Drive mechanism

Abstract

A driving mechanism is used for driving an optical element to move and mainly comprises a fixed part, a movable part and a driving assembly. The movable part is movably connected with the fixed part, the optical element is arranged on the movable part, and the driving assembly is used for driving the movable part to move relative to the fixed part.

Description

Technical Field

[0001] The present invention relates to a driving mechanism, and more particularly to a driving mechanism for driving an optical element to move. Background Art

[0002] With the development of technology, many electronic devices (such as smart phones or digital cameras) now have the function of taking photos or recording videos. These electronic devices are becoming more and more popular and are developing in the direction of convenient and thinner designs to provide users with more choices.

[0003] Some electronic devices with camera or video recording functions are equipped with a lens driving module to drive an optical element to move, thereby achieving the functions of auto focusing (AF) and optical image stabilization (OIS), wherein light can pass through the aforementioned optical element and form an image on a photosensitive element.

[0004] However, how to further miniaturize the lens driving module and improve its stability and reliability has become an important challenge for researchers in this related technical field. Summary of the invention

[0005] The object of the present invention is to provide a driving mechanism to solve at least one of the above problems.

[0006] In view of the above-mentioned known problems, one embodiment of the present invention provides a driving mechanism for driving an optical element to move. The driving mechanism mainly includes a fixed portion, a movable portion, and a driving assembly. In one embodiment, the movable portion is connected to the fixed portion, the optical element is disposed on the movable portion, the optical element has an optical axis, and the driving assembly is used to drive the optical element to move relative to the fixed portion.

[0007] In one embodiment, the driving component includes a first magnetic element disposed on the movable part and a first coil and a second coil disposed on the fixed part, wherein the first and second coils at least partially overlap in the direction of the optical axis, and the first magnetic element is adjacent to the first and second coils. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 An exploded view of a driving mechanism according to an embodiment of the present invention is shown.

[0009] Figure 2 express Figure 1 Another exploded view of the drive mechanism in .

[0010] Figure 3 express Figure 1, Figure 2 A three-dimensional view of the drive mechanism after assembly.

[0011] Figure 4 An exploded view showing the drive mechanism with the housing, base, and flexible circuit board removed.

[0012] Figure 5 A three-dimensional diagram showing the driving mechanism after removing the housing, base and flexible circuit board.

[0013] Figure 6 A schematic diagram showing the relative position relationship of the flexible printed circuit board, the base, and the first and second magnetic elements after assembly.

[0014] Figure 7 An exploded view showing the flexible printed circuit board and the base before being combined.

[0015] Figure 8 Another exploded view showing the flexible printed circuit board and the base before being combined.

[0016] Fig. 9 A schematic diagram showing the relative position relationship between the first and second coils and the position sensor.

[0017] Fig.10 Schematic diagram showing the position sensor deviating from the center of the first magnetic element in the Z-axis direction.

[0018] Fig.11 A cross-sectional view showing the aforementioned driving mechanism with the housing removed.

[0019] Fig.12 Another cross-sectional view showing the aforementioned driving mechanism with the housing removed.

[0020] Fig.13 A schematic diagram showing a conductive element connecting the inner surface of a body of a flexible printed circuit board and the side surface of a circuit substrate.

[0021] Fig.14 A schematic diagram showing a protruding structure of a component connection base and a flexible printed circuit board.

[0022] The reference numerals are as follows:

