drive mechanism

Abstract

A driving mechanism for driving an optical element to move, comprising a fixed part, a movable part, a winding element and a driving assembly. The movable part is movably connected to the fixed part, wherein the optical element is disposed on the movable part. The winding element is disposed on the fixed part or the movable part, and the driving assembly is used to drive the movable part to move relative to the fixed part, wherein the driving assembly comprises a coil, and the coil is wound on the winding element.

Description

TECHNICAL FIELD

[0001] The present application relates to a driving mechanism. More particularly, the present application relates to a driving mechanism for moving an optical element. BACKGROUND

[0002] With the development of technology, many electronic devices (e.g. smart phones or digital cameras) nowadays have the function of taking pictures or videos. These electronic devices are increasingly popular and are developing towards the direction of convenience and thinness, to provide users with more choices.

[0003] Some electronic devices with the function of taking pictures or videos are provided with a lens driving module to drive an optical element to move, thereby achieving the functions of autofocus and optical image stabilization (OIS). Light can pass through the optical element to form an image on a photosensitive element.

[0004] However, the lens driving module often needs to include multiple magnets and coils arranged around the optical element, which makes it impossible to further reduce the size of the lens driving module and the electronic device. Therefore, how to solve the above problems has become an important issue. SUMMARY

[0005] In view of the above existing problems, an embodiment of the present application provides a driving mechanism for moving an optical element, comprising a fixed part, a movable part, a winding element and a driving assembly.

[0006] The movable part is movably connected to the fixed part, wherein the optical element is arranged on the movable part. The winding element is arranged on the fixed part or the movable part, and the driving assembly is used to drive the movable part to move relative to the fixed part, wherein the driving assembly comprises a coil, and the coil is wound on the winding element.

[0007] In an embodiment, the fixed part has a body, and the body forms a groove, wherein the winding element is fixed in the groove.

[0008] In an embodiment, the driving mechanism further comprises a circuit unit, and the body is located between the coil and the circuit unit.

[0009] In an embodiment, the body further forms an opening, and the coil deviates from a center point of the opening.

[0010] In an embodiment, the driving assembly further comprises multiple magnets and multiple coils, wherein the magnets are arranged on the movable part, and the coils are arranged on the body and the winding element, respectively.

[0011] In one embodiment, the coil includes a first coil and a second coil, the body is further formed with a plurality of first protrusions, and the winding element is further formed with a plurality of second protrusions, wherein the first coil is wound on the first protrusions, and the second coil is wound on the second protrusions.

[0012] In one embodiment, the second protrusions are different in size.

[0013] In one embodiment, the body is further formed with a first curved surface, and the winding element is further formed with a second curved surface corresponding to the first curved surface, wherein the first curved surface connects the second curved surface when the winding element is combined with the body.

[0014] In one embodiment, the winding element is formed with two second protrusions, and the volume of one of the second protrusions closer to the second curved surface is greater than the other second protrusion.

[0015] In one embodiment, the second coil wound on the second protrusions protrudes from the second curved surface.

[0016] In one embodiment, the body is further formed with two first protrusions, and the winding element is further formed with two second protrusions, wherein two ends of the first coil are wound on the first protrusions respectively, and two ends of the second coil are wound on the second protrusions respectively, wherein the distance between the first protrusions is greater than the distance between the second protrusions.

[0017] In one embodiment, the driving mechanism further includes a circuit unit, the body is located between the coil and the circuit unit, and the winding element is formed with a through hole, the circuit unit has a substrate and a position sensor disposed on the substrate, wherein the position sensor is accommodated in the through hole. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 FIG. 1 shows an exploded view of a driving mechanism 1 according to an embodiment of the present application.

[0019] Figure 2 FIG. 2 shows an assembled perspective view of the driving mechanism 1 of FIG. 1. Figure 1

[0020] FIG. 3 shows a cross-sectional view along the center line segment X1-X1 of FIG. 1. Figure 3 Figure 2 FIG. 4 shows a cross-sectional view along the center line segment Y1-Y1 of FIG. 1.

[0021] Figure 4 Figure 2 FIG. 5 shows a cross-sectional view along the center line segment Y1-Y1 of FIG. 1.​​

[0022] Figure 5 An exploded view showing a base 20, a coil unit 30, and a circuit unit 60 according to another embodiment of the present application.

[0023] Figure 6 An enlarged view showing a portion A in FIG. 4. Figure 5 An upper view showing the base 20 and the coil unit 30 of FIG. 4 after assembly.

