction liquid 16 is fully contacted with the heat dissipation surface of the image sensor 151, and a certain flow space is reserved for thermal expansion of the heat conduction liquid 16; further, the heat transfer liquid 16 is prevented from overflowing the annular sealing plate 17 by the surface tension of the heat transfer liquid 16 in the gap between the surface of the annular sealing plate 17 and the heat radiation surface of the image sensor 151.

With continued reference to fig. 1D, a plurality of seal holes 171 may be disposed on the annular sealing plate 17 at intervals, and the overflowed heat-conducting liquid 16 is stored in a sealed manner through the seal holes 171, so that the heat-conducting liquid 16 is prevented from overflowing out of the annular sealing plate 17. Instead of the seal hole 171, the surface of the annular seal plate 17 may be a rugged corrugated surface, and the extending direction of the corrugations of the corrugated surface may coincide with the extending direction of the respective sides of the annular seal plate 17; alternatively, a plurality of strip-shaped grooves may be provided at intervals on the surface of the annular sealing plate 17, the strip-shaped grooves extending in the contour line direction of the annular sealing plate 17.

In some embodiments of the present application, the camera module 1 further includes a focusing assembly 14 (not shown in fig. 1D) disposed in the housing 11 for adjusting the focal length of the lens 12. For example, the focusing assembly may drive the lens 12 to move in the direction of its optical axis to achieve a focusing function of the lens 12. A voice coil motor may be used as the focusing element 14 in the camera module 1 to adjust the focal length of the lens 12.

When a user holds a portable electronic device (such as a mobile phone) to take a photograph, the photographed image is often blurred due to shake of the hand. In contrast, a driving device 13 is provided in the housing 11 of the image pickup module 1, and the driving device 13 is configured to drive the lens 12 to move in a plane perpendicular to the optical axis direction. By moving the lens 12 in a plane perpendicular to its optical axis, the amount of displacement generated by the shake of the user's hand is compensated, and the quality of the influence of photographing is improved.

In some embodiments of the present application, the camera module 1 further includes a driving assembly 13 (not shown in fig. 1D) disposed in the housing 11 for driving the lens 12 to move in a plane perpendicular to the optical axis direction thereof. A voice coil motor may be employed as the driving unit 13 in the image pickup module 1 for driving the lens 12 to move in a plane perpendicular to the optical axis direction thereof.

Voice Coil Motor (VCM), abbreviated as VCM. VCM is a device capable of converting electrical energy into mechanical energy.

The VCM can be used as a focusing component in the camera module and also can be used as a driving component in the camera module.

First, the operation principle of the VCM in the prior art will be described.

The basic structure of the VCM includes a coil and a permanent magnet, and in some embodiments, the VCM may also include structure for fixation.

The permanent magnet of the VCM is used for providing a magnetic field, and the coil is electrified and then receives ampere force in the magnetic field to generate movement. The coil can be controlled to move to the corresponding position by controlling the driving voltage or current of the driving coil, and when the coil is relatively fixed with the appointed movable component, the coil moves to drive the appointed movable component to move to the appointed position.

The VCM is mainly applied to small-stroke, high-speed or high-acceleration movements and is suitable for small spaces.

Therefore, the VCM is widely applied to cameras of electronic equipment, and the lens is driven to move through movement of the coil so as to adjust the position of the lens, so that the lens is automatically focused, and the electronic equipment can obtain clear images.

Referring to fig. 1E, fig. 1E is a schematic diagram illustrating an operation principle of a voice coil motor.

As shown in fig. 1E, the VCM100 includes a first magnet 101, a second magnet 102, and a coil 103.

Wherein the magnetic poles of the first magnet 101 and the second magnet 102 are opposite, a magnetic field is formed between the first magnet 101 and the first magnet 102, and the coil 103 is positioned in the magnetic field between the first magnet 101 and the second magnet 102.

When a driving voltage is supplied to the VCM, a current is generated in the coil 103. The driving voltage is typically a dc voltage.

The energized coil 103 receives an ampere force in a magnetic field between the first magnet 101 and the second magnet 102, and the direction of the received ampere force can be determined by a left-hand rule.

As shown in fig. 1E, the direction of the magnetic field between the first magnet 101 and the second magnet 102 is directed by the first magnet 101 toward the second magnet 102, and the direction of the current in the coil 103 is shown as the arrow in fig. 1E. At this time, according to the left hand rule, it is determined that the coil 103 receives an ampere force rightward, and the coil 103 moves rightward by the ampere force.

By controlling the dc voltage for driving the movement of the coil 103, the movement of the coil 103 to the corresponding position can be controlled, thereby driving the movable member to move to the designated position. I.e. different direct voltages can control the coil 103 to move to different positions, thereby driving the moving member to move to different positions.

The electronic device adopts the VCM as a focusing component to drive the lens in the lens 12 to move through the coil 103 in the VCM.

The following describes an assembled structure of the VCM and the lens 12 in the electronic device of fig. 1A.

Referring to fig. 1F, fig. 1F is a schematic structural diagram of a voice coil motor and lens assembly according to an embodiment of the present application. As shown in fig. 1C and 1F, in one embodiment, the focusing assembly 14 in the lens module 1 is disposed within the housing 11.

As shown in FIG. 1F, in one embodiment, using a VCM as the focus assembly, the focus assembly 14 may include a focus coil 141 and a magnetic member 142. The focusing coil 141 is sleeved on the outer wall of the lens 12, the magnetic piece 142 is fixed in the shell 11, and the magnetic piece 142 is arranged opposite to the focusing coil 141.

In practical applications, the magnetic member 142 may be fixed on an inner wall of the housing 11, for example, the magnetic member 142 is fixed on an inner wall of the housing 11 opposite to an outer wall of the lens 12; alternatively, a fixing structure is disposed in the housing 11, the magnetic member 142 is fixed on the fixing structure, and the magnetic member 142 faces the focusing coil 141 on the outer side wall of the lens 12.

When the user holds the electronic device to shoot, the circuit board 4 controls the focusing coil 141 to work, the focusing coil 141 is electrified to generate an electromagnetic field, and magnetic force is generated between the focusing coil 141 and the magnetic piece 142, the magnetic force drives the focusing coil 141 to move, and the focusing coil 141 drives the lens 12 to move.

For example, the circuit board 4 controls the current direction and magnitude in the focusing coil 141 according to a photographing instruction input by a user, adjusts the magnetic field direction and magnitude of magnetic force generated between the focusing coil 141 and the magnetic member 142, and controls the moving direction and moving amount of the focusing coil 141, thereby controlling the moving direction and moving amount of the lens 12 to focus the photographing object.

In order to make the focusing assembly 14 smoothly drive the lens 12 to move, a plurality of magnetic members 142 may be provided at intervals along the circumference of the focusing coil 141 at the periphery thereof. For example, one magnetic member 142 is disposed on each of opposite sides of the focusing coil 141; alternatively, four, six or eight magnetic pieces 142 are provided at uniform intervals along the circumferential direction of the focusing coil 141.

Illustratively, the outer wall of the lens 12 may be sleeved with the supporting seat 18, and the focusing coil 141 is sleeved on the outer wall of the supporting seat 18. The lens 12 is supported by the support base 18 and the focusing coil 141 is fixed.

In the above description, as shown in fig. 1F, a VCM is used as the focusing assembly, and specifically, a focusing coil and a magnetic member may be included.

In some embodiments of the present application, a VCM is used as a focusing assembly, and the VCM provided in embodiments of the present application includes a magnetic core in addition to a focusing coil and a magnetic member.

In order to facilitate understanding of the technical solution provided by the embodiments of the present application, the following describes application scenarios common to the embodiments of the present application.

Currently, electronic devices such as mobile phones and PADs generally have shooting functions, and lens auto-focusing can be achieved in the shooting process.

In the shooting process, the electronic equipment firstly obtains the distance between a shot object and the electronic equipment, namely the object distance of a lens by a ranging mode such as laser ranging; then, a direct current voltage for controlling the coil of the VCM to move is determined according to the object distance, and the lens is driven to move by the movement of the coil.

The control of the displacement generated by the coil is realized by controlling the direct-current voltage for driving, so that the lens is controlled to reach the appointed position, and the automatic focusing is realized.

There is a correspondence between the above object distance and the dc voltage driving the VCM. In general, a correspondence relationship between an object distance and a dc voltage is pre-stored in an electronic device.

According to the description of the operation principle of the VCM above, there is a correspondence between the dc voltage driving the VCM and the displacement generated by the coil.

However, due to the influence of the environment in which the lens is located during actual shooting, the coil drives the lens to move to actually generate displacement, which may be different from the preset displacement corresponding to the dc voltage driving the VCM.

For example, when a user uses an electronic apparatus to take a tilt or a pan, the entire lens is in a state of being tilted with respect to the horizontal plane. The coil is driven by direct current voltage to drive the lens to move so as to generate preset displacement, and the coil and the lens can generate certain offset under the action of gravity at the moment; or, the temperature during actual shooting can influence the movement of the lens, so that the coil is influenced to drive the displacement actually generated by the lens.

When the displacement actually generated by the coil driving the lens is different from the preset displacement corresponding to the current direct-current voltage driving the VCM, the focusing of the camera lens is inaccurate and the imaging is unclear.

Currently, in order to acquire the displacement actually generated by the coil, thereby acquiring the lens position, a Hall sensor (Hall sensor) is generally used. Adding orthogonal magnetic and electric fields to the semiconductor to deflect the semiconductor carriers, thereby generating a potential difference across the semiconductor; then, the potential difference is equivalent to the displacement actually generated by the coil, thereby obtaining the lens position.

However, the cost of the hall sensor is high, and in order to avoid the position of the hall sensor, the size of the camera module needs to be increased in the optical axis direction and the direction perpendicular to the optical axis, that is, the hall element occupies more additional space.

Therefore, the above-described manner of acquiring the lens position increases the hardware cost and the space occupation to a large extent.

In order to solve the above technical problems, embodiments of the present application provide a system, a method, and a device for detecting a lens position.

By means of the technical scheme, the magnetic core is embedded in the coil, the controller firstly controls the driving voltage of the coil to be direct-current voltage, the coil drives the lens to move under the driving of the direct-current voltage, when the coil reaches the first position, namely after the coil stops moving, the controller controls the driving voltage of the coil to be alternating-current voltage, then the current of the output end of the coil is obtained, and the position of the lens is determined according to the obtained current of the output end of the coil.

The lens position obtained in the process is the position reached after the coil drives the lens to shift actually, and the position considers the influence of gravity and other factors on the coil and the lens, namely the accurate detection of the lens position is realized.

In order to achieve clear imaging, the obtained lens position may be compared with a preset position corresponding to a dc voltage for driving the VCM. When the two positions have differences, the compensation of the lens displacement is carried out according to the differences, so that the lens reaches the preset position.

By adopting the scheme provided by the application, only one magnetic core is nested in the coil of the VCM, so that the Hall sensor is avoided, the hardware cost is reduced, and the occupied space is reduced.

In addition, by adopting the scheme provided by the application, waves with strong radiation can not appear in the process of determining the lens position, so that the imaging quality of the electronic equipment can not be influenced.

The embodiment of the application provides a lens position detection system.

Referring to fig. 2A, fig. 2A is a schematic structural diagram of a lens position detection system according to an embodiment of the present application.

As shown in fig. 2A, the detection system 200 includes a controller 201 and a detection module 202.

The detection module 202 includes a first magnet 203, a second magnet 204, a coil 205, and a magnetic core 206.

The coil 205 is located in a magnetic field formed by the first magnet 203 and the second magnet 204, the relative position of the coil 205 and the lens is fixed, the coil 205 surrounds the outside of the magnetic core 206, and the position of the magnetic core 206 is fixed.

A controller 201 for controlling the driving voltage of the coil to be a first voltage so as to enable the coil 205 and the magnetic core 206 to relatively move; when it is determined that the coil 205 reaches the first position, the driving voltage of the coil 205 is controlled to be a second voltage, the position of the lens is determined by using the current at the output end of the coil 205, the first voltage is a direct current voltage, the second voltage is an alternating current voltage, and the effective values of the first voltage and the second voltage are the same.

When the controller 201 supplies a first voltage to the coil 205 as a driving voltage, the coil 205 is energized to be in a magnetic field formed by the first magnet 203 and the second magnet 204, and the coil 205 is moved by an ampere force, and at this time, the coil 205 and the core 206 are moved relatively.

For example, when the magnetic field direction between the first magnet 203 and the second magnet 204 is directed by the first magnet 203 toward the second magnet 204, the current direction in the coil 205 is shown as the arrow direction in fig. 2A. At this time, according to the left hand rule, the coil 205 moves rightward due to receiving the rightward ampere force.

Because the relative positions of the coil 205 and the lens are fixed, the movement of the coil 205 will drive the lens to move.

Since the magnetic core 206 is fixed, there is a relative movement between the coil 205 and the magnetic core 206 during the movement of the coil 205, which may cause the inductance of the coil 205 to change.

When the coil 205 reaches the first position, the coil 205 is stopped at this time, that is, the coil 205 is driven to move by the first voltage, and the coil 205 reaches the first position in a state of stopping the movement.

Since the inductance of the coil 205 changes, when the controller 201 controls the driving voltage of the coil 205 to be the second voltage of the ac voltage, the current at the output terminal of the coil 205 changes.

Since the effective values of the first voltage and the second voltage are the same, when the coil 205 reaches the first position, i.e., the coil 205 stops moving, under the drive of the first voltage, the drive voltage of the coil 205 becomes the second voltage, and the coil 205 does not continue to move.

The controller 201 is also configured to obtain the current at the output of the coil 205.

The current at the output of the coil 205 is related to the inductance of the coil 205, i.e. to the displacement caused by the movement of the coil 205; further, since the relative positions of the coil 205 and the lens are fixed, the position of the lens can be determined from the current at the output end of the coil 205.

By adopting the scheme provided by the application, the magnetic core is nested in the coil of the VCM, so that the detection of the lens position is realized, the Hall sensor is avoided, the hardware cost can be reduced, and the occupied space is reduced.

