Focusing device

Abstract

According to the focusing device, an alternating magnetic field is generated through a mover part in a linear motor, a second stator generates thrust or tension under the action of the magnetic field, the mover is pushed to move linearly, then a lens connected with the mover is driven to move, the distance between the lens and an object to be shot is adjusted, the depth-of-field position is adjusted, and imaging is clear. The first stator of the rotating motor generates a magnetic field, and the rotor rotates under the influence of the magnetic field generated by the first stator, so that torque is output, the lens focusing ring connected with the rotor is driven to rotate, the focal length is changed, and the imaging range is controlled. In the focusing process, the rotation angle value of the focusing ring and the displacement amount of the lens are obtained through the angle measurement module and the displacement measurement module, closed-loop focusing is achieved, and the focusing precision can be greatly improved, for example, the submicron-level focusing precision is achieved.

Description

Technical Field

[0001] This application relates to the field of optical imaging technology, and in particular to focusing devices. Background Technology

[0002] Lens focusing is a crucial step in photography and optical imaging, aimed at ensuring that the subject is captured in the sharpest and clearest possible image on the image sensor or film.

[0003] Among related technologies, the focusing accuracy of the lens is relatively low. Utility Model Content

[0004] Therefore, it is necessary to provide a focusing device to address the problem of low focusing accuracy in existing lenses.

[0005] A focusing device, the focusing device comprising:

[0006] Base;

[0007] A rotary motor, disposed within the base, the rotary motor including a first stator and a rotor responsive to the first stator to rotate about a first axis;

[0008] An angle measurement module, connected to the rotor, is used to obtain the rotation angle value of the rotor;

[0009] A linear motor, disposed within the base, the linear motor including a mover and a second stator responsive to the mover to drive axial movement of the mover along the first axis; and,

[0010] A displacement measurement module is connected to the mover and is used to obtain the displacement of the mover.

[0011] In one embodiment, the first stator includes a first winding coil fixedly disposed within the base, and the rotor includes a rotating magnet rotatably disposed within the base.

[0012] In one embodiment, a silicon steel sheet is attached to one side surface of the first winding coil along the axial direction of the first axis; or,

[0013] The first stator includes at least two sets of first winding coils, and silicon steel sheets are connected between the at least two sets of first winding coils.

[0014] In one embodiment, the rotary motor further includes a first magnetic yoke, the first magnetic yoke having a snap-fit ​​groove, into which the rotating magnet snaps.

[0015] The first magnetic yoke is rotatably connected to a bearing on the side of its surface opposite to the first winding coil.

[0016] In one embodiment, the angle measuring module includes a first grating ruler and a first reading head, one of which is connected to the first magnetic yoke, and the other is connected to the first winding coil.

[0017] In one embodiment, the mover includes a second winding coil slidably disposed within the base, and the second stator includes a second magnet fixedly disposed within the base.

[0018] In one embodiment, the second stator further includes a magnetic ring connected to the second magnet;

[0019] The linear motor also includes a second magnetic yoke connected to the second magnet.

[0020] In one embodiment, the second magnet and the magnetic ring are arranged axially along the first axis; and / or,

[0021] A receiving space is provided between the second magnetic yoke and the second magnet, the receiving space being used to accommodate a portion of the second winding coil.

[0022] In one embodiment, the focusing device further includes a linear moving plate connected to the second winding coil;

[0023] The base is provided with a guide portion, and the linear moving plate is slidably connected to the guide portion.

[0024] In one embodiment, the displacement measurement module includes a second grating ruler and a second reading head, one of which is connected to the base and the other is connected to the linear moving plate.

