WO2023015527A1

WO2023015527A1 - Camera lens module having voice coil motor, camera, and mobile platform

Info

Publication number: WO2023015527A1
Application number: PCT/CN2021/112318
Authority: WO
Inventors: 赵阳; 孙笑轩; 刘煜程; 陈水添
Original assignee: 深圳市大疆创新科技有限公司
Priority date: 2021-08-12
Filing date: 2021-08-12
Publication date: 2023-02-16

Abstract

A camera lens module having a voice coil motor, a camera, and a mobile platform. The camera lens module comprises: a camera lens, provided with a lens; a seat, and an image sensor secured onto the seat, the image sensor being disposed at an image side of the lens; a voice coil motor, the voice coil motor comprising a coil and a magnetic member, the magnetic member being secured onto the seat, and the coil being wound outside the lens and located within in a magnetic field of the magnetic member, and used to generate a driving force under the action of a driving current, so as to drive the lens to move along an optical axis direction; and a fluid damper, mechanically coupled to the camera lens and used to provide damping during movement of the lens. By means of providing a fluid damper in the camera lens module having the voice coil motor, shaking of the camera lens module caused by high-frequency vibrational excitation of the mobile platform can be prevented, a damping oscillation phenomenon occurring in a focusing process of the voice coil motor can be alleviated, and focusing speed and stability can be improved.

Description

Lens module, camera and movable platform with voice coil motor

manual

technical field

The present invention generally relates to the field of cameras, and more specifically relates to a lens module with a voice coil motor, a camera and a movable platform.

Background technique

Mobile platforms such as aircraft need to be equipped with cameras to take pictures or video during operation. The movable platform usually generates vibrations during operation. For example, since an aircraft usually provides a power source through a propeller, large high-frequency vibrations are generated during flight. If a zoom lens is used, the lens module will shake under the excitation of high-frequency vibration, thereby affecting the shooting quality. If a fixed-focus lens is used, in order to ensure that the lens module can complete focusing in a high-low temperature environment, a glass-plastic hybrid lens module is usually used, but the fixed-focus glass-plastic hybrid lens module has poor focusing performance and reduced image quality. , The thickness of the lens module is large, and the focus distance cannot be adjusted.

Contents of the invention

A series of concepts in simplified form are introduced in the Summary of the Invention, which will be further detailed in the Detailed Description. The summary of the invention in the present invention does not mean to limit the key features and essential technical features of the claimed technical solution, nor does it mean to try to determine the protection scope of the claimed technical solution.

In view of the deficiencies in the prior art, the first aspect of the embodiment of the present invention provides a lens module with a voice coil motor, the lens module includes:

Lens, provided with lens;

a base, and an image sensor fixed on the base, the image sensor being arranged on the image side of the lens;

A voice coil motor, the voice coil motor includes a coil and a magnetic part, the magnetic part is fixed on the base, the coil is wound outside the lens and in the magnetic field of the magnetic part, and is used for driving current A driving force is generated under the action of to drive the lens to move along the optical axis; and

A fluid damper, mechanically coupled with the lens, is used to provide damping during the movement of the lens.

The second aspect of the embodiment of the present invention provides a camera, including a lens module and a processor, wherein the lens module includes:

Lens, provided with lens;

A voice coil motor, the voice coil motor includes a coil and a magnetic part, the magnetic part is fixed on the base, the coil is wound outside the lens and in the magnetic field of the magnetic part, and is used for driving current A driving force is generated under the action of to drive the lens to move along the optical axis;

a fluid damper, mechanically coupled to the lens, for providing damping during the movement of the lens;

The processor is used for signal processing the signal collected by the image sensor to generate an image, and the processor is also used for generating the driving current to control the voice coil motor to drive the lens to focus.

The third aspect of the embodiment of the present invention provides a mobile platform, including:

Movable platform body;

As for the above-mentioned camera, the camera is mounted on the movable platform body.

In the lens module with a voice coil motor, the camera and the movable platform in the embodiment of the present invention, a fluid damper is arranged in the lens module with a voice coil motor, which can avoid the vibration of the lens module caused by the high-frequency vibration excitation of the movable platform. Vibration enables the lens module with a voice coil motor to be applied to a movable platform; at the same time, it can also improve the damping oscillation phenomenon of the voice coil motor during the focusing process, and improve the speed and stability of focusing.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

FIG. 1A is a cross-sectional view of a lens module according to an embodiment of the present invention;

FIG. 1B is a top view of a lens module according to an embodiment of the present invention;

Fig. 1C is a perspective view of a lens module according to an embodiment of the present invention;

1D is a side view of a lens module according to an embodiment of the present invention;

2A is a cross-sectional view of a fluid damper according to an embodiment of the present invention;

Figure 2B is a perspective view of a fluid damper according to an embodiment of the present invention;

Figure 2C is a side view of a fluid damper according to one embodiment of the present invention;

Figure 2D is a cross-sectional view of the fluid damper in another direction according to one embodiment of the present invention;

Fig. 3 is a schematic diagram of the relationship between the response of the fluid damper and the excitation frequency according to an embodiment of the present invention;

Fig. 4 is the schematic diagram of the impact response of the fluid damper of an embodiment of the present invention;

Fig. 5 is a schematic diagram of the influence relationship of the hole diameter or number on the resistance of the fluid damper according to an embodiment of the present invention;

Fig. 6 is a schematic diagram of the relationship between the damping of the internal fluid and the resistance of the fluid damper according to an embodiment of the present invention;

Fig. 7 is a structural block diagram of a camera according to an embodiment of the present invention;

FIG. 8 is a flow chart of camera focus control according to an embodiment of the present invention.