The controller in the above embodiments of the present application may be an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), a programmable logic device (Programmable Logic Device, PLD), a digital signal processor (Digital Signal Processor, DSP), or a combination thereof.

The PLD may be a complex programmable logic device (Complex Programmable Logic Device, CPLD), a Field programmable gate array (Field-programmable Gate Array, FPGA), a general-purpose array logic (Generic Array Logic, GAL), or any combination thereof, and embodiments of the present application are not particularly limited.

One implementation of the controller is described below.

Referring to fig. 2B, the structure of another lens position detection system according to an embodiment of the present application is shown.

The controller 201 includes a control circuit 2011, a driving circuit 2012, and a sampling circuit 2013.

The control circuit 2011 is configured to control the driving voltage output from the driving circuit 2012, and the control circuit 2011 may be, for example, an image pickup chip (Integrated Circuit Chip, IC) of an electronic device such as a mobile phone.

The driving circuit 2012 is configured to output a driving voltage to the coil, i.e., a first voltage and a second voltage to the coil.

The sampling circuit 2013 is configured to collect a current at an output end of the coil, and transmit a sampling result to the control circuit 2011.

The specific procedure of the controller controlling the driving voltage of the coil and obtaining the current at the output terminal of the coil will be described below.

The controller is used for controlling the driving voltage of the coil and acquiring the current of the output end of the coil.

Referring to fig. 2C, fig. 2C is a schematic diagram of the driving voltage of the coil and the current at the output end of the coil provided in the embodiment of the present application.

In the upper part of fig. 2C, the horizontal axis represents time, and the vertical axis represents the driving voltage of the coil; in the lower part of fig. 2C, the horizontal axis represents time, and the vertical axis represents current at the output end of the coil.

Referring to the upper part of fig. 2C, before time t0, the controller controls the driving voltage of the coil to be a first voltage, i.e., a dc voltage V; when the coil is determined to reach the first position, that is, when the coil is determined to stop moving, the controller controls the driving voltage of the coil to be the second voltage at the time t0, that is, the driving voltage of the coil is the alternating voltage u at the time t0-t 1.

The dc voltage V and the ac voltage u have the same effective value.

The coil movement causes a relative movement between the coil and the core, which causes a change in inductance of the coil.

Referring to the lower part of fig. 2C, the coil stops moving after time t0, and the inductance of the coil is not changed any more, so that the current at the output terminal of the coil is substantially stable at the driving voltage u of the t0-t1 coil.

Before time t0, the controller controls the driving voltage of the coil to be a dc voltage V, and the coil moves under the action of the magnetic field to cut the magnetically induced line, so that an electromotive force generated by cutting the magnetically induced line is generated in the coil.

Thus, the current at the output of the coil is not constant before time t0, but is dependent on the driving voltage of the coil and the movement of the coil, which is typically variable.

Referring to the lower part of fig. 2C, before time t0, the straight line in the figure does not indicate that the current is constant, but only the presence of current at the output.

The following description is made in connection with specific implementations.

Referring to fig. 3A, fig. 3A is a schematic structural diagram of a lens position detection system according to another embodiment of the present application.

The system for detecting the lens position provided by the embodiment of the invention is applied to the electronic equipment shown in fig. 1A, and specifically, is applied to the lens module 1 shown in fig. 1C.

As shown in fig. 3A, the detection system 300 includes a controller 301 and a detection module 302.

The detection module 302 includes a first magnet 303, a second magnet 304, a coil 305, and a magnetic core 306.

The positions of the first magnet 303, the second magnet 304, and the magnetic core 306 are fixed. The first magnet 303 and the second magnet 304 have opposite magnetic poles.

In one possible implementation, the first magnet 303, the second magnet 304, and the magnetic core 306 may be fixed to a fixture such as a iron case.

The coil 305 is located in a magnetic field between the first magnet 303 and the second magnet 304, the magnetic field being formed by the first magnet 303 and the second magnet 304.

The controller 301 is configured to provide a driving voltage to the coil 305.

Specifically, the controller 301 firstly provides a dc voltage to the coil 305 as a driving voltage, and the coil 305 drives the lens to move along the optical axis direction under the driving of the dc voltage.

In fig. 3A, the optical axis direction is a direction perpendicular to the magnetic field between the first magnet 303 and the second magnet 304, and is parallel to the paper surface of fig. 3A. When it is determined that the coil 305 stops moving, that is, when it is determined that the coil 305 reaches the first position, the controller 301 superimposes a preset ac voltage on the dc voltage and supplies the coil 305 with the driving voltage superimposed with the preset ac voltage. The driving voltage superimposed with the preset alternating voltage is the same as the effective value of the direct voltage.

The driving voltage superimposed with the preset ac voltage has the same effective value as the dc voltage, so that the coil 305 is not continuously moved by the driving voltage superimposed with the preset ac voltage.

Specifically, in order that the coil 305 is not moved further by the driving voltage superimposed with the preset ac voltage, the preset ac voltage may be an ac voltage having a small amplitude.

In the process of moving the coil 305, due to the existence of damping, the driving action of the ac voltage with smaller amplitude on the coil 305 can be counteracted by the damping, so that the coil 305 does not continue to move when being driven by the driving voltage superimposed with the preset ac voltage.

In order to maintain the coil 305 at the above position after the movement is stopped, it is necessary that the controller 301 continuously supplies the dc voltage to the coil 605 and keeps the effective value of the driving voltage the same as the dc voltage.

In this embodiment, for the electronic device shown in fig. 1A, the lens module uses a VCM as a focusing component, where the VCM specifically includes a first magnet 303, a second magnet 304, a coil 305, and a magnetic core 306.

Referring to fig. 3B and 3C, fig. 3B is a schematic cross-sectional view illustrating assembly of a voice coil motor according to an embodiment of the present application.

S is a section parallel to the z direction.

And expanding the complete VCM structure corresponding to the structure of FIG. 3B to obtain a structure of FIG. 3C, wherein FIG. 3C is an explosion diagram of FIG. 3B.

Fig. 3B shows a structural section of assembly of each component in the VCM according to the embodiment of the present application, where the structure in the VCM corresponds to that in fig. 3C, respectively.

In fig. 3B, 307 is a housing of the camera module, and the housing 307 in fig. 3B corresponds to the housing 11 in fig. 1C. Specifically, the housing 307 in fig. 3B shows a circumferential housing portion of the housing 11 in fig. 1C along the focusing coil 141.

As shown in fig. 3B and 3C, in one possible implementation, the coil 305 is a loop of multi-turn wire.

The core 306 has a hollow structure, and the coil 305 surrounds the outside of the core 306, that is, the core 306 is nested in a hollow position inside the coil 305. In order to improve the detection accuracy while avoiding the magnetic core 306 from occupying an extra space as much as possible, there is an overlapping portion between the coil 305 and the magnetic core 306 in the direction of the optical axis of the lens.

The specific structure of the VCM assembly as shown in fig. 3B and 3C, and the assembled structure of the VCM are only examples, and it is understood that the specific structure of the VCM assembly and the assembled structure of the VCM are not limited to those shown in fig. 3B and 3C.

In some embodiments, the lens is nested at the hollow structure of the magnetic core 306.

The structure of VCM assembly provided by the embodiment of the present application and the structure of fig. 1F may be different from the structure of VCM assembly provided by the embodiment of the present application: the magnetic core 306 may be disposed between the magnetic member 142 and the lens 12, with the lens nested within the hollow structure of the magnetic core 306.

The controller 301 is also configured to draw current at the output of the coil 305.

The specific principle of the controller 301 to realize the lens position detection is described in detail below.

When the controller 301 supplies a dc voltage to the coil 305, a current flows in the coil 305.

When the energized coil 305 is placed in a magnetic field between the first magnet 303 and the second magnet 304, the coil 305 is moved by an ampere force. The direction of the ampere force experienced by the coil 305 in the magnetic field can be determined according to the left hand rule.

For example, as shown in fig. 3A, the direction of the magnetic field between the first magnet 303 and the second magnet 304 is directed from the first magnet 303 to the second magnet 304; for the coil, the direction of the current is shown as the arrow pointing in fig. 3A.

According to the left hand rule, the direction of the ampere force received by the coil 305 can be determined. As shown in fig. 3A, the coil 305 moves rightward under the force.

At this time, the coil 305 moves from the initial position and drives the lens to move. Coil 305 is stopped after displacement d. For example, coil 305 is now moved to the first position in fig. 3A. The dc voltages across the coil 305 are different and the corresponding displacements d are different. In practical applications, the displacement d of the coil 305 may also characterize the position of the coil 305, since the moving direction of the coil is parallel to the optical axis direction.

In order to maintain the coil 305 at the above position after the movement is stopped, it is necessary that the controller 301 continuously supplies the driving voltage to the coil 305 and keeps the effective value of the driving voltage unchanged.

The direct current voltage output by the controller 301 and the displacement generated by the movement of the coil 305 under the ampere force have a corresponding relationship. For convenience of description, the corresponding relationship is simply referred to as a corresponding relationship between the dc voltage and the coil displacement.

In one possible implementation, to enable a reduction in the size of the entire camera module, a magnetic core 306 having a hollow structure may be nested in a hollow position inside the coil 305; and the lens is nested in the hollow position of the magnetic core 306, so that the imaging module takes on a structure of coil 305, magnetic core 306 and lens nesting from outside to inside.

Since the magnetic core 306 is fixed, there is relative movement between the coil 305 and the magnetic core 306 during movement of the coil 305, which can cause the inductance of the coil 305 to change.

Upon determining that the movement of the coil 305 is stopped, the controller 301 supplies an alternating voltage to the coil 305. At this time, the controller 301 superimposes a preset ac voltage on the dc voltage and outputs the superimposed ac voltage to the coil 305. Parameters such as amplitude, frequency and the like of the preset alternating voltage are known.

Because of the varying inductance of the coil 305, the current at the output of the coil 305 varies when the controller 301 provides an ac voltage to the coil 305.

The controller 301 calculates the inductance of the coil 305 according to the acquired current at the output end of the coil 305, specifically, the following formula is shown:

L＝udt/di (1)

in equation (1), L is the inductance of the coil 305, u is a preset ac voltage, t is time, and i is the current at the output terminal of the coil 305.

Then, the controller 301 obtains the actual displacement of the coil corresponding to the inductance from the correspondence between the inductance and the actual displacement of the coil obtained by calibration through the test in advance.

The correspondence between the above inductance and the actual displacement of the coil is stored in the memory of the electronic device and is called when the controller 301 is used.

In some embodiments, the correspondence between inductance and actual displacement of the coil may be stored in the form of a data table. For example, when the inductance is L1, the actual displacement of the coil is d1, when the inductance is L2, the actual displacement of the coil is d2, …, and when the inductance is Ln, the actual displacement of the coil is dn, the stored correspondence is (L1, d 1), (L2, d 2), …, (Ln, dn).

The actual displacement of the coil obtained through the above process is the displacement generated by the actual movement of the coil 305, and the displacement already covers the displacement of the coil 305 and the lens caused by gravity and other factors.

From the above description, the coil displacement corresponding to the direct current voltage refers to the corresponding coil displacement that the control direct current voltage can generate in an ideal case. I.e. the coil displacement corresponding to the dc voltage does not take into account the offset due to gravity etc.

The actual displacement of the coil obtained by the controller 301 according to the inductance may be different from the displacement of the coil corresponding to the dc voltage due to the influence of the environment in which the lens is located at the time of actual photographing.

The controller 301 can determine the position of the lens from the actual displacement of the coil obtained by the above-described process.

Because the relative position of the coil and the lens is unchanged, the coil can drive the lens to move when moving. Therefore, by determining the actual displacement of the coil, i.e. the displacement of the lens, the position of the lens can be determined.

In another possible implementation, since the relative positions of the coil and the lens are fixed, after determining the relative positions of the coil and the lens, the displacement of the coil may be converted into the position of the lens, so the data table stored in the above memory may also be a corresponding relationship between the inductance and the position of the lens.

For example, when the inductance is L1, the lens position is L1, when the inductance is L2, the lens position is L2, …, and when the inductance is Ln, the lens position is Ln, the stored correspondence is (L1, L1), (L2, L2), …, (Ln, ln) by test calibration.

From the above description, it is determined that the coil 305 stops moving, that is, it is determined that the coil 305 reaches the first position, which is a trigger condition that the controller 301 supplies the coil 305 with the driving voltage superimposed with the preset alternating voltage.

The following are two implementations of determining that the coil 305 stops moving, that is, an implementation of determining that the coil 305 reaches the first position, provided in this embodiment.

The first implementation mode:

the controller 301 provides a dc voltage to the coil 305 and determines that the coil 305 stops moving after a predetermined period of time, that is, determines that the coil 305 reaches the first position.

In some embodiments, the predetermined period corresponds to a dc voltage, and is determined according to a pre-calibrated correspondence between the predetermined period and the dc voltage. The correspondence relation indicates that the coil 305 is moved by the driving of the direct current voltage, and the movement of the coil 305 is stopped within a preset period corresponding to the direct current voltage.

For example, when the dc voltage is V1, the preset period is T1, indicating that the coil 305 stops moving during the preset period T1 when the coil 305 is driven to move in the magnetic field with the dc voltage V1 during the preset period T1.

For example, the controller 301 supplies the dc voltage V to the coil 305 at time t0, and the controller 301 supplies the dc voltage superimposed ac voltage to the coil 305 after the preset period t reaches time t 1. The preset time period t corresponding to the direct current voltage V is obtained according to the corresponding relation between the preset time period and the direct current voltage, and the corresponding relation is calibrated in advance.

According to the corresponding relation between the preset time period and the direct current voltage, the preset time period corresponding to the current direct current voltage is determined, and after the controller 301 supplies the direct current voltage for the preset time period, the coil 305 is determined to stop moving.

Because the corresponding relation between the preset time period and the direct current voltage is calibrated in advance, when the coil is determined to stop moving, only the preset time period corresponding to the current direct current voltage is required to be acquired, and other extra calculation is not required, so that the method is simple, convenient and efficient.

The second implementation mode:

the controller 301 provides a dc voltage to the coil 305 and determines that the coil 305 stops moving when the current at the output of the coil 305 is unchanged, i.e. the coil 305 reaches the first position.