[0025] The aforementioned focusing device utilizes an alternating magnetic field generated by the mover in a linear motor. The second stator, acting on this magnetic field, generates a pushing or pulling force, propelling the mover linearly. This, in turn, moves the lens connected to the mover, adjusting the distance between the lens and the object being photographed, thereby adjusting the depth of field and ensuring a sharp image. Alternatively, a rotary motor generates a magnetic field through its first stator. The rotor, influenced by this magnetic field, rotates, outputting torque that drives the lens focusing ring connected to the rotor, thus changing the focal length and controlling the imaging range. During focusing, angle and displacement measurement modules acquire the rotation angle of the focusing ring and the displacement of the lens, feeding this information back to the control system. This enables closed-loop focusing, significantly improving focusing accuracy, such as achieving sub-micron level precision. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a focusing device provided in an embodiment of this application.

[0027] Figure 2 for Figure 1 The focusing device shown is a cross-sectional view from another perspective.

[0028] Reference numerals: 100, base; 110, guide section; 120, outer cover; 210, first stator; 211, first winding coil; 212, silicon steel sheet; 220, rotor; 221, rotating magnet; 230, first magnetic yoke; 240, bearing; 250, retaining ring; 300, angle measuring module; 320, first grating ruler;

[0029] 410. Moving element; 411. Second winding coil; 420. Second stator; 421. Second magnet; 422. Magnetic ring; 430. Second yoke; 431. Accommodation space; 500. Displacement measurement module; 510. Second grating ruler; 520. Second reading head; 610. Linear moving element plate; 620. Moving element connecting plate;

[0030] 700, Lens; 710, Focusing ring; X, Axis of the first axis. Detailed Implementation

[0031] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0032] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0033] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0034] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0035] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0036] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0037] See Figure 1 and Figure 2 As shown, Figure 2 for Figure 1The focusing device shown flips the viewing angle by 180 degrees. One embodiment of this application provides a focusing device including a base 100, a rotary motor, an angle measuring module 300, a linear motor, and a displacement measuring module 500. The rotary motor includes a first stator 210 fixedly disposed within the base 100 and a rotor 220 rotatably disposed within the base 100. The rotor 220 responds to the first stator 210 and can rotate around a first axis. The rotor 220 is used to connect to the focusing ring 710 of the lens 700, thereby driving the focusing ring 710 to rotate about the axial direction X of the first axis. The angle measuring module... Block 300 is connected to rotor 220. Angle measurement module 300 is used to acquire the rotation angle value of rotor 220. The linear motor includes a mover 410 slidably disposed in base 100 and a second stator 420 fixedly disposed in base 100. The second stator 420 responds to the mover 410 to drive the mover 410 to move axially along the first axis X. The mover 410 is used to connect with lens 700, thereby enabling the lens 700 to move axially along the first axis. Displacement measurement module 500 is connected to the mover 410 and is used to acquire the displacement of the mover 410. Figure 2 As shown, the first axis is indicated by a dashed line, and the axial direction of the first axis is indicated by an arrow X. The first axis is also the central axis of the linear motor and the rotary motor, and the axial direction X of the first axis is also the axial direction of the linear motor and the rotary motor.

[0038] The aforementioned focusing device utilizes an alternating magnetic field generated by the mover 410 of a linear motor. The second stator 420, acting on this magnetic field, generates a pushing or pulling force, propelling the mover 410 linearly. This, in turn, moves the lens 700 connected to the mover 410, adjusting the distance between the lens 700 and the object being photographed, thereby adjusting the depth of field and ensuring a clear image. Alternatively, a magnetic field is generated by the first stator 210 of a rotary motor. The rotor 220 rotates under the influence of this magnetic field, outputting torque that rotates the focusing ring 710 of the lens 700 connected to the rotor 220, thus changing the focal length of the lens 700 and controlling the imaging range. During focusing, the rotation angle of the focusing ring 710 and the displacement of the lens 700 are acquired by the angle measurement module 300 and the displacement of the lens 700, and fed back to the control system. This enables closed-loop focusing, significantly improving focusing accuracy, such as achieving sub-micron level focusing precision, and also improving focusing response speed. In addition, by directly connecting the rotor 220 of the rotary motor to the focusing ring 710 and the mover 410 of the linear motor to the lens 700, this application can reduce the assembly gap, improve the adjustment accuracy, and improve the overall compactness of the device.

[0039] In some embodiments, the linear motor is configured as a voice coil direct drive motor.