Detailed ways

In order to make the objects, technical solutions and advantages of the present invention more apparent, exemplary embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. Apparently, the described embodiments are only some embodiments of the present invention, rather than all embodiments of the present invention, and it should be understood that the present invention is not limited by the exemplary embodiments described here. Based on the embodiments of the present invention described in the present invention, all other embodiments obtained by those skilled in the art without creative effort shall fall within the protection scope of the present invention.

In the following description, numerous specific details are given in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without one or more of these details. In other examples, some technical features known in the art are not described in order to avoid confusion with the present invention.

It should be understood that the invention can be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the/the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It should also be understood that the terms "consists of" and/or "comprising", when used in this specification, identify the presence of stated features, integers, steps, operations, elements and/or parts, but do not exclude one or more other Presence or addition of features, integers, steps, operations, elements, parts and/or groups. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

In order to thoroughly understand the present invention, a detailed structure will be provided in the following description to illustrate the technical solution proposed by the present invention. Alternative embodiments of the invention are described in detail below, however the invention may have other embodiments beyond these detailed descriptions.

The mobile platform usually needs to be equipped with a camera to take pictures or video during operation. Among various types of mobile platforms, the multi-rotor aircraft has achieved relatively rapid development in the civil and military fields due to its good stability, strong anti-interference ability, active hovering and relatively low requirements for take-off and landing conditions. development and wide application. Since the aircraft usually provides a power source through the propeller, a large high-frequency vibration will be generated during the flight.

At present, the lens module on the mobile phone usually adopts VCM (Voice Coil Motor, voice coil motor) to focus, and the voice coil motor realizes the forward and backward movement of the lens component through magnetic force. The driving circuit of the voice coil motor is actually a DAC (Digital to Analog Converter, digital-to-analog converter) circuit with a control algorithm, which can convert the DAC code containing digital position information from the I2C bus into the corresponding output current, and then The output current is converted into the focus distance through the VCM device. Different output currents form a loop through the voice coil motor to generate different ampere forces, which push the lens on the voice coil motor to move.

The movement of the lens on the voice coil motor will generate damped oscillation before stopping, and the size of the damped oscillation directly affects the stability of the lens. The greater the damping vibration, the worse the stability of the lens, making it difficult for the lens to capture clear points during the focusing process, and it is easy to produce out of focus. For the high-frequency vibration of UAV due to blade rotation and aerodynamic coupling, the broadband excitation of wind load and the low-frequency excitation of flight control control, at present, the vibration is attenuated mainly by adding a vibration reduction mechanism in the connection between the camera and the aircraft, and The gimbal motors are used to separately control each axis arm to provide stabilization. The above two measures can reduce the final vibration level at the lens module of the camera, but cannot eliminate the vibration at the lens module. Due to the small output of the voice coil motor and the limitation of the control bandwidth of the conventional lens module with a voice coil motor, the lens module will vibrate under the excitation of high-frequency vibration, which seriously affects the shooting quality. Therefore, the conventional lens module with a voice coil motor The lens module cannot be applied to mobile platforms with strong vibrations such as drones.

Due to the inability to solve the above problems, cameras mounted on mobile platforms such as drones generally can only use fixed-focus lens modules. In order to ensure that the fixed-focus lens module can complete focusing in high and low temperature environments and eliminate thermal errors, drones usually use a glass-plastic hybrid lens module to eliminate the effects of deformation by offsetting each other through thermal deformation. However, the use of glass-plastic hybrid lenses will bring disadvantages such as poor focusing performance, reduced image quality, thick lens modules, and inability to adjust the focusing distance.

In view of the above problems, an embodiment of the present invention provides a lens module with a voice coil motor, a camera, and a movable platform. Adding a fluid damper to the lens module with a voice coil motor can avoid the high-frequency vibration of the movable platform. The vibration excitation causes the lens module to vibrate, so that the lens module on the movable platform can use the voice coil motor to focus, and can reduce the damping oscillation that occurs during the focusing process of the voice coil motor.

A lens module with a voice coil motor according to an embodiment of the present invention will be further described below in conjunction with the accompanying drawings. The lens module with a voice coil motor in the embodiment of the present invention is used for a movable platform.

Referring to Fig. 1A-Fig. 1D, the lens module of the embodiment of the present invention comprises: lens, is provided with lens 101; The coil motor 104, the voice coil motor 104 includes a coil and a magnetic part, the magnetic part is fixed on the base 102, the coil is wound outside the lens 101 and is in the magnetic field of the magnetic part, and is used to generate a driving force under the action of a driving current to drive The lens 101 moves along the optical axis; and the fluid damper 105 is mechanically coupled with the lens to provide damping during the movement of the lens 101 .