[0024] Figure 7 An enlarged view showing a portion A in FIG. 5. Figure 6 An enlarged view showing a portion A in FIG. 5.

[0025] BRIEF DESCRIPTION OF REFERENCE NUMERALS

[0026] Drive mechanism 1

[0027] Housing 10

[0028] Base 20

[0029] Body 201

[0030] Protrusion 2011

[0031] First curved surface 2012

[0032] Winding element 202

[0033] Protrusion 2021

[0034] Second curved surface 2022

[0035] Conductive terminal 21

[0036] Coil unit 30

[0037] Carrier 40

[0038] Aperture 41

[0039] Frame 50

[0040] Circuit unit 60

[0041] Position sensor 61

[0042] Position sensor 62

[0043] Coil C1

[0044] Coil C21

[0045] Coil C22

[0046] First protruding structure E1

[0047] Second protruding structure E2

[0048] Aperture H

[0049] Center point H'

[0050] perforation H1

[0051] perforation H2

[0052] magnet HM

[0053] sensing element HS

[0054] magnet M1

[0055] magnet M2

[0056] magnet M3

[0057] optical axis O

[0058] magnetic permeable element P1

[0059] recess R

[0060] upper spring S1

[0061] lower spring S2

[0062] elastic element W DETAILED DESCRIPTION

[0063] The following describes a drive mechanism according to an embodiment of the present application. However, it can be readily appreciated that the embodiments of the present application provide many suitable inventive concepts and can be implemented in a wide variety of specific contexts. The specific embodiments disclosed are merely intended to illustrate the use of the present application in a particular manner and are not intended to limit the scope of the present application.

[0064] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0065] The foregoing and other technical features, aspects and effects of the present application will become more apparent from the following detailed description of a preferred embodiment with reference to the attached drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front or rear, etc., are only with reference to the direction of the accompanying drawings. Therefore, the directional terms used in the embodiments are used to illustrate and not to limit the present application.

[0066] First, refer to Figures 1 to 4 wherein Figure 1 represents an exploded view of a drive mechanism 1 according to an embodiment of the present application, Figure 2 represents Figure 1 a combined perspective view of the drive mechanism 1 of Figure 3 represents a cross-sectional view taken alongFigure 2 A sectional view of the midline segment X1-X1. Figure 4 Then it means along Figure 2 A cross-sectional view of the midline segment Y1-Y1.

[0067] It should be understood that the drive mechanism 1 in this embodiment is, for example, a voice coil motor (VCM), which can be installed inside a mobile phone or other portable electronic device to drive an optical element (e.g., an optical lens) to move, thereby achieving functions such as autofocus (AF) or optical image stabilization (OIS).

[0068] like Figure 1 As shown, the aforementioned drive mechanism 1 mainly includes a housing 10, a base 20, a coil unit 30, a carrier 40, a frame 50, an upper spring S1, and a lower spring S2.

[0069] In this embodiment, the aforementioned housing 10 has a hollow structure and is connected to the base 20. The coil unit 30 is, for example, a flexible printed circuit board (FPC) fixed on the base 20. The housing 10 and the base 20 can form a fixed part of the drive mechanism 1, and the carrier 40 and the frame 50 can form a movable part of the drive mechanism 1. The aforementioned movable part can move relative to the fixed part.

[0070] Furthermore, the aforementioned carrier 40 and frame 50 are movably housed within the housing 10, and an optical element (not shown) is disposed within the opening 41 of the carrier 40, wherein the aforementioned frame 50, carrier 40 and the optical element disposed therein constitute a movable module that can move relative to the aforementioned fixed module.

[0071] Specifically, the aforementioned support member 40 is connected to the frame 50 via upper and lower springs S1 and S2, allowing the support member 40 to be movably suspended inside the frame 50. Furthermore, the aforementioned base 20 connects the frame 50 to the upper spring S1 via four elastic elements W, allowing the frame 50 to be movably housed inside the housing 10. In one embodiment, the aforementioned upper and lower springs S1 and S2 may be made of metal, and the aforementioned elastic elements W may be elongated metal components.

[0072] With the aforementioned mechanism configuration, external light can enter the drive mechanism 1 along the optical axis O of the optical element, and the light will pass through the optical lens and reach an image sensing element (not shown) located below the base 20, thereby generating a digital image.

[0073] It is to be noted that the frame 50, the carrier 40 and the optical element disposed therein are movable relative to the base 20 and the coil unit 30 along a first axial direction parallel to the XY plane, thereby achieving the function of optical image stabilization (OIS).

