Detection unit, camera module and electronic equipment

Abstract

The embodiment of the invention provides a detection unit, a camera module and electronic equipment, and relates to the technical field of detection. The detection unit comprises at least two magnetic field sensors which are connected in parallel. The output ends of the at least two magnetic field sensors are electrically connected to form a connection node, and the input end of the operational amplification module is electrically connected with the connection node. In the embodiment of the invention, a plurality of operational amplification modules are not required to be electrically connected with the plurality of magnetic field sensors in a one-to-one correspondence manner, so that the number of the operational amplification modules is reduced, and the cost of the camera module is reduced. Besides, the operational amplification module can obtain the average value of the output voltages of the at least two magnetic field sensors through the connection node, digital calculation of the output voltages of the at least two magnetic field sensors through a digital device is not needed, the time needed for obtaining the average value of the output voltages of the at least two magnetic field sensors is shortened, and the accuracy of the detection result is improved. And the response speed of the camera module during closed-loop automatic focusing is improved.

Description

Technical Field

[0001] Embodiments of the present application relate to the technical field of detection, and in particular, to a detection unit, a camera module, and an electronic device. Background Art

[0002] In the related art, the cost of the camera module is relatively high, and the response speed during closed-loop autofocus is relatively slow. Summary of the invention

[0003] The embodiments of the present application provide a detection unit, a camera module and an electronic device for reducing the cost of the camera module and improving the response speed of the camera module during closed-loop autofocus.

[0004] In order to achieve the above purpose, the following technical solutions are provided:

[0005] In one aspect, an embodiment of the present application provides a detection unit. The detection unit includes at least two magnetic field sensors, and the at least two magnetic field sensors are connected in parallel. The output ends of the at least two magnetic field sensors are electrically connected to form a connection node, and the input end of the operational amplifier module is electrically connected to the connection node.

[0006] In an embodiment of the present application, the number of magnetic field sensors is set to at least two, and the at least two magnetic field sensors can respectively detect the magnetic field strength in the detection direction of their current position in the magnetic field, and convert the detected magnetic field strength into a corresponding voltage signal, thereby increasing the width of the linear region in the relationship curve between the distance between the lens and the image sensor and the magnetic field strength detected by the magnetic field sensor, thereby increasing the focusing range of the lens.

[0007] It can be understood that the connection node is not an actual component, but a junction point representing the relevant electrical connection. In other words, the connection node is a node formed by the junction point after the output ends of at least two magnetic field sensors are electrically connected. The output ends of at least two magnetic field sensors are electrically connected to form a connection node, and the voltage value of the connection node can be equal to the average value of the output voltages of at least two magnetic field sensors. The input end of the operational amplifier module is electrically connected to the connection node, so that the operational amplifier module can obtain the average value of the output voltages of at least two magnetic field sensors through the connection node, and amplify the average value of the output voltages of at least two magnetic field sensors. In this way, there is no need to set multiple operational amplifier modules to be electrically connected to multiple magnetic field sensors one by one, which reduces the number of operational amplifier modules, reduces the cost of the camera module, and reduces the occupied area of ​​the operational amplifier module on the circuit board (or in the chip).

[0008] In addition, the output ends of at least two magnetic field sensors are electrically connected to form a connection node, and the output voltages of the at least two magnetic field sensors are averaged through a hardware circuit, so that the digital processing module does not need to perform digital calculations (such as summing or averaging) on ​​the output voltages of the at least two magnetic field sensors, thereby saving the computing power of the digital processing module, reducing the delay of the digital processing module, reducing the time required for obtaining the average value of the output voltages of the at least two magnetic field sensors, and improving the response speed of the camera module during closed-loop autofocus, thereby improving the closed-loop autofocus efficiency of the camera module.

[0009] That is, by adopting the above-mentioned setting method, the camera module can achieve low-cost, high-efficiency and long-distance (long focusing range) closed-loop autofocus.

[0010] In some possible implementations, the magnetic field sensor has a first output terminal and a second output terminal, the first output terminals of at least two magnetic field sensors are electrically connected to form a first connection node, and the second output terminals of at least two magnetic field sensors are electrically connected to form a second connection node. In this way, the voltage value of the first connection node can be equal to the average value of the output voltages of the first output terminals of the at least two magnetic field sensors, and the voltage value of the second connection node can be equal to the average value of the output voltages of the second output terminals of the at least two magnetic field sensors. In this way, the output voltages of the first output terminals of the at least two magnetic field sensors are averaged, and the output voltages of the second output terminals of the at least two magnetic field sensors are averaged through the hardware circuit, which saves the computing power of the digital processing module and reduces the delay of the digital processing module, thereby reducing the time required for the camera module in closed-loop autofocus and improving the efficiency of the camera module in closed-loop autofocus.

[0011] In some possible implementations, the detection unit further includes at least two current limiting elements. The first ends of the at least two current limiting elements are electrically connected to the output ends of the at least two magnetic field sensors in a one-to-one correspondence, and the second ends of the at least two current limiting elements are electrically connected to the connection node. The current limiting element is used to limit the current value of the current flowing between the output ends of any two magnetic field sensors. In this way, the current limiting element can be connected in series between the output end of the magnetic field sensor and the connection node, so that the current value of the current flowing between the output end of the magnetic field sensor and the connection node can be limited, that is, the current value of the current flowing between the output ends of any two magnetic field sensors can be limited. In this way, the risk of current flowing from the output end of one magnetic field sensor (for example, the first magnetic field sensor) to the output end of another magnetic field sensor (a magnetic field sensor other than the first magnetic field sensor, for example, the second magnetic field sensor) via the connection node can be reduced, thereby reducing the impact of the output ends of at least two magnetic field sensors being electrically connected to form a connection node on the output voltage of each magnetic field sensor, so that the voltage value of the connection node and the average value of the output voltage of at least two magnetic field sensors when the at least two magnetic field sensors are electrically connected to at least two operational amplifier modules can be roughly the same, thereby improving the reliability of the detection unit.

[0012] In some possible implementations, the current limiting element includes a first sub-element and a second sub-element. The first ends of at least two first sub-elements are electrically connected to the first output ends of at least two magnetic field sensors in a one-to-one correspondence, and the second ends of at least two first sub-elements are electrically connected to the first connection node. The first ends of at least two second sub-elements are electrically connected to the second output ends of at least two magnetic field sensors in a one-to-one correspondence, and the second ends of at least two second sub-elements are electrically connected to the second connection node. By providing the first sub-element, the risk of current flowing from the first output end of a magnetic field sensor (for example, the first magnetic field sensor) into the first output end of another magnetic field sensor (a magnetic field sensor other than the first magnetic field sensor, for example, the second magnetic field sensor) via the first connection node can be reduced; by providing the second sub-element, the risk of current flowing from the second output end of a magnetic field sensor (for example, the first magnetic field sensor) into the second output end of another magnetic field sensor (a magnetic field sensor other than the first magnetic field sensor, for example, the second magnetic field sensor) via the second connection node can be reduced, and the mutual influence between the first output ends of at least two magnetic field sensors and the mutual influence between the second output ends of at least two magnetic field sensors are reduced, that is, the influence on the output voltage of each magnetic field sensor after the output ends of at least two magnetic field sensors are electrically connected to form a connection node is reduced, and the influence of the different output internal resistance values ​​of at least two magnetic field sensors after the output ends of at least two magnetic field sensors are electrically connected, which leads to the decrease in sensitivity and linearity of the detection unit.

[0013] In some possible implementations, the first sub-element includes a first resistor, the second sub-element includes a second resistor, and the resistance value of the first resistor is equal to the resistance value of the second resistor; or, the first sub-element includes a plurality of first resistors, and the plurality of first resistors are electrically connected. The second sub-element includes a plurality of second resistors, and the plurality of second resistors are electrically connected. The resistance value of the plurality of first resistors after being electrically connected is equal to the resistance value of the plurality of second resistors after being electrically connected. Such an arrangement enables the first sub-element and the second sub-element to play a role in current limiting. In addition, the calculation process when calculating the amplification factor of the operational amplifier module is simplified, thereby improving the convenience of use of the detection unit.

[0014] In some possible implementations, the operational amplifier module includes a differential amplifier circuit. The differential amplifier circuit is configured to: obtain an average voltage value of the first output terminals of at least two magnetic field sensors, and an average voltage value of the second output terminals of at least two magnetic field sensors. Calculate the difference between the average voltage value of the first output terminals of at least two magnetic field sensors and the average voltage value of the second output terminals of at least two magnetic field sensors to obtain the average value of the output voltages of the at least two magnetic field sensors. Amplify the average value of the output voltages of at least two magnetic field sensors. The differential amplifier circuit can amplify and output the average value of the output voltages of at least two magnetic field sensors (the output voltage of the magnetic field sensor is the difference between the voltage value of the first output terminal of the magnetic field sensor and the voltage value of the second output terminal of the magnetic field sensor), thereby improving the accuracy of determining the distance between the lens and the image sensor according to the output voltage of the operational amplifier.

[0015] In some possible implementations, the differential amplifier circuit includes an operational amplifier, a third resistor, a fourth resistor, a fifth resistor, and a sixth resistor. The resistance of the third resistor is equal to the resistance of the fourth resistor. The resistance of the fifth resistor is equal to the resistance of the sixth resistor. The first end of the third resistor is electrically connected to the in-phase input terminal of the operational amplifier, and the second end of the third resistor is electrically connected to the first connection node. The first end of the fourth resistor is electrically connected to the inverting input terminal of the operational amplifier, and the second end of the fourth resistor is electrically connected to the second connection node. The first end of the fifth resistor is electrically connected to the in-phase input terminal of the operational amplifier, and the second end of the fifth resistor is electrically connected to the power supply terminal or the ground terminal. The first end of the sixth resistor is electrically connected to the inverting input terminal of the operational amplifier, and the second end of the sixth resistor is electrically connected to the output terminal of the operational amplifier. It can be understood that the second end of the fifth resistor is electrically connected to the power supply or the ground terminal, so that the current flowing out of the first output terminal of at least two magnetic field sensors can flow to the power supply terminal or the ground terminal after flowing through the third resistor and the fifth resistor, thereby improving the setting flexibility of the circuit structure. In addition, the non-inverting input terminal of the operational amplifier is electrically connected to the first connection node, and the inverting input terminal of the operational amplifier is electrically connected to the second connection node, so that the operational amplifier can obtain the average value of the output voltages of the first output terminals of at least two magnetic field sensors and the average value of the output voltages of the second output terminals of at least two magnetic field sensors, and the average value of the output voltages of the first output terminals of the at least two magnetic field sensors is subtracted from the average value of the output voltages of the second output terminals of the at least two magnetic field sensors to obtain the average value of the output voltages of the at least two magnetic field sensors.

[0016] In some possible implementations, the resistance of the third resistor and the resistance of the fourth resistor are much greater than the output internal resistance of the magnetic field sensor. This arrangement can reduce the impact of the output internal resistance of the magnetic field sensor on the amplification factor of the operational amplifier module, thereby improving the convenience of use of the detection unit.

[0017] In some possible implementations, the resistance value of the third resistor and the resistance value of the fourth resistor are a first resistance value, the resistance value of the fifth resistor and the resistance value of the sixth resistor are a second resistance value, and the second resistance value is m times the first resistance value, where m is a positive number and is greater than 1. With such an arrangement, the operational amplifier module can amplify the difference between the voltage value of the non-inverting input terminal of the operational amplifier and the voltage value of the inverting input terminal of the operational amplifier, that is, the operational amplifier module can amplify the difference between the average value of the output voltage of the first output terminals of at least two magnetic field sensors and the average value of the output voltage of the second output terminals of at least two magnetic field sensors, thereby increasing the output voltage output by the operational amplifier module and improving the accuracy of determining the distance between the lens and the image sensor according to the output voltage of the operational amplifier module.

[0018] In some possible implementations, the differential amplifier circuit is electrically connected to the power supply terminal (for example, the second end of the fifth resistor is electrically connected to the power supply terminal). The voltage value of the power supply terminal is -k times the average of the bias voltages of at least two magnetic field sensors. Wherein, k is the amplification factor of the operational amplifier module. In this way, the power supply terminal can compensate for the bias voltages of at least two magnetic field sensors, reduce the influence of the bias voltages of at least two magnetic field sensors on the input voltage and output voltage of the operational amplifier module, so that the operational amplifier module can continue to work in the linear range, and ensure the focusing accuracy of the camera module.

[0019] In some possible implementations, the detection unit further includes a first circuit board, and the first circuit board includes a conductive trace. The magnetic field sensor and the current limiting element are electrically connected through the conductive trace. In this way, the magnetic field sensor and the current limiting element can be located on the same circuit board (first circuit board), and the electrical connection is achieved through the conductive trace on the circuit board, which reduces the distance between the magnetic field sensor and the current limiting element, and is conducive to the miniaturization of the detection unit.

[0020] In some possible implementations, the resistances of at least two magnetic field sensors are equal, and the power input terminals of at least two magnetic field sensors are electrically connected to the same power supply; or, the number of power supplies is at least two, and the power input terminals of at least two magnetic field sensors are electrically connected to at least two power supplies in a one-to-one correspondence. When the resistances of at least two magnetic field sensors are equal, the power input terminals of at least two magnetic field sensors are electrically connected to the same power supply, which reduces the number of power supplies, reduces the cost of the camera module, and reduces the area occupied by the power supply on the circuit board (or in the chip). Or, the number of power supplies is set to at least two, and the power input terminals of at least two magnetic field sensors are electrically connected to at least two power supplies in a one-to-one correspondence, which can reduce the mutual influence of at least two power supplies when supplying power to at least two magnetic field sensors, and improve the accuracy of the camera module.

[0021] In some possible implementations, the output end of the operational amplifier module is electrically connected to the input end of the digital processing module. The digital processing module is used to generate a control signal based on the output result of the operational amplifier module. In this way, the digital processing module can obtain the output voltage of the operational amplifier module, and determine the distance between the lens and the image sensor according to the output voltage of the operational amplifier module to generate a control signal, so that other components (such as a driving unit) can be controlled according to the control signal, thereby realizing closed-loop autofocus of the camera module.

[0022] On the other hand, an embodiment of the present application provides a camera module. The camera module includes a lens, an image sensor and a detection unit. The detection unit is used to detect the distance between the lens and the image sensor.

[0023] The camera module provided in the embodiment of the present application includes the detection unit as described above, and therefore has all the above-mentioned beneficial effects, which will not be repeated here.