The lens module of the embodiment of the present invention uses the fluid damper 105 to provide damping. The fluid damper 105 is small in size and light in weight. The volume and weight requirements of the load can also meet the large damping requirements of the lens module, and are more suitable for application on a movable platform. At the same time, the voice coil motor 104 has the advantages of miniaturization, real-time performance, high precision, linear motion, closed-loop control, and fast response. The voice coil motor 104 and the fluid damper 105 act on the lens module in parallel.

When the lens module needs to focus due to temperature changes, object distance changes, etc., the voice coil motor 104 drives the lens 101 to move according to the control instructions of the controller, and the fluid damper 105 provides damping for the lens 101, realizing physical The effect similar to low-pass filtering, while not affecting the movement of the voice coil motor, ensures that the lens module will not vibrate under the action of high-frequency excitation generated when the movable platform is running, so that the lens module with a voice coil motor It can be applied to a movable platform, and the voice coil motor drives the lens to move and focus, without using a fixed-focus glass-plastic hybrid lens module, which avoids the disadvantages of the wave-speed hybrid lens module, such as large thickness and inability to adjust the focusing distance. Figure 3 shows the response at different excitation frequencies with and without a fluid damper. It can be seen from Figure 3 that the fluid damper has a more prominent suppression effect on high-frequency excitation, and can be used for lens modules very well. Vibration occurs under the action of high-frequency excitation of the movable platform.

In addition, the movement of the lens on the voice coil motor will generate damped oscillations before stopping, and the size of the damped oscillations directly affects the stability of the lens. The greater the damping vibration, the worse the stability of the lens, so it is difficult for the lens to capture a clear point during the focusing process, and it is easy to lose focus. Conversely, the smaller the damping vibration, the better the stability of the lens, so that the lens is easier to stabilize at the focal point during the focusing process. The fluid damper 105 can improve the damping vibration of the voice coil motor 104 during the focusing process and improve the focusing effect. The lens module completes the focusing work under the joint action of the voice coil motor 104 and the fluid damper 105 . Figure 4 shows the shock response with and without the fluid damper. It can be seen from Figure 4 that the fluid damper has a significant suppression effect on the shock response, and thus can improve the damping of the voice coil motor during the focusing process Shock phenomenon, improve the speed and stability of focusing.

Exemplarily, the voice coil motor 104 includes a coil and a magnetic part, the magnetic part is fixed on the base 102, and a space for accommodating the coil and the lens 101 is formed inside it; in space. When the driving current flows through the coil, an electromagnetic force is generated between the coil and the magnetic member, and the electromagnetic force pushes the coil to move in the axial direction, so that the lens 101 wound by the coil moves in the direction of the optical axis to achieve focusing.

The fluid damper 105 is mechanically coupled with the lens for providing damping during the movement of the lens 101 . Exemplarily, referring to FIG. 2A to FIG. 2D , the fluid damper 105 includes a housing 201 provided with a chamber, a fluid 202 sealed in the chamber, a piston 203 disposed in the chamber, and a valve penetrating through the housing 201 and connected to the piston 203 The piston rod 204, and the channel 205 for the fluid 202 on both sides of the piston to communicate.

When an external force acts on the piston rod 204, the piston rod 204 stretches outward or compresses inward, and drives the piston 203 to move in the chamber, so that the chambers at the front and rear of the piston 203 are stretched and compressed respectively, and pressure is generated on both sides of the piston 203 The fluid flows through the channel 205 to the chamber on the other side under the action of the pressure difference. Wherein, when the chamber in front of the piston 203 is stretched, the fluid in the chamber in the rear of the piston 203 will be replenished in the chamber in front through the channel 205; when the chamber in front of the piston 203 is compressed, the fluid in the chamber in front of the piston 203 will will flow into the chamber behind the piston 203 through the channel 205 .

In the process of fluid flow, if the cross-sectional area of the flow channel changes significantly, due to the incompressible characteristics of the fluid, according to the Bernoulli equation and the continuity of fluid flow, the through-hole resistance can be obtained through calculation and testing, where The size of the through-hole resistance is significantly related to the rate of change of the cross-section of the flow channel, fluid velocity, fluid viscosity, pipe diameter and other factors. Generally speaking, the greater the rate of change of the cross-section, the greater the fluid velocity, the greater the fluid viscosity, the The smaller the diameter, the greater the via resistance. The structure, shape, size and fluid damping of the fluid damper 105 can affect the resistance of the fluid damper 105 . By adjusting multiple parameters such as the damping of the fluid 202 inside the fluid damper 105, the diameter and number of channels 205, and the inner diameter of the chamber, the fluid damper 105 can be adapted to the vibration frequency of lens modules and movable platforms of different masses and sizes. .