[0074] In addition, the carrier 40 and the optical element disposed therein are movable relative to the frame 50 along a second axial direction (Z-axis direction) parallel to the optical axis O of the optical element, thereby achieving the function of auto-focusing (AF).

[0075] Referring to FIGS. 1, 3 and 4, the opposite sides of the carrier 40 are respectively provided with an oval coil C1, and the four sides of the coil unit 30 are respectively embedded with coils C21, C22. In addition, a plurality of magnets M1, M2, M3 are disposed on the four inner surfaces of the rectangular frame 50.

[0076] In the present embodiment, the magnets M1, M2 are multipolar magnets, wherein the position of the magnet M1 corresponds to both the coil C1 on the carrier 40 and the coil C21 inside the coil unit 30, and the positions of the magnets M2, M3 correspond to the coil C22 inside the coil unit 30, respectively.

[0077] For example, the coils C21, C22 are planar coils or FP-coils, and can be electrically connected to the conductive terminals 21 below the base 20 through an external circuit.

[0078] The upper spring S1 can be electrically connected to the coil C1 through a wire, and the two ends of the four elastic elements W are respectively connected to the wire on the base 20 and the upper spring S1, thereby enabling an external circuit electrically connected to the conductive terminals 21 below the base 20 to supply current to the coil C1 on the carrier 40.

[0079] When current is applied to the coil C1, the carrier 40 and the optical element can be driven to move relative to the frame 50 along the Z-axis direction (second axial direction) by the magnetic force generated between the coil C1 and the magnet M1, thereby achieving the function of auto-focusing (AF).

[0080] Similarly, the external circuit can also supply current to the coils C21, C22 in the coil unit 30 through the conductive terminals 21 below the base 20.

[0081] When current is applied to the aforementioned coils C21, C22, the frame 50, the carrier 40 and the optical element disposed therein are driven to move relative to the base 20 and the coil unit 30 along the horizontal direction (first axial direction) by the magnetic force generated between the coils C21, C22 and the magnets M2, M3, so as to achieve the function of optical image stabilization (OIS).

[0082] In addition, as can be seen from Figure 1 , a magnetic conductive element P1 and a magnet HM are further disposed above the magnet M2 and fixed to the frame 50, and a magnetic field sensing element HS electrically connected to the upper spring S1 is disposed on one side of the carrier 40, for sensing the aforementioned magnet HM. The aforementioned magnetic conductive element P1 can improve the magnetic field distribution near the magnet M2, so as to reduce the magnetic interference between the magnet M2 and other magnetic elements.

[0083] For example, the aforementioned magnetic field sensing element HS can be a Hall effect sensor, a magnetic resistance sensor (MR sensor), or a fluxgate, for sensing the position of the magnet HM, so as to know the relative position change between the carrier 40 and the frame 50 in the Z-axis direction.

[0084] As shown in Figure 4 , in the driving mechanism 1 of the present embodiment, two magnets M3 are disposed on the right side of the carrier 40, the aforementioned two magnets M3 are arranged along the Z-axis direction, the height thereof corresponds to the upper and lower halves M11, M12 of the magnet M1, and the magnetic pole direction (N-S) thereof is parallel to the Z-axis direction (second axial direction).

[0085] Next, please refer to Figures 5 to 7 , wherein Figure 5 , an exploded view of the base 20, the coil unit 30 and a circuit unit 60 according to another embodiment of the present application is shown, Figure 6 , a top view of the base 20 and the coil unit 30 after assembly in Figure 5 , a top view of the base 20 and the coil unit 30 after assembly in Figure 7 , an enlarged view of part A in Figure 6 .

[0086] As shown in FIGS. 5, 6 and 7, the base 20, the coil unit 30 and the circuit unit 60 of another embodiment of the present application can be used to replace the base 20 and the coil unit 30 in FIGS. 1-4.

[0087] It should be understood that the aforementioned circuit unit 60 is, for example, a flexible printed circuit board (FPC), and it includes a substrate 601 and position sensors 61, 62 disposed on the substrate 601, and the aforementioned base 20 is disposed between the coil unit 30 and the circuit unit 60.

[0088] Specifically, the main difference between the base 20 and the coil unit 30 in the present embodiment and the first to fourth drawings is that the base 20 in the present embodiment comprises a body 201 and two long strip-shaped and flat winding elements 202, wherein the winding elements 202 are respectively fixedly bonded to the opposite sides of the body 201 by glue.