[0024] In some possible implementations, the detection unit includes an operational amplifier module, and the input end of the operational amplifier module is electrically connected to the connection node; or, the camera module also includes an operational amplifier module, and the input end of the operational amplifier module is electrically connected to the connection node. Such a configuration enables the operational amplifier module to amplify the average value of the output voltage of at least two magnetic field sensors without the need for additional average calculation, thereby improving the convenience of determining the distance between the lens and the image sensor and shortening the time required for the camera module to focus. In addition, the detection unit may include an operational amplifier module, or the camera module may include an operational amplifier module, which can improve the flexibility of the electronic device (such as the operational amplifier module) in the camera module and meet different usage requirements.

[0025] In some possible implementations, the detection unit also includes a power supply, which is electrically connected to the power input terminal of the magnetic field sensor; or the camera module also includes a power supply, which is electrically connected to the power input terminal of the magnetic field sensor. This arrangement enables the power supply to power the magnetic field sensor, so that the magnetic field sensor can work normally. In addition, the detection unit can include a power supply, or the camera module can include a power supply, which can improve the flexibility of the electronic components (such as the power supply) in the camera module and meet different usage requirements.

[0026] In some possible implementations, the camera module further includes a driving unit, which is used to drive the lens to move. The detection unit further includes a digital processing module, the input end of the digital processing module is electrically connected to the output end of the operational amplifier module, and the output end of the digital processing module is electrically connected to the driving unit; or, the camera module further includes a digital processing module, the input end of the digital processing module is electrically connected to the output end of the operational amplifier module, and the output end of the digital processing module is electrically connected to the driving unit. The input end of the digital processing module is electrically connected to the output end of the operational amplifier module, so that the digital processing module can obtain the output voltage of the operational amplifier module, and determine the distance between the lens and the image sensor according to the output voltage of the operational amplifier module to generate a control signal. The output end of the digital processing module is electrically connected to the driving unit, so that the digital processing module can control the driving unit based on the control signal, so that the driving unit can drive the lens to move according to the distance between the lens and the image sensor, so that the camera module can achieve closed-loop automatic focusing, which improves the accuracy and reliability of the camera module when focusing. The detection unit may include a digital processing module, or the camera module may include a digital processing module, which can improve the flexibility of setting electronic devices (such as digital processing modules) in the camera module and meet different usage requirements.

[0027] In another aspect, an embodiment of the present application provides an electronic device, which includes a housing and the camera module as described above, wherein the camera module is located in the housing, and a portion of the camera module is exposed to the housing.

[0028] The electronic device provided by the embodiment of the present application includes the camera module as described above, and therefore has all the above-mentioned beneficial effects, which will not be repeated here. In addition, the camera module is located in the housing, so that the housing can protect the camera module, reducing the risk of damage to the camera module. A portion of the camera module is exposed to the housing, so that light can be irradiated to the camera module, avoiding the housing from blocking the camera module, so that the camera module can realize the image acquisition function. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the structure of an electronic device provided in some embodiments of the present application;

[0030] Figure 2 A schematic diagram of the structure of a camera module provided in some embodiments of the present application;

[0031] Figure 3 A schematic diagram of the structure of a camera module provided for some embodiments of the present application without showing a magnet;

[0032] Figure 4 A schematic diagram of the positional relationship of a lens, a magnet and a magnetic field sensor provided in some embodiments of the present application;

[0033] Figure 5 An equivalent circuit diagram of a Hall sensor provided in some embodiments of the present application;

[0034] Figure 6 A schematic diagram of the connection relationship of the camera modules provided in some embodiments of the present application;

[0035] Figure 7 A schematic diagram of the circuit topology of a camera module provided in some embodiments of the present application;

[0036] Figure 8 A schematic diagram of a circuit topology of a camera module provided in some other embodiments of the present application;

[0037] Fig. 9 A schematic diagram of a curve showing the magnetic field strength detected by the magnetic field sensor according to some embodiments of the present application and the change with the distance between the lens and the image sensor;

[0038] Fig.10 A schematic diagram of the positional relationship of a lens, a magnet and a magnetic field sensor provided in other embodiments of the present application;

[0039] Fig.11 A schematic diagram of a curve showing the magnetic field strength detected by a magnetic field sensor and the change with the distance between the lens and the image sensor provided in some other embodiments of the present application;

[0040] Fig.12 A schematic diagram of a circuit topology of a camera module provided in some other embodiments of the present application;

[0041] Fig.13 A schematic diagram of the connection relationship of camera modules provided in other embodiments of the present application;

[0042] Fig.14 A schematic diagram of the connection relationship of camera modules provided in some embodiments of the present application;

[0043] Fig.15 A schematic diagram of a circuit topology of a camera module provided in some other embodiments of the present application;

[0044] Fig.16 A schematic diagram of the connection relationship of camera modules provided in some embodiments of the present application;

[0045] Fig.17 A schematic diagram of the connection relationship of camera modules provided in some embodiments of the present application;

[0046] Fig.18 A schematic diagram of a circuit topology of a camera module provided in some other embodiments of the present application;

[0047] Fig.19 A schematic diagram of a circuit topology of a camera module provided in some other embodiments of the present application;

[0048] Fig. 20 A schematic diagram of the connection relationship of camera modules provided in some embodiments of the present application;

[0049] Fig.21 A schematic diagram of the connection relationship of camera modules provided in some embodiments of the present application;

[0050] Fig. 22 A schematic diagram of a circuit topology of a camera module provided in some other embodiments of the present application;

[0051] Fig.23 A schematic diagram of a circuit topology of a camera module provided in some other embodiments of the present application;

[0052] Fig.24 A schematic diagram of a curve showing the magnetic field strength detected by a magnetic field sensor and changes with the distance between the lens and the image sensor provided in some other embodiments of the present application. DETAILED DESCRIPTION

[0053] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments provided by the present application, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present application.

[0054] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and other forms thereof, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open, inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present application. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics described may be included in any one or more embodiments or examples in any appropriate manner.

[0055] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, unless otherwise specified, "plurality" means two or more.

[0056] “At least one of A, B, and C” has the same meaning as “at least one of A, B, or C” and both include the following combinations of A, B, and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B, and C.

[0057] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0058] As used herein, "parallel", "perpendicular", and "equal" include the situations described and situations similar to the situations described, and the range of the similar situations is within the acceptable deviation range, wherein the acceptable deviation range is determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism may be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity may also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality may be, for example, the difference between the two equalities is less than or equal to 5% of either one.

[0059] Figure 1 A schematic diagram of the structure of an electronic device provided for some embodiments of the present application. Figure 2 A schematic diagram of the structure of a camera module provided in some embodiments of the present application. Figure 3 The camera module provided for some embodiments of the present application does not show a structural schematic diagram of the magnet. Figure 4 Schematic diagram of the positional relationship of the lens, magnet and magnetic field sensor provided in some embodiments of the present application.

[0060] like Figure 1 As shown, an embodiment of the present application provides an electronic device 300. The electronic device 300 may be an electronic device with an image acquisition function, such as a mobile phone, a computer, a camera, a phone watch, a wearable device, and a video camera, etc. It can be understood that the embodiment of the present application does not further limit the type of the electronic device 300.

[0061] like Figure 1As shown, the electronic device 300 may include a housing 301 and a camera module 200, wherein the camera module 200 is located in the housing 301. It can be understood that the housing 301 can enclose a receiving space, the camera module 200 is located in the receiving space enclosed by the housing 301, and a portion of the camera module 200 can be exposed to the housing 301.

[0062] The camera module 200 is arranged inside the housing 301, so that the housing 301 can protect the camera module 200, reducing the risk of damage to the camera module 200. A portion of the camera module 200 is arranged to be exposed to the housing 301, so that light can irradiate the camera module 200, avoiding the housing 301 from blocking the camera module 200, so that the camera module 200 can realize the image acquisition function.

[0063] In some examples, the electronic device 300 may include one camera module 200. In other examples, the electronic device 300 may also include multiple camera modules 200. The embodiment of the present application does not further limit the number of camera modules 200 included in the electronic device 300.

[0064] In some examples, such as Figure 2 and Figure 3 As shown, the camera module 200 may include a housing 202 and a lens 221. For example, the lens 221 may include one or more of a convex lens, a concave lens or other optical lenses. The lens 221 has an optical axis, and the optical axis may extend along a first direction X. Figure 1 The housing 301 of the electronic device 300 may have a through hole Q, and the light passing through the through hole Q may directly irradiate the lens 221 , or the light passing through the through hole Q may also be reflected to the lens 221 .

[0065] like Figure 4 As shown, the camera module 200 may further include an image sensor 201, and the image sensor 201 may be located in the housing 202. For example, the image sensor 201 may be disposed on a circuit board (e.g., a PCB board, the full English name: Printed Circuit Board, Chinese name: printed circuit board), and the circuit board may be connected to the housing 202 by bonding or bolting, so that the image sensor 201 is connected to the housing 202 through the circuit board.

[0066] like Figure 4As shown, along the first direction X (that is, along the direction along which the optical axis of the lens 221 extends), the image sensor 201 is located on one side of the lens 221. The light irradiated to the lens 221 can be irradiated to the image sensor 201 under the effect of reflection or refraction of the lens 221, and the image sensor 201 can obtain image information through the light irradiated to itself, so that the camera module 200 can realize the image acquisition function.

[0067] It can be understood that when collecting image information, the lens 221 needs to move relative to the image sensor 201 along the extension direction of the optical axis (the first direction X) to achieve focusing, so that the camera module 200 can clearly collect image information at different positions along the first direction X. In order to achieve the focusing function, Figure 2 and Figure 3 As shown, the camera module 200 may further include a motor 210 , and the motor 210 may be located inside the housing 202 .

[0068] The motor 210 may include a driving unit 211 and a detection unit 100, that is, the camera module 200 may include a driving unit 211 and a detection unit 100. The driving unit 211 is used to drive the lens 221 to move (move along the first direction X), and the detection unit 100 is used to detect the distance between the lens 221 and the image sensor 201. In this way, the driving unit 211 can drive the lens 221 to move along the first direction X according to the distance between the lens 221 and the image sensor 201, so that the camera module 200 can achieve closed-loop auto focus (English full name: Auto Focus, English abbreviation: AF), thereby improving the performance of the camera module 200.

[0069] In some examples, the camera module 200 may include a magnet 222 , and the detection unit 100 may include a magnetic field sensor 101 .

[0070] For example, the magnet 222 may be a single magnet or an array of multiple magnets. Figure 4 The dotted line in the figure represents the magnetic field generated by the magnet 222, and the arrow on the dotted line represents the direction of the magnetic field. Figure 4 Only one magnet 222 and the magnetic field generated by the magnet 222 are shown, and no further limitation is imposed on the number of magnets 222 and the strength of the magnetic field generated by the magnet 222 in the embodiment of the present application.

[0071] It can be understood that the magnetic field sensor 101 has a detection direction (a specific direction, such as Figure 4The magnetic field sensor 101 can detect the magnetic field strength of its current position in the magnetic field in the detection direction, and convert the detected magnetic field strength into a corresponding electrical signal, such as a voltage signal. The output voltage of the magnetic field sensor 101 can be proportional to the magnetic field strength detected by the magnetic field sensor 101.

[0072] By way of example, the magnetic field sensor 101 can be any one of a Hall sensor, a TMR (English full name: Tunnel Magneto Resistance, Chinese name: tunnel magnetoresistance) sensor, a GMR (English full name: Giant Magneto Resistive, Chinese name: giant magnetoresistance) sensor and an AMR (English full name: Anisotropy of Magneto Resistance, Chinese name: anisotropic magnetoresistance) sensor.

[0073] In some examples, one of the magnet 222 and the magnetic field sensor 101 may be fixed relative to the lens 221, and the other may be fixed relative to the image sensor 201. When the lens 221 moves along the first direction X, the relative position between the magnet 222 and the magnetic field sensor 101 will change, so that the position of the magnetic field sensor 101 in the magnetic field will change, so that the magnetic field strength in the detection direction of the magnetic field sensor 101 will change, and the output voltage of the magnetic field sensor 101 can also change.

[0074] It can be understood that during the focusing process, the magnetic field strength detected by the magnetic field sensor 101 corresponds to the distance between the lens 221 and the image sensor 201, and the magnetic field strength detected by the magnetic field sensor 101 corresponds to the output voltage of the magnetic field sensor 101, so that the output voltage of the magnetic field sensor 101 can correspond to the distance between the lens 221 and the image sensor 201 one by one, and the distance between the lens 221 and the image sensor 201 can be obtained according to the output voltage of the magnetic field sensor 101.

[0075] For example, during the production process of the camera module 200, the corresponding relationship between the output voltage of the magnetic field sensor 101 and the distance between the lens 221 and the image sensor 201 can be calibrated. That is, the distance between the lens 221 and the image sensor 201 is obtained by laser ranging, and different output voltages of the magnetic field sensor 101 are obtained when the lens 221 and the image sensor 201 are at different distances. The output voltage of the magnetic field sensor 101 and the distance between the lens 221 and the image sensor 201 are matched one by one to improve the linearity of the relationship curve between the two, thereby improving the accuracy and reliability of the camera module 200 in closed-loop autofocus.

[0076] It is understandable that in different camera modules 200 , when the distance between the lens 221 and the image sensor 201 is the same, the output voltage of the magnetic field sensor 101 may be the same or different.

[0077] The embodiments of the present application take the magnet 222 and the lens 221 being relatively fixed, the magnetic field sensor 101 and the housing 202 and the image sensor 201 as examples for further explanation.

[0078] It can be understood that the lens 221 and the magnet 222 are relatively fixed, that is, the lens 221 and the magnet 222 can remain relatively still. In some examples, the lens 221 can be connected to the magnet 222, such as a fixed connection or a detachable connection, so that the lens 221 and the magnet 222 can be relatively fixed. In other examples, the camera module 200 may include a fixing member (not shown in the figure), and the lens 221 and the magnet 222 are respectively connected to the fixing member, so that the lens 221 and the magnet 222 can be relatively fixed.

[0079] In some examples, the magnet 222 may be located on one side of the lens 221 along the second direction Y. In other examples, the magnet 222 may also be located on one side of the lens 221 along the third direction Z. Such an arrangement can prevent the magnet 222 from blocking the light. It can be understood that the second direction Y intersects with the first direction X. For example, the second direction Y and the first direction X may be perpendicular or approximately perpendicular. The third direction Z intersects with the plane where the first direction X and the second direction Y are located. For example, the third direction Z may be perpendicular or approximately perpendicular to the plane where the first direction X and the second direction Y are located.