Exemplarily, the lens further includes a carrier for carrying the lens 101 , the coil of the voice coil motor 104 is wound on the carrier, and the lens 101 is driven to move by the carrier. The fluid damper 105 is connected to the carrier to provide damping through the carrier instead of directly connecting to the lens 101 to avoid affecting the optical performance of the lens 101 .

In one embodiment, the piston rod 204 may be disposed substantially perpendicular to the piston 203 as shown in FIG. 2A , and extend through the end of the housing 201 . The piston rod 204 can be arranged on one side of the piston 203 as shown in FIG. 2A , or on both sides of the piston 203 . When the piston rod 204 is arranged on one side of the piston 203, the piston rod 204 and the housing 201 are respectively connected to the lens and the base 102; .

When the piston rod 204 is arranged substantially perpendicular to the piston 203 , the fluid damper 105 can be arranged between the lens 101 and the base 102 , and the piston rod 204 is arranged substantially parallel to the optical axis direction of the lens 101 . Exemplarily, a groove for accommodating the fluid damper 105 is formed in the base 102, and the fluid damper 105 is arranged in the groove to save space. The shape of the cross section of the housing 201 can be a circle or any polygon, and correspondingly, the shape of the groove matches the shape of the housing 201 .

In one embodiment, as shown in FIG. 1A , the housing 201 of the fluid damper 105 is mechanically coupled to the base 102 of the lens module; meanwhile, the end of the piston rod 204 is mechanically coupled to the lens. That is, the housing 201 is fixed relative to the base 102 , and when the voice coil motor 104 drives the lens to focus, the piston rod 204 moves accordingly, and drives the piston 203 to move in the fluid 202 inside the housing 201 . In another embodiment, the end of the piston rod 204 is mechanically coupled to the base 102 , and at the same time, the housing 201 is mechanically coupled to the lens, that is, the piston rod 104 is fixed relative to the base 102 .

When the housing 201 is mechanically coupled with the base 102 of the lens module, the housing 201 of the fluid damper can form an integral structure with the base 102 of the lens module to improve the stability of the lens module and avoid the fluid damper fall off. Optionally, the housing 201 and the base 102 can also be separately provided and mechanically coupled to increase the flexibility of the lens module and facilitate adjustment and replacement of the fluid damper.

In another embodiment, the fluid damper 105 is disposed on the side of the lens 101 , the piston rod 204 penetrates the side wall of the housing 201 , and the piston rod 204 is disposed substantially perpendicular to the optical axis of the lens 101 . At this time, the groove for accommodating the fluid damper 103 can be provided at the bottom of the magnetic part of the voice coil motor 104 , wherein the housing 201 is mechanically coupled to the base, and the piston rod 204 is mechanically coupled to the side wall of the lens 101 .

The channel 205 of the fluid damper 105 for the fluid 202 to communicate can be realized as a hole as shown in FIG. 2A , that is, a hole provided in the piston 203 . The fluid 202 on both sides of the piston 203 communicates directly through the holes in the piston 203 . The shape of the hole can be circular, square or any other shape. The number of holes can be one or more.

The channel 205 can also adopt other forms, as long as it can provide the fluid 202 on both sides of the piston 203 to communicate. For example, the channel 205 can be realized as a groove provided on the inner wall of the chamber, so that the fluid can circulate on both sides of the piston 203 through the groove around the piston 203 . Alternatively, the channel 205 may also be a pipe connecting both sides of the piston 203 , the pipe is arranged outside the casing 201 , and two ends of the pipe communicate with the side walls of the chamber on both sides of the piston 203 respectively.

The diameter and number of channels 205 directly affect the amount of damping of the fluid damper 105 . In one embodiment, the lens module further includes an adjusting device (not shown) for adjusting the size of the channel 205 of the fluid damper 105, so that the damping provided by the fluid damper 105 is adapted to the current operating environment of the lens module , such as adapting to the current vibration frequency of the movable platform. In some cases, an adjustment device may close a portion of channel 205 . Exemplarily, the control device obtains the currently required damping size, and then obtains the corresponding channel size, and sends a control instruction to the adjustment device; the adjustment device receives the control instruction sent by the control device, and adjusts the size of each channel according to the control instruction . Exemplarily, the adjusting device comprises a valve, which is movable relative to the housing 201 to at least partially block the channel 205 . The regulating device also includes drive means for driving the valve.

Referring to Figure 5, Figure 5 shows the response curves of fluid dampers with different numbers and diameters of channels to impact excitation. Among them, the number of channels corresponding to curve 1, curve 2 and curve 5 is 1, and the channel diameters are 3mm, 2mm and 1mm respectively. According to the comparison of curve 1, curve 2 and curve 5, it can be seen that when the number of channels is the same, the smaller the channel diameter, the greater the damping and the higher the stability. The channel diameters corresponding to curve 3, curve 4 and curve 5 are all 1 mm, and the number of channels is 9, 4 and 1 respectively. According to the comparison of curve 3, curve 4 and curve 5, when the channel diameters are the same, the number of channels The less, the greater the damping and the greater the stability. According to the above rules, the adjustment device can be controlled to adjust the size of the channel of the fluid damper 105 according to actual needs, so as to obtain the required damping size.