When the voltage across the coil 305 is a constant dc voltage, the current of the coil 305 is typically constant.

However, when the energized coil 305 moves in the magnetic fields of the first magnet 303 and the second magnet 304, the magnetically induced wire is cut, and an electromotive force is generated in the coil 305, and the electromotive force is in the opposite direction to the direct current voltage.

Thus, the current of the coil 305 is not constant during the movement of the coil 305.

When the movement of the coil 305 is stopped, the electromotive force generated by the coil 305 cutting the magnetic induction line disappears, and thus the current of the coil 305 remains unchanged.

Thus, when the current at the output of the coil 305 is unchanged, it can be determined that the coil 305 stops moving, i.e. that the coil 305 reaches the first position.

In one possible implementation, after determining the lens position according to the actual displacement of the coil, the target lens position may also be obtained according to the coil displacement determined by the dc voltage; and comparing the lens position with the target lens position, and adjusting the lens position to the target lens position according to the difference of the lens position and the target lens position.

The lens position determined according to the actual displacement of the coil refers to the displacement of the lens generated in the actual shooting process, and the displacement covers the deflection of the coil and the lens under the factors of gravity and the like; the target lens position does not take into account the offset of the coil and lens due to gravity or the like.

By comparing the lens position with the target lens position, the lens position is adjusted to the target lens position according to the difference between the lens position and the target lens position, for example, the lens is compensated and moved, and the automatic focusing function of the lens is realized.

In the detection system provided by the embodiment of the application, the coil surrounds the outside of the magnetic core, namely, the magnetic core is nested in the hollow position inside the coil, and the position of the magnetic core is fixed. When the coil is controlled to move through direct-current voltage, relative movement occurs between the coil and the magnetic core, and the inductance of the coil is changed.

When the coil is determined to stop moving, the alternating current voltage is superposed with the direct current voltage and output to the coil. Calculating to obtain the inductance of the coil through the current of the coil output end; then, according to the corresponding relation between the inductance calibrated in advance and the actual displacement of the coil, the actual displacement of the coil is obtained; since the relative positions of the coil and the lens are fixed, the lens position can be determined from the actual displacement of the coil.

In summary, in the detection system provided in the embodiment of the present application, the magnetic core is added to the VCM, and the coil surrounds the outside of the magnetic core, so as to realize detection of the lens position.

Compared with the mode of realizing lens position feedback by adding the Hall element, the detection system provided by the embodiment of the application has the advantages that the device size is not excessively increased in the direction of the optical axis and the direction perpendicular to the optical axis, so that the structural limitation on the camera module is reduced.

In addition, because the magnetic core is lower in cost than the Hall element, the detection system provided by the embodiment of the application can reduce the cost of a device for detecting the position of the lens.

In the above embodiment, after the inductance of the coil is obtained, the actual displacement of the coil is determined according to the correspondence between the inductance calibrated in advance through the test and the actual displacement of the coil.

The manner in which the correspondence between inductance and actual displacement of the coil is calibrated is specifically described below with reference to the accompanying drawings.

The lens position detection system provided in the above embodiment can be used to realize the following ways of calibrating the correspondence between the inductance and the actual displacement of the coil.

With continued reference to fig. 3A, the specific structure of the detection system is referred to in the description corresponding to fig. 3A, and the embodiments of the present application will not be described herein.

As is known from the principle of VCM for moving a movable member, there is a correspondence between the dc voltage for driving the movement of the coil 305 and the displacement generated by the movement of the coil 305, that is, the correspondence between the dc voltage and the coil displacement.

The correspondence relationship between the dc voltage and the coil displacement is pre-stored for the electronic device capable of realizing lens movement by the VCM.

In some embodiments, the correspondence between the dc voltage and the coil displacement may be stored in the form of a data table.

For example, when the dc voltage is V1, the coil displacement is d '1, when the dc voltage is V2, the coil displacement is d'2, …, and when the dc voltage is Vn, the coil displacement is d 'n, and the stored correspondence is (V1, d' 1), (V2, d '2), …, (Vn, d' n).

For example, when the controller 301 outputs the dc voltage V1 to drive the coil 305 to move, the displacement of the coil generated by the driving of the dc voltage V1 can be obtained as d'1 according to the pre-stored correspondence relationship between the dc voltage and the coil displacement.

When the movement of the coil 305 is stopped, the controller 301 outputs a preset ac voltage to the coil 305.

The implementation of determining the stop of the movement of the coil 305 is the same as that described in the above embodiments, and will not be described here again.

During movement of the coil 305, relative movement between the coil 305 and the magnetic core 306 causes a change in the inductance of the coil 305 and thus a change in the current at the output of the coil 305.

At this time, the current at the output end of the coil 305 is obtained, and the inductance corresponding to the displacement generated by the movement of the coil 305 can be obtained by performing calculation using equation (1).

The controller 301 obtains the corresponding inductances when the coil 305 generates different displacements by outputting different direct current voltages, and can complete the calibration of the corresponding relationship between the inductances and the actual displacement of the coil.

Referring to fig. 3D, fig. 3D is a graph of correspondence between inductance and actual displacement of a coil provided in an embodiment of the present application.

In fig. 3D, the horizontal axis represents the inductance obtained through the above process, the vertical axis represents the actual displacement of the coil corresponding to different inductances, and a good positive correlation exists between the actual displacement of the coil and the inductance.

Therefore, the correspondence obtained through the above calibration process can be used for detecting the lens position in the above embodiment.

In some embodiments, the corresponding relationship between the inductance and the actual displacement of the coil may be stored in the form of a data table, and the specific manner is described above, which is not repeated here.

In summary, the method for calibrating the correspondence between the inductance and the actual displacement of the coil provided in the embodiment of the present application can be completed by the lens position detection system provided in the above embodiment, without adding additional structure.

In another possible implementation, the data table stored in the above memory may also be a correspondence between inductance and lens position, due to the fixed relative positions of the coil and lens.

In order to calibrate the corresponding relation between the inductance and the lens position, the inductance of the coil can be obtained by calculating according to the obtained current of the output end of the coil by using the formula (1).

The direct current voltage at two ends of the control coil is used for controlling the coil to drive the lens to move, so that different lens positions are obtained, and the calibration of the corresponding relation between the inductance and the lens positions can be completed.

In the above embodiment, the lens position is determined based on the correspondence between the inductance and the displacement/position.

Another implementation of determining the lens position based on the correspondence of current and displacement/position is described below.

The controller 301 outputs a dc voltage to move the coil 305.

When it is determined that the coil 305 stops moving, the controller 301 outputs a direct-current voltage superimposed alternating-current voltage to the coil 305.

And superposing alternating voltage output on the direct voltage, wherein the effective value of the voltage is kept unchanged.

For the implementation of determining that the coil 305 stops moving, the same as that described in the above embodiment is not repeated here.

Since the magnetic core 306 is fixed, there is relative movement between the coil 305 and the magnetic core 306 during movement, resulting in a change in inductance of the coil 305.

At this time, since the inductance of the coil 305 changes, the current at the output terminal of the coil 305 changes.

The controller 301 obtains the actual displacement of the coil corresponding to the current according to the correspondence between the current obtained by the test calibration in advance and the actual displacement of the coil.

In some embodiments, the current may be the magnitude or frequency of the current at the output of the coil 305 in the correspondence between the above current and the actual displacement of the coil, taking into account the change in inductance of the coil 305, which may result in a change in the magnitude or frequency of the current at the output of the coil 305.

The correspondence between the above current and the actual displacement of the coil may be stored in a memory of the electronic device, and invoked when the controller 301 is used.

In some embodiments, the correspondence between the current and the actual displacement of the coil may be stored in the form of a data table. For example, when the current is i1, the actual displacement of the coil is d1, when the inductance is i2, the actual displacement of the coil is d2, …, and when the current is in, the actual displacement of the coil is dn, the stored correspondence is (i 1, d 1), (i 2, d 2), …, (in, dn).

The actual displacement of the coil obtained through the above process is the displacement actually generated by the coil 305, and the displacement already covers the offset of the coil 305 and the lens caused by gravity and other factors; the coil displacement corresponding to the dc voltage refers to the coil displacement corresponding to the dc voltage that can be generated by controlling the voltage value of the dc voltage in an ideal case, that is, the coil displacement corresponding to the dc voltage does not consider the offset caused by gravity and other factors.

The controller 301 determines the position of the lens based on the actual displacement of the coil obtained by the above-described process.

In summary, the lens position is determined based on the correspondence between the current and the displacement/position, so that the current at the output end of the coil can be directly utilized, and the inductance of the coil is not required to be obtained through current calculation, thereby simplifying the processing process.

In another possible implementation, since the relative positions of the coil and the lens are fixed, the displacement of the coil may be converted into the position of the lens after determining the relative positions of the coil and the lens.

Therefore, the data table stored in the above memory may be a correspondence relationship between the current and the lens position.

For example, when the current is i1, the lens position is l1, when the current is i2, the lens position is l2, …, and when the current is in, the lens position is ln, the stored correspondence is (i 1, l 1), (i 2, l 2), …, (in, ln) by test calibration.

In the above embodiment, after the current at the output end of the coil is obtained, the actual displacement of the coil is determined according to the corresponding relationship between the current calibrated by the test in advance and the actual displacement of the coil. The manner of calibrating the correspondence between the current and the actual displacement of the coil is specifically described below with reference to the accompanying drawings.

The lens position detection system provided in the above embodiment can be used to realize the following ways of calibrating the correspondence between the current and the actual displacement of the coil.

According to the principle that the VCM realizes the movement of the movable member, there is a correspondence between the direct current driving the coil movement and the displacement generated by the coil movement, that is, the correspondence between the direct current voltage and the coil displacement.

In order to realize the movement of the lens by the VCM, the correspondence relationship between the dc voltage and the coil displacement is stored in the memory of the electronic device.

In some embodiments, the correspondence between the dc voltage and the coil displacement may be stored in the form of a data table. For example, when the voltage value of the dc voltage is V1, the coil displacement is d '1, when the voltage value of the dc voltage is V2, the coil displacement is d'2, …, and when the voltage value of the dc voltage is Vn, the coil displacement is d 'n, and the stored correspondence is (V1, d' 1), (V2, d '2), …, (Vn, d' n).

The controller 301 outputs a dc voltage to drive the coil 305 to move, for example, the controller 301 outputs a dc voltage V1.

According to the pre-stored corresponding relation between the direct-current voltage and the coil displacement, the displacement generated by the coil under the drive of the direct-current voltage V1 can be obtained to be d'1.

When the movement of the coil 305 is stopped, the controller 301 outputs an ac voltage superimposed on the ac voltage to the coil 305.

At this time, the current at the output of the coil 305 is obtained.

The controller 301 outputs different direct current voltages to obtain the current of the coil 305 when the coil generates different displacements, and thus the calibration of the corresponding relation between the current and the actual displacement of the coil can be completed.

In some embodiments, the correspondence between the current and the actual displacement of the coil may be stored in the form of a data table, and the specific manner is described above, which is not repeated here.

In summary, the manner of the corresponding relationship between the calibration current and the actual displacement of the coil provided in the embodiment of the present application can be completed by the lens position detection system provided in the above embodiment, without adding additional structure.

In another possible implementation, the data table stored in the above memory may also be a correspondence between current and lens position.

Because the relative position of the coil and the lens is unchanged, the coil can drive the lens to move when moving. Therefore, by determining the actual displacement of the coil, i.e. the displacement of the lens, the lens position can be determined.

In order to calibrate the corresponding relation between the current and the lens position, the direct current voltage at two ends of the coil is controlled to obtain the current at the output end of the corresponding coil when the coil drives the lens to move to obtain different lens positions, so that the corresponding relation between the current and the lens position can be calibrated.

The technical scheme provided by the application can be applied to correction of lens optical axis offset in electronic equipment besides being applied to the scene of electronic equipment lens automatic focusing in the embodiment.

Referring to fig. 4, fig. 4 is a schematic structural diagram of a lens position detection system according to another embodiment of the present disclosure.

The direction along the optical axis is denoted as the z-axis direction, and the directions perpendicular to the optical axis are the x-axis direction and the y-axis direction, respectively.

In the above-described embodiments, the detection system applied to the lens position in the scene of the electronic device lens auto-focusing is used to detect the lens position along the optical axis direction, that is, the z-axis direction.

In order to correct the shift of the optical axis of the lens in the electronic device, the detection system in the embodiment of the present application is used to detect the position of the lens perpendicular to the optical axis direction, that is, the x-axis and/or y-axis direction.

The detection system 400 includes a controller and a detection module, where the detection module includes a first magnet, a second magnet, a coil, and a magnetic core.

The coil is positioned in a magnetic field formed by the first magnet and the second magnet, the relative position of the coil and the lens is fixed, the coil surrounds the outside of the magnetic core, and the position of the magnetic core is fixed;

the controller is used for controlling the driving voltage of the coil to be a first voltage, controlling the driving voltage of the coil to be a second voltage when the coil is determined to reach the first position, determining the displacement of the coil by utilizing the current of the output end of the coil, determining the position of the lens according to the displacement of the coil, wherein the first voltage is a direct current voltage, the second voltage is an alternating current voltage, and the effective values of the second voltage and the first voltage are the same.

For the specific structure of the detection system, refer to the corresponding description of fig. 3A, and the embodiments of the present application are not repeated here.

The present embodiment will be described with reference to an example in which a detection system is used to detect the lens position in the y-axis direction.

When the driving voltage of the coil is controlled to be the first voltage, that is, the dc voltage by the controller, the coil drives the lens 401 to move along the y direction. As shown in fig. 4, the coil drives the lens 401 to move along the y direction by a displacement d. In fig. 4, the moved lens is indicated by a dashed box below the lens 401. At this time, the optical axis direction of the lens 401 moves from the first optical axis position to the second optical axis position.

From the above description, it can be understood that the displacement of the coil to move the lens 401 corresponds to the first voltage.

When the coil movement is stopped, the controller outputs alternating voltage to the coil.

The controller is also used for acquiring the current of the output end of the coil, and the position of the lens can be obtained according to the acquired current, and the specific principle is described above.