[0080] In some examples, there may be multiple magnets 222. For example, multiple magnets 222 may be located on both sides of the lens 221 along the second direction Y; or, multiple magnets 222 may be located on both sides of the lens 221 along the third direction Z; or, a portion of the multiple magnets 222 may be located on one side or both sides of the lens 221 along the second direction Y, and another portion of the multiple magnets 222 may be located on one side or both sides of the lens 221 along the third direction Z.

[0081] In some examples, such as Figure 4 As shown, the magnetic field sensor 101 is connected to the housing 202 and is located on one side of the lens 221 along the second direction Y (or along the third direction Z), so that the magnetic field sensor 101 can be fixed relative to the image sensor 201. In some examples, the magnetic field sensor 101 and the magnet 222 are located on the same side of the lens 221 to improve the accuracy of the magnetic field sensor 101 in detecting the magnetic field strength.

[0082] In some examples, the driving unit 211 of the motor 210 may directly drive the lens 221 to move along the first direction X. In other examples, the driving unit 211 of the motor 210 may also drive the magnet 222 to move along the first direction X, and the lens 221 may be driven to move along the first direction X by the magnet 222 .

[0083] When the motor 210 drives the lens 221 to move through the magnet 222, the magnet 222 driven by the motor 210 and the magnet 222 detected by the detection unit 100 can be the same magnet 222 to simplify the structure of the camera module 200. Alternatively, the magnet 222 driven by the motor 210 and the magnet 222 detected by the detection unit 100 can also be different magnets 222. At this time, one of the magnets 222 can be located on one side of the lens 221 along the second direction Y, and the other magnet 222 can be located on one side of the lens 221 along the third direction Z to reduce the mutual influence between the motor 210 and the magnetic field sensor 101.

[0084] In some examples, the driving unit 211 may include a motor coil, and a magnetic field can be generated around the motor coil by energizing the motor coil. It can be understood that when the current flowing through the motor coil changes, the magnetic field generated by the motor coil can change. The magnetic field generated by the motor coil interacts with the magnetic field of the magnet 222 (attracting or repelling each other), so that the motor coil can drive the magnet 222 to move along the first direction X, so that the magnet 222 can drive the lens 221 to move along the first direction X.

[0085] For example, the number of motor coils can be two, and the two motor coils respectively drive the two magnets 222 located on both sides of the lens 221 along the second direction Y to move, so that the two magnets 222 located on both sides of the lens 221 along the second direction Y can jointly drive the lens 221 to move along the first direction X, so as to improve the stability and reliability of the driving unit 211 when driving the lens 221 to move.

[0086] In some other examples, the driving unit 211 may also include a motor, and the motor provides a driving force to enable the lens 221 to move along the first direction X to achieve closed-loop autofocus.

[0087] Figure 5 An equivalent circuit diagram of a Hall sensor provided in some embodiments of the present application. Figure 6 A schematic diagram of the connection relationship of the camera modules provided in some embodiments of the present application. Figure 7 A schematic diagram of the circuit topology of a camera module provided for some embodiments of the present application. Figure 8 A schematic diagram of the circuit topology of a camera module provided for some other embodiments of the present application.

[0088] Take the magnetic field sensor 101 as a Hall sensor as an example, see Figure 5 , the Hall sensor can be equivalent to a first equivalent resistor Ra, a second equivalent resistor Rb, a third equivalent resistor Rc and a fourth equivalent resistor Rd. It can be understood that Figure 5 This is the equivalent circuit diagram of the Hall sensor, not the actual circuit structure inside the Hall sensor.

[0089] like Figure 5 As shown, the first end of the first equivalent resistor Ra is electrically connected to the first end of the third equivalent resistor Rc, the second end of the first equivalent resistor Ra is electrically connected to the first end of the second equivalent resistor Rb, the second end of the third equivalent resistor Rc is electrically connected to the first end of the fourth equivalent resistor Rd. The second end of the second equivalent resistor Rb is electrically connected to the second end of the fourth equivalent resistor Rd.

[0090] like Figure 5 As shown, the first end of the first equivalent resistor Ra and the first end of the third equivalent resistor Rc can be the first power input terminal 101a1 of the magnetic field sensor 101 (Hall sensor), and the second end of the second equivalent resistor Rb and the second end of the fourth equivalent resistor Rd can be the second power input terminal 101a2 of the magnetic field sensor 101 (Hall sensor).

[0091] like Figure 6 and Figure 7 As shown, the power supply 420 may be electrically connected to the power input terminal 101 a (including the first power input terminal 101 a 1 and the second power input terminal 101 a 2 ) of the magnetic field sensor 101 to supply power to the magnetic field sensor 101 .

[0092] In some examples, the power supply 420 can provide current for the magnetic field sensor 101, and the magnetic field sensor 101 operates in a current driving mode. At this time, the power supply 420 can be a current source (English: current source) or a current sink (English: current sink). When the power supply 420 is a current source, the first power input terminal 101a1 of the magnetic field sensor 101 can be electrically connected to the current source, and the second power input terminal 101a2 of the magnetic field sensor 101 can be grounded. When the power supply is a current sink, the current sink can be electrically connected to the second power input terminal 101a2 of the magnetic field sensor 101.

[0093] In other examples, the power supply 420 can provide voltage for the magnetic field sensor 101, and the magnetic field sensor 101 operates in a voltage drive mode. At this time, the power supply 420 can be a voltage source (English: voltage source) or a voltage sink (English: voltage sink). When the power supply 420 is a voltage source, the first power input terminal 101a1 of the magnetic field sensor 101 can be electrically connected to the voltage source, and the second power input terminal 101a2 of the magnetic field sensor 101 can be grounded. When the power supply 420 is a voltage sink, the voltage sink can be electrically connected to the second power input terminal 101a2 of the magnetic field sensor 101. It can be understood that the power supply 420 can also be other forms of power supplies, and the embodiments of the present application do not further limit the circuit structure of the power supply 420.

[0094] In some examples, the detection unit 100 may include a power supply 420 . In other examples, the camera module 200 may include a power supply 420 .

[0095] For example, the detection unit 100 may include a first circuit board (not shown in the figure), and the circuit board may be a PCB (full name in English: Printed Circuit Board, Chinese name: printed circuit board). The first circuit board may include a conductive trace, for example, the conductive layer (copper layer) of the circuit board may be etched to form the conductive trace. The magnetic field sensor 101 may be located on the first circuit board of the detection unit 100 and electrically connected to the conductive trace.

[0096] When the detection unit 100 includes a power supply 420, the power supply 420 may be located on a first circuit board of the detection unit 100, and the power supply 420 may be electrically connected to the magnetic field sensor 101 through a conductive trace. When the camera module 200 includes a power supply 420, the power supply 420 may be located on a circuit board other than the first circuit board of the detection unit 100, and may be electrically connected to the magnetic field sensor 101 through a structure such as a cable.

[0097] It is understandable that the power supply 420 is electrically connected to the power input terminal 101a of the magnetic field sensor 101, so that the power supply 420 can supply power to the magnetic field sensor 101, so that the magnetic field sensor 101 can work normally. In addition, the detection unit 100 is configured to include the power supply 420, or the camera module 200 is configured to include the power supply 420, which can improve the flexibility of setting the electronic components (such as the power supply 420) in the camera module 200 to meet different usage requirements. It is understandable that in the embodiments of the present application, the electronic device can be a complete working system including one or more electronic components (capacitors, resistors, switching tubes, etc.), or it can be a subsystem in a working system (such as a chip) including one or more electronic components. Figure 5 As shown, the second end of the first equivalent resistor Ra and the first end of the second equivalent resistor Rb can be the first output end 101b1 of the magnetic field sensor 101 (Hall sensor), and the second end of the third equivalent resistor Rc and the first end of the fourth equivalent resistor Rd can be the second output end 101b2 of the magnetic field sensor 101 (Hall sensor).

[0098] It can be understood that when the magnetic field strength in the detection direction of the current position of the Hall sensor in the magnetic field changes, the resistance value of at least one of the first equivalent resistor Ra, the second equivalent resistor Rb, the third equivalent resistor Rc, and the fourth equivalent resistor Rd will change, so that the output voltage of the first output terminal 101b1 of the magnetic field sensor 101 or the output voltage of the second output terminal 101b2 of the magnetic field sensor 101 will change. The output voltage of the magnetic field sensor 101 is the difference between the output voltage of the first output terminal 101b1 of the magnetic field sensor 101 and the output voltage of the second output terminal 101b2 of the magnetic field sensor 101. In this way, when the output voltage of the first output terminal 101b1 of the magnetic field sensor 101 or the output voltage of the second output terminal 101b2 of the magnetic field sensor 101 changes, the output voltage of the magnetic field sensor 101 will change.

[0099] like Figure 6 As shown, the output terminal 101b of the magnetic field sensor 101 can be electrically connected to the input terminal 410a of the operational amplifier module 410, so that the operational amplifier module 410 can obtain the output voltage of the magnetic field sensor 101 and amplify the output voltage of the magnetic field sensor 101. In some examples, the operational amplifier module 410 may include a PGA (English full name: Programmable Gain Amplifier, Chinese name: Programmable Gain Amplifier).

[0100] For example, Figure 7 and Figure 8As shown, the input end 410a of the operational amplifier module 410 can be electrically connected to the first output end 101b1 of the magnetic field sensor 101 to obtain the output voltage of the first output end 101b1 of the magnetic field sensor 101. In addition, the input end 410a of the operational amplifier module 410 can also be electrically connected to the second output end 101b2 of the magnetic field sensor 101 to obtain the output voltage of the second output end 101b2 of the magnetic field sensor 101. The operational amplifier module 410 can calculate the difference between the output voltage of the first output end 101b1 of the magnetic field sensor 101 and the output voltage of the second output end 101b2 of the magnetic field sensor 101, and amplify the difference between the output voltage of the first output end 101b1 of the magnetic field sensor 101 and the output voltage of the second output end 101b2 of the magnetic field sensor 101, that is, the operational amplifier module 410 can amplify the output voltage of the magnetic field sensor 101.

[0101] Since the output voltage of the magnetic field sensor 101 corresponds to the distance between the lens 221 and the image sensor 201, the operational amplifier module 410 amplifies the output voltage of the magnetic field sensor 101 so that the output voltage of the operational amplifier module 410 can correspond to the distance between the lens 221 and the image sensor 201. In this way, the distance between the lens 221 and the image sensor 201 can be determined according to the output voltage of the operational amplifier module 410.

[0102] It can be understood that since the output voltage of the operational amplifier module 410 is greater than the output voltage of the magnetic field sensor 101, determining the distance between the lens 221 and the image sensor 201 based on the output voltage of the operational amplifier module 410 can improve the accuracy in determining the distance between the lens 221 and the image sensor 201.

[0103] In some examples, the detection unit 100 may include an operational amplifier module 410 . In other examples, the camera module 200 may include an operational amplifier module 410 .

[0104] When the detection unit 100 includes the operational amplifier module 410, the operational amplifier module 410 may be located on the first circuit board of the detection unit 100, and the operational amplifier module 410 may be electrically connected to the magnetic field sensor 101 through a conductive trace. When the camera module 200 includes the operational amplifier module 410, the operational amplifier module 410 may be located on a circuit board other than the first circuit board of the detection unit 100, and may be electrically connected to the magnetic field sensor 101 through a structure such as a cable.

[0105] It can be understood that the detection unit 100 can be set to include an operational amplifier module 410, or the camera module 200 can be set to include an operational amplifier module 410, which can improve the setting flexibility of electronic devices (such as the operational amplifier module 410) in the camera module 200 and meet different usage requirements.

[0106] In an ideal state, if the magnetic field strength in the detection direction of the current position of the magnetic field sensor 101 in the magnetic field is zero, the output voltage of the magnetic field sensor 101 is also zero. If the magnetic field strength in the detection direction of the current position of the magnetic field sensor 101 in the magnetic field is p (p represents any magnetic field strength except zero), the output voltage of the magnetic field sensor 101 is q (q represents the voltage value corresponding to the magnetic field strength p, and q is not equal to zero).

[0107] However, the magnetic field sensor 101 usually has a bias voltage, which is the output voltage of the magnetic field sensor 101 when the magnetic field strength in the detection direction of the current position of the magnetic field sensor 101 in the magnetic field is zero. For example, when the magnetic field strength in the detection direction of the current position of the magnetic field sensor 101 in the magnetic field is zero, the output voltage of the magnetic field sensor 101 is x, where x is the bias voltage of the magnetic field sensor 101 (x is not equal to zero). When the magnetic field strength in the detection direction of the current position of the magnetic field sensor 101 in the magnetic field is p, the output voltage of the magnetic field sensor 101 is q+x. It can be seen that the bias voltage affects the output voltage of the magnetic field sensor 101.

[0108] Since the output terminal 101b of the magnetic field sensor 101 is electrically connected to the input terminal 410a of the operational amplifier module 410, the bias voltage of the magnetic field sensor 101 will be amplified by the operational amplifier module 410, affecting the input voltage and output voltage of the operational amplifier module 410, thereby affecting the accuracy of determining the distance between the lens 221 and the image sensor 201 based on the output voltage of the operational amplifier module 410.

[0109] Based on this, Figure 7 and Figure 8 As shown, in some examples, the input terminal 410a of the operational amplifier module 410 (e.g., the non-inverting input terminal OP1 of the operational amplifier OP) can be electrically connected to the power supply terminal VDD, and the power supply terminal VDD plays a role in compensating the bias voltage of the magnetic field sensor 101. For example, the voltage value of the power supply terminal VDD is -k times the bias voltage of the magnetic field sensor 101, where k is the amplification factor of the operational amplifier module 410.

[0110] It can be understood that the output voltage of the operational amplifier module 410 and the magnetic field strength in the detection direction at the current position of the magnetic field sensor 101 in the magnetic field satisfy formula (1).

[0111]

[0112] Among them, V out is the output voltage of the operational amplifier module 410, VDD is the voltage value of the power supply terminal VDD, k is the amplification factor of the operational amplifier module 410, Vp is the output voltage of the first output terminal 101b1 of the magnetic field sensor 101, and Vn is the output voltage of the second output terminal 101b2 of the magnetic field sensor 101. offset is the bias voltage of the magnetic field sensor 101, I is the current value of the current flowing through the magnetic field sensor 101, B is the magnetic field strength of the magnetic field sensor 101 in the current position in the magnetic field in the detection direction, R H is the Hall coefficient of the magnetic field sensor 101 , and d is the thickness of the semiconductor magnetoelectric device (eg, Hall element) in the magnetic field sensor 101 along the magnetic field direction.