[0089] In addition, the coil unit 30 in the present embodiment mainly comprises two pairs of coils C21 (first coils) and coils C22 (second coils), and is not a flexible printed circuit board (FPC), wherein the coils C21 and C22 can jointly form a driving assembly with the magnets M1, M2 and M3 in the first to fourth drawings to drive the movable part (the carrier 40 and the frame 50) to move relative to the fixed part (the housing 10 and the base 20) along the X-axis or Y-axis direction.

[0090] In actual assembly, one set of coils C21 can be wound on the protruding column 2011 (first protruding column) of the body 201, and the other set of coils C22 can be wound on the protruding column 2021 (second protruding column) of the winding element 202, and the coils C21 (first coils) and C22 (second coils) are distributed on the four sides of the rectangular or square base 20 after assembly.

[0091] It should be particularly noted that the body 201 of the base 20 in the present embodiment is formed with a substantially circular opening H (fifth and sixth drawings), wherein in order to effectively reduce the size of the driving mechanism 1 in the X-axis and Y-axis directions to achieve the purpose of product miniaturization, the present embodiment deviates the position of the coils C21 and C22 from a center point H' of the opening H, which can help to reduce the size of the base 20 in the X-axis and Y-axis directions.

[0092] On the other hand, considering that the coils C21 and C22 located on the adjacent sides of the base 20 are close to each other and are prone to cause assembly difficulties, the present embodiment specially provides the winding element 202 for winding the coils C22, which can be used to wind the coils C22 on the protruding column 2021 (second protruding column) of the winding element 202 in assembly, and then wind the other set of coils C21 on the protruding column 2011 (first protruding column) of the body 201, and then use glue to fixedly bond the winding element 202 in the groove R of the body 201, so as to simultaneously consider the convenience of winding assembly and the miniaturization of the whole product.

[0093] In an embodiment, only one winding element 202 can be provided, and one of the coils C22 of the coil unit 30 is arranged on the winding element 202, and the other three coils C21 and C22 are arranged on the body 201, so the present embodiment is not limited thereto.

[0094] In addition, in one embodiment, the coil C1 shown in FIGS. 1 and 3 can be pre-wound on a winding element (not shown) and then the winding element is adhered and fixed to the side of the movable part (the carrier 40). In other words, the winding element can also be used as a part of the carrier 40 to wind the coil C1. In this way, the convenience of winding assembly can be improved.

[0095] As shown in FIGS. 5 and 6, the plurality of protrusions 2011 (first protrusions) on the body 201 can be arranged symmetrically or asymmetrically, and a through hole H1 (FIGS. 6 and 7) is formed between two adjacent protrusions 2011 to pass through the body 201 of the base 20 to accommodate a position sensor 61 (FIG. 8) on the substrate 601 of the circuit unit 60. Figure 6 Figure 5

[0096] Similarly, as shown in FIGS. 5 to 7, the plurality of protrusions 2021 (second protrusions) on each winding element 202 can be arranged symmetrically or asymmetrically, and a through hole H2 (FIGS. 6 and 7) is formed between two protrusions 2021 of one winding element 202 to pass through the winding element 202 to accommodate another position sensor 62 (FIG. 8) on the substrate 601 of the circuit unit 60. Figure 5

[0097] The position sensors 61 and 62 can be used to detect the position change of the magnets M1 and M2 on the frame 50 relative to the base 20 to determine the displacement of the movable part (the carrier 40 and the frame 50) relative to the fixed part (the housing 10 and the base 20) in the X-axis and the Y-axis.

[0098] In addition, as shown in FIGS. 5 to 7, a first curved surface 2012 is formed on the outside of the body 201, and a second curved surface 2022 is formed on the inside of the winding element 202 corresponding to the first curved surface 2012. When the winding element 202 is combined with the body 201, the first curved surface 2012 connects the second curved surface 2022, and the coil C22 wound on the protrusion 2021 protrudes from the second curved surface 2022 (FIG. 7) to make the space above the base 20 more effectively and sufficiently utilized, thereby helping to achieve miniaturization of the drive mechanism 1. Figure 7