Because the difference between the present embodiment and the above embodiment is that the coil drives the lens to generate displacement in different directions, the specific principle of the detection system provided in the present embodiment for realizing the detection of the position of the lens in the y-axis direction is not repeated.

Embodiments of the present application are not limited to cores having a hollow structure, for example, cores may also have a solid structure.

It can be understood that the magnetic core is nested in the hollow position inside the coil, so that when the coil moves, the coil and the magnetic core move relatively, and the detection of the position of the lens in the y-axis direction can be completed.

The basic principle of the detection system in the embodiment of the present application for detecting the position of the lens in the x direction is similar to that described above for the y direction, and will not be described here again.

Similar to the description in the above embodiments, in some embodiments, in order to realize detection of a lens position in a corrected optical axis shift scene, in a memory of an electronic device, one of a correspondence of an inductance and a coil actual displacement, a correspondence of an inductance and a lens position, a correspondence of a current and a coil actual displacement, or a correspondence of a current and a lens position is stored.

The implementation manner of determining the actual moving distance of the coil according to the above corresponding relationship, thereby determining the lens position, or directly determining the lens position according to the above relationship is described in the above embodiment, and will not be described herein.

Similar to the description in the above embodiments, the implementation manner of the calibration of the correspondence between the inductance and the actual displacement of the coil, the correspondence between the inductance and the lens position, the correspondence between the current and the actual displacement of the coil, or the correspondence between the current and the lens position is also described in the above embodiments, and will not be described herein again.

In summary, in order to implement the lens auto-focusing function, the electronic device generally includes a VCM. In order to realize correction of optical axis offset of a lens, a magnetic core is added in a VCM, and the magnetic core is nested in a hollow position of a coil, so that detection of the position of the lens is realized.

Compared with the mode of realizing lens position feedback by adding the Hall element, the detection system provided by the embodiment of the application is utilized, and the size of a device is not excessively increased in the optical axis direction, so that the structural limitation on the camera module is reduced.

Based on the detection system of the lens position provided in the above embodiment, the embodiment of the present application further provides a voice coil motor, which is specifically described below with reference to the accompanying drawings.

Referring to fig. 5, fig. 5 is a schematic structural diagram of a voice coil motor according to an embodiment of the present application.

As shown in fig. 5, the voice coil motor 500 includes a first magnet 501, a second magnet 502, a coil 503, and a core 504.

The coil 503 is located in a magnetic field formed by the first magnet 501 and the second magnet 502, the relative position of the coil 503 and the lens is fixed, the coil 503 surrounds the outside of the magnetic core 504, and the position of the magnetic core 504 is fixed.

The coil is used for generating displacement corresponding to the external driving voltage when the external driving voltage is applied.

Compared to moving coil VCMs commonly found in electronic devices today, the voice coil motor provided in the embodiments of the present application has a fixed position magnetic core 504 nested within the coil.

The structural schematic diagrams of the components of the voice coil motor 500 and the sectional structural diagram of the assembly of the voice coil motor 500 provided in the embodiment of the present application are shown in fig. 3B and 3C.

The structure of VCM assembly provided in the embodiment of the present application and the structure of fig. 1F are different from each other in that: a fixed core is nested within the coil, which can be positioned between the magnetic member 142 and the lens 12, which is nested within the hollow structure of the core.

Referring to the explanation of the VCM principle in the above embodiment, when the coil 503 is driven by the dc voltage, the coil 503 and the core 504 are relatively moved.

When the voice coil motor 500 is used for moving a movable component, such as a lens, the relative positions of the coil 503 and the lens are fixed, and the movement of the coil 503 can drive the lens to move, so as to realize adjustment of the position of the lens.

When the coil 503 is moved to the first position by the drive of the dc voltage, the drive voltage of the control coil 503 becomes the same ac voltage as the dc voltage effective value.

At this time, the inductance of the coil 503 is changed due to the relative movement of the coil 503 and the core 504, and the displacement of the coil 503 can be determined by the current at the output end of the coil 503, thereby determining the position of the lens.

The specific principles of the above implementation manner have been described in the above embodiments, and this embodiment is not repeated here.

In summary, by using the voice coil motor of the embodiment of the present application, adjustment and determination of a lens position can be achieved, and without using a hall sensor, hardware cost can be reduced, and occupied space can be reduced.

In one possible implementation, the magnetic core 504 may have a hollow structure.

When voice coil motor 500 is used in an imaging module, the lens may be nested at the hollow structure of core 504. Since the coil 503 is surrounded on the outside of the magnetic core 504, the lens module has a structure of coil 503-magnetic core 504-lens nesting from the outside to the inside, so that the size of the whole camera module can be reduced.

The embodiment of the application also provides a method for detecting the lens position, which is applied to the detection module in the embodiment.

The detection module comprises a first magnet, a second magnet, a coil and a magnetic core, wherein the coil is positioned in a magnetic field formed by the first magnet and the second magnet, the relative position of the coil and a lens is fixed, the coil surrounds the outside of the magnetic core, and the position of the magnetic core is fixed. The following is a detailed description with reference to the accompanying drawings.

Referring to fig. 6, fig. 6 is a flowchart of a method for detecting a lens position according to an embodiment of the present application.

The detection method comprises S101-S103.

S101, controlling the driving voltage of a coil to be a first voltage so as to enable the coil and a magnetic core to move relatively, wherein the first voltage is a direct current voltage;

s102, when the coil is determined to reach the first position, controlling the driving voltage of the coil to be a second voltage, wherein the second voltage is an alternating voltage, and the effective value of the first voltage is the same as that of the second voltage;

s103, determining the position of the lens by using the current of the output end of the coil.

When the driving voltage of the control coil is a first voltage, and the first voltage is a direct current voltage, the energized coil moves under the action of ampere force when being in a magnetic field formed by the magnet.

Because the relative positions of the coil and the lens are fixed, the coil moves to drive the lens to move.

Since the core is stationary, there is relative movement between the coil and the core during movement of the coil, which can result in a change in inductance of the coil.

When the coil reaches the first position, it indicates that the coil stops moving, that is, the coil reaches the first position and stops moving under the drive of the first voltage.

Since the inductance of the coil changes, when the driving voltage of the control coil is the second voltage, that is, the ac voltage having the same effective value as the first voltage, the current at the output terminal of the coil changes.

Since the current at the output end of the coil changes along with the change of the inductance of the coil, the inductance of the coil is related to the displacement of the coil, and the relative positions of the coil and the lens are fixed, the position of the lens can be determined according to the current at the output end of the coil.

The embodiment of the application also provides another method for detecting the lens position, which is applied to the detection module in the above embodiment, namely the detection module in the embodiment corresponding to fig. 2.

The detection module comprises a first magnet, a second magnet, a coil and a magnetic core, wherein the coil is positioned in a magnetic field formed by the first magnet and the second magnet, the relative position of the coil and a lens is fixed, the coil surrounds the outside of the magnetic core, and the position of the magnetic core is fixed.

The following is a detailed description with reference to the accompanying drawings.

Referring to fig. 7, fig. 7 is a flowchart of a method for detecting a lens position according to another embodiment of the present application.

The method includes S201-S206.

S201, outputting direct-current voltage to enable the coil to move so as to enable the coil and the magnetic core to move relatively.

The principle of the relative movement between the coil and the magnetic core is described in the above embodiments, and will not be described herein.

S202, after the coil movement is determined to be stopped, a preset alternating voltage output is overlapped on the direct voltage.

And superposing a preset alternating voltage on the direct current voltage to output, wherein the effective value of the voltage is kept unchanged.

The implementation manner of determining the coil movement stop in S202 has been described in the above embodiments, and the embodiments of the present application are not described herein.

S203, detecting the current of the output end of the coil.

In S203, the inductance of the coil changes due to the relative movement between the coil and the magnetic core during the movement of the coil. When an ac voltage is supplied to the coil, the current at the output of the coil changes.

S204, calculating the inductance of the coil according to the detected current.

In some embodiments, the manner in which the inductance of the coil is calculated from the current may be implemented according to equation (1). Specific implementation manner is described in the foregoing embodiments, and the embodiments of the present application are not repeated herein.

S205, obtaining the actual displacement of the coil according to the corresponding relation between the inductance calibrated in advance and the actual displacement of the coil.

In some embodiments, the correspondence between the inductance and the actual displacement of the coil may be stored in the form of a data table, and the specific manner is described in the above embodiments, which is not repeated here.

S206, determining the lens position according to the actual displacement of the coil.

The effects that each step in the above method can play and the implementation manner corresponding to each step have been described in the above embodiments, so that the embodiments of the present application are not described herein again.

Since the positions of the coil and the lens are fixed, the corresponding relationship according to which the position of the lens is determined after the inductance of the coil is obtained in S204 may be the corresponding relationship between the inductance and the position of the lens.

In another possible implementation, after the inductance of the coil is obtained in S204, the position of the lens is obtained according to the correspondence between the inductance and the lens position calibrated in advance.

Through the corresponding relation of the pre-calibrated inductor and the lens position, the lens position can be directly obtained according to the inductor without determining the actual displacement of the coil, and then the lens position is determined through the actual displacement of the coil, so that the processing process can be simplified.

In the above embodiment, it is determined that the coil movement stop is an out-triggering condition that the ac voltage output is superimposed on the dc voltage. To determine that the coil movement is stopped, i.e., that the coil 305 reaches the first position, embodiments of the present application provide the following two implementations, see fig. 8 and 9.

Referring to fig. 8, fig. 8 is a flowchart of a method for detecting a lens position according to another embodiment of the present application.

The method is applied to the detection module in the corresponding embodiment of fig. 2, and the method comprises S301-S306.

S301, outputting direct-current voltage to enable the coil to move so as to enable the coil and the magnetic core to move relatively.

S302, after the output direct-current voltage continues for a preset period, the preset alternating-current voltage is superposed on the direct-current voltage for output, and the preset period is obtained according to the corresponding relation between the preset period and the direct-current voltage which are calibrated in advance.

In S302, a preset ac voltage output is superimposed on the dc voltage, and the effective value of the voltage remains unchanged.

The preset time period corresponds to the direct current voltage and is determined according to the corresponding relation between the preset time period and the direct current voltage, which are calibrated in advance. The correspondence relationship indicates that the coil is driven to move by the direct current voltage, and the coil stops moving within a preset period corresponding to the direct current voltage.

S303, detecting the current of the output end of the coil.

S304, calculating the inductance of the coil according to the detected current.

S305, obtaining the actual displacement of the coil according to the corresponding relation between the inductance and the actual displacement of the coil, which are calibrated in advance.

S306, determining the lens position according to the actual displacement of the coil.

The effects that each step in the above method can play, and the implementation manner corresponding to each step, have been described in the above embodiments, and the embodiments of the present application are not described herein again.

And determining a preset time period corresponding to the current direct current voltage according to the corresponding relation between the preset time period and the direct current voltage, and determining that the coil stops moving after the direct current voltage continues for the preset time period.

Since the positions of the coil and the lens are fixed, after the inductance of the coil is obtained in S304, the correspondence relationship according to which the position of the lens is determined may also be the correspondence relationship between the inductance and the position of the lens.

In another possible implementation, after the inductance of the coil is obtained in S304, the position of the lens is obtained according to the correspondence between the inductance and the lens position calibrated in advance.

Referring to fig. 9, fig. 9 is a flowchart of a method for detecting a lens position according to another embodiment of the present application.

The method is applied to the detection module in the corresponding embodiment of fig. 2, and the method comprises S401-S406.

S401, outputting direct-current voltage to enable the coil to move so as to enable the coil and the magnetic core to move relatively.

S402, detecting the current of the output end of the coil.

S403, when the current at the output end of the coil is unchanged, the preset alternating voltage is superposed on the direct voltage for output.

When the voltage across the coil is a constant dc voltage, the current of the coil is a constant dc current.

However, when the energized coil moves in the magnetic fields of the first magnet and the second magnet, the magnetically induced wire is cut, and an electromotive force is generated in the coil, and the electromotive force has a direction opposite to the direction of the dc voltage.

Thus, the current of the coil is not constant during the movement of the coil.

When the coil stops moving, the electromotive force generated by the coil cutting the magnetic induction wire disappears, so that the current of the coil is not changed any more. Thus, when the current at the output of the coil is unchanged, it can be determined that the coil stops moving.

In some embodiments, when the magnitude of the current at the coil output remains unchanged, the current is characterized as unchanged at that time.

S404, calculating the inductance of the coil according to the detected current.

S405, obtaining the actual displacement of the coil according to the corresponding relation between the inductance and the actual displacement of the coil, which are calibrated in advance.

S406, determining the lens position according to the actual displacement of the coil.

Unexpected movement of the coil may occur due to other factors during movement. For example, during coil movement, the dc voltage used to drive the coil movement unexpectedly fluctuates, causing the coil to move irregularly.

In this case, the above-described manner of determining the stop of the movement of the coil can reduce the occurrence of erroneous results due to an occasional case.

Since the positions of the coil and the lens are fixed, after the inductance of the coil is obtained in S405, the correspondence relationship according to which the position of the lens is determined may be the correspondence relationship between the inductance and the position of the lens.

In another possible implementation, after the inductance of the coil is obtained in S405, the position of the lens is obtained according to the correspondence between the inductance and the lens position calibrated in advance.

Further, in order to obtain the corresponding relationship between the inductance and the actual displacement of the coil in S205, the embodiment of the present application further provides a calibration method for the corresponding relationship between the inductance and the actual displacement of the coil, where the method is applied to the detection module in the embodiment corresponding to fig. 2.

Referring to fig. 10, fig. 10 is a flowchart of a calibration method for a correspondence between inductance and actual displacement of a coil according to an embodiment of the present application.

The calibration method comprises S501-S505.

S501, outputting direct-current voltage to enable the coil to move so as to enable the coil and the magnetic core to move relatively.

S502, when the coil movement is determined to stop, a preset alternating voltage output is overlapped on the direct voltage.

S503, detecting the current of the output end of the coil.

S504, calculating the inductance of the coil according to the detected current.