[0113] It can be understood that the voltage value of the power supply terminal VDD is -k times the bias voltage of the magnetic field sensor 101, so that the voltage value of the power supply terminal VDD is k*V offset can offset each other, reducing the bias voltage of the magnetic field sensor 101 on the input voltage and output voltage V of the operational amplifier module 410. out The effect caused by this is to increase the output voltage V of the operational amplifier module 410. out Accuracy in determining the distance between lens 221 and image sensor 201 .

[0114] In some examples, such as Figure 6 As shown, the output terminal 410b of the operational amplifier module 410 is electrically connected to the input terminal 430a of the digital processing module 430 (that is, the input terminal 430a of the digital processing module 430 is electrically connected to the output terminal 410b of the operational amplifier module 410), and the digital processing module 430 is used to generate a control signal based on the output result of the operational amplifier module 410.

[0115] It is understandable that the digital processing module 430 is used to implement digital processing and calculation functions. In some examples, the digital processing module 430 may include a CPU (full name: Central-Processing-Unit, Chinese name: Central Processing Unit), and in other examples, the digital processing module 430 may also include other processing chips.

[0116] The input terminal 430a of the digital processing module 430 is electrically connected to the output terminal 410b of the operational amplifier module 410, so that the digital processing module 430 can obtain the output voltage of the operational amplifier module 410, and determine the distance between the lens 221 and the image sensor 201 according to the output point voltage of the operational amplifier module 410 to generate a control signal, so that other components (such as the driving unit 211) can be controlled according to the control signal, so that the camera module 200 can achieve closed-loop autofocus.

[0117] In some examples, such as Figure 6 As shown, the output end 430b of the digital processing module 430 can be electrically connected to the driving unit 211. For example, the digital processing module 430 may include a plurality of output ports 430b, a portion (one, two or more) of the plurality of output ports 430b may be electrically connected to the driving unit 211, and another portion (one, two or more) of the plurality of output ports 430b may be electrically connected to other control elements.

[0118] It can be understood that the output terminal 430b of the digital processing module 430 is electrically connected to the driving unit 211, so that the digital processing module 430 can control the driving unit 211 based on the control signal, so that the driving unit 211 can drive the lens 221 to move according to the current distance between the lens 221 and the image sensor 201, so that the camera module 200 can achieve closed-loop autofocus control, thereby improving the accuracy and reliability of the camera module 200 during autofocus.

[0119] In some examples, the detection unit 100 may further include a digital processing module 430. In other examples, the camera module 200 may further include a digital processing module 430.

[0120] When the detection unit 100 includes the digital processing module 430, the digital processing module 430 may be located on the first circuit board of the detection unit 100, and the digital processing module 430 may be electrically connected to the magnetic field sensor 101 through a conductive trace. When the camera module 200 includes the digital processing module 430, the digital processing module 430 may be located on a circuit board other than the first circuit board of the detection unit 100, and may be electrically connected to the magnetic field sensor 101 through a structure such as a cable.

[0121] It can be understood that the detection unit 100 can be set to include a digital processing module 430, or the camera module 200 can be set to include a digital processing module 430, which can improve the setting flexibility of electronic devices (such as the digital processing module 430) in the camera module 200 and meet different usage requirements.

[0122] In some examples, at least two of the power supply 420, the operational amplifier module 410, and the digital processing module 430 may be located on the same circuit board (or in the same chip). When at least two of the power supply 420, the operational amplifier module 410, and the digital processing module 430 are located on the same circuit board (or in the same chip), the detection unit 100 may be located on the circuit board (or in the chip) or on another circuit board (or in the chip).

[0123] In other examples, the power supply 420, the operational amplifier module 410, and the digital processing module 430 may also be located on different circuit boards (or in different chips). The detection unit 100 may be located on the same circuit board (or in the same chip) as any one of the power supply 420, the operational amplifier module 410, and the digital processing module 430, or may be located on other circuit boards (or in chips).

[0124] In some examples, such as Figure 8 As shown, the camera module 200 may further include a switch 203, which is connected in series between the output terminal 410b of the operational amplifier module 410 and the input terminal 430a of the digital processing module 430, and is used to control the conduction or disconnection between the output terminal 410b of the operational amplifier module 410 and the input terminal 430a of the digital processing module 430.

[0125] Fig. 9 A schematic diagram of a curve showing the magnetic field strength detected by a magnetic field sensor according to some embodiments of the present application and the variation of the distance between the lens and the image sensor.

[0126] Fig. 9 The horizontal axis represents the distance between the lens 221 and the image sensor 201. Fig. 9 The vertical axis represents the magnetic field strength detected by the magnetic field sensor 101. It can be understood that when the lens 221 moves along the first direction X, the distance between the lens 221 and the image sensor 201 will change. The magnet 222 is relatively fixed to the lens 221, so that the distance between the magnet 222 and the image sensor 201 will change. The magnetic field sensor 101 and the image sensor 201 are relatively fixed, so that the relative arrangement between the magnet 222 and the magnetic field sensor 101 will change, so that the magnetic field strength in the detection direction of the current position of the magnetic field sensor 101 in the magnetic field will change, that is, the magnetic field strength detected by the magnetic field sensor 101 will change.

[0127] Depend on Fig. 9It can be seen that the distance between the lens 221 and the image sensor 201 and the magnetic field strength detected by the magnetic field sensor 101 only present a good linear correspondence in a certain area. For example, this area can be called a linear area (e.g. Fig. 9 Outside the linear region, the linear relationship between the distance between the lens 221 and the image sensor 201 and the magnetic field strength detected by the magnetic field sensor 101 is poor. Even outside the linear region, the same magnetic field strength may correspond to multiple distances between the lens 221 and the image sensor 201, affecting the one-to-one correspondence between the two.

[0128] In order to make the distance between the lens 221 and the image sensor 201 and the magnetic field strength detected by the magnetic field sensor 101 correspond one to one, and thus make the distance between the lens 221 and the image sensor 201 and the output voltage of the magnetic field sensor 101 correspond one to one, the lens 221 can only move within the range corresponding to the linear region.

[0129] Taking the electronic device 300 as a mobile phone as an example, the camera module 200, as one of the core components of the mobile phone, has an increasing requirement for the focusing stroke (i.e., movable range) of the lens 221. Therefore, it is necessary to increase the width of the linear region in the relationship curve between the distance between the lens 221 and the image sensor 201 and the magnetic field strength detected by the magnetic field sensor 101.

[0130] Fig.10 Schematic diagram of the positional relationship of the lens, magnet and magnetic field sensor provided in other embodiments of the present application. Fig.11 A schematic diagram of a curve showing the magnetic field strength detected by a magnetic field sensor and changes with the distance between the lens and the image sensor provided in some other embodiments of the present application. Fig.12 A circuit topology diagram of a camera module provided for some further embodiments of the present application.

[0131] In some implementations, it is possible, for example Fig.10 As shown, the detection unit 100 may include at least two magnetic field sensors 101. For example, the detection unit 100 may include two, three or more magnetic field sensors 101, and the embodiment of the present application does not further limit the number of magnetic field sensors 101 included in the detection unit 100.

[0132] like Fig.10 As shown, taking the detection unit 100 including three magnetic field sensors 101 as an example, the three magnetic field sensors 101 may include a first magnetic field sensor 1011, a second magnetic field sensor 1012, and a third magnetic field sensor 1013. The first magnetic field sensor 1011, the second magnetic field sensor 1012, and the third magnetic field sensor 1013 may be arranged on the housing 202 of the camera module 200 along the first direction X at intervals.

[0133] It can be understood that when the magnet 222 moves along the first direction X, the positions of the first magnetic field sensor 1011, the second magnetic field sensor 1012, and the third magnetic field sensor 1013 in the magnetic field are not the same, so that the magnetic field strengths detected by the first magnetic field sensor 1011, the second magnetic field sensor 1012, and the third magnetic field sensor 1013 are different, so that the output voltages of the first magnetic field sensor 1011, the second magnetic field sensor 1012, and the third magnetic field sensor 1013 are not the same. For example, the distance between the lens 221 and the image sensor 201 can be determined according to the output voltages of the first magnetic field sensor 1011, the second magnetic field sensor 1012, and the third magnetic field sensor 1013.

[0134] like Fig.11 As shown, Fig.11 The horizontal axis represents the distance between the lens 221 and the image sensor 201. Fig.11 The vertical axis represents the magnetic field intensity detected by the magnetic field sensor 101 .

[0135] Curve a represents the correspondence between the distance between the lens 221 and the image sensor 201, and the magnetic field strength detected by the first magnetic field sensor 1011, curve b represents the correspondence between the distance between the lens 221 and the image sensor 201, and the magnetic field strength detected by the second magnetic field sensor 1012, curve c represents the correspondence between the distance between the lens 221 and the image sensor 201, and the magnetic field strength detected by the third magnetic field sensor 1013, and curve d represents the correspondence between the distance between the lens 221 and the image sensor 201, and the sum of the magnetic field strength detected by the first magnetic field sensor 1011, the magnetic field strength detected by the second magnetic field sensor 1012, and the magnetic field strength detected by the third magnetic field sensor 1013.

[0136] For example, curve a, curve b and curve c can be superimposed to obtain curve d. Fig.11 It can be seen that the trends of curves a, b and c are Fig. 9 The trend of the curve e is roughly the same, and after superimposing the magnetic field intensities detected by the first magnetic field sensor 1011, the second magnetic field sensor 1012 and the third magnetic field sensor 1013, the linear region of the curve d is obtained (see Fig.11 The width of the second region M2) is greater than Fig. 9 The linear region of curve e (see Fig. 9 The width of the first area M1) in.

[0137] It can be seen that by providing at least two magnetic field sensors 101 to respectively detect the distance between the lens 221 and the image sensor 201 , the width of the linear region in the relationship curve between the distance between the lens 221 and the image sensor 201 and the magnetic field strength detected by the magnetic field sensor 101 can be increased, thereby increasing the focusing stroke of the lens 221 .

[0138] In some implementations, such as Fig.12 As shown, the number of operational amplifier modules 410 may be the same as the number of magnetic field sensors 101. Taking the number of magnetic field sensors 101 as an example, the number of operational amplifier modules 410 may also be three, and the three operational amplifier modules 410 may include a first operational amplifier module 4101, a second operational amplifier module 4102, and a third operational amplifier module 4103.

[0139] like Fig.12 As shown, the input terminal 410a of the first operational amplifier module 4101 can be electrically connected to the output terminal 101b of the first magnetic field sensor 1011, so that the first operational amplifier module 4101 can amplify the output voltage of the first magnetic field sensor 1011. The input terminal 410a of the second operational amplifier module 4102 can be electrically connected to the output terminal 101b of the second magnetic field sensor 1012, so that the second operational amplifier module 4102 can amplify the output voltage of the second magnetic field sensor 1012. The input terminal 410a of the third operational amplifier module 4103 can be electrically connected to the output terminal 101b of the third magnetic field sensor 1013, so that the third operational amplifier module 4103 can amplify the output voltage of the third magnetic field sensor 1013.

[0140] like Fig.12 As shown, the input terminal 430a of the digital processing module 430 can be electrically connected to the output terminal 410b of the first operational amplifier module 4101, the output terminal 410b of the second operational amplifier module 4102, and the output terminal 410b of the third operational amplifier module 4103, so that the digital processing module 430 can obtain the output voltages of the first operational amplifier module 4101, the second operational amplifier module 4102, and the third operational amplifier module 4103.

[0141] In some examples, such as Fig.12As shown, the switch 203 may include a first switch 2031, a second switch 2032, and a third switch 2033. The first switch 2031 is connected in series between the output terminal 410b of the first operational amplifier module 4101 and the input terminal 430a of the digital processing module 430 to control the conduction or disconnection between the output terminal 410b of the first operational amplifier module 4101 and the input terminal 430a of the digital processing module 430. The second switch 2032 is connected in series between the output terminal 410b of the second operational amplifier module 4102 and the input terminal 430a of the digital processing module 430 to control the conduction or disconnection between the output terminal 410b of the second operational amplifier module 4102 and the input terminal 430a of the digital processing module 430. The third switch 2033 is connected in series between the output terminal 410b of the third operational amplifier module 4103 and the input terminal 430a of the digital processing module 430 to control the conduction or disconnection between the output terminal 410b of the third operational amplifier module 4103 and the input terminal 430a of the digital processing module 430.

[0142] The digital processing module 430 can respectively obtain the output voltages of the first operational amplifier module 4101, the second operational amplifier module 4102, and the third operational amplifier module 4103. In some examples, the first switch 2031 can be controlled to be closed within a unit acquisition time period (for example, within 1 second), so that the digital processing module 430 can obtain the output voltage of the first operational amplifier module 4101; then, the first switch 2031 is controlled to be disconnected and the second switch 2032 is controlled to be closed, so that the digital processing module 430 can obtain the output voltage of the second operational amplifier module 4102; then, the second switch 2032 is controlled to be disconnected and the third switch 2033 is controlled to be closed, so that the digital processing module 430 can obtain the output voltage of the third operational amplifier module 4103. In other examples, the first switch 2031, the second switch 2032, and the third switch 2033 can also be closed and opened in other orders.

[0143] In some examples, the digital processing module 430 can calculate the sum of the output voltages of the first operational amplifier module 4101, the second operational amplifier module 4102, and the third operational amplifier module 4103 to determine the distance between the lens 221 and the image sensor 201 through the sum of the output voltages of the first operational amplifier module 4101, the second operational amplifier module 4102, and the third operational amplifier module 4103.

[0144] In other examples, the digital processing module 430 can calculate the average of the output voltages of the first operational amplifier module 4101, the second operational amplifier module 4102, and the third operational amplifier module 4103 to determine the distance between the lens 221 and the image sensor 201 through the average of the output voltages of the first operational amplifier module 4101, the second operational amplifier module 4102, and the third operational amplifier module 4103.

[0145] That is, in the above implementation, it is necessary to set up multiple operational amplifier modules 410 to be electrically connected to multiple magnetic field sensors 101 in a one-to-one correspondence, and it is necessary for the digital processing module 430 to perform digital calculation (sum or average) on the output voltages of the multiple operational amplifier modules 410 to obtain the distance between the lens 221 and the image sensor 201.