Referring to Fig. 6, Fig. 6 shows the relationship between the impact response of the fluid damper and the fluid damping. It can be seen from FIG. 6 that the greater the fluid damping, the smaller the impact response and the higher the stability. Therefore, the fluid damper can be adapted to lens modules of different qualities and sizes and movable by adjusting the damping of the fluid inside the fluid damper 105. The vibration excitation frequency of the platform.

Based on the above description, in the embodiment of the present invention, a fluid damper is provided in the lens module with a voice coil motor, which can avoid the vibration of the lens module caused by the high-frequency vibration excitation of the movable platform, and make the lens module with a voice coil motor It can be applied to a movable platform; at the same time, it can also improve the damping and oscillation phenomenon of the voice coil motor during the focusing process, and improve the speed and stability of the focusing.

Referring to FIG. 7 , another aspect of the embodiment of the present invention provides a camera 700 , including a lens module 710 and a processor 720 . Wherein, the lens module 710 may be the lens module as described above, specifically, the lens module 710 includes: a lens, provided with a lens; a base, and an image sensor fixed on the base, and the image sensor is arranged on the image of the lens Side; voice coil motor, the voice coil motor includes a coil and a magnetic part, the magnetic part is fixed on the base, the coil is wound outside the lens and is in the magnetic field of the magnetic part, and is used to generate driving force under the action of the driving current to drive the lens moving along the direction of the optical axis; and a fluid damper, mechanically coupled with the lens, for providing damping during the movement of the lens. The processor 720 is used to perform signal processing on the signal collected by the image sensor to generate an image, and the processor is also used to generate a driving current to control the voice coil motor to drive the lens to focus.

The camera 700 of the embodiment of the present invention adopts a lens module with a voice coil motor, and the lens module also includes a fluid damper, and the fluid damper provides damping, which can prevent the lens module from moving while not affecting the movement of the voice coil motor. Vibration occurs under the action of high-frequency excitation of the movable platform, which realizes the application of the lens module with voice coil motor in the movable platform, and can improve the damping vibration of the voice coil motor during the focusing process, and improves the camera's performance. Shooting effect.

Exemplarily, the fluid damper includes a housing with a chamber, a fluid sealed in the chamber, a piston disposed in the chamber, a piston rod penetrating through the housing and connected to the piston, and passages for fluid communication on both sides of the piston. Wherein, the chamber is fixedly arranged on the base, or the end of the piston rod is fixedly arranged on the base. The housing of the fluid damper and the base of the lens module form an integral structure together, or the housing of the fluid damper and the base of the lens module are separately provided.

The fluid damper can be arranged between the lens and the base, the piston rod passes through the end of the housing, and the piston rod is arranged parallel to the direction of the optical axis. Alternatively, the fluid damper may be arranged on the side of the lens, the piston rod penetrates through the side wall of the housing, and the piston rod is arranged perpendicular to the direction of the optical axis.

Exemplarily, the channel of the fluid damper includes at least one of the following: a hole provided in the piston, a groove provided on the inner wall of the chamber, and a pipe connecting two sides of the piston.

Exemplarily, the lens further includes a carrier for carrying the lens, and the coil is wound on the carrier; the fluid damper is connected to the carrier.

In one embodiment, the processor 720 is used to output control current according to the definition of the image, so as to control the voice coil motor to drive the lens to focus until the definition of the image meets the preset requirements, so as to perform real-time closed-loop control to improve the focus precision. Specifically, referring to FIG. 8, the focus control process includes the following steps:

In step 810, acquire the focus command sent by the command end;

In step 820, signal processing is performed on the signal collected by the image sensor to generate an image, and a driving current is output according to the definition of the image and the calibration parameters;

In step 830, the voice coil motor drives the lens and the fluid damper to move according to the driving current, and the fluid damper provides damping during the movement;

At step 840, the image sensor collects the signal again;

In step 850, signal processing is performed on the signal collected by the image sensor in the current state to generate an image;

In step 860, the sharpness of the image is judged, and if the sharpness does not meet the preset requirements, repeat steps 820 to 850; if the sharpness meets the preset requirements, then the focusing ends.

During the focusing process, the processor 720 may also adjust the fluid damper, so as to obtain a target damping suitable for actual needs. Exemplarily, the damping force of the fluid damper can be deduced according to the following formula:

The known mass conservation equation is:

u ₁ A ₁ =u ₂ A ₂ (Formula 1)

The Bernoulli equation is:

Among them, δ is the dissipation energy of the via hole, which is related to the Reynolds number R _ed and the area ratio m of the pipeline flow;

The corrected formula is:

According to formula 1 to formula 4, the derivation formula of the damping force can finally be obtained as:

Where: n is the number of channels, t is the thickness of the piston, ρ is the fluid density, μ is the fluid dynamic viscosity, d ₁ is the inner diameter of the chamber, d ₂ is the channel radius, and u is the piston pushing speed.