S505, according to the inductance of the coil, based on the corresponding relation between the direct-current voltage and the coil displacement calibrated in advance, the corresponding relation between the inductance and the actual coil displacement is obtained.

According to the principle that the VCM realizes lens movement, there is a correspondence between the dc voltage used to drive the coil movement and the displacement generated by the coil movement, that is, the correspondence between the dc voltage and the coil displacement.

And after the coil movement is stopped, outputting a preset alternating voltage to the coil.

During the movement of the coil, the relative movement between the coil and the core causes a change in the inductance of the coil and thus a change in the current at the output of the coil.

At this time, the current at the output end of the coil is obtained, and the inductance of the coil is obtained by performing calculation using the formula (1).

And by outputting different direct-current voltages, the corresponding inductance is obtained when the coil generates different displacements, and the calibration of the corresponding relation between the inductance and the actual displacement of the coil can be completed.

In summary, the calibration method for the correspondence between the inductance and the actual displacement of the coil provided in the embodiment of the present application can be applied to the detection module in the lens position detection system provided in the above embodiment, without adding additional structure for completing the calibration process.

In one possible implementation, the correspondence between the inductance and the lens position may also be calibrated due to the fixed relative positions of the coil and the lens.

The embodiment of the application also provides another method for detecting the lens position, which is used for determining the lens position based on the corresponding relation between the current and the actual displacement of the coil, so that the current at the output end of the coil is directly utilized, and the inductance of the coil is not required to be obtained through current calculation, thereby simplifying the processing process.

Referring to fig. 11, fig. 11 is a flowchart of a method for detecting a lens position according to another embodiment of the present application.

The method is applied to the detection module in the corresponding embodiment of fig. 2, and the method comprises S601-S604.

S601, outputting direct-current voltage to enable the coil to move so as to enable the coil and the magnetic core to move relatively.

S602, when the coil movement is determined to stop, a preset alternating voltage output is overlapped on the direct voltage.

S603, detecting the current of the output end of the coil.

S604, according to the detected current, obtaining the lens position according to the corresponding relation between the current calibrated in advance and the lens position.

It will be appreciated that the method of determining the lens position based on the correspondence between the current and the actual displacement of the coil is similar to the method of determining the lens position based on the correspondence between the inductance and the actual displacement of the coil in the above-described embodiment.

Since the positions of the coil and the lens are fixed, in another possible implementation manner, after the current of the output end of the coil is obtained in S603, the process of determining the corresponding relationship according to the position of the lens may also be that the actual displacement of the coil is obtained according to the current of the output end of the coil, and then the position of the lens is determined according to the actual displacement of the coil.

Further, in order to obtain the correspondence between the current and the lens position in S604, the embodiment of the present application further provides a calibration method for the correspondence between the current and the lens position, where the method is applied to the detection module in the embodiment corresponding to fig. 2.

Referring to fig. 12, fig. 12 is a flowchart of a calibration method for a correspondence relationship between current and lens position according to an embodiment of the present application.

The calibration method comprises S701-S704.

S701, outputting direct-current voltage to enable the coil to move so as to enable the coil and the magnetic core to move relatively.

S702, after the coil movement is determined to be stopped, a preset alternating voltage output is overlapped on the direct voltage.

S703, detecting the current of the output end of the coil.

S704, according to the current of the output end of the coil, the corresponding relation between the current and the lens position is obtained based on the corresponding relation between the pre-calibrated direct-current voltage and the coil displacement.

When the coil movement is stopped, an alternating voltage is output to the coil.

The controller obtains corresponding currents when the coil generates different displacements by outputting different direct-current voltages, and the calibration of the corresponding relation between the currents and the actual displacement of the coil can be completed.

In summary, the calibration method for the correspondence between the current and the lens position provided in the embodiment of the present application can be applied to the detection module in the lens position detection system provided in the above embodiment, without adding additional structure for completing the calibration process.

In one possible implementation, the corresponding relationship between the inductance and the actual displacement of the coil can also be calibrated due to the fixed relative positions of the coil and the lens.

The structure of the VCM in the above embodiment is realized based on the principle of moving coil VCM, that is, in the VCM, when the positions of the two magnets are fixed and the relative positions of the coil and the lens are fixed, the coil is utilized to receive ampere force in the magnetic fields of the two magnets to move, so as to drive the lens to move, thereby changing the position of the lens.

In addition, the embodiment of the application also provides a system for detecting the position of the lens, and the system for detecting the position of the lens is realized based on the principle of the moving-magnet VCM.

The principle of the moving-magnet VCM is first described herein.

The moving-magnet VCM includes a coil and a magnetic member. Unlike the moving coil VCM, in the moving coil VCM, the coil is fixed and the magnetic member is movable.

When the coil provides a direct current driving voltage, the current passing through the coil generates a magnetic field around the coil, and the magnetic component is positioned in the magnetic field and stressed to move under the action of the magnetic field.

Because the relative positions of the magnetic component and the lens are fixed, the movement of the magnetic component can drive the lens to move, so that the position of the lens is changed.

The moving coil VCM can be used for adjusting the position of the lens along the direction of the optical axis and the direction perpendicular to the optical axis, namely, the moving coil VCM can be applied to an automatic focusing scene of the lens and a correction scene of the optical axis deviation of the lens.

For moving-magnet VCM, the lens position is adjusted perpendicular to the optical axis, i.e. the moving-magnet VCM is applied to correcting the lens optical axis offset.

As shown in fig. 1C, the image pickup module 1 employs a VCM as a driving component for driving the lens 12 to move in a plane perpendicular to the optical axis direction thereof.

When the VCM is applied to correcting a scene of the optical axis offset of the lens, the magnetic component drives the lens to move to generate displacement actually due to the influence of the environment where the lens is actually located, and the displacement may be different from the preset displacement corresponding to the direct current voltage driving the VCM.

For example, when a dc driving voltage is provided to the coil, the magnetic component drives the lens to move to generate a predetermined displacement. When the whole lens is in an inclined state relative to the horizontal plane, the magnetic component and the lens generate certain offset under the action of gravity besides the preset displacement; or, the temperature during actual shooting can influence the movement of the lens, so that the magnetic component is influenced to drive the displacement actually generated by the lens.

When the displacement actually generated by the magnetic component driving the lens is different from the preset displacement corresponding to the current direct-current voltage driving the VCM, the correction of the optical axis offset of the lens is inaccurate.

Based on the detection method, the detection system for the lens position is further provided.

The following is a lens position detection system according to another embodiment of the present application.

Referring to fig. 13, fig. 13 is a schematic structural diagram of a lens position detection system according to another embodiment of the present disclosure.

The detection system 600 includes a controller 601 and a detection module 602.

The detection module 602 includes a magnetic component 603, a coil 604 and a magnetic core 605, where the coil 604 surrounds the magnetic core 605, and the relative positions of the magnetic component 603 and the magnetic core 605 are fixed.

The controller 601 is configured to control a driving voltage of the coil 604 to be a first voltage, and the first voltage is a dc voltage, so that the magnetic component 603 and the coil 604 move relatively.

Since the relative positions of the magnetic member 603 and the core 605 are fixed, at this time, the core 605 and the coil 604 are relatively moved.

Since the relative positions of the magnetic component 603 and the lens are fixed, the movement of the magnetic component 603 can drive the lens to move.

When it is determined that the magnetic member 603 reaches the first position, that is, it is determined that the magnetic member 603 stops moving, the controller 601 controls the driving voltage of the coil 604 to be a second voltage, the second voltage is an alternating voltage, and the effective values of the first voltage and the second voltage are the same.

As shown in fig. 13, the magnetic member 603 moves a distance d from the initial position to the first position.

Since the effective values of the first voltage and the second voltage are the same, when the magnetic member 603 reaches the first position, that is, the magnetic member 603 stops moving, the driving voltage of the control coil 604 becomes the second voltage, and the magnetic member 603 does not continue to move.

The controller 601 is also configured to obtain the current at the output of the coil 604.

The current at the output of coil 604 is related to the inductance of coil 604, i.e. to the displacement of magnetic component 603 relative to the movement of coil 604; further, since the relative positions of the magnetic member 603 and the lens are fixed, the position of the lens can be determined from the current at the output end of the coil 604.

By adopting the scheme provided by the application, the magnetic core is nested in the coil of the VCM, so that the detection of the lens position is realized, the Hall sensor is avoided, the hardware cost can be reduced, and the occupied space is reduced. In addition, by adopting the scheme provided by the application, waves with strong radiation can not appear in the process of determining the lens position, so that the imaging quality of the electronic equipment can not be influenced.

The following description is made in connection with specific implementations.

Since the magnetic field generated by the energized coil exists inside and outside the coil, the magnetic member may be located inside or outside the coil in order to move the magnetic member by the magnetic field.

In the following description, the magnetic member is described as being located inside the coil. The VCM can be reduced in size when the magnetic member is located inside the coil, i.e., when the coil is wrapped around the outside of the magnetic member.

Since the magnetic field generated by the energized coil exists inside and outside the coil, the magnetic member may still be in the magnetic field generated by the coil and move when subjected to a force, although it is located outside the coil.

Therefore, when the magnetic member is located outside the coil, the principle of determining the lens position is the same as when the magnetic member is located inside the coil, and thus, a description thereof will not be repeated.

The lens position detection system provided by the embodiment of the application is applied to the electronic equipment shown in fig. 1A.

As shown in fig. 13, the detection system 700 includes a controller 601 and a detection module 602.

The detection module 602 includes a magnetic component 603, a coil 604, and a magnetic core 605.

The coil 604 is wound around the core 605, the relative positions of the magnetic member 603 and the core 605 are fixed, and the magnetic member 603 is located inside the coil 604.

The controller 601 supplies a driving voltage to the coil 604.

Specifically, the controller 601 first supplies a direct current voltage to the coil 604 as a driving voltage.

The current in the coil 604 generates a magnetic field around the coil 604 by the driving of the dc voltage, so that the magnetic member 603 located in the magnetic field moves.

Because the relative positions of the magnetic component 603 and the lens are fixed, the magnetic component 603 will drive the lens to move when moving.

Since the relative positions of the magnetic part 603 and the core 605 are fixed, the relative positions of the magnetic part 603 and the lens are fixed, and in one possible implementation, the core 605 may be located on the lens.

In the embodiment of the present application, for the electronic device shown in fig. 1A, the lens module uses VCM as a driving component, and specifically includes a magnetic component 603, a coil 604, and a magnetic core 605.

The section of VCM assembly provided in the embodiment of the present application provided in this embodiment is different from the schematic section of VCM assembly in fig. 3B in that:

In fig. 3B, the positions of the first magnet 303, the second magnet 304, and the magnetic core 306 are fixed, and the magnetic core 306 is nested in a hollow position inside the coil 305; for the VCM provided in this embodiment, the coil 604 surrounds the core 605, the relative positions of the magnetic member 603 and the core 605 are fixed, and the magnetic member 603 is located inside the coil 604.

The VCM provided in the embodiment of the present application may be used as a driving component in a lens module, and the VCM provided in the embodiment of the present application may be assembled with a lens in the lens module to drive the lens to move in a plane perpendicular to an optical axis direction thereof.

Since the magnetic field generated by the energized coil 604 exists inside and outside the coil 604, the magnetic member 603 inside the coil 604 is in the magnetic field generated by the coil 604 and moves when force is applied.

When it is determined that the coil 604 stops moving, that is, when it is determined that the coil 305 reaches the first position, the controller 601 superimposes a preset ac voltage on the dc voltage and supplies the coil 604 with the driving voltage superimposed with the ac voltage. The driving voltage superimposed with the preset alternating voltage is the same as the effective value of the direct voltage.

The driving voltage on which the preset ac voltage is superimposed has the same effective value as the dc voltage so that the magnetic member 603 does not move by the driving of the coil 604 by the driving voltage on which the preset ac voltage is superimposed after the movement of the magnetic member 603 is stopped.

Specifically, in order that the coil 604 is driven by a driving voltage superimposed with a preset ac voltage, which may be an ac voltage having a small amplitude, the magnetic member 603 does not continue to move.

During the movement of the magnetic member 603, the force generated by the magnetic field of the coil 604 on the magnetic member 603 can be counteracted by the damping due to the damping, so that the magnetic member 603 does not continue to move when the coil 604 is driven by the driving voltage superimposed with the preset alternating voltage.

In order to maintain the magnetic member 603 at the above position after stopping the movement, it is necessary that the controller 601 continuously supplies the dc voltage to the coil 604 and keeps the effective value of the driving voltage the same as the dc voltage.

Since coil 604 is fixed, the relative positions of magnetic component 603 and core 605 are fixed. Thus, when the magnetic member 603 moves, the core 605 also moves, resulting in movement of the core 605 relative to the coil 604.

The core 605 moves relative to the coil 604 such that the inductance of the coil 604 changes. When the coil 604 is supplied with a driving voltage superimposed with a preset alternating voltage, the current at the output of the coil 604 changes, i.e., the current at the output of the coil 604 can reflect the inductance of the coil 604.

The controller 601 calculates the inductance of the coil 604 according to the acquired current of the output end of the coil 604, and the specific formula is as follows:

L＝udt/di (2)

in equation (2), L is the inductance of the coil 604, u is the preset ac voltage, t is the time, and i is the current at the output of the coil 604.

Therefore, the inductance of the coil 604 can be obtained from the current at the output end of the coil 604, and the displacement generated by the actual movement of the core 605 relative to the coil 604 can be obtained.

Since the relative positions of the magnetic member 603 and the core 605 are fixed, a displacement of the magnetic member 603 with respect to the actual movement of the coil 604, that is, an actual displacement of the magnetic member can be obtained from the current at the output end of the coil 604.

Then, the controller 601 obtains the actual displacement of the coil corresponding to the inductance from the correspondence between the inductance obtained by calibration through the test in advance and the actual displacement of the magnetic member.

The correspondence between the above inductance and the actual displacement of the magnetic component is stored in the memory of the electronic device and is called when the controller 601 is used.

In some embodiments, the correspondence between the inductance and the actual displacement of the magnetic component may be stored in the form of a data table. For example, when the inductance is L1, the actual displacement of the magnetic member is d1, when the inductance is L2, the actual displacement of the magnetic member is d2, …, and when the inductance is Ln, the actual displacement of the magnetic member is dn, the stored correspondence is (L1, d 1), (L2, d 2), …, (Ln, dn).