[0146] The inventor of the present application has found that the above implementation method has at least the following technical problems:

[0147] Setting up multiple operational amplifier modules 410 to be electrically connected to multiple magnetic field sensors 101 in a one-to-one correspondence increases the number of operational amplifier modules 410 in the camera module 200, increases the area occupied by the operational amplifier modules 410 on the circuit board (or in the chip), and also leads to an increase in the cost of the camera module 200.

[0148] In addition, the digital processing module 430 needs to sum or average the output voltages of multiple operational amplifier modules 410, which takes a long time and increases the time required for closed-loop autofocus of the camera module 200, affecting the performance of the camera module 200.

[0149] Fig.13 A schematic diagram of the connection relationship of the camera modules provided in other embodiments of the present application. Fig.14 A schematic diagram of the connection relationship of the camera module provided in some other embodiments of the present application. Fig.15 A circuit topology diagram of a camera module provided for some further embodiments of the present application.

[0150] Based on this, an embodiment of the present application provides a detection unit 100. It can be understood that the detection unit 100 is used to detect the distance between the lens 221 and the image sensor 201. The detection unit 100 includes at least two magnetic field sensors 101. It can be understood that the types of the at least two magnetic field sensors 101 can be the same or different. In some examples, the at least two magnetic field sensors 101 can both be Hall sensors.

[0151] For example, Fig.13As shown, the at least two magnetic field sensors 101 may include a first magnetic field sensor 1011 , a second magnetic field sensor 1012 , . . . an nth magnetic field sensor 101n (n is a positive integer greater than or equal to 3).

[0152] In some examples, such as Fig.13 As shown, at least two magnetic field sensors 101 are connected in parallel. The output terminals 101 b of the at least two magnetic field sensors 101 are electrically connected to form a connection node P, and the input terminal 410 a of the operational amplifier module 410 is electrically connected to the connection node P.

[0153] Understandably, if Fig.13 As shown, the connection node P is not an actual component, but represents the junction point of the relevant electrical connections in the circuit topology diagram. That is, the connection node P is a node formed by the junction point of the output terminals 101b of at least two magnetic field sensors 101 being electrically connected. The output terminals 101b of at least two magnetic field sensors 101 are electrically connected to form the connection node P, so that the voltage value of the connection node P can be equal to the average value of the output voltages of the at least two magnetic field sensors 101.

[0154] In an embodiment of the present application, the number of magnetic field sensors 101 is set to at least two, and the at least two magnetic field sensors 101 can respectively detect the magnetic field strength in the detection direction of their current position in the magnetic field, and convert the detected magnetic field strength into a corresponding voltage signal, thereby increasing the width of the linear region in the relationship curve between the distance between the lens 221 and the image sensor 201 and the magnetic field strength detected by the magnetic field sensor 101, thereby increasing the focusing stroke of the lens 221.

[0155] Furthermore, the output terminals 101b of at least two magnetic field sensors 101 are electrically connected to form a connection node P, and the voltage value of the connection node P can be equal to the average value of the output voltages of the at least two magnetic field sensors 101. The input terminal 410a of the operational amplifier module 410 is electrically connected to the connection node P, so that the operational amplifier module 410 can obtain the average value of the output voltages of the at least two magnetic field sensors 101 through the connection node P, and amplify the average value of the output voltages of the at least two magnetic field sensors 101. In this way, there is no need to set up multiple operational amplifier modules 410 to be electrically connected to multiple magnetic field sensors 101 in a one-to-one correspondence, which reduces the number of operational amplifier modules 410, reduces the cost of the camera module 200, and reduces the occupied area of ​​the operational amplifier module 410 on the circuit board (or in the chip).

[0156] In addition, the output ends of at least two magnetic field sensors 101 are electrically connected to form a connection node P, and the output voltages of at least two magnetic field sensors 101 are averaged through a hardware circuit, so that the digital processing module 430 does not need to perform digital calculations (such as summing or averaging) on ​​the output voltages of at least two magnetic field sensors 101, thereby saving the computing power of the digital processing module 430, reducing the delay of the digital processing module 430, and reducing the time required to obtain the average value of the output voltages of at least two magnetic field sensors 101, thereby improving the response speed of the camera module 200 during closed-loop autofocus, thereby improving the efficiency of the camera module 200 during closed-loop autofocus.

[0157] That is, by adopting the above configuration, the camera module 200 can achieve low-cost, high-efficiency and long-distance (long focusing stroke) closed-loop autofocus.

[0158] For example, the detection unit 100 may be disposed in a chip, in which case the connection node P may be a pin of the chip. Alternatively, the detection unit 100 may be disposed on a circuit board (e.g., a first circuit board), in which case the output ends of at least two magnetic field sensors 101 may be electrically connected on the circuit board to form a connection node, and the output ends of at least two magnetic field sensors 101 may also form a connection node through a peripheral circuit electrically connected to the circuit board.

[0159] In some examples, such as Fig.14 and Fig.15 As shown, the magnetic field sensor 101 has a first output terminal 101b1 and a second output terminal 101b2, and the first output terminals 101b1 of at least two magnetic field sensors 101 are electrically connected to form a first connection node P1. The second output terminals 101b2 of at least two magnetic field sensors 101 are electrically connected to form a second connection node P2.

[0160] It can be understood that the first output terminals 101b1 of at least two magnetic field sensors 101 are electrically connected to form a first connection node P1, so that the voltage value of the first connection node P1 can be the average value of the output voltages of the first output terminals 101b1 of the at least two magnetic field sensors 101. The second output terminals 101b of at least two magnetic field sensors 101 are electrically connected to form a second connection node P2, so that the voltage value of the second connection node P2 can be the average value of the output voltages of the second output terminals 101b2 of the at least two magnetic field sensors 101.

[0161] For example, Fig.14 and Fig.15As shown, the input terminal 410a of the operational amplifier module 410 can be electrically connected to the first connection node P1 and the second connection node P2, so that the operational amplifier module 410 can obtain the average value of the output voltages of the first output terminals 101b1 of at least two magnetic field sensors 101, and the average value of the output voltages of the second output terminals 101b2 of at least two magnetic field sensors 101. The operational amplifier module 410 can perform a difference process on the average value of the output voltages of the first output terminals 101b1 of at least two magnetic field sensors 101 and the average value of the output voltages of the second output terminals 101b2 of at least two magnetic field sensors 101 to obtain the average value of the output voltages of the at least two magnetic field sensors 101, and amplify the average value of the output voltages of the at least two magnetic field sensors 101.

[0162] The first output terminals 101b1 of at least two magnetic field sensors 101 are electrically connected to form a first connection node P1, and the second output terminals 101b2 of at least two magnetic field sensors 101 are electrically connected to form a second connection node P2, so that the voltage value of the first connection node P1 is equal to the average value of the output voltages of the first output terminals 101b1 of the at least two magnetic field sensors 101, and the voltage value of the second connection node P2 is equal to the average value of the output voltages of the second output terminals 101b2 of the at least two magnetic field sensors 101. The output voltages of the first output terminals 101b1 of the at least two magnetic field sensors 101 and the output voltages of the second output terminals 101b2 of the at least two magnetic field sensors 101 are averaged through the hardware circuit, thereby saving the computing power of the digital processing module 430 and reducing the delay of the digital processing module 430, thereby reducing the time required for the camera module 200 to perform closed-loop autofocus, and improving the efficiency of the camera module 200 to perform closed-loop autofocus.

[0163] In some examples, such as Fig.14 As shown, the first connection node P1 can be electrically connected to the first input terminal 410a1 of the operational amplifier module 410, and the second connection node P2 can be electrically connected to the second input terminal 410a2 of the operational amplifier module 410, so that the operational amplifier module 410 can obtain the voltage value of the first connection node P1 through the first input terminal 410a1 of the operational amplifier module 410, and obtain the voltage value of the second connection node P2 through the second input terminal 410a2 of the operational amplifier module 410.

[0164] Fig.16 A schematic diagram of the connection relationship of the camera module provided in some other embodiments of the present application. Fig.17 A schematic diagram of the connection relationship of the camera module provided in some other embodiments of the present application. Fig.18 A circuit topology diagram of a camera module provided for some further embodiments of the present application. Fig.19 A circuit topology diagram of a camera module provided for some further embodiments of the present application.

[0165] In some examples, such as Fig.16 As shown, the detection unit 100 further includes at least two current limiting elements 102. The first ends of the at least two current limiting elements 102 are electrically connected to the output ends 101b of the at least two magnetic field sensors 101 in a one-to-one correspondence, and the second ends of the at least two current limiting elements 102 are electrically connected to the connection node P. The current limiting element 102 is used to limit the current value of the current flowing between the output ends 101b of any two magnetic field sensors 101.

[0166] For example, the current limiting element 102 may include a resistor, so that the current limiting element 102 can play a role in current limiting. In some examples, the current flowing through the current limiting element 102 can be ignored.

[0167] The number of current limiting elements 102 may be equal to the number of magnetic field sensors 101, so that the first ends of at least two current limiting elements 102 can be electrically connected to the output ends 101b of at least two magnetic field sensors 101 in a one-to-one correspondence. Fig.16 As shown, the at least two current limiting elements 102 may include a first current limiting element 1021 , a second current limiting element 1022 , . . . an nth current limiting element 102n.

[0168] The first end of the first current limiting element 1021 can be electrically connected to the output end 101b of the first magnetic field sensor 1011, the first end of the second current limiting element 1022 can be electrically connected to the output end 101b of the second magnetic field sensor 1022, ... the first end of the nth current limiting element 102n can be electrically connected to the output end 101b of the nth magnetic field sensor 101n. The second ends of the first current limiting element 1021, the second current limiting element 1022, ... the nth current limiting element 102n are all electrically connected to the connection node P.

[0169] The first ends of at least two current limiting elements 102 are electrically connected to the output ends 101b of at least two magnetic field sensors 101 in a one-to-one correspondence, and the second ends of at least two current limiting elements 102 are electrically connected to the connection node P, so that the current limiting elements 102 can be connected in series between the output end 101b of the magnetic field sensor 101 and the connection node P, thereby being able to limit the current value of the current flowing between the output end 101b of the magnetic field sensor 101 and the connection node P, that is, being able to limit the current value of the current flowing between the output ends 101b of any two magnetic field sensors 101.

[0170] In this way, the risk of current flowing from the output end 101b of one magnetic field sensor 101 (for example, the first magnetic field sensor 1011) into the output end 101b of another magnetic field sensor 101 (magnetic field sensor 101 other than the first magnetic field sensor 1011) via the connection node P can be reduced, thereby reducing the impact of the output voltage of each magnetic field sensor 101 after the output ends 101b of at least two magnetic field sensors 101 are electrically connected to form the connection node P, so that the voltage value of the connection node P and the average value of the output voltages of at least two magnetic field sensors 101 when the at least two magnetic field sensors 101 are respectively electrically connected to at least two operational amplifier modules 410 can be roughly the same, thereby improving the reliability of the detection unit 100.

[0171] In some examples, the magnetic field sensor 101 and the current limiting element 102 are electrically connected via conductive traces on a circuit board of the detection unit 100 .

[0172] Such an arrangement enables the magnetic field sensor 101 and the current limiting element 102 to be located on the same circuit board (i.e., the first circuit board), and to be electrically connected through the conductive traces on the first circuit board, thereby reducing the distance between the magnetic field sensor 101 and the current limiting element 102, and facilitating the miniaturization of the detection unit 100.

[0173] In some examples, such as Fig.17 and Fig.18 As shown, the current limiting element 102 may include a first sub-element 103 and a second sub-element 104. The first ends of at least two first sub-elements 103 are electrically connected to the first output ends 101b1 of at least two magnetic field sensors 101 in a one-to-one correspondence, and the second ends of at least two first sub-elements 103 are electrically connected to the first connection node P1. The first ends of at least two second sub-elements 104 are electrically connected to the second output ends 101b2 of at least two magnetic field sensors 101 in a one-to-one correspondence, and the second ends of at least two second sub-elements 104 are electrically connected to the second connection node P2.

[0174] In some examples, the number of the first sub-element 103, the second sub-element 104, and the magnetic field sensor 101 is the same. The resistance value of the first sub-element 103 and the resistance value of the second sub-element 104 may be equal or different. The resistance values ​​of different first sub-element 103 electrically connected to different magnetic field sensors 101 may be equal or different. The resistance values ​​of different second sub-element 104 electrically connected to different magnetic field sensors 102 may be equal or different.

[0175] like Fig.17As shown, the first ends of at least two first sub-elements 103 are electrically connected to the first output ends 101b1 of at least two magnetic field sensors 101 in a one-to-one correspondence, and the second ends of at least two first sub-elements 103 are electrically connected to the first connection node P1, so that the first sub-elements 103 can be connected in series between the first output end 101b1 of the magnetic field sensor 101 and the first connection node P1, so as to limit the current value of the current flowing between the first output end 101b1 of the magnetic field sensor 101 and the first connection node P1, and reduce the risk of the current flowing from the first output end 101b1 of one magnetic field sensor 101 (for example, the first magnetic field sensor 1011) to the first output end 101b1 of another magnetic field sensor 101 (magnetic field sensor 101 other than the first magnetic field sensor 1011) via the first connection node P1, thereby reducing the influence on the output voltage of the first output end 101b1 of each magnetic field sensor 101 after the first output ends 101b1 of at least two magnetic field sensors 101 are electrically connected to form the connection node P, and improving the reliability of the detection unit 100.

[0176] like Fig.17 As shown, the first ends of at least two second sub-elements 104 are electrically connected to the second output ends 101b2 of at least two magnetic field sensors 101 in a one-to-one correspondence, and the second ends of at least two second sub-elements 104 are electrically connected to the second connection node P2, so that the second sub-elements 104 can be connected in series between the second output end 101b2 of the magnetic field sensor 101 and the second connection node P2, so as to limit the current value of the current flowing between the second output end 101b2 of the magnetic field sensor 101 and the second connection node P2, and reduce the risk of the current flowing from the second output end 101b2 of one magnetic field sensor 101 (for example, the first magnetic field sensor 1011) through the second connection node P2 to the second output end 101b2 of another magnetic field sensor 101 (magnetic field sensor 101 other than the first magnetic field sensor 1011), thereby reducing the influence on the output voltage of the second output end 101b2 of each magnetic field sensor 101 after the second output ends 101b2 of at least two magnetic field sensors 101 are electrically connected to form the connection node P, and improve the reliability of the detection unit 100.