[0040] See Figure 2 As shown, in one embodiment, the first stator 210 includes a first winding coil 211 fixedly disposed within the base 100, and the rotor 220 includes a rotating magnet 221 rotatably disposed within the base 100. When current passes through the first winding coil 211, a rotating magnetic field is generated, and the rotating magnet 221 rotates in the direction of the magnetic field under the influence of the rotating magnetic field. In some embodiments, the rotating magnet 221 is disposed within the first winding coil 211. In some embodiments, multiple sets of winding coils are provided. In some embodiments, the rotating magnet 221 includes a permanent magnet.

[0041] In other embodiments, the first stator may be constructed as a rotating magnet and the rotor may be constructed as a first winding coil.

[0042] See Figure 2 As shown, in one embodiment, a silicon steel sheet 212 is connected to one side surface of the first winding coil 211 along the axial direction X of the first axis. In some embodiments, the first stator 210 includes at least two sets of first winding coils 211 arranged along the axial direction X of the first axis, with silicon steel sheets 212 connected between the at least two sets of first winding coils 211. The silicon steel sheets are made of very thin steel plates and coated with an insulating layer. This design ensures that each silicon steel sheet is insulated from the others, effectively shortening the path of eddy currents and reducing eddy current losses. Simultaneously, the silicon steel contains a certain proportion of silicon, which alters the crystal structure of the material, making it easier to magnetize and demagnetize, reducing hysteresis. Therefore, using silicon steel sheets can significantly reduce hysteresis losses and improve the overall efficiency of the motor. Silicon steel has high permeability, which allows for more effective guidance and concentration of the magnetic field, ensuring more magnetic flux passes through the windings, thereby enhancing the electromagnetic performance of the motor. High permeability also helps reduce the required excitation current, thus reducing copper losses (i.e., resistive losses in the winding coils). In addition, silicon steel sheet 212 can also support the winding coil and maintain mechanical strength.

[0043] See Figure 2 As shown, in one embodiment, the rotary motor further includes a first magnetic yoke 230 for guiding and concentrating the magnetic field to ensure that the magnetic flux is maximized on the rotor 220, thereby improving efficiency and enhancing torque output.

[0044] See Figure 2 As shown, in some embodiments, the first magnetic yoke 230 is configured with a snap-fit ​​groove, into which the rotating magnet 221 snaps. By snapping the rotating magnet 221 into the first magnetic yoke 230, the radial space occupied by both is reduced, making the overall layout of the focusing device more compact.

[0045] See Figure 2As shown, in some embodiments, a bearing 240 is rotatably connected to the side surface of the first magnetic yoke 230 opposite to the first winding coil 211. The bearing 240 supports the rotor 220, ensuring that the rotor 220 can rotate smoothly within the first stator 210, while reducing rotational noise.

[0046] like Figure 2 As shown, in some embodiments, the length of the rotating magnet 221 is greater than the length of the silicon steel sheet 212. In some embodiments, the length of the rotating magnet 221 is greater than or equal to the sum of the dimension of the silicon steel sheet 212 along the moving direction and the travel distance of the linear motor, so that after the linear motor drives the lens 700 to move linearly, the rotating magnet 221 is still located within the first winding coil 211, thereby being able to rotate following the rotating magnetic field generated by the first winding coil 211 to achieve focusing.

[0047] See Figure 2 As shown, in one embodiment, the angle measurement module 300 includes a first grating ruler 320 and a first reading head (not shown). One of the first grating ruler 320 and the first reading head is connected to the first magnetic yoke 230, and the other is connected to the first winding coil 211. Data on the first grating ruler 320 is read using the first reading head to achieve accurate feedback of the rotation angle. For example, in some embodiments, the first grating ruler 320 is attached to the first magnetic yoke 230, and the first reading head is attached to the first winding coil 211. The positions of the first grating ruler 320 and the first reading head can also be interchanged; for example, in other embodiments, the first reading head is attached to the first magnetic yoke, and the first grating ruler is attached to the first winding coil.