The actual displacement of the magnetic component obtained through the above process is the displacement actually generated by the magnetic component 603, and the displacement already covers the displacement of the magnetic component 603 and the lens caused by gravity and other factors.

From the above description, the displacement of the magnetic member corresponding to the direct current voltage refers to the displacement of the corresponding magnetic member which is ideally generated by controlling the direct current voltage. I.e. the displacement of the magnetic component corresponding to the dc voltage does not take into account the offset due to gravity etc.

The actual displacement of the magnetic member by the controller 601 according to the inductance may be different from the displacement of the magnetic member corresponding to the dc voltage due to the influence of the environment in which the lens is located at the time of actual photographing.

The controller 601 can determine the position of the lens from the actual displacement of the magnetic member obtained by the above-described process.

Because the relative positions of the magnetic component and the lens are fixed, the magnetic component can drive the lens to move when moving. Therefore, by determining the actual displacement of the magnetic member, i.e., the displacement of the lens, the position of the lens can be determined.

In another possible implementation, since the relative positions of the magnetic component and the lens are fixed, after determining the relative positions of the magnetic component and the lens, the displacement of the magnetic component may be converted into the position of the lens, so the data table stored in the above memory may also be a correspondence relationship between the inductance and the position of the lens.

From the above description, it is determined that the magnetic member 603 stops moving, that is, it is determined that the coil 305 reaches the first position, which is a trigger condition that the controller 601 supplies the coil 604 with the driving voltage superimposed with the preset alternating voltage.

The following are two implementations of determining that the magnetic member 603 stops moving, that is, determining that the magnetic member 603 reaches the first position, provided in this embodiment.

The first implementation mode:

the controller 601 supplies a dc voltage to the coil 604 for a preset period of time, i.e. determines that the magnetic part 603 has reached the first position.

In some embodiments, the predetermined period corresponds to a dc voltage, and is determined according to a pre-calibrated correspondence between the predetermined period and the dc voltage. The correspondence relation described above shows that when the direct current voltage is supplied to the coil 305, the magnetic member 603 moves, and the magnetic member 603 stops moving within a preset period corresponding to the direct current voltage.

For example, when the direct current voltage is V1, the preset period is T1, indicating that the magnetic member 603 stops moving during the preset period T1 when the coil 604 is driven with the direct current voltage V1 and the magnetic member 603 moves in the magnetic field generated by the energized coil 604.

For example, the controller 601 supplies the coil 305 with the dc voltage V at time t0, and the controller 601 supplies the coil 604 with the dc voltage superimposed ac voltage after a preset period t reaches time t 1. The preset time period t corresponding to the direct current voltage V is obtained according to the corresponding relation between the preset time period and the direct current voltage, and the corresponding relation is calibrated in advance.

According to the corresponding relation between the preset time period and the direct current voltage, the preset time period corresponding to the current direct current voltage is determined, and after the controller 601 supplies the direct current voltage for the preset time period, the magnetic component 603 is determined to stop moving.

Because the corresponding relation between the preset time period and the direct current voltage is calibrated in advance, when the magnetic component is determined to stop moving, only the preset time period corresponding to the current direct current voltage is required to be acquired, and other extra calculation is not required, so that the method is simple, convenient and efficient.

The second implementation mode:

the controller provides a first voltage to the coil and determines that the magnetic component stops moving when the current at the output end of the coil is unchanged, i.e. the magnetic component reaches the first position.

When the voltage across the coil is a constant dc voltage, the current of the coil is typically a constant current.

However, when a magnetic field is generated around the energized coil, the magnetic member moves in the magnetic field. Since the position of the coil is fixed, a relative motion is generated between the coil and the magnetic member, so that the energized coil cuts the magnetic induction line in the magnetic field generated by the magnetic member, and the coil cuts the magnetic induction line to generate electromotive force.

Therefore, during the movement of the magnetic component, the coil cuts the electromotive force generated by the magnetic induction wire, so that the current passing through the coil is variable.

When the magnetic member stops moving, the electromotive force generated by the coil cutting the magnetic induction wire disappears, and thus the current of the coil is not changed any more.

Thus, when the current at the output of the coil is unchanged, it can be determined that the magnetic component stops moving, i.e. that the magnetic component reaches the first position.

Unexpected movement of the magnetic component may occur due to other factors during movement. For example, during movement of the magnetic component, the first voltage across the coil accidentally fluctuates, causing the magnetic component to move irregularly. In this case, the above-described manner of determining the stop of the movement of the magnetic member can reduce the occurrence of erroneous results due to an occasional case.

In one possible implementation, after determining the lens position according to the actual displacement of the magnetic component, the target lens position may also be obtained according to the displacement of the magnetic component determined by the dc voltage; and comparing the lens position with the target lens position, and adjusting the lens position to the target lens position according to the difference of the lens position and the target lens position.

The lens position determined according to the actual displacement of the magnetic component refers to the displacement of the lens generated in the actual shooting process, and the displacement covers the deflection of the magnetic component and the lens under the factors of gravity and the like; the target lens position does not take into account the offset of the magnetic component and the lens due to gravity or the like.

By comparing the lens position with the target lens position, the lens position is adjusted to the target lens position according to the difference between the lens position and the target lens position, for example, the lens is compensated and moved, and the optical axis offset of the lens is corrected more accurately.

In the detection system provided by the embodiment of the application, the coil surrounds the outside of the magnetic core, and the position of the coil is fixed. When the magnetic component is controlled to move by controlling the driving voltage of the coil to be direct-current voltage, the magnetic core and the magnetic component are fixed in relative position, so that the coil and the magnetic core relatively move, and the inductance of the coil is changed. When it is determined that the magnetic part stops moving, a preset alternating voltage is added to a direct voltage and output to the coil. Calculating to obtain the inductance of the coil through the current of the coil output end; then, according to the corresponding relation between the inductance calibrated in advance and the actual displacement of the magnetic component, the actual displacement of the magnetic component is obtained; since the relative positions of the magnetic member and the lens are fixed, the lens position can be determined from the actual displacement of the magnetic member.

In the above embodiment, after the inductance of the coil is obtained, the actual displacement of the magnetic member is determined according to the correspondence between the inductance calibrated in advance by the test and the actual displacement of the magnetic member.

The manner in which the correspondence between inductance and actual displacement of the magnetic component is calibrated is described in detail below with reference to the accompanying drawings.

The lens position detection system provided in the above embodiment can be used to realize the following ways of calibrating the correspondence between the inductance and the actual displacement of the magnetic component.

With continued reference to fig. 13, the specific structure of the detection system is described with reference to fig. 13, and the embodiments of the present application will not be described herein.

As is known from the principle of VCM for moving a movable member, there is a correspondence between a dc voltage for generating a magnetic field by the driving coil 604 and a displacement generated by the movement of the magnetic member 603, that is, a correspondence between the dc voltage and the displacement of the magnetic member.

The correspondence relationship between the dc voltage and the displacement of the magnetic member is pre-stored in an electronic device capable of realizing lens movement by the VCM.

In some embodiments, the correspondence between the dc voltage and the displacement of the magnetic member may be stored in the form of a data table.

For example, when the dc voltage is V1, the magnetic member is displaced by d '1, when the dc voltage is V2, the magnetic member is displaced by d'2, …, and when the dc voltage is Vn, the magnetic member is displaced by d 'n, the stored correspondence is (V1, d' 1), (V2, d '2), …, (Vn, d' n).

For example, when the controller 601 outputs the dc voltage V1 to the coil 604 so that the magnetic member 603 moves, the displacement of the magnetic member at this time can be obtained as d'1 from the correspondence relationship between the dc voltage and the displacement of the magnetic member, which is previously stored.

When the movement of the magnetic member 603 is stopped, the controller 601 outputs a preset ac voltage to the coil 604.

The preset alternating voltage and the superimposed alternating voltage have the same effective value as the direct voltage.

The implementation of determining the movement stop of the magnetic member 603 is the same as that described in the above embodiments, and will not be described here again.

During the movement of the magnetic part 603, the magnetic core 605 will also move, and at this time, the relative movement between the coil 604 and the magnetic core 605 will cause the inductance of the coil 604 to change, thereby causing the current at the output end of the coil 604 to change.

At this time, the current at the output end of the coil 604 is obtained, and the inductance of the coil 604 corresponding to the displacement generated by the movement of the magnetic member 603 is obtained by performing calculation using the equation (2).

The controller 601 obtains the corresponding inductances when the magnetic component 603 generates different displacements by outputting different direct current voltages, and can finish the calibration of the corresponding relationship between the inductances and the actual displacement of the magnetic component.

In some embodiments, the corresponding relationship between the actual displacement of the inductance and the actual displacement of the magnetic component may be stored in the form of a data table, and the specific manner is described above, which is not repeated here.

In summary, the method for calibrating the correspondence between the inductance and the actual displacement of the magnetic component provided in the embodiment of the present application can be completed by the lens position detection system provided in the above embodiment, without adding additional structure.

In another possible implementation, since the relative positions of the magnetic component and the lens are fixed, the displacement of the magnetic component can be converted into the position of the lens after determining the relative positions of the magnetic component and the lens.

Therefore, the data table stored in the above memory may also be a correspondence relationship between inductance and lens position.

In order to obtain the corresponding relation between the inductance and the lens position, in the process of calibrating the corresponding relation between the inductance and the actual position of the magnetic component, after the corresponding relation between the inductance and the actual displacement of the magnetic component is obtained, the lens position is obtained according to the actual displacement of the magnetic component, so that the corresponding relation between the inductance and the lens position is obtained.

Through the implementation mode of storing the corresponding relation between the inductor and the lens position, the lens position can be obtained directly according to the inductor without determining the actual displacement of the magnetic component, and then the lens position is determined through the actual displacement of the magnetic component, so that the processing process can be simplified.

The controller 601 outputs a dc voltage to the coil 604, and the magnetic field generated by the coil 604 causes the magnetic member 603 to move.

When it is determined that the magnetic member 603 stops moving, the controller 601 outputs a direct current voltage to superimpose a preset alternating current voltage on the coil 604.

For the implementation of determining that the magnetic member 603 stops moving, the description in the above embodiment is omitted here.

Since the coil 604 is fixed and the relative positions of the magnetic member 603 and the core 605 are fixed, there is a relative movement of the coil 604 and the core 605 during movement of the magnetic member 603, resulting in a change in inductance of the coil 604.

At this time, since the inductance of the coil 604 changes, the current at the output of the coil 604 changes.

The controller 601 obtains the actual displacement of the magnetic member corresponding to the current according to the correspondence between the current obtained by the test calibration in advance and the actual displacement of the magnetic member.

In some embodiments, the current may be the magnitude or frequency of the current at the output of the coil 604 in the correspondence between the above current and the actual displacement of the magnetic component, taking into account the change in inductance of the coil 604, which may result in a change in the magnitude or frequency of the current at the output of the coil 604.

The correspondence between the above current and the actual displacement of the magnetic component may be stored in a memory of the electronic device, invoked when the controller 601 is used.

In some embodiments, the correspondence between the current and the actual displacement of the magnetic component may be stored in the form of a data table. For example, when the current is i1, the actual displacement of the magnetic member is d1, when the inductance is i2, the actual displacement of the magnetic member is d2, …, and when the current is in, the actual displacement of the magnetic member is dn, the stored correspondence is (i 1, d 1), (i 2, d 2), …, (in, dn) by the test calibration in advance.

The actual displacement of the magnetic component obtained through the process is the displacement actually generated by the magnetic component 603, and the displacement already covers the displacement of the magnetic component 603 and the lens caused by gravity and other factors; the displacement of the magnetic component corresponding to the dc voltage refers to the displacement of the coil corresponding to the dc voltage that can be generated by controlling the voltage value of the dc voltage in an ideal case, that is, the displacement of the magnetic component corresponding to the dc voltage does not consider the offset caused by factors such as gravity.

The controller 601 determines the position of the lens based on the actual displacement of the magnetic member obtained by the above-described process.

Because the relative position of the magnetic component and the lens is unchanged, the magnetic component can drive the lens to move when moving. Therefore, by determining the actual displacement of the magnetic member, i.e., the displacement of the lens, the position of the lens can be determined.

In summary, the lens position is determined based on the correspondence between the current and the displacement/position, so that the current at the output end of the magnetic component can be directly utilized, and the inductance of the coil is not required to be obtained through current calculation, thereby simplifying the processing procedure.

Therefore, the data table stored in the above memory may be a correspondence relationship between the current and the lens position. For example, when the current is i1, the lens position is l1, when the current is i2, the lens position is l2, …, and when the current is in, the lens position is ln, the stored correspondence is (i 1, l 1), (i 2, l 2), …, (in, ln) by test calibration.

In the above embodiment, after the current at the output end of the coil is obtained, the actual displacement of the coil is determined according to the correspondence between the current calibrated in advance through the test and the actual displacement of the magnetic member.

The manner in which the correspondence between the calibration current and the actual displacement of the magnetic member is described in detail below with reference to the accompanying drawings.

The lens position detection system provided in the above embodiment can be used to realize the following ways of calibrating the correspondence between the current and the actual displacement of the magnetic component.

In some embodiments, the correspondence between the dc voltage and the displacement of the magnetic member may be stored in the form of a data table. For example, when the dc voltage is V1, the magnetic member is displaced by d '1, when the dc voltage is V2, the magnetic member is displaced by d'2, …, and when the dc voltage is Vn, the magnetic member is displaced by d 'n, the stored correspondence is (V1, d' 1), (V2, d '2), …, (Vn, d' n).

At this time, the current at the output of the coil 604 is obtained.

The controller 601 obtains the current of the coil 604 when the magnetic component generates different displacements by outputting different direct current voltages to the coil 604, and can complete the calibration of the corresponding relation between the current and the actual displacement of the magnetic component.

In some embodiments, the correspondence between the current and the actual displacement of the magnetic component may be stored in the form of a data table, and the specific manner is described above, which is not repeated here.