[0177] In some examples, such as Fig.18 As shown, the first sub-element 103 includes a first resistor R1, and the second sub-element 104 includes a second resistor R2. The resistance value of the first resistor R1 is equal to the resistance value of the second resistor R2. In other examples, the first sub-element 103 includes a plurality of first resistors R1, and the plurality of first resistors R1 are electrically connected. The second sub-element 104 includes a plurality of second resistors R2, and the plurality of second resistors R2 are electrically connected. The resistance value of the plurality of first resistors R1 after being electrically connected is equal to the resistance value of the plurality of second resistors R2 after being electrically connected.

[0178] For example, the way in which the multiple first resistors R1 are electrically connected may include at least one of series connection and parallel connection, and the way in which the multiple second resistors R2 are electrically connected may include at least one of series connection and parallel connection. The way in which the multiple first resistors R1 are electrically connected and the way in which the multiple second resistors R2 are electrically connected may be the same or different.

[0179] The first sub-element 103 is configured to include a first resistor R1, and the second sub-element 104 is configured to include a second resistor R2, so that the first sub-element 103 and the second sub-element 104 can play a role in current limiting. In addition, the resistance value of the first resistor R1 is set to be equal to the resistance value of the second resistor R2, or the resistance value of multiple first resistors R1 after being electrically connected is set to be equal to the resistance value of multiple second resistors R2 after being electrically connected, which simplifies the calculation process when calculating the amplification factor of the operational amplifier module 410, and improves the convenience of use of the detection unit 100.

[0180] In the embodiment of the present application, an example is taken in which the first sub-element 103 includes a first resistor R1 and the second sub-element 104 includes a second resistor R2 for illustration.

[0181] In some examples, the resistance of the first resistor R1 is equal to the resistance of the second resistor R2, and is much larger than the output internal resistance of the magnetic field sensor 101. As the magnetic field strength in the detection direction of the magnetic field sensor 101 changes, the output internal resistance of the magnetic field sensor 101 will change. For example, the resistance of the first resistor R1 and the second resistor R2 can be 20 times, 30 times, 40 times, 50 times or 60 times the output internal resistance of the magnetic field sensor 101 (for example, the maximum value, minimum value or average value of the output internal resistance of the magnetic field sensor 101). It can be understood that the embodiments of the present application do not further limit the resistance of the first resistor R1 and the second resistor R2.

[0182] In other examples, the resistance value of the first resistor R1 and the resistance value of the second resistor R2 may also be different. The resistance values ​​of different first resistors R1 electrically connected to different magnetic field sensors 101 may be equal or different. The resistance values ​​of different second resistors R2 electrically connected to different magnetic field sensors 102 may be equal or different.

[0183] In some examples, such as Fig.18 and Fig.19As shown, the operational amplifier module 410 includes a differential amplifier circuit. The differential amplifier circuit is configured to: obtain the average voltage value of the first output terminal 101b1 of at least two magnetic field sensors 101, and the average voltage value of the second output terminal 101b2 of at least two magnetic field sensors 101. Calculate the difference between the average voltage value of the first output terminal 101b1 of at least two magnetic field sensors 101 and the average voltage value of the second output terminal 101b2 of at least two magnetic field sensors 101 to obtain the average value of the output voltage of the at least two magnetic field sensors 101. Amplify the average value of the output voltage of the at least two magnetic field sensors 101.

[0184] It can be understood that the differential amplifier circuit can amplify and output the average value of the output voltages of at least two magnetic field sensors 101 (the output voltage of the magnetic field sensor 101 is the difference between the voltage value of the first output terminal 101b1 of the magnetic field sensor 101 and the voltage value of the second output terminal 101b2 of the magnetic field sensor 101), thereby improving the accuracy of determining the distance between the lens 221 and the image sensor 201 based on the output voltage of the operational amplifier module 410.

[0185] The following uses a differential amplifier circuit as an example of a typical negative feedback amplifier to illustrate the structure of the differential amplifier circuit.

[0186] In some examples, such as Fig.18 and Fig.19 As shown, the differential amplifier circuit may include an operational amplifier OP, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6. The resistance of the third resistor R3 is equal to the resistance of the fourth resistor R4. The resistance of the fifth resistor R5 is equal to the resistance of the sixth resistor R6.

[0187] The first end of the third resistor R3 is electrically connected to the non-inverting input terminal OP1 of the operational amplifier OP, and the second end of the third resistor R3 is electrically connected to the first connection node P1. The first end of the fourth resistor R4 is electrically connected to the inverting input terminal OP2 of the operational amplifier OP, and the second end of the fourth resistor R4 is electrically connected to the second connection node P2. The first end of the fifth resistor R5 is electrically connected to the non-inverting input terminal OP1 of the operational amplifier OP, and the second end of the fifth resistor R5 is electrically connected to the power supply terminal VDD (see Fig.18 ) or ground GND (see Fig.19 A first end of the sixth resistor R6 is electrically connected to an inverting input terminal OP2 of the operational amplifier OP, and a second end of the sixth resistor R6 is electrically connected to an output terminal OP3 of the operational amplifier OP.

[0188] It can be understood that the non-inverting input terminal OP1 of the operational amplifier OP can be the first input terminal 410a1 of the operational amplifier module 410, the inverting input terminal OP2 of the operational amplifier OP can be the second input terminal 410a2 of the operational amplifier module 410, and the output terminal OP3 of the operational amplifier OP can be the output terminal 410b of the operational amplifier module 410.

[0189] It is understandable that the differential amplifier circuit may also be a negative feedback amplifier circuit of other structures. The embodiment of the present application does not further limit the structure of the differential amplifier circuit.

[0190] In some examples, the resistance of the third resistor R3 is equal to the resistance of the fourth resistor R4. For example, the resistance of the third resistor R3 and the resistance of the fourth resistor R4 can be a first resistance. The resistance of the fifth resistor R5 is equal to the resistance of the sixth resistor R6. For example, the resistance of the fifth resistor R5 and the resistance of the sixth resistor R6 can be a second resistance. In some examples, the second resistance is greater than the first resistance.

[0191] It can be understood that the second end of the fifth resistor R5 is electrically connected to the power supply terminal VDD or the ground terminal GND, so that the current flowing out of the first output terminal 101b1 of at least two magnetic field sensors 101 can flow to the power supply terminal VDD or the ground terminal GND after passing through the third resistor R3 and the fifth resistor R5, thereby improving the setting flexibility of the circuit structure of the camera module 200.

[0192] It can be understood that the operational amplifier OP can make a difference between the voltage value of the non-inverting input terminal OP1 of the operational amplifier OP and the voltage value of the inverting input terminal OP2 of the operational amplifier OP. In this way, the non-inverting input terminal OP1 of the operational amplifier OP is electrically connected to the first connection node P1, and the inverting input terminal OP2 of the operational amplifier OP is electrically connected to the second connection node P2, so that the operational amplifier OP can obtain the average value of the output voltage of the first output terminal 101b1 of at least two magnetic field sensors 101 and the average value of the output voltage of the second output terminal 101b2 of at least two magnetic field sensors 101, and make a difference between the average value of the output voltage of the first output terminal 101b1 of the at least two magnetic field sensors 101 and the average value of the output voltage of the second output terminal 101b2 of the at least two magnetic field sensors 101.

[0193] It can be understood that the difference between the average value of the output voltages of the first output terminals 101b1 of the at least two magnetic field sensors 101 and the average value of the output voltages of the second output terminals 101b2 of the at least two magnetic field sensors 101 is the average value of the output voltages of the at least two magnetic field sensors 101. After the operational amplifier OP makes a difference between the average value of the output voltages of the first output terminals 101b1 of the at least two magnetic field sensors 101 and the average value of the output voltages of the second output terminals 101b2 of the at least two magnetic field sensors 101 to obtain the average value of the output voltages of the at least two magnetic field sensors 101, it can amplify and output the average value of the output voltages of the at least two magnetic field sensors 101, thereby improving the accuracy of determining the distance between the lens 221 and the image sensor 201 according to the output terminal OP3 of the operational amplifier OP (i.e., the output terminal 410b of the operational amplifier module 410).

[0194] The voltage at the connection point P will be demonstrated and explained in the following formula.

[0195] For example, Fig.18 and Fig.19 As shown, the output voltage of the first output terminal 101b1 of the first magnetic field sensor 1011 is V p1 , the output voltage of the second output terminal 101b2 of the first magnetic field sensor 1011 is V n1 , the output voltage of the first output terminal 101b1 of the second magnetic field sensor 1012 is V p2 , the output voltage of the second output terminal 101b2 of the second magnetic field sensor 1012 is V n2 , ... the output voltage of the first output terminal 101b1 of the nth magnetic field sensor 101n is V pn , the output voltage of the second output terminal 101b2 of the nth magnetic field sensor 101n is V nn The voltage at the first end of the third resistor R3 (the end electrically connected to the in-phase input end OP1 of the operational amplifier OP) is V + , the voltage at the second end of the third resistor R3 is Vp (i.e., the voltage at the first connection point P1). The voltage at the first end of the fourth resistor R4 (the end electrically connected to the inverting input end OP2 of the operational amplifier OP) is V - , the voltage at the second end of the fourth resistor R4 is V n (ie, the voltage of the second connection node P2).

[0196] In order to simplify the calculation process, it is assumed that the resistance value of the first resistor R1 is equal to the resistance value of the second resistor R2, and the resistance values ​​of multiple first resistors R1 are equal, and the resistance values ​​of multiple second resistors R2 are equal. in express.

[0197] According to Kirchhoff's current law, the current flowing through the first connection node P1 satisfies formula (2).

[0198]

[0199] According to Kirchhoff's current law, the current flowing through the second connection node P2 satisfies formula (3).

[0200]

[0201] When the resistance values ​​of the third resistor R3 and the fourth resistor R4 are very large, the current flowing through the third resistor R3 is very small and can be ignored, and the value on the right side of the equal sign in formula (2) is approximately equal to zero. Similarly, the current flowing through the fourth resistor R4 is very small and can be ignored, and the value on the right side of the equal sign in formula (3) is also approximately equal to zero.

[0202] By transforming formula (2), we can get formula (2.1):

[0203]

[0204] By transforming formula (3), we can get formula (3.1):

[0205]

[0206] It can be seen from formula (2.1) that the voltage at the second end of the third resistor R3 is V p (ie, the voltage at the first connection node P1) is the average of the output voltages of the first output terminals 101b1 of at least two magnetic field sensors 101. As can be seen from formula (3.1), the voltage V at the second terminal of the fourth resistor R4 is n (ie, the voltage of the second connection node P2 ) is the average value of the output voltages of the second output terminals 101 b 2 of at least two magnetic field sensors 101 .

[0207] That is, the first output terminals 101b1 of at least two magnetic field sensors 101 are electrically connected to form a first connection node P1, so that the output voltages of the first output terminals 101b1 of the at least two magnetic field sensors 101 can be averaged. The second output terminals 101b2 of at least two magnetic field sensors 101 are electrically connected to form a second connection node P2, so that the output voltages of the second output terminals 101b2 of the at least two magnetic field sensors 101 can be averaged.

[0208] In this way, the output voltages of at least two magnetic field sensors 101 are averaged through the hardware circuit, so that the digital processing module 430 does not need to perform digital calculations (such as summing or averaging) on ​​the output voltages of at least two magnetic field sensors 101, thereby saving the computing power of the digital processing module 430 and reducing the delay of the digital processing module 430, thereby reducing the time required for the camera module 200 to perform closed-loop autofocus and improving the efficiency of the camera module 200 in closed-loop autofocus.

[0209] The amplification factor of the operational amplifier module 410 is demonstrated and explained in the following through a formula.

[0210] See again Fig.12 When the magnetic field sensor 101 and the operational amplifier module 410 are electrically connected in a one-to-one correspondence, taking a magnetic field sensor 101 and an operational amplifier module 410 electrically connected to the magnetic field sensor 101 as an example (for example, the first magnetic field sensor 1011 and the first operational amplifier module 4101), the second end of the fifth resistor R5 is electrically connected to the power supply terminal VDD. Since the operational amplifier OP has a "virtual off" characteristic in the negative feedback circuit, that is, the current flowing into the operational amplifier OP is approximately zero, according to Kirchhoff's current law, the current passing through the third resistor R3 and the fifth resistor R5 satisfies formula (4).

[0211]

[0212] According to Kirchhoff's current law, the current passing through the fourth resistor R4 and the sixth resistor R6 satisfies formula (5).

[0213]

[0214] In formula (4), VDD represents the voltage of the power supply terminal VDD. In formula (5), V out represents the output voltage of the operational amplifier OP in the first operational amplifier module 4101. Since the resistance of the third resistor R3 is equal to the resistance of the fourth resistor R4, and the resistance of the fifth resistor R5 is equal to the resistance of the sixth resistor R6, the fourth resistor R4 in formula (5) can be replaced by the third resistor R3, and the sixth resistor R6 in formula (5) can be replaced by the fifth resistor R5. It can be understood that the operational amplifier OP has a "virtual short" characteristic in the negative feedback circuit, that is, V + =V - For example, formula (4) can be subtracted from formula (5) to obtain formula (6).

[0215]

[0216] It can be seen from formula (6) that when the magnetic field sensor 101 and the operational amplifier module 410 are electrically connected in a one-to-one correspondence, the amplification factor of the operational amplifier module 410 is

[0217] like Fig.18 As shown, when the output ends of at least two magnetic field sensors 101 are electrically connected to form a connection node P, in order to simplify the calculation process, taking the case where the resistance value of the first resistor R1 is equal to the resistance value of the second resistor R2, and the resistance values ​​of the plurality of first resistors R1 are equal, and the resistance values ​​of the plurality of second resistors R2 are equal as an example, the first resistor R1 and the second resistor R2 are both represented by R in express.

[0218] According to Kirchhoff's current law, the current flowing through the first connection node P1, the third resistor R3 and the fifth resistor R5 satisfies formula (7).

[0219]

[0220] According to Kirchhoff's current law, the current flowing through the second connection node P2, the fourth resistor R4 and the sixth resistor R6 satisfies formula (8).