[0048] In other embodiments, the angle measurement module may also be a Hall effect sensor, which uses changes in the magnetic field to generate a voltage output. When the magnet moves closer or further away, the sensor senses the change in the magnetic field strength and determines the angle information accordingly.

[0049] See Figure 2 As shown, in one embodiment, the mover 410 includes a second winding coil 411 slidably disposed within the base 100, and the second stator 420 includes a second magnet 421 fixedly disposed within the base 100. When an alternating current passes through the second winding coil 411 in the mover 410, an alternating magnetic field in a specific direction is generated, which interacts with the constant magnetic field of the second magnet 421. The interaction between the alternating magnetic field and the constant magnetic field generates a pushing or pulling force, propelling the mover 410 to move. In some embodiments, the second winding coil 411 can be one or more sets. In some embodiments, the second magnet 421 can be a permanent magnet. In other embodiments, the second stator can also be made of a magnetically conductive material.

[0050] See Figure 2As shown, in one embodiment, the second stator 420 further includes a magnetic ring 422 connected to the second magnet 421. The magnetic ring 422 is used to effectively guide and concentrate the magnetic field generated by the second winding coil 411 onto the second magnet 421, thereby improving the magnetic field strength and uniformity. Furthermore, the magnetic ring 422 can reduce unnecessary magnetic leakage, helping to reduce energy loss and improve the efficiency of the entire system. Simultaneously, the magnetic ring 422 not only has electromagnetic functions but also provides physical support for the second winding coil 411, ensuring it maintains the correct position during movement.

[0051] See Figure 2 As shown, the linear motor also includes a second magnetic yoke 430 connected to the second magnet 421. The second magnetic yoke 430 is used to guide and concentrate the magnetic field, ensuring that the force is applied in the correct direction and is maximized, while reducing unnecessary magnetic leakage. In one embodiment, the second magnet 421 and the magnetic ring 422 are arranged along the axial direction X of the first axis.

[0052] See Figure 2 As shown, in some embodiments, a receiving space 431 is provided between the second yoke 430 and the second magnet 421, the receiving space 431 being used to receive a portion of the second winding coil 411. By accommodating the second winding coil 411 between the second yoke 430 and the second magnet 421, the compactness of the linear motor layout is improved. Figure 2 As shown, in some embodiments, the second yoke 430 is L-shaped, with one end connected to the second magnet 421 and the other end located outside the second winding coil 411.

[0053] See Figure 2 As shown, in one embodiment, the focusing device further includes a mover connecting plate 620 connected to the second winding coil 411. In some embodiments, the aforementioned bearing 240 is disposed between the mover connecting plate 620 and the first magnetic yoke 230. In some embodiments, the second winding coil 411 overlaps the side of the mover connecting plate 620 away from the bearing 240, and the second winding coil 411 moves synchronously with the mover connecting plate 620. In some embodiments, one end of the mover connecting plate 620 is engaged with the lens 700, and the other end of the mover connecting plate 620 away from the lens 700 is connected to a linear mover plate 610. A guide portion 110 is provided on the base 100, and the linear mover plate 610 is slidably connected to the guide portion 110. By providing the guide portion 110, the second magnet 421 and the lens 700 are guided to move smoothly along a predetermined path and withstand lateral forces and other non-axial forces. In some embodiments, the guide portion 110 can be a guide rail.

[0054] like Figure 2As shown, in some embodiments, the lens 700 is detachably fixed to the moving part connecting plate 620, for example, the lens 700 is fixed to the moving part connecting plate 620 by a threaded connection, so as to move linearly synchronously with the moving part connecting plate 620. In some embodiments, a fixing ring 250 is connected to the inner side of the rotor 220, and the fixing ring 250 is fixedly connected to the focusing ring 710 of the lens 700. The rotor 220 realizes the rotational adjustment of the focusing ring 710 through the fixing ring 250. By setting the fixing ring 250 between the rotor 220 and the focusing ring 710, the contact wear between the rotor 220 and the focusing ring 710 is reduced, and the service life of the rotor 220 and the focusing ring 710 is improved. The focusing ring 710 of the lens 700 can rotate while the linear motor is performing linear motion.