In summary, the manner of the correspondence between the calibration current and the actual displacement of the magnetic component provided in the embodiment of the present application can be completed by the lens position detection system provided in the above embodiment, without adding additional structure.

In the above embodiment, the technical solution provided in the present application is applied to correction of lens optical axis offset in an electronic device, that is, for adjusting a lens position in a direction perpendicular to an optical axis.

In addition, the technical scheme provided by the application can be applied to the automatic focusing scene of the lens in the electronic equipment, and the implementation principle is the same as that in the embodiment, and only the adjustment directions of the lenses are different.

Because the moving-magnet VCM is applied to a correction scene of the lens optical axis offset, the description of the technical scheme provided in the application in the lens auto-focusing scene is not repeated here.

Referring to fig. 14, fig. 14 is a schematic structural diagram of a voice coil motor according to another embodiment of the present disclosure.

As shown in fig. 14, voice coil motor 700 includes magnetic member 701, coil 702, and magnetic core 703.

The coil 702 is wound around the outside of the magnetic core 703, the position of the coil 702 is fixed, the relative positions of the magnetic member 701 and the magnetic core 703 are fixed, and the magnetic member 701 is configured to move in response to an external driving voltage when the coil is externally connected to the driving voltage.

In contrast to moving-magnet VCMs currently common in electronics, embodiments of the present application provide voice coil motors having a magnetic core 703 nested within the coil.

Referring to the explanation of the VCM principle in the above embodiment, when the driving voltage of the control coil 702 is a direct current voltage, the magnetic member 701 and the coil 702 are relatively moved.

Since the relative positions of magnetic member 701 and magnetic core 703 are fixed, at this time, magnetic core 703 and coil 702 are relatively moved.

When the voice coil motor 700 is used for moving a movable component, such as a lens, the relative positions of the magnetic component 701 and the lens are fixed, and the movement of the magnetic component 701 can drive the lens to move, so as to adjust the position of the lens.

When it is determined that the magnetic member 701 reaches the first position, that is, it is determined that the magnetic member 701 stops moving, the driving voltage of the control coil 702 is the same ac voltage as the effective value of the dc voltage described above.

At this time, the inductance of the coil 702 is changed by the relative movement of the coil 702 and the core 703, and the displacement of the magnetic member 701 can be determined by the current at the output end of the coil 702, thereby determining the position of the lens.

In one possible implementation, the magnetic component may be located inside the coil, i.e., the coil surrounds the outside of the magnetic component, enabling the size of the VCM to be reduced.

The detection module comprises a magnetic component, a coil and a magnetic core, wherein the coil surrounds the outside of the magnetic core, the position of the coil is fixed, and the relative positions of the magnetic component and the magnetic core are fixed.

Referring to fig. 15, fig. 15 is a flowchart of a method for detecting a lens position according to another embodiment of the present application.

The detection method includes S801 to S803.

S801, controlling the driving voltage of a control coil to be a first voltage so as to enable the magnetic component and the coil to move relatively, wherein the first voltage is a direct current voltage;

s802, when the magnetic component is determined to reach a first position, controlling the driving voltage of the coil to be a second voltage, wherein the second voltage is an alternating voltage, and the effective value of the first voltage is the same as that of the second voltage;

s803, determining the position of the lens by using the current of the output end of the coil.

The driving voltage of the control coil is a first voltage, and when the first voltage is a direct current voltage, the magnetic component and the coil relatively move.

Since the relative positions of the magnetic member and the magnetic core are fixed, the magnetic core and the coil are relatively moved at this time.

Because the relative position of the magnetic component and the lens is fixed, the movement of the magnetic component can drive the lens to move.

When the magnetic component is determined to reach the first position, namely the magnetic component is determined to stop moving, the driving voltage of the control coil is a second voltage, the second voltage is an alternating voltage, and the effective values of the first voltage and the second voltage are the same.

Since the effective values of the first voltage and the second voltage are the same, when the magnetic member reaches the first position, that is, the magnetic member stops moving, the driving voltage of the control coil becomes the second voltage, and the magnetic member does not continue to move.

The current at the output of the coil is related to the inductance of the coil, i.e. to the displacement of the magnetic component relative to the movement of the coil; further, since the relative positions of the magnetic member and the lens are fixed, the position of the lens can be determined from the current at the output end of the coil.

The embodiment of the application also provides another method for detecting the lens position, which is applied to the detection module in the above embodiment, namely the detection module in the embodiment corresponding to fig. 13.

Referring to fig. 16, fig. 16 is a flowchart of a method for detecting a lens position according to another embodiment of the present application.

The detection method comprises S901-S906.

And S901, outputting direct-current voltage to the coil so as to enable the magnetic component and the coil to move relatively.

The principle of the relative movement between the magnetic member and the coil is described in the above embodiments, and will not be described herein.

S902, when it is determined that the movement of the magnetic component is stopped, a preset alternating voltage is superimposed on the direct current voltage and output to the coil.

The implementation of determining that the magnetic component is stopped in S902 has been described in the above embodiments, and the embodiments of the present application are not described herein.

S903, detecting the current of the output end of the coil.

In S903, there is a relative movement between the coil and the core during the movement of the magnetic member, resulting in a change in inductance of the coil. When an ac voltage is supplied to the coil, the current at the output of the coil changes.

S904, calculating the inductance of the coil according to the detected current.

In some embodiments, the manner in which the inductance of the coil is calculated from the current may be implemented according to equation (2). Specific implementation manner is described in the foregoing embodiments, and the embodiments of the present application are not repeated herein.

S905, obtaining the actual displacement of the magnetic component according to the corresponding relation between the inductance calibrated in advance and the actual displacement of the magnetic component.

In some embodiments, the correspondence between the actual displacement of the inductance and the actual displacement of the magnetic component may be stored in the form of a data table, and the specific manner is described in the above embodiments, which is not repeated here.

S906, determining the lens position according to the actual displacement of the magnetic component.

Since the positions of the magnetic member and the lens are fixed, the correspondence relationship according to which the position of the lens is determined after the inductance of the coil is obtained in S904 may be the correspondence relationship between the inductance and the position of the lens.

In another possible implementation, after the inductance of the coil is obtained in S904, the position of the lens is obtained according to the correspondence between the inductance and the lens position calibrated in advance.

Through the corresponding relation of the pre-calibrated inductor and the lens position, the lens position can be directly obtained according to the inductor without determining the actual displacement of the magnetic component, and then the lens position is determined through the actual displacement of the magnetic component, so that the processing process can be simplified.

In the above embodiment, it is determined that the magnetic member movement stop is an out-triggering condition of superimposing the alternating-current voltage output on the direct-current voltage. To determine that the magnetic component is moving to a stop, i.e., to determine that the magnetic component is reaching the first position, embodiments of the present application provide the following two implementations, see fig. 17 and 18.

Referring to fig. 17, fig. 17 is a flowchart of a method for detecting a lens position according to another embodiment of the present application, where the method is applied to a detection module in the embodiment corresponding to fig. 13.

The method includes S1001-S1006.

S1001, outputting a direct-current voltage to the coil so as to enable the magnetic component and the coil to move relatively.

S1002, after the output direct-current voltage continues for a preset period, the preset alternating-current voltage is superposed on the direct-current voltage for output, and the preset period is obtained according to the corresponding relation between the preset period and the direct-current voltage which are calibrated in advance.

In S1002, a preset ac voltage output is superimposed on the dc voltage, and the effective value of the voltage remains unchanged.

The preset time period corresponds to the direct current voltage and is determined according to the corresponding relation between the preset time period and the direct current voltage, which are calibrated in advance. The correspondence relation indicates that when the voltage across the coil is the dc voltage, the magnetic member moves, and the movement of the magnetic member is stopped within a preset period corresponding to the dc voltage.

S1003, detecting the current of the output end of the coil.

S1004, calculating the inductance of the coil according to the detected current.

S1005, obtaining the actual displacement of the magnetic component according to the corresponding relation between the inductance calibrated in advance and the actual displacement of the magnetic component.

S1006, determining the lens position according to the actual displacement of the magnetic component.

And determining a preset time period corresponding to the current direct current voltage according to the corresponding relation between the preset time period and the direct current voltage, and determining that the magnetic component stops moving after the direct current voltage continues for the preset time period.

Since the positions of the magnetic member and the lens are fixed, after the inductance of the coil is obtained in S1004, the correspondence relationship according to which the position of the lens is determined may be the correspondence relationship between the inductance and the position of the lens.

In another possible implementation, after the inductance of the coil is obtained in S1004, the position of the lens is obtained according to the correspondence between the inductance and the lens position calibrated in advance.

Referring to fig. 18, fig. 18 is a flowchart of a method for detecting a lens position according to another embodiment of the present application, where the method is applied to a detection module in the embodiment corresponding to fig. 13.

The method includes S1101-S1106.

S1101, outputting a direct-current voltage to the coil so as to enable the magnetic component and the coil to move relatively.

S1102, detecting the current of the output end of the coil.

S1103, when the current at the output end of the coil is unchanged, the preset alternating voltage is superposed on the direct voltage for output.

When the voltage across the coil is a constant dc voltage, the current of the coil is typically a constant dc current.

Therefore, during the movement of the magnetic component, the coil cuts the electromotive force generated by the magnetic induction wire so that the current through the coil is not constant.

When the movement of the magnetic member is stopped, the electromotive force generated by the coil cutting the magnetic induction wire disappears, and thus the current of the coil becomes constant.

Thus, when the current at the output end of the coil is unchanged, it can be determined that the magnetic member stops moving.

And S1104, calculating the inductance of the coil according to the detected current.

S1105, obtaining the actual displacement of the magnetic component according to the corresponding relation between the inductance calibrated in advance and the actual displacement of the magnetic component.

S1106, determining the lens position according to the actual displacement of the magnetic component.

Unexpected movement of the magnetic component may occur due to other factors during movement. For example, during movement of the magnetic component, the dc voltage applied across the coil accidentally fluctuates, causing the magnetic component to move irregularly. In this case, the above-described manner of determining the stop of the movement of the magnetic member can reduce the occurrence of erroneous results due to an occasional case.

Since the positions of the magnetic member and the lens are fixed, the correspondence relationship on which the lens position is determined after the inductance of the coil is obtained in S1105 may be the correspondence relationship between the inductance and the lens position.

In another possible implementation, after the inductance of the coil is obtained in S1105, the position of the lens is obtained according to the correspondence between the inductance and the lens position calibrated in advance. Through the corresponding relation of the pre-calibrated inductor and the lens position, the lens position can be directly obtained according to the inductor without determining the actual displacement of the magnetic component, and then the lens position is determined through the actual displacement of the magnetic component, so that the processing process can be simplified.

Further, in order to obtain the corresponding relationship between the inductance and the actual displacement of the magnetic component in S1105, the embodiment of the present application further provides a calibration method for the corresponding relationship between the inductance and the actual displacement of the magnetic component, where the method is applied to the detection module in the embodiment corresponding to fig. 13.

First, a DC voltage is output to the coil to make the magnetic component and the coil move relatively.

When the movement of the magnetic part is determined to stop, superposing a preset alternating voltage on the direct voltage for outputting; and superposing a preset alternating voltage on the direct current voltage to output, wherein the effective value of the voltage is kept unchanged.

Then, the current at the output of the coil is detected, and the inductance of the coil is calculated from the detected current.

After the inductance of the coil is obtained, the corresponding relation between the inductance and the actual displacement of the magnetic component is obtained based on the corresponding relation between the direct current voltage and the displacement of the magnetic component, which are calibrated in advance, according to the inductance of the coil.

According to the principle that the VCM realizes lens movement, the direct current voltage at two ends of the coil and the displacement generated by the movement of the magnetic component have a corresponding relation, namely the corresponding relation between the direct current voltage and the displacement of the magnetic component.

When the movement of the magnetic component is stopped, a preset alternating voltage is output to the coil to be overlapped with the alternating voltage.

During movement of the magnetic component, relative movement between the coil and the core causes a change in the inductance of the coil and thus a change in the current at the output of the coil.

At this time, the current at the output end of the coil is obtained, and the inductance of the coil is obtained by performing calculation using equation (2).

By outputting different direct-current voltages, corresponding inductances when the magnetic component generates different displacements are obtained, and the calibration of the corresponding relationship between the inductances and the actual displacement of the magnetic component can be completed.

In summary, the calibration method for the correspondence between the actual displacement of the inductance and the actual displacement of the magnetic component provided in the embodiment of the present application can be applied to the detection module in the lens position detection system provided in the above embodiment, without adding additional structures for completing the calibration process.

In one possible implementation, the correspondence between the inductance and the lens position may also be calibrated due to the fixed relative positions of the magnetic component and the lens.

In order to calibrate the corresponding relation between the inductance and the lens position, the inductance of the coil can be obtained by calculating according to the acquired current of the output end of the coil by using the formula (2). The magnetic component is controlled to drive the lens to move by controlling the direct current voltage at two ends of the coil, so that different lens positions are obtained, and the calibration of the corresponding relation between the inductance and the lens positions can be completed.

The embodiment of the application also provides another method for detecting the lens position, which is used for determining the lens position based on the corresponding relation between the current and the actual displacement of the magnetic component. The method is used for directly utilizing the current of the output end of the coil, and the inductance of the coil is obtained without current calculation, so that the processing process is simplified.

Referring to fig. 19, fig. 19 is a flowchart of a method for detecting a lens position according to another embodiment of the present application, where the method is applied to a detection module in the embodiment corresponding to fig. 13.

The method includes S1201-S1204.

S1201, outputting a dc voltage to the coil, so that the magnetic component and the coil move relatively.

S1202, when it is determined that the movement of the magnetic component is stopped, a preset alternating voltage output is superimposed on the direct voltage.

S1203 detects the current at the output of the coil.

And S1204, obtaining the lens position according to the detected current and the corresponding relation between the current calibrated in advance and the lens position.

It will be appreciated that the method of determining the lens position based on the correspondence between the current and the actual displacement of the magnetic member is similar to the method of determining the lens position based on the correspondence between the inductance and the actual displacement of the magnetic member in the above-described embodiment.