[0023] 100: Driving mechanism

[0024] B: Base

[0025] B1: Protruding structure

[0026] B11: Card block

[0027] C1: Vertical coil

[0028] C2: Horizontal coil

[0029] E1: First Electronic Components

[0030] E2: Second electronic component

[0031] F: Framework

[0032] F1: Plastic block

[0033] F2:Metal bracket

[0034] FR: Buffer element

[0035] G: Connecting components

[0036] G1: First Adhesive

[0037] G2: Second adhesive

[0038] H: Shell

[0039] HS: Position sensor

[0040] J: Magnetic sheet

[0041] K: Conductive element

[0042] L: Guide rod

[0043] LH: Bearing

[0044] LH1: First Component

[0045] LH2: Second Component

[0046] M1: The first magnetic element

[0047] m1: first magnetic unit

[0048] M2: Second magnetic element

[0049] m2: second magnetic unit

[0050] N: Clamping piece

[0051] O: Optical axis

[0052] P: Flexible printed circuit board

[0053] P1: Ontology

[0054] P11: Inner surface

[0055] P2: Bending section

[0056] PC: Circuit board

[0057] PC0: Groove

[0058] PC1: First coil

[0059] PC2: Second coil

[0060] PC3: Side surface

[0061] Q:Metal parts

[0062] Q1: Positioning column

[0063] S: Elastic element

[0064] T:Metal sheet

[0065] W: Thin metal rod DETAILED DESCRIPTION

[0066] The following describes the drive mechanism of the embodiment of the present invention. However, it is easy to understand that the embodiment of the present invention provides many suitable inventive concepts and can be implemented in a wide variety of specific contexts. The specific embodiments disclosed are only used to illustrate the use of the present invention in a specific way, and are not intended to limit the scope of the present invention.

[0067] Unless otherwise defined, all terms (including technical and scientific terms) used in this patent have the same meanings as commonly understood by those skilled in the art to which this disclosure belongs. It is understood that these terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with the background or context of the relevant technology and the present disclosure, and should not be interpreted in an idealized or overly formal manner unless specifically defined herein.

[0068] The above and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front or back, etc., are only referenced to the directions of the attached drawings. Therefore, the directional terms used in the embodiments are used to illustrate and are not used to limit the present invention.

[0069] First, please refer to Figures 1 to 6 ,in Figure 1 An exploded view of a driving mechanism 100 according to an embodiment of the present invention is shown. Figure 2 express Figure 1 Another exploded view of the drive mechanism 100, Figure 3 express Figure 1 , Figure 2 The driving mechanism 100 is a three-dimensional view after assembly, Figure 4 The exploded view of the driving mechanism 100 after removing the housing H, the base B and the flexible circuit board P is shown. Figure 5 The driving mechanism 100 is a three-dimensional diagram after the housing H, the base B and the flexible circuit board P are removed. Figure 6 A schematic diagram showing the relative position relationship of the flexible printed circuit board P, the base B, and the first and second magnetic elements M1 and M2 after assembly.

[0070] like Figure 1 to Figure 6 As shown, the driving mechanism 100 of the present 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 (such as an optical lens) to move, thereby achieving functions such as auto focusing (AF) or optical image stabilization (OIS).

[0071] The aforementioned driving mechanism 100 mainly includes a hollow housing H, a base B, a flexible printed circuit board P, a carrier LH, a frame F, a clamping member N, a plurality of elastic elements S, and a plurality of metal thin rods W. In this embodiment, the aforementioned housing H has a hollow structure and is combined with the base B, and the flexible printed circuit board P is fixed on the base B, wherein the housing H and the base B can together constitute a fixed portion of the driving mechanism 100.

[0072] In addition, the aforementioned carrier LH and frame F are movably accommodated in the shell H, and an optical element (not shown) can be fixed in the carrier LH, wherein the aforementioned carrier LH and frame F constitute a movable part that can move relative to the aforementioned fixed part (shell H and base B).

[0073] Specifically, the aforementioned carrier LH is connected to the frame F via an elastic element S (spring), and the elastic element S is further connected to the base B below via a thin metal rod W, so that the carrier LH and the frame F can be suspended in the driving mechanism 100 in a movable manner. Through the aforementioned mechanism configuration, external light can enter the driving mechanism 100 along the optical axis O (Z-axis direction) 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 B, thereby generating a digital image.

[0074] It should be particularly noted that the aforementioned carrier LH is composed of a first component LH1 and a second component LH2 which are fixed to each other, wherein a vertical coil C1 is provided on the opposite side of the aforementioned second component LH2, and a first magnetic element M1 (such as a magnet) corresponding to the aforementioned vertical coil C1 is provided on the opposite side of the frame F.

[0075] When a current signal is applied to the aforementioned vertical coil C1, the magnetic force generated between the vertical coil C1 and the first magnetic element M1 can drive the carrier LH and the optical element disposed therein to move relative to the frame F along the optical axis O direction (Z-axis direction), thereby achieving the function of auto focus (AF) or optical image stabilization (OIS).