[0055] See Figure 1 As shown, in one embodiment, the displacement measurement module 500 includes a second grating ruler 510 and a second reading head 520. One of the second grating ruler 510 and the second reading head 520 is connected to the base 100, and the other is connected to the linear actuator plate 610. For example, in some embodiments, the second grating ruler 510 is attached to the linear actuator plate, and the second reading head 520 is attached to the base 100. The positions of the second grating ruler 510 and the second reading head 520 can also be interchanged. For example, in other embodiments, the second reading head is attached to the linear actuator plate, and the second grating ruler is attached to the base.

[0056] In other embodiments, the displacement measurement module may also be a magnetic encoder.

[0057] See Figure 1 As shown, in some embodiments, the focusing device further includes an outer cover 120, which is connected to one side surface of the base 100 along the axial direction X of the first axis. The outer cover 120 covers at least a portion of the rotary motor and seals the opening of the base 100 to prevent dust, moisture, etc. from entering the interior of the rotary motor and the linear motor.

[0058] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A focusing device, characterized in that, The focusing device includes: Base (100); A rotary motor, disposed within the base (100), the rotary motor comprising a first stator (210) and a rotor (220) responsive to the first stator (210) to rotate about a first axis. An angle measurement module (300) is connected to the rotor (220) and is used to obtain the rotation angle value of the rotor (220); A linear motor, disposed within the base (100), the linear motor comprising a mover (410) and a second stator (420) responsive to the mover (410) to drive the mover (410) to move axially (X) along the first axis; and, A displacement measurement module (500) is connected to the mover (410) and is used to obtain the displacement of the mover (410).

2. The focusing device according to claim 1, characterized in that, The first stator (210) includes a first winding coil (211) fixedly disposed in the base (100), and the rotor (220) includes a rotating magnet (221) rotatably disposed in the base (100).

3. The focusing device according to claim 2, characterized in that, The first winding coil (211) has a silicon steel sheet (212) connected to one side surface along the axial direction (X) of the first axis; or, The first stator (210) includes at least two sets of first winding coils (211), and silicon steel sheets (212) are connected between the at least two sets of first winding coils (211).

4. The focusing device according to claim 2, characterized in that, The rotary motor further includes a first magnetic yoke (230), which has a snap-fit ​​groove, and the rotating magnet (221) snaps into the snap-fit ​​groove; The first magnetic yoke (230) has a bearing (240) rotatably connected to the side surface opposite to the first winding coil (211).

5. The focusing device according to claim 4, characterized in that, The angle measurement module (300) includes a first grating ruler (320) and a first reading head, one of which is connected to the first magnetic yoke (230) and the other is connected to the first winding coil (211).

6. The focusing device according to any one of claims 1 to 5, characterized in that, The mover (410) includes a second winding coil (411) slidably disposed within the base (100), and the second stator (420) includes a second magnet (421) fixedly disposed within the base (100).

7. The focusing device according to claim 6, characterized in that, The second stator (420) also includes a magnetic ring (422) connected to the second magnet (421); The linear motor also includes a second magnetic yoke (430) connected to the second magnet (421).

8. The focusing device according to claim 7, characterized in that, The second magnet (421) and the magnetic ring (422) are arranged along the axial direction (X) of the first axis; and / or, A receiving space (431) is provided between the second magnetic yoke (430) and the second magnet (421), the receiving space (431) being used to receive a portion of the second winding coil (411).

9. The focusing device according to claim 6, characterized in that, The focusing device also includes a linear moving plate (610) connected to the second winding coil (411). The base (100) is provided with a guide part (110), and the linear moving plate (610) is slidably connected to the guide part (110).

10. The focusing device according to claim 9, characterized in that, The displacement measurement module (500) includes a second grating ruler (510) and a second reading head (520), one of which is connected to the base (100) and the other is connected to the linear moving plate (610).

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