[0099] In addition, as shown in FIGS. 5 to 7, a first curved surface 2012 is formed on the outside of the body 201, and a second curved surface 2022 is formed on the inside of the winding element 202 corresponding to the first curved surface 2012. When the winding element 202 is combined with the body 201, the first curved surface 2012 connects the second curved surface 2022, and the coil C22 wound on the protrusion 2021 protrudes from the second curved surface 2022 (FIG. 7) to make the space above the base 20 more effectively and sufficiently utilized, thereby helping to achieve miniaturization of the drive mechanism 1. Figure 7 ​​​​As shown in the winding element 202, the aforementioned perforation H2 is located between two protrusions 2021 on the same winding element 202, and the length and volume of the protrusion 2021 closer to the second curved surface 2022 are greater than those of the other protrusion 2021, that is, the plurality of protrusions 2021 (second protrusions) on the winding element 202 are different in size and arranged in an asymmetric manner. This is because the second curved surface 2022 is concave, which causes the local structure of the winding element 202 to be weak in strength, so the protrusion 2021 closer to the second curved surface 2022 has a greater length and volume to ensure that the winding element 202 itself has sufficient mechanical strength to prevent it from being broken by external impact.

[0100] On the other hand, as can be seen from FIGS. 5-7, first protruding structures E1 are formed on both sides of the body 201 of the base 20, and the two ends of the coil C21 can be wound around the aforementioned first protruding structures E1, respectively, so as to further electrically connect the coil C21 to an external circuit. Similarly, two second protruding structures E2 are formed on each winding element 202 of the base 20, and the two ends of the coil C22 can be wound around the aforementioned second protruding structures E2, respectively, so as to further electrically connect the coil C22 to an external circuit.

[0101] In particular, the distance between two adjacent first protruding structures E1 on the same side of the body 201 is greater than the distance between two adjacent second protruding structures E2 on the same winding element 202.

[0102] Although the embodiments of the present application and their advantages have been disclosed above, it should be understood that any person skilled in the art, without departing from the concept and scope of the present application, can make changes, substitutions and modifications. In addition, the scope of protection of the present application is not limited to the specific embodiments described in the specification, and any person skilled in the art can understand the current or future developed processes, machines, manufactures, compositions of matter, devices, methods and steps from the disclosure of the present application, as long as they can substantially achieve the same function or obtain substantially the same results as in the embodiments described herein.

[0103] Therefore, the scope of protection of the present application includes the above-mentioned processes, machines, manufactures, compositions of matter, devices, methods and steps. In addition, each claim constitutes a separate embodiment, and the scope of protection of the present application also includes the combination of each claim and embodiment.

[0104] Although the present application has been disclosed above with preferred embodiments, it is not intended to limit the present application, and any person skilled in the art, without departing from the concept and scope of the present application, can make some changes and modifications, therefore the scope of protection of the present application shall be subject to the claims.

Claims

1. A driving mechanism for driving an optical element to move, comprising: a base having a body; a movable portion movably connected to the base, wherein the optical element is disposed on the movable portion; a winding element disposed on the base; and a driving assembly for driving the movable portion to move relative to the base, wherein the driving assembly comprises a plurality of magnets, a first coil and a second coil, the plurality of magnets are disposed on the movable portion, and the first coil and the second coil are disposed on the body and the winding element, respectively; wherein the body forms a recess and a first curved surface, the winding element is fixed in the recess, and the winding element forms a second curved surface corresponding to the first curved surface, wherein the first curved surface is located outside the body, and the first curved surface connects the second curved surface when the winding element is combined with the body; wherein the body further forms a plurality of first protrusions, and the winding element forms a plurality of second protrusions, the first coil is wound on the first protrusions, the second coil is wound on the second protrusions, and the second coil wound on the second protrusions protrudes from the second curved surface.

2. The driving mechanism of claim 1, wherein the driving mechanism further comprises a circuit unit, and the body is located between the coil and the circuit unit.

3. The driving mechanism of claim 1, wherein the body further forms an opening, and the coil is offset from a center point of the opening.

4. The driving mechanism of claim 1, wherein the second protrusions have different sizes.

5. The driving mechanism of claim 1, wherein the winding element forms two second protrusions, and a volume of one of the second protrusions closer to the second curved surface is greater than that of the other second protrusion.

6. The driving mechanism of claim 1, wherein the body further forms two first protrusions, and the winding element further forms two second protrusions, wherein two ends of the first coil are wound on the first protrusions, respectively, and two ends of the second coil are wound on the second protrusions, respectively, wherein a distance between the first protrusions is greater than a distance between the second protrusions.

7. The driving mechanism of claim 1, wherein the driving mechanism further comprises a circuit unit, the body is located between the coil and the circuit unit, and the winding element forms a through hole, the circuit unit has a substrate and a position sensor disposed on the substrate, wherein the position sensor is accommodated in the through hole. ​ ​ ​ ​ ​ ​

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