It can be seen from Formula 5 that the damping force is related to factors such as the number of channels and the radius of the channel, therefore, in one embodiment, the processor 720 is also used to: obtain the target damping force of the fluid damper, and adjust the channel according to the target damping force the size of. Wherein, the target damping force may be obtained according to the vibration frequency of the lens. Exemplarily, the lens module further includes an adjusting device for adjusting the size of the channel. The adjusting device can be realized as a valve which is movable relative to the housing of the fluid damper in order to at least partially block the passage. The regulating device also includes drive means for driving the valve. The processor 720 outputs control instructions to the driving device, so as to drive the valve through the driving device to adjust the size of the channel.

In some embodiments, the processor 720 is also used to: acquire the threshold speed at which the fluid damper is stuck; control the movement speed of the lens to not exceed the threshold speed, thereby avoiding the fluid damper from being stuck due to the piston pushing too fast death phenomenon.

Based on the above description, the camera of the embodiment of the present invention is equipped with a fluid damper in the lens module with a voice coil motor, which can avoid the vibration of the lens module caused by the high-frequency vibration excitation of the movable platform, and improve the focus of the voice coil motor. The damping oscillation phenomenon that occurs during the process improves the speed and stability of focusing.

Another aspect of the embodiment of the present invention provides a movable platform, the movable platform includes a movable platform body and a camera mounted on the movable platform body, and the camera is used to photograph the target object during the operation of the movable platform body . The camera may be the camera 700 as described above, which specifically includes a lens module and a processor, wherein the lens module includes: a lens, provided with a lens; a base, and an image sensor fixed on the base, and the image sensor is arranged on the lens The image side of the voice coil motor, the voice coil motor includes a coil and a magnetic part, the magnetic part is fixed on the base, the coil is wound outside the lens and in the magnetic field of the magnetic part, and is used to generate driving force under the action of the driving current to drive the lens to move along the optical axis; and the fluid damper, which is mechanically coupled with the lens, is used to provide damping during the movement of the lens; the processor is used to perform signal processing on the signal collected by the image sensor to generate an image, and the processor also It is used to generate driving current to control the voice coil motor to drive the lens to focus.

Exemplarily, the movable platform may include an aircraft (such as a drone), a robot, an unmanned vehicle, an unmanned boat, and the like. When the movable platform is an unmanned aerial vehicle, the movable platform body is the body of the unmanned aerial vehicle. When the movable platform is an unmanned vehicle, the body of the movable platform is the body of the unmanned vehicle. The mobile platform is described below by taking an unmanned aerial vehicle as an example, but it can be understood that this is not intended to limit the application scenario of the present application.

Exemplarily, a drone may include a processor, a memory, a power mechanism, a sensing system, and a communication system. These components are interconnected by bus systems and/or other forms of connection mechanisms. In some embodiments, the camera can be set on the drone through a carrier such as a pan/tilt.

The power mechanism may include one or more rotating bodies, propellers, paddles, engines, motors, wheels, bearings, magnets, nozzles. For example, the rotating body of the power mechanism may be a self-fastening rotating body, a rotating body assembly, or other rotating body power units. A UAV can have one or more power mechanisms. All power mechanisms can be of the same type. Optionally, one or more power mechanisms may be of different types. The power unit can be mounted on the drone by suitable means, such as via a support element (eg drive shaft). The power mechanism can be installed in any suitable position of the drone, such as the top, bottom, front, rear, side or any combination thereof.

In some embodiments, the power mechanism enables the drone to take off vertically from a surface, or land vertically on a surface, without requiring any horizontal movement of the drone (eg, without needing to taxi on a runway). Optionally, the power mechanism may allow the UAV to hover in a preset position and/or direction in the air. One or more powered mechanisms may be controlled independently of other powered mechanisms. Optionally, one or more power mechanisms can be controlled simultaneously. For example, a drone may have multiple horizontal rotators to track the lifting and/or pushing of a target. The rotating body in the horizontal direction can be actuated to provide the ability of the UAV to take off vertically, land vertically, and hover. In some embodiments, one or more of the horizontally oriented rotators may rotate clockwise, while the other one or more of the horizontally oriented rotators may rotate counterclockwise. For example, there are as many rotators that rotate clockwise as there are rotators that rotate counterclockwise. The rate of rotation of each horizontal rotator can be varied independently to enable the lifting and/or pushing maneuvers caused by each rotator to adjust the spatial orientation, velocity, and/or acceleration of the drone (e.g., relative to up to three degrees of freedom rotation and translation).

The sensing system may include one or more sensors to sense the drone's spatial orientation, velocity, and/or acceleration (eg, rotation and translation with respect to up to three degrees of freedom). The one or more sensors include any of the aforementioned sensors, including GPS sensors, motion sensors, inertial sensors, proximity sensors, or image sensors. The sensing data provided by the sensing system can be used to track the spatial orientation, velocity and/or acceleration of the target. Optionally, the sensing system may be used to collect data about the drone's environment, such as weather conditions, potential obstacles to approach, locations of geographic features, locations of man-made structures, image information, and the like.