[0221]

[0222] In formula (7), VDD represents the voltage of the power supply terminal VDD. In formula (8), V out represents the output voltage of the operational amplifier OP. Since the resistance of the third resistor R3 is equal to the resistance of the fourth resistor R4, and the resistance of the fifth resistor R5 is equal to the resistance of the sixth resistor R6, the fourth resistor R4 in formula (8) can be replaced by the third resistor R3, and the sixth resistor R6 in formula (8) can be replaced by the fifth resistor R5. It can be understood that the operational amplifier OP has a "virtual short" characteristic in the negative feedback circuit, that is, V + =V - For example, formula (7) can be subtracted from formula (8) to obtain formula (9).

[0223]

[0224] It can be seen from formula (9) that when the output ends of at least two magnetic field sensors 101 are electrically connected to form a connection point P, and the first resistor R1 and the second resistor R2 are set to play a current limiting role, the first resistor R1 and the second resistor R2 (that is, the resistor R in ) participates in the amplification of the operational amplifier module 410, and the amplification factor of the operational amplifier module 410 is Compared with arranging the magnetic field sensor 101 and the operational amplifier module 410 to be electrically connected in a one-to-one correspondence, the amplification factor of the operational amplifier module 410 is reduced.

[0225] In some examples, the amplification factor of the operational amplifier module 410 can be increased by adjusting the resistance of the third resistor R3 and the resistance of the fifth resistor R5.

[0226] When the resistance values ​​of the first resistor R1 and the second resistor R2 electrically connected to the same magnetic field sensor 101 are equal, the resistance values ​​of the plurality of first resistors R1 are different, and the resistance values ​​of the plurality of second resistors R2 are different, the amplification factor of the operational amplifier module 410 is determined by the following derivation formula.

[0227] For example, the first resistor R1 electrically connected to the first output terminal 101b1 of the first magnetic field sensor 1011 can be expressed as R in1 Since the resistance value of the second resistor R2 electrically connected to the second output terminal 101b2 of the first magnetic field sensor 1011 is equal to the resistance value of the first resistor R1 electrically connected to the first output terminal 101b1 of the first magnetic field sensor 1011, the second resistor R2 electrically connected to the second output terminal 101b2 of the first magnetic field sensor 1011 can also be expressed as R in1 .

[0228] Similarly, the first resistor R1 electrically connected to the first output terminal 101b1 of the second magnetic field sensor 1012 can be expressed as R in2 The second resistor R2 electrically connected to the second output terminal 101b2 of the second magnetic field sensor 1012 can also be expressed as R in2 , ... The first resistor R1 electrically connected to the first output terminal 101b1 of the nth magnetic field sensor 101n can be expressed as R inn The second resistor R2 electrically connected to the second output terminal 101b2 of the nth magnetic field sensor 101n can also be expressed as R inn .

[0229] According to Kirchhoff's current law, the current flowing through the first connection node P1, the third resistor R3 and the fifth resistor R5 satisfies the following formula.

[0230]

[0231]

[0232] According to Kirchhoff's current law, the current flowing through the second connection node P2, the fourth resistor R4 and the sixth resistor R6 satisfies the following formula.

[0233]

[0234]

[0235] In formula (11), VDD represents the voltage of the power supply terminal VDD. In formula (13), V out Represents the output voltage of the operational amplifier OP. Since the resistance value of the third resistor R3 is equal to the resistance value of the fourth resistor R4, and the resistance value of the fifth resistor R5 is equal to the resistance value of the sixth resistor R6, the fourth resistor R4 in formula (12) and formula (13) can be replaced by the third resistor R3, and the sixth resistor R6 in (13) can be replaced by the fifth resistor R5.

[0236] Subtracting formula (12) from formula (10) yields formula (14).

[0237]

[0238] By transforming formula (14), we can obtain formula (14.1).

[0239]

[0240] It can be understood that the operational amplifier OP has a "virtual short" characteristic in the negative feedback circuit, that is, V + =V - Therefore, formula (14.1) can be simplified to obtain formula (14.2).

[0241]

[0242] Subtracting formula (13) from formula (11) yields formula (15).

[0243]

[0244] By transforming formula (15), we can obtain formula (15.1).

[0245]

[0246] Substituting formula (15.1) into formula (14.2), we get V out Expression (Formula (16)).

[0247]

[0248] By transforming formula (16), we can obtain formula (16.1).

[0249]

[0250] In formula (16.1), is the amplification factor of the operational amplifier module 410 , and the third resistor R3 and the fifth resistor R5 affect the amplification factor of the operational amplifier module 410 . is the average value of the output voltage of each magnetic field sensor 101, before averaging, the value is increased arrive Weight.

[0251] When the resistance values ​​of the first resistor R1 and the second resistor R2 electrically connected to the same magnetic field sensor 101 are not equal, the resistance values ​​of the multiple first resistors R1 are not equal, and the resistance values ​​of the multiple second resistors R2 are not equal, the amplification factor of the operational amplifier module 410 refers to the following derivation formula.

[0252] For example, the first resistor R1 electrically connected to the first output terminal 101b1 of the first magnetic field sensor 1011 can be expressed as R in11 The second resistor R2 electrically connected to the second output terminal 101b2 of the first magnetic field sensor 1011 can also be expressed as R in21 The first resistor R1 electrically connected to the first output terminal 101b1 of the second magnetic field sensor 1012 can be expressed as R in12 The second resistor R2 electrically connected to the second output terminal 101b2 of the second magnetic field sensor 1012 can also be expressed as R in22 , ... The first resistor R1 electrically connected to the first output terminal 101b1 of the nth magnetic field sensor 101n can be expressed as R in1n The second resistor R2 electrically connected to the second output terminal 101b2 of the nth magnetic field sensor 101n can also be expressed as R in2n .

[0253] According to Kirchhoff's current law, the current flowing through the first connection node P1, the third resistor R3 and the fifth resistor R5 satisfies the following formula.

[0254]

[0255]

[0256] According to Kirchhoff's current law, the current flowing through the second connection node P2, the fourth resistor R4 and the sixth resistor R6 satisfies the following formula.

[0257]

[0258]

[0259] Since the resistance of the third resistor R3 is equal to the resistance of the fourth resistor R4, and the resistance of the fifth resistor R5 is equal to the resistance of the sixth resistor R6, the fourth resistor R4 can be replaced by the third resistor R3, and the sixth resistor R6 can be replaced by the fifth resistor R5. In addition, because the denominators in formula (17) and formula (19) are different, the previous subtraction and then extraction of V cannot be used. p-V n The method of post-merge elimination is to directly calculate V p and V n .

[0260] Replace V in formula (17) p Combining, we can get formula (17.1).

[0261]

[0262] By transforming formula (18), we can obtain formula (18.1).

[0263]

[0264] By transforming formula (18.1), we can obtain formula (18.11).

[0265]

[0266] Substituting formula (18.11) into formula (17.1), we can obtain formula (21).

[0267]

[0268] Formula (21) extracts V + Then we can get formula (21.1) and formula (21.2).

[0269]

[0270]

[0271] According to formula (21.1) and formula (21.2), we can get formula (21.3).

[0272]

[0273] Using the same method, the calculation formula of V- can be obtained, see formula (22).

[0274]

[0275] It can be understood that the operational amplifier OP has a "virtual short" characteristic in the negative feedback circuit, that is, V + =V - Therefore, formula (21.3) and formula (22) are equal, and formula (23) can be obtained.

[0276]

[0277] Simplify formula (23) and use a to represent Use b to represent We can obtain formula (23.1).

[0278]

[0279] According to formula (23.1), we can obtain formula (23.11) and formula (23.12).

[0280]

[0281]

[0282] From formula (23.12), it can be seen that the amplification factor of the operational amplifier module 410 is The voltage values ​​of the first output terminals 101b1 of at least two magnetic field sensors 101 and the voltage values ​​of the second output terminals 101b2 of at least two magnetic field sensors 101 are multiplied by different weights respectively, then subtracted to obtain differences, and finally the differences are averaged.

[0283] The weight of the first output terminal 101b1 of the i-th magnetic field sensor 101 is (i is a positive integer between 1 and n), the weight of the second output terminal 101b2 of the i-th magnetic field sensor 101 is (i is a positive integer between 1 and n).

[0284] In some examples, the resistance of the third resistor R3 and the resistance of the fourth resistor R4 are much greater than the output internal resistance of the magnetic field sensor 101 .

[0285] It can be understood that the resistance value of the third resistor R3 and the resistance value of the fourth resistor R4 can be 20 times, 30 times, 40 times, 50 times or 60 times the output internal resistance value of the magnetic field sensor 101 (for example, the maximum value, minimum value or average value of the output internal resistance value of the magnetic field sensor 101). The resistance value of the third resistor R3 and the resistance value of the fourth resistor R4 can be equal to or different from the resistance value of the current limiting element 102 (including the first sub-element 103 and the second sub-element 104).

[0286] The resistance of the third resistor R3 and the resistance of the fourth resistor R4 are set to be much larger than the output internal resistance of the magnetic field sensor 101, which can reduce the influence of the output internal resistance of the magnetic field sensor 101 on the amplification factor of the operational amplifier module 410, thereby ensuring the accuracy of the amplification factor of the operational amplifier module 410. In this way, there is no need to adjust the driving unit 110 according to the amplification factor of the operational amplifier module 410, thereby improving the convenience of use of the detection unit 100.

[0287] In some examples, the resistance of the third resistor R3 and the fourth resistor R4 are a first resistance, the resistance of the fifth resistor R5 and the sixth resistor R6 are a second resistance, and the second resistance is m times the first resistance, where m is a positive number and is greater than 1.

[0288] The second resistance is set to be m times the first resistance, where m is a positive number and is greater than 1, so that the operational amplifier module 410 can amplify the difference between the voltage value of the non-inverting input terminal OP1 of the operational amplifier OP and the voltage value of the inverting input terminal OP2 of the operational amplifier OP, that is, the operational amplifier module 410 can amplify the difference between the average value of the output voltage of the first output terminal 101b1 of at least two magnetic field sensors 101 and the average value of the output voltage of the second output terminal 101b2 of at least two magnetic field sensors 101, thereby improving the output voltage of the operational amplifier module 410, thereby improving the accuracy of determining the distance between the lens 221 and the image sensor 201 according to the output voltage of the operational amplifier module 410.

[0289] It can be understood that when the detection unit 100 does not include the current limiting element 102, or when the resistance of the current limiting element 102 is small and can be ignored, the ratio m of the second resistance to the first resistance is equal to the amplification factor k of the operational amplifier module 410. When the resistance of the current limiting element 102 is large and cannot be ignored, the current limiting element 102 participates in the amplification of the operational amplifier module 410, and the ratio m of the second resistance to the first resistance is greater than the amplification factor k of the operational amplifier module 410.

[0290] In some examples, the differential amplifier circuit is electrically connected to the power supply terminal VDD. Fig.18 As shown, when the differential amplifier circuit includes a typical negative feedback amplifier circuit, the second end of the fifth resistor R5 is electrically connected to the power supply terminal VDD. The voltage value of the power supply terminal VDD is -k times the average value of the bias voltages of at least two magnetic field sensors 101. Wherein, k is the gain factor of the operational amplifier OP.

[0291] The voltage value of the power supply terminal VDD is set to -k times the average value of the bias voltages of at least two magnetic field sensors 101, where k is the amplification factor of the operational amplifier module, so that the power supply terminal VDD can compensate for the bias voltages of at least two magnetic field sensors 101, reduce the influence of the bias voltages of at least two magnetic field sensors 101 on the input voltage of the operational amplifier module 410 and the output voltage of the operational amplifier module 410 (that is, the output voltage of the operational amplifier OP), and improve the reliability of the camera module 200.

[0292] Fig. 20 A schematic diagram of the connection relationship of the camera module provided in some other embodiments of the present application. Fig.21A schematic diagram of the connection relationship of the camera module provided in some other embodiments of the present application. Fig. 22 A circuit topology diagram of a camera module provided for some further embodiments of the present application. Fig.23 A circuit topology diagram of a camera module provided for some further embodiments of the present application. Fig.24 A schematic diagram of a curve showing the magnetic field strength detected by a magnetic field sensor and changes with the distance between the lens and the image sensor provided in some other embodiments of the present application.

[0293] like Fig. 20 and Fig.21 As shown, the magnetic field sensor 101 has a power input terminal 101 a . In some examples, the resistances of at least two magnetic field sensors 101 are equal, and the power input terminals 101 a of at least two magnetic field sensors 101 are electrically connected to the same power supply 420 .

[0294] It can be understood that the resistance of the magnetic field sensor 101 is the resistance between the power input terminal 101a of the magnetic field sensor 101 and the ground terminal GND of the magnetic field sensor 101. When the magnetic field strength in the detection direction of the current position of the magnetic field sensor 101 in the magnetic field changes, the resistance of the magnetic field sensor 101 changes slightly (basically unchanged). In some examples, the difference between the resistance of the magnetic field sensor 101 and the rated resistance (preset resistance) is less than or equal to 15%.

[0295] When the resistances of at least two magnetic field sensors 101 are equal, the resistances of at least two magnetic field sensors 101 may be completely equal or approximately equal. Fig. 22 and Fig.23 As shown, at least two magnetic field sensors 101 can be electrically connected to the same power supply 420, so that one power supply 420 can power at least two magnetic field sensors 101, reducing the number of power supplies 420, reducing the area occupied by the power supply 420 on the circuit board (or in the chip), and reducing the cost of the camera module 200.

[0296] In other examples, such as Fig.19 As shown, the number of the power supplies 420 is at least two, and the power input terminals 101 a of the at least two magnetic field sensors 101 are electrically connected to the at least two power supplies 420 in a one-to-one correspondence.

[0297] like Fig.19As shown, the number of power supplies 420 and the number of magnetic field sensors 101 may be the same, and the first power supply 4201 may be electrically connected to the power input terminal 101a of the first magnetic field sensor 1011, for supplying power to the first magnetic field sensor 1011. The second power supply 4202 may be electrically connected to the power input terminal 101a of the second magnetic field sensor 1012, for supplying power to the second magnetic field sensor 1012. The nth power supply 420n may be electrically connected to the power input terminal 101a of the nth magnetic field sensor 101n, for supplying power to the nth magnetic field sensor 101n.

[0298] It can be understood that the number of power supplies 420 is set to at least two, and the power input terminals 101a of at least two magnetic field sensors 101 are electrically connected to at least two power supplies 420 in a one-to-one correspondence, so that one power supply 420 can supply power to one magnetic field sensor 101, thereby reducing the mutual influence between at least two magnetic field sensors 101 and improving the reliability of the camera module 200.