Since the positions of the magnetic component and the lens are fixed, in another possible implementation manner, after the current of the output end of the coil is obtained in S1203, the process of determining the correspondence relationship according to the position of the lens may also be that the actual displacement of the magnetic component is obtained according to the current of the output end of the coil, and then the position of the lens is determined according to the actual displacement of the magnetic component.

Further, in order to obtain the corresponding relationship between the current and the lens position in S1104, the embodiment of the present application further provides a calibration method for the corresponding relationship between the current and the lens position, where the method is applied to the detection module in the embodiment corresponding to fig. 13.

First, a DC voltage is output to the coil to cause the magnetic member and the coil to move relatively.

When the movement of the magnetic part is determined to be stopped, the preset alternating voltage output is superposed on the direct voltage, and the effective value of the voltage is kept unchanged.

Detecting the current of the output end of the coil, and then obtaining the corresponding relation between the current and the lens position based on the corresponding relation between the pre-calibrated direct-current voltage and the displacement of the magnetic component according to the current of the output end of the coil.

When the movement of the magnetic member is stopped, an alternating voltage is output to the coil.

The controller obtains corresponding currents when the magnetic component generates different displacements by outputting different direct-current voltages, and the calibration of the corresponding relation between the currents and the actual displacement of the magnetic component can be completed.

In one possible implementation, the correspondence between the inductance and the actual displacement of the magnetic component may also be calibrated due to the fixed relative positions of the magnetic component and the lens.

Based on the detection system provided by the above embodiment, the embodiment of the application further provides an electronic device applying the detection system, and the following detailed description is given with reference to the accompanying drawings.

The hardware structure of the electronic device provided in the embodiment of the present application is shown in fig. 1A, and the lens module of the electronic device provided in the embodiment of the present application includes the detection system in the embodiment of the detection system for the lens position.

Referring to fig. 20, fig. 20 is a schematic structural diagram of an electronic device according to another embodiment of the present application, where the electronic device 800 includes a detection system 801 and a lens 802 in the embodiment of the detection system for a lens position, and the detection system 801 specifically includes a controller 803 and a detection module 804.

The detection system 801 is referred to above as an embodiment of a lens position detection system to implement the functions described in the above embodiment of a lens position detection system.

To achieve an auto-focus function of an electronic device lens, the electronic device may include a detection system to determine a lens position along an optical axis; in order to realize the correction function of the lens optical axis offset, the electronic device may include two detection systems for determining lens positions perpendicular to the optical axis direction, respectively;

in order to achieve the above two functions, that is, the auto-focusing function of the lens and the correction function of the optical axis deviation of the lens, the electronic device may include three detection systems for determining the lens position along the optical axis direction and perpendicular to the optical axis direction, respectively.

The detection system provided by the embodiment of the application can have different structures and realize corresponding functions. When the electronic device 800 includes a plurality of the above-described detection devices, the plurality of detection devices may have the same structure or may have different structures, which is not limited in the embodiment of the present application.

When the electronic device 800 includes a plurality of the above detection systems, the controllers in the plurality of detection systems may be the same controller to realize corresponding functions, that is, the detection modules in the plurality of detection systems are controlled by the same controller to realize functions of the plurality of detection systems; the detection systems may also be respectively corresponding to the respective controllers, which is not limited in the embodiment of the present application.

When the electronic device 800 includes a plurality of the above-mentioned detection systems for detecting lens positions along the optical axis direction and perpendicular to the optical axis direction, the detection module for detecting the lens positions along the optical axis direction may be controlled by the same controller, and the detection module for detecting the lens positions perpendicular to the optical axis direction may be controlled by another controller.

The embodiments of the present application are not particularly limited to the type of electronic device, and the electronic device may be a mobile phone, a notebook computer, a wearable electronic device (e.g., a smart watch), a tablet computer, an augmented reality (augmented reality, AR) device, a Virtual Reality (VR) device, or the like.

It can be understood that the specific implementation manner of the detection system in the electronic device and the functions that can be implemented by the detection system in this embodiment are described in the above embodiments, and the embodiments of the present application are not described herein again.

In summary, with the detection system provided in the above embodiment, the number and/or type of detection systems included in the electronic device are selected according to the functional requirements of the electronic device, for example, the requirement of implementing an auto-focusing function of the lens and/or a correction function of the optical axis offset.

Because of the function of adjusting the lens position, electronic devices typically include a VCM.

In order to achieve lens automatic focusing or lens optical axis offset correction, the electronic device provided by the embodiment of the application is provided with the magnetic core in the VCM, and the magnetic core is nested in the hollow position of the coil, so that detection of the lens position is achieved.

Compared with the mode of realizing lens position feedback by adding the Hall element, in the electronic equipment provided by the embodiment of the application, the device size is not excessively increased along the optical axis direction of the lens and the optical axis direction perpendicular to the lens, so that the structural limitation on the camera module is reduced.

In addition, because the magnetic core is lower in cost compared with the Hall element, the electronic equipment provided by the embodiment of the application can reduce the cost of a device for detecting the position of the lens.

In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. The apparatus embodiments described above are merely illustrative, wherein the units and modules illustrated as separate components may or may not be physically separate.

In addition, some or all of the units and modules can be selected according to actual needs to achieve the purpose of the embodiment scheme. Those of ordinary skill in the art will understand and implement the present invention without undue burden.

The foregoing is merely exemplary of the application and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the application and are intended to be comprehended within the scope of the application.

Claims

1. A system for detecting a lens position, the system comprising: the device comprises a detection module and a controller;

the detection module comprises a first magnet, a second magnet, a coil and a magnetic core;

the controller is used for controlling the driving voltage of the coil to be a first voltage so as to enable the coil and the magnetic core to move relatively, when the coil is determined to reach a first position, the driving voltage of the coil is controlled to be a second voltage, the position of the lens is determined by utilizing the current of the output end of the coil, the first voltage is a direct current voltage, the second voltage is an alternating current voltage, and the effective value of the first voltage is the same as that of the second voltage.

2. The lens position detection system according to claim 1, wherein the controller is specifically configured to superimpose the first voltage on a preset ac voltage to obtain the second voltage.

3. The system of claim 2, wherein the controller is configured to determine the displacement of the coil using the current at the output of the coil, and determine the position of the lens based on the relative positions of the coil and the lens.

4. The lens position detection system according to claim 3, wherein the controller is specifically configured to determine an inductance of the coil according to a current at an output end of the coil and the preset ac voltage, and determine a displacement of the coil according to a corresponding relationship between a pre-calibrated inductance and a coil displacement.

5. A lens position detection system according to claim 3, wherein the controller is specifically configured to determine the displacement of the coil according to a pre-calibrated correspondence between the current and the coil displacement, and the current at the output end of the coil.

6. The system according to claim 2, wherein the controller is specifically configured to determine an inductance of the coil by using a current at an output end of the coil and the preset ac voltage, and determine the position of the lens according to a pre-calibrated correspondence between the inductance and the lens position.

7. The system for detecting a lens position according to claim 2, wherein the controller is specifically configured to determine the lens position using a pre-calibrated correspondence between the current and the lens position, and the current at the output of the coil.

8. The lens position detection system according to claim 1, wherein the controller is specifically configured to determine that the coil reaches the first position after controlling the driving voltage of the coil to be the first voltage for a preset period of time.

9. The lens position detection system according to claim 1, wherein the controller is configured to determine that the coil reaches the first position when the current at the output of the coil is unchanged.

10. The lens position detection system according to any one of claims 1 to 9, wherein the magnetic core has a hollow structure.

11. A system for detecting a lens position, the system comprising: the device comprises a detection module and a controller;

the detection module comprises a magnetic component, a coil and a magnetic core;

the coil surrounds the outside of the magnetic core, and the position of the coil is fixed;

the relative positions of the magnetic component and the magnetic core are fixed;

the controller is used for controlling the driving voltage of the coil to be a first voltage so as to enable the magnetic component and the coil to move relatively, when the magnetic component is determined to reach a first position, the driving voltage of the coil is controlled to be a second voltage, the position of the lens is determined by utilizing the current of the output end of the coil, the first voltage is a direct current voltage, the second voltage is an alternating current voltage, and the effective value of the first voltage is the same as that of the second voltage.

12. The lens position detection system according to claim 11, wherein the controller is specifically configured to superimpose the first voltage on a preset ac voltage to obtain the second voltage.

13. The system of claim 12, wherein the controller is configured to determine the displacement of the magnetic component using the current at the output of the coil, and determine the position of the lens based on the relative positions of the magnetic component and the lens.

14. The system of claim 13, wherein the controller is specifically configured to determine an inductance of the coil according to a current at an output end of the coil and the preset ac voltage, and determine a displacement of the magnetic component according to a pre-calibrated correspondence between the inductance and the displacement of the magnetic component.

15. The lens position detection system according to claim 13, wherein the controller is specifically configured to determine the displacement of the magnetic component according to a pre-calibrated correspondence between the current and the displacement of the magnetic component, and the current at the output end of the coil.

16. The system of claim 12, wherein the controller is specifically configured to determine an inductance of the coil by using a current at an output end of the coil and the preset ac voltage, and determine the position of the lens according to a pre-calibrated correspondence between the inductance and the lens position.

17. The system of claim 12, wherein the controller is configured to determine the position of the lens using a pre-calibrated correspondence between current and lens position, and current at the output of the coil.

18. The lens position detection system according to claim 11, wherein the controller is specifically configured to determine that the magnetic component reaches the first position after controlling the driving voltage of the coil to be the first voltage for a preset period of time.

19. The lens position detection system of claim 11, wherein the controller is configured to determine that the magnetic component reaches the first position when the current at the output of the coil is unchanged.

20. The lens position detection system according to any one of claims 11 to 19, wherein the coil is surrounded outside the magnetic member.

21. A voice coil motor, comprising: the first magnet, the second magnet, the coil and the magnetic core;

the coil is positioned in a magnetic field formed by the first magnet and the second magnet, the coil surrounds the outside of the magnetic core, and the position of the magnetic core is fixed;

the output end of the coil is used for outputting current to a controller of a lens position detection system;

the coil is used for generating displacement corresponding to the external driving voltage when the external driving voltage is applied, and outputting current to the controller so that the controller can determine the position of the lens according to the current of the output end of the coil.

22. A voice coil motor, comprising: a magnetic component, a coil, and a core;

the magnetic component is used for generating movement corresponding to the external driving voltage when the coil is externally connected with the driving voltage, so that the output end of the coil outputs current to the controller, and the controller determines the position of the lens according to the current of the output end of the coil.

23. The detection method of the lens position is characterized by being applied to a detection module, wherein the detection module comprises a first magnet, a second magnet, a coil and a magnetic core; the coil is positioned in a magnetic field formed by the first magnet and the second magnet, the relative position of the coil and the lens is fixed, the coil surrounds the outside of the magnetic core, and the position of the magnetic core is fixed, and the method comprises the following steps:

controlling the driving voltage of the coil to be a first voltage so as to enable the coil and the magnetic core to move relatively, wherein the first voltage is a direct current voltage;

when the coil is determined to reach a first position, controlling the driving voltage of the coil to be a second voltage, wherein the second voltage is an alternating voltage, and the effective value of the first voltage is the same as that of the second voltage;

and determining the position of the lens by using the current of the output end of the coil.

24. The method for detecting a lens position according to claim 23, wherein the controlling the driving voltage of the coil to be the second voltage specifically includes:

and superposing the first voltage and a preset alternating voltage to obtain the second voltage.

25. The method for detecting a lens position according to claim 24, wherein determining the lens position by using the current at the output end of the coil comprises:

Determining a displacement of the coil using a current at an output of the coil;

and determining the position of the lens according to the relative positions of the coil and the lens.

26. The method for detecting a lens position according to claim 25, wherein determining the displacement of the coil by using the current at the output end of the coil comprises:

determining the inductance of the coil according to the current of the output end of the coil and the preset alternating voltage;

and determining the displacement of the coil according to the corresponding relation between the inductance and the coil displacement calibrated in advance.

27. The method for detecting a lens position according to claim 25, wherein determining the displacement of the coil by using the current at the output end of the coil comprises:

28. The method for detecting a lens position according to claim 24, wherein determining the lens position by using the current at the output end of the coil comprises:

determining the inductance of the coil by using the current of the output end of the coil and the preset alternating voltage;

And determining the position of the lens according to the corresponding relation between the pre-calibrated inductance and the position of the lens.

29. The method for detecting a lens position according to claim 24, wherein determining the lens position by using the current at the output end of the coil comprises:

30. The detection method of the lens position is characterized by being applied to a detection module, wherein the detection module comprises a magnetic component, a coil and a magnetic core; the coil surrounds the outside of the magnetic core, and the position of the coil is fixed; the relative positions of the magnetic component and the magnetic core are fixed, and the method comprises the following steps:

controlling the driving voltage of the coil to be a first voltage so as to enable the magnetic component and the coil to move relatively, wherein the first voltage is a direct current voltage;

when the magnetic component is determined to reach a first position, controlling the driving voltage of the coil to be a second voltage, wherein the second voltage is an alternating voltage, and the effective value of the first voltage is the same as that of the second voltage;

31. The method of claim 30, wherein controlling the driving voltage of the coil to be a second voltage, specifically comprises:

32. The method for detecting a lens position according to claim 31, wherein determining the lens position using the current at the output end of the coil comprises:

determining a displacement of the magnetic component using a current at an output of the coil;

and determining the position of the lens according to the relative positions of the magnetic component and the lens.

33. The method for detecting a lens position according to claim 32, wherein determining the displacement of the magnetic member using the current at the output end of the coil comprises:

and determining the displacement of the magnetic component according to the corresponding relation between the inductance and the displacement of the magnetic component, which are calibrated in advance.

34. The method for detecting a lens position according to claim 32, wherein determining the displacement of the magnetic member using the current at the output end of the coil comprises:

35. The method for detecting a lens position according to claim 31, wherein determining the lens position using the current at the output end of the coil comprises:

36. The method for detecting a lens position according to claim 31, wherein determining the lens position using the current at the output end of the coil comprises:

37. An electronic device, characterized in that the electronic device comprises the lens position detection system of any one of claims 1 to 20, further comprising a lens.