The communication system can communicate with the control device with the communication system through wireless signals. A communication system may include any number of transmitters, receivers, and/or transceivers for wireless communication. The communication may be one-way communication, such that data is sent in one direction. For example, one-way communication can include that only the drone transmits data to the control device, or vice versa. One or more transmitters of the communication system can send data to one or more receivers of the communication system, and vice versa. Optionally, the communication may be bi-directional, such that data can be transmitted in both directions between the drone and the control device. Two-way communication involves that one or more transmitters of the communication system can send data to one or more receivers of the communication system, and vice versa.

In some embodiments, the control device may provide control data to one or more of the drone, the carrier, and the camera, and receive information from one or more of the drone, the carrier, and the camera (such as The location and/or movement information of the drone, the carrier or the camera, such as the image data captured by the camera, etc.). In some embodiments, the control data of the control device may include instructions regarding position, movement, actuation, or control of the drone, carrier and/or camera. For example, the control data may cause a change in the position and/or orientation of the drone (eg, by controlling a power mechanism), or cause a movement of the carrier relative to the drone (eg, by controlling the carrier). The control data of the control device can lead to camera control, such as controlling the camera or other camera operations (capturing still or moving images, zooming, turning on or off, switching shooting modes, changing image resolution, changing focal length, changing depth of field, changing exposure time , change the viewing angle or field of view). In some embodiments, drone, vehicle, and/or camera communications may include information from one or more sensors (eg, sensor systems or cameras). The communication may include sensory information transmitted from one or more different types of sensors, such as GPS sensors, motion sensors, inertial sensors, proximity sensors, or image sensors. The sensing information is about the position (such as direction, position), motion, or acceleration of the drone, the carrier, and/or the camera. The sensory information transmitted from the camera includes the data captured by the camera or the state of the camera. The control data transmitted and provided by the control device can be used to track the state of one or more of the drone, the carrier or the camera. Optionally or simultaneously, each of the carrier and the camera may include a communication module for communicating with the control device, so that the control device can communicate or track the drone, the carrier and the camera individually.

In some embodiments, the drone can communicate with other remote devices than the control device, and the control device can also communicate with other remote devices besides the drone. For example, the drone and/or the control device may communicate with another drone or with another drone's carrier or camera. The additional remote device may be a second control device or other computing device (such as a computer, desktop, tablet, smart phone, or other mobile device), when desired. The remote device can transmit data to the drone, receive data from the drone, transmit data to the control device, and/or receive data from the control device. Optionally, the remote device may be connected to the Internet or other telecommunication network to enable uploading of data received from the drone and/or control device to a website or server.

In some embodiments, the movement of the drone, the movement of the carrier and the movement of the camera relative to a fixed reference object (such as the external environment), and/or the movement between each other, can all be controlled by the control device. The control device may be a remote control terminal, which is located away from the drone, the carrier and/or the camera. The control device may be located or attached to the support platform. Optionally, the control device may be handheld or wearable. For example, the control device may include a smart phone, a tablet computer, a desktop computer, a computer, glasses, gloves, a helmet, a microphone, or any combination thereof. The control means may comprise a user interface such as a keyboard, mouse, joystick, touch screen or display. Any suitable user input may interact with the control device, such as manual input commands, voice control, gesture control, or positional control (eg by movement, position or tilt of the control device).

Because the movable platform of the embodiment of the present invention has the camera of the embodiment of the present invention, the shooting effect can be improved.

Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above-described example embodiments are illustrative only and are not intended to limit the scope of the invention thereto. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of the invention. All such changes and modifications are intended to be included within the scope of the invention as claimed in the appended claims.

Those skilled in the art can appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present invention.

In the several embodiments provided in this application, it should be understood that the disclosed devices and methods may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or May be integrated into another device, or some features may be omitted, or not implemented.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure the understanding of this description.

Similarly, it should be understood that in the description of the exemplary embodiments of the invention, in order to streamline the disclosure and to facilitate an understanding of one or more of the various inventive aspects, various features of the invention are sometimes grouped together in a single embodiment, figure , or in its description. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the corresponding claims reflect, the inventive point lies in that the corresponding technical problem may be solved by using less than all features of a single disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.

It will be appreciated by those skilled in the art that all features disclosed in this specification (including accompanying claims, abstract and drawings) and all features of any method or apparatus so disclosed may be used in any combination, except where the features are mutually exclusive. process or unit. Each feature disclosed in this specification (including accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Furthermore, those skilled in the art will understand that although some embodiments described herein include some features included in other embodiments but not others, combinations of features from different embodiments are meant to be within the scope of the invention. and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

The various component embodiments of the present invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art should understand that a microprocessor or a digital signal processor (DSP) may be used in practice to implement some or all functions of some modules according to the embodiments of the present invention. The present invention can also be implemented as an apparatus program (for example, a computer program and a computer program product) for performing a part or all of the methods described herein. Such a program for realizing the present invention may be stored on a computer-readable medium, or may be in the form of one or more signals. Such a signal may be downloaded from an Internet site, or provided on a carrier signal, or provided in any other form.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The invention can be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The use of the words first, second, and third, etc. does not indicate any order. These words can be interpreted as names.