[0299] like Fig.21 and Fig. 22 As shown, taking the case where the power input terminals 101a of at least two magnetic field sensors 101 are electrically connected to the same power supply 420 as an example, at this time, the current split of each magnetic field sensor 101 is inversely proportional to the resistance of the magnetic field sensor 101. That is, the deviation between the currents flowing through each magnetic field sensor 101 comes from the resistance deviation of each magnetic field sensor 101.

[0300] In an ideal state, the resistance of each magnetic field sensor 101 is the same, the ratio of the resistance of each magnetic field sensor 101 is 1:1…:1, and the ratio of the current flowing through each magnetic field sensor 101 is also 1:1…:1. However, in reality, the resistance of each magnetic field sensor 101 is not exactly the same, resulting in the shunt ratio of each magnetic field sensor 101 not being ideal. For example, the shunt ratio of each magnetic field sensor 101 (i.e., the ratio of the current flowing through each magnetic field sensor 101) can be k1:k2…:kn.

[0301] Take the magnetic field sensor 101 as a Hall sensor as an example, see Figure 5, when the magnetic field strength in the detection direction of the current position of the magnetic field sensor 101 in the magnetic field changes (that is, when the magnetic field strength detected by the magnetic field sensor 101 changes), the resistance change of the first equivalent resistor Ra and the resistance change of the third equivalent resistor Rb cancel each other, and the resistance change of the second equivalent resistor Rc and the resistance change of the fourth equivalent resistor Rd cancel each other, so that the resistance of the magnetic field sensor 101 can remain unchanged or approximately unchanged. For example, when the magnetic field strength detected by the magnetic field sensor 101 changes, the resistance change of the magnetic field sensor 101 is within 2%, and the error of the change of the output voltage of the magnetic field sensor 101 is within (the limit error of the magnetic field sensor 101) 2%.

[0302] That is, when the magnetic field intensity detected by the magnetic field sensor 101 changes, the resistance of the magnetic field sensor 101 changes very little, so that the influence on the current flowing through the magnetic field sensor 101 is very small and can be ignored, so that the magnetic field sensor 101 can work in the constant current mode. In other words, when the magnetic field intensity detected by the magnetic field sensor 101 changes, the influence on the shunt ratio of each magnetic field sensor 101 is very small, so that when the lens 221 moves along the first direction X, the shunt ratio of each magnetic field sensor 101 can remain unchanged k1:k2…:kn.

[0303] like Fig. 22 and Fig.23 As shown, taking the number of magnetic field sensors 101 as three as an example, the three magnetic field sensors 101 include a first magnetic field sensor 1011, a second magnetic field sensor 1012, and a third magnetic field sensor 1013. The number of current limiting elements 102 may also be three, and the three current limiting elements 102 may include a first current limiting element 1021, a second current limiting element 1022, and a third current limiting element 1023. The first current limiting element 1021 may be electrically connected to the first magnetic field sensor 1011, the second current limiting element 1022 may be electrically connected to the second magnetic field sensor 1012, and the third current limiting element 1023 may be electrically connected to the third magnetic field sensor 1013. The number of power supply 420 may be one, and one power supply 420 may be electrically connected to the first magnetic field sensor 1011, the second magnetic field sensor 1012, and the third magnetic field sensor 1013, and is used to supply power to the first magnetic field sensor 1011, the second magnetic field sensor 1012, and the third magnetic field sensor 1013.

[0304] The resistance error of the magnetic field sensor 101 is generally within ±15% of the rated resistance. For example, the resistance errors of the three magnetic field sensors 101 are all 15% of the rated resistance. For example, the resistance of the first magnetic field sensor 1011 is 85% of the rated resistance, the resistance of the second magnetic field sensor 1012 is 85% of the rated resistance, and the resistance of the third magnetic field sensor 1013 is 115% of the rated resistance. The circuit of the camera module 200 is simulated, and the simulation results are as follows. Fig.24 shown.

[0305] like Fig.24 As shown, Fig.24 The horizontal axis represents the distance between the lens 221 and the image sensor 201. Fig.23 The vertical axis represents the magnetic field intensity detected by the magnetic field sensor 101 .

[0306] Curve f represents the corresponding relationship between the distance between the lens 221 and the image sensor 201 and the magnetic field strength obtained by superimposing the magnetic field strengths detected by the three magnetic field sensors 101 when the three power supplies 420 are electrically connected to the three magnetic field sensors 101 respectively and the magnetic field sensors 101 are electrically connected to the three operational amplifier modules 410 respectively. Curve g represents the corresponding relationship between the distance between the lens 221 and the image sensor 201 and the magnetic field strength detected by the magnetic field sensor 101 when the power supplies 420 are electrically connected to the three magnetic field sensors 101 and the output ends of the three magnetic field sensors 101 are electrically connected to form a connection node P and the input end 410a of the operational amplifier module 410 is electrically connected to the connection node P.

[0307] Depend on Fig.24 It can be seen that both curve f and curve g are linear. Since the current limiting element 102 is connected in series to the magnetic field sensor 101 and the connection node P, the amplification factor of the operational amplifier module 410 is reduced, so that the change amplitude of the curve g becomes smaller. In some examples, the resistance values ​​of the third resistor R3 and the fifth resistor R5 can be adjusted to increase the amplification factor of the operational amplifier module 410.

[0308] Since the resistance ratio of the three magnetic field sensors 101 is not strictly 1:1:1, the current splitting ratio of the three magnetic field sensors 101 is not strictly 1:1:1, resulting in that the linearity of curve g is less than that of curve f. Fig.24 By fitting the points in the M3 region, it can be obtained that the linearity of curve f is about 0.995 and the linearity of curve g is about 0.989. In some examples, laser calibration can be used to compensate for the linearity of curve g to improve the accuracy of camera module 200.

[0309] For example, the working current of the magnetic field sensor 101 is 3mA (unit: milliampere), the resistance values ​​of the first resistor R1 and the second resistor R2 are both 90KΩ (unit: kiloohm), the resistance values ​​of the third resistor R3 and the fourth resistor R4 are both 30KΩ, and the resistance values ​​of the fifth resistor R5 and the sixth resistor R6 are both 90KΩ.

[0310] For example, when three magnetic field sensors 101 are electrically connected to three operational amplifier modules 410 in one-to-one correspondence, the amplification factor of the operational amplifier module 410 is 3 (90KΩ / 30KΩ), and the output voltage of each operational amplifier OP is 3 times Vp-Vn. At this time, the average value of the output voltages of the three operational amplifiers OP is shown in formula (24).

[0311]

[0312] For example, when the output ends of the three magnetic field sensors 101 are electrically connected to form a connection node P, the input end of the operational amplifier module 410 is electrically connected to the connection node P, and the power supply 420 outputs a current of 9 mA to power the three magnetic field sensors 101, the output voltage of the operational amplifier is shown in formula (25).

[0313]

[0314] It can be understood that in formula (11), V out is the output voltage of the operational amplifier OP, k1, k2 and k3 are the shunt ratios of the three magnetic field sensors 101, k1, k2 and k3 remain unchanged, and the sum of k1, k2 and k3 is 3.

[0315] It can be seen from formula (24) and formula (25) that the current limiting element 102 participates in the amplification of the operational amplifier module 410, resulting in the amplification factor of the operational amplifier module 410 changing from 3 to 1.5. Since the initial resistances of the magnetic field sensors 101 are different, the outputs of the magnetic field sensors 101 account for different proportions.

[0316] In summary, the embodiments of the present application have at least the following beneficial effects:

[0317] In an embodiment of the present application, the number of magnetic field sensors 101 is set to at least two, and the at least two magnetic field sensors 101 can respectively detect the magnetic field strength in the detection direction of their current position in the magnetic field, and convert the detected magnetic field strength into a corresponding voltage signal, thereby increasing the width of the linear region in the relationship curve between the distance between the lens 221 and the image sensor 201 and the magnetic field strength detected by the magnetic field sensor 101, thereby increasing the focusing stroke of the lens 221.

[0318] Furthermore, the output terminals 101b of at least two magnetic field sensors 101 are electrically connected to form a connection node P, and the voltage value of the connection node P can be equal to the average value of the output voltages of the at least two magnetic field sensors 101. The input terminal 410a of the operational amplifier module 410 is electrically connected to the connection node P, so that the operational amplifier module 410 can obtain the average value of the output voltages of the at least two magnetic field sensors 101 through the connection node P, and amplify the average value of the output voltages of the at least two magnetic field sensors 101. In this way, there is no need to set up multiple operational amplifier modules 410 to be electrically connected to multiple magnetic field sensors 101 in a one-to-one correspondence, which reduces the number of operational amplifier modules 410, reduces the cost of the camera module 200, and reduces the occupied area of ​​the operational amplifier module 410 on the circuit board (or in the chip).

[0319] In addition, the output ends of at least two magnetic field sensors 101 are electrically connected to form a connection node P, and the output voltages of at least two magnetic field sensors 101 are averaged through a hardware circuit, so that the digital processing module 430 does not need to perform digital calculations (such as summing or averaging) on ​​the output voltages of at least two magnetic field sensors 101, thereby saving the computing power of the digital processing module 430, reducing the delay of the digital processing module 430, and reducing the time required to obtain the average value of the output voltages of at least two magnetic field sensors 101, thereby improving the response speed of the camera module 200 during closed-loop autofocus, thereby improving the efficiency of the camera module 200 during closed-loop autofocus.

[0320] That is, by adopting the above configuration, the camera module 200 can achieve low-cost, high-efficiency and long-distance (long focusing stroke) closed-loop autofocus.

[0321] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that a person skilled in the art can think of within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A detection unit, characterized in that: include: At least two magnetic field sensors, the at least two magnetic field sensors are connected in parallel; The output ends of the at least two magnetic field sensors are electrically connected to form a connection node, and the input end of the operational amplifier module is electrically connected to the connection node.

2. The detection unit according to claim 1, characterized in that: The magnetic field sensor has a first output terminal and a second output terminal. The first output terminals of the at least two magnetic field sensors are electrically connected to form a first connection node. The second output terminals of the at least two magnetic field sensors are electrically connected to form a second connection node.

3. The detection unit according to claim 2, characterized in that: Also includes: At least two current limiting elements; the first ends of the at least two current limiting elements are electrically connected to the output ends of the at least two magnetic field sensors in a one-to-one correspondence, and the second ends of the at least two current limiting elements are electrically connected to the connection node; the current limiting elements are used to limit the current value of the current flowing between any two output ends of the magnetic field sensors.

4. The detection unit according to claim 3, characterized in that: The current limiting element includes a first sub-element and a second sub-element; The first ends of at least two of the first sub-elements are electrically connected to the first output ends of the at least two magnetic field sensors in a one-to-one correspondence, and the second ends of at least two of the first sub-elements are electrically connected to the first connection node; The first ends of at least two of the second sub-elements are electrically connected to the second output ends of the at least two magnetic field sensors in a one-to-one correspondence, and the second ends of at least two of the second sub-elements are electrically connected to the second connection node.

5. The detection unit according to claim 4, characterized in that: The first sub-element includes a first resistor, and the second sub-element includes a second resistor; the resistance value of the first resistor is equal to the resistance value of the second resistor; or, The first sub-element includes a plurality of first resistors, which are electrically connected; the second sub-element includes a plurality of second resistors, which are electrically connected; the resistance value of the plurality of first resistors after being electrically connected is equal to the resistance value of the plurality of second resistors after being electrically connected.

6. The detection unit according to any one of claims 3 to 5, characterized in that: The operational amplifier module includes a differential amplifier circuit; The differential amplifier circuit is configured as follows: Acquire an average voltage value of the first output ends of the at least two magnetic field sensors and an average voltage value of the second output ends of the at least two magnetic field sensors; Calculating a difference between an average voltage value of the first output terminals of the at least two magnetic field sensors and an average voltage value of the second output terminals of the at least two magnetic field sensors to obtain an average value of the output voltages of the at least two magnetic field sensors; An average value of the output voltages of the at least two magnetic field sensors is amplified.

7. The detection unit according to claim 6, characterized in that: The differential amplifier circuit is electrically connected to a power supply terminal; a voltage value of the power supply terminal is -k times the average value of the bias voltages of the at least two magnetic field sensors; wherein k is the gain factor of the operational amplifier module.

8. The detection unit according to any one of claims 3 to 7, characterized in that: Also includes: A first circuit board, wherein the first circuit board comprises a conductive trace; the magnetic field sensor and the current limiting element are electrically connected via the conductive trace.

9. The detection unit according to any one of claims 1 to 8, characterized in that: The resistances of the at least two magnetic field sensors are equal, and the power input terminals of the at least two magnetic field sensors are electrically connected to the same power supply; or, The number of the power supplies is at least two, and the power input terminals of the at least two magnetic field sensors are electrically connected to the at least two power supplies in a one-to-one correspondence.

10. The detection unit according to any one of claims 1 to 9, characterized in that: The output end of the operational amplifier module is electrically connected to the input end of the digital processing module; the digital processing module is used to generate a control signal based on the output result of the operational amplifier module.

11. A camera module, characterized in that: include: Lens; Image sensor; The detection unit according to any one of claims 1 to 10; The detection unit is used to detect the distance between the lens and the image sensor.

12. The camera module according to claim 11, characterized in that: The detection unit includes the operational amplifier module, and the input end of the operational amplifier module is electrically connected to the connection node; or, The camera module also includes the operational amplifier module, and the input end of the operational amplifier module is electrically connected to the connection node.

13. The camera module according to claim 11 or 12, characterized in that: The detection unit further includes a power supply, and the power supply is electrically connected to a power input terminal of the magnetic field sensor; or, The camera module also includes a power supply, which is electrically connected to a power input terminal of the magnetic field sensor.

14. The camera module according to any one of claims 11 to 13, characterized in that: It also includes a driving unit, which is used to drive the lens to move; The detection unit further includes a digital processing module, an input end of the digital processing module is electrically connected to an output end of the operational amplifier module, and an output end of the digital processing module is electrically connected to the driving unit; or, The camera module further includes a digital processing module, an input end of the digital processing module is electrically connected to an output end of the operational amplifier module, and an output end of the digital processing module is electrically connected to the driving unit.

15. An electronic device, characterized in that: include: case; The camera module according to any one of claims 11 to 14, wherein the camera module is located in the housing, and a portion of the camera module is exposed to the housing.

Images