Claims

A lens module with a voice coil motor, characterized in that the lens module includes:

Lens, provided with lens;

a base, and an image sensor fixed on the base, the image sensor being arranged on the image side of the lens;

A voice coil motor, the voice coil motor includes a coil and a magnetic part, the magnetic part is fixed on the base, the coil is wound outside the lens and in the magnetic field of the magnetic part, and is used for driving current A driving force is generated under the action of to drive the lens to move along the optical axis; and

A fluid damper, mechanically coupled with the lens, is used to provide damping during the movement of the lens.
The lens module according to claim 1, wherein the fluid damper comprises a housing provided with a chamber, a fluid sealed in the chamber, a piston disposed in the chamber, and a piston penetrating through the housing a body and a piston rod connected to the piston, and a channel for fluid communication on both sides of the piston;

Wherein, the housing is mechanically coupled to the base, or the end of the piston rod is mechanically coupled to the base.
The lens module according to claim 2, wherein the housing and the base jointly form an integrated structure, or the housing and the base are separately provided.
The lens module according to claim 2, wherein the channel comprises at least one of the following: a hole provided in the piston, a groove provided on the inner wall of the chamber, and a channel communicating with the piston pipes on both sides.
The lens module according to claim 2, wherein the fluid damper is arranged between the lens and the base, the piston rod passes through the end of the housing, and the piston rod substantially parallel to the direction of the optical axis.
The lens module according to claim 2, wherein the fluid damper is arranged on the side of the lens, the piston rod passes through the side wall of the housing, and the piston rod is substantially perpendicular to the The direction of the optical axis is set.
The lens module according to claim 2, further comprising an adjustment device for adjusting the size of the channel.
The lens module according to claim 7, wherein the adjusting device comprises a valve, and the valve is movable relative to the housing to at least partially block the channel.
The lens module according to claim 8, wherein the adjusting device further comprises a driving device for driving the valve.
The lens module according to claim 1, wherein the lens further comprises a carrier, the carrier is used to carry the lens, and the coil is wound on the carrier; the fluid damper and the The carrier is mechanically coupled.
A camera, characterized in that it includes a lens module and a processor, wherein the lens module includes:

Lens, provided with lens;

a base, and an image sensor fixed on the base, the image sensor being arranged on the image side of the lens;

A voice coil motor, the voice coil motor includes a coil and a magnetic part, the magnetic part is fixed on the base, the coil is wound outside the lens and in the magnetic field of the magnetic part, and is used for driving current A driving force is generated under the action of to drive the lens to move along the optical axis;

a fluid damper, mechanically coupled to the lens, for providing damping during the movement of the lens;

The processor is used for signal processing the signal collected by the image sensor to generate an image, and the processor is also used for generating the driving current to control the voice coil motor to drive the lens to focus.
The camera according to claim 11, wherein the processor is configured to output the control current according to the definition of the image to control the voice coil motor to drive the lens to focus until the The clarity meets the preset requirements.
The camera of claim 11, wherein the fluid damper comprises a housing having a chamber, a fluid sealed within the chamber, a piston disposed within the chamber, penetrating through the housing and a piston rod connected to the piston, and a channel for fluid communication on both sides of the piston;

Wherein, the housing is mechanically coupled to the base, or the end of the piston rod is mechanically coupled to the base.
The lens module according to claim 13, wherein the housing and the base jointly form an integrated structure, or the housing and the base are separately provided.
The camera according to claim 13, wherein the channel comprises at least one of the following: a hole provided in the piston, a groove provided on the inner wall of the chamber, and a channel connecting two sides of the piston pipeline.
The camera of claim 13, wherein said fluid damper is disposed between said lens and said base, said piston rod extends through the end of said housing, and said piston rod is substantially parallel set in the direction of the optical axis.
The camera according to claim 13, wherein said fluid damper is disposed on a side of said lens, said piston rod penetrates the side wall of said housing, said piston rod is substantially perpendicular to said light Axis direction setting.
The lens module according to claim 13, further comprising an adjusting device for adjusting the size of the channel.
The lens module according to claim 18, wherein the adjusting device comprises a valve, and the valve is movable relative to the housing to at least partially block the channel.
The lens module according to claim 19, wherein the adjusting device further comprises a driving device for driving the valve.
The camera according to any one of claims 18-20, wherein the processor is further configured to:

acquiring the target damping force of the fluid damper according to the vibration frequency of the lens;

The size of the channel is adjusted according to the target damping force.
The camera of claim 11, wherein the processor is further configured to:

Obtaining a threshold speed at which the fluid damper is stuck;

The speed at which the movement of the lens is controlled is not greater than the threshold speed.
The camera according to claim 11, wherein the lens further comprises a carrier, the carrier is used to carry the lens, and the coil is wound on the carrier; the fluid damper is mechanically connected with the carrier coupling connection.
A mobile platform, characterized in that it comprises:

Movable platform body;

The camera according to any one of claims 11-23, wherein the camera is mounted on the movable platform body.
24. The mobile platform of claim 24, wherein said mobile platform comprises a drone.