[0076] In this embodiment, the aforementioned clamping member N is fixed to the top side of the frame F. In addition, two guide rods L extending in the Z-axis direction are clamped between the carrier LH and the clamping member N to stably guide the carrier LH to move relative to the frame F along the optical axis O direction (Z-axis direction).

[0077] On the other hand, from Figure 1 to Figure 6 It can be seen that the flexible circuit board P has a C-shaped main body P1 and a bending portion P2 bent relative to the main body, wherein a horizontal coil C2 is provided on the bottom side of the bending portion P2, and a second magnetic element M2 (such as a magnet) adjacent to the horizontal coil C2 is provided on one side of the frame F, wherein the horizontal coil C2 is electrically connected to the bending portion P2, and the long axis of the horizontal coil C2 is perpendicular to the optical axis O (Z axis), wherein the horizontal coil C2 and the second magnetic element M2 are arranged along the direction of the optical axis O.

[0078] In addition, a metal part Q and at least one positioning column Q1 are provided above the bending portion P2, wherein the positioning column Q1 passes through the metal part Q, the bending portion P2 and the horizontal coil C2 along the optical axis O direction, so as to accurately position the horizontal coil C2 on the bending portion P2, wherein the aforementioned horizontal coil C2 is, for example, an enameled wire.

[0079] When a current signal is applied to the aforementioned horizontal coil C2, the magnetic force generated between the horizontal coil C2 and the second magnetic element M2 can drive the frame F and the carrier LH to move along a first axial direction (Y-axis direction) relative to the base B, thereby achieving the function of optical image stabilization (OIS).

[0080] In addition, from Figure 1 , Figure 6 It can be seen that circuit substrates PC which are not parallel to the bending portion P2 are respectively provided on both sides of the body P1 of the flexible circuit board P, wherein the thickness of the flexible circuit board P is smaller than the thickness of the circuit substrate PC, and a coil adjacent to the first magnetic element M1 is provided inside the circuit substrate PC.

[0081] When a current signal is applied to the coil inside the aforementioned circuit substrate PC, the magnetic force generated between the coil and the first magnetic element M1 can drive the carrier LH and the frame to move along a second axial direction (X-axis direction) relative to the base B, thereby achieving the function of optical image stabilization (OIS).

[0082] In this embodiment, the vertical coil C1, the horizontal coil C2, the first and second magnetic elements M1, and the first and second coils C1 and C2 ( Figure 7 , Figure 8) is a driving component of the driving mechanism 100, which can be used to drive the carrier LH to move relative to the frame F. In addition, it can also be used to drive the movable part (the carrier LH and the frame F) to move relative to the fixed part (the base B and the shell H).

[0083] In addition, from Figure 1 , Figure 4 It can be seen that a first electronic component E1 and a second electronic component E2 are provided on the first component LH1 of the carrier LH, wherein the first electronic component E1 is, for example, a Hall sensing element for sensing the position change of a second magnetic element M2 (such as a magnet) provided on the frame F, and the second electronic component E2 is an integrated circuit component, such as a control IC.

[0084] In this embodiment, the frame F is composed of two plastic blocks F1 that fit into each other and a U-shaped metal bracket F2 ( Figure 4 ), wherein the first magnetic element M1 is fixed on the metal bracket F2 and is located between the two plastic blocks F1.

[0085] Please also read Figure 7 , Figure 8 , Fig. 9 , Fig.10 ,in Figure 7 An exploded view showing the flexible printed circuit board P and the base B before being combined. Figure 8 Another exploded view showing the flexible printed circuit board P and the base B before being combined. Fig. 9 A schematic diagram showing the relative position relationship between the first and second coils PC1, PC2 and the position sensor HS, Fig.10 A schematic diagram showing the position sensor HS deviating from the center of the first magnetic element M1 in the Z-axis direction.

[0086] like Figure 7 , Figure 8 , Fig. 9 , Fig.10 As shown, the base B of this embodiment is formed with a protruding structure B1 extending in the direction of the Z-axis O, and the protruding structure B1 is formed with at least one block B11 ( Figure 8 ), wherein the aforementioned block B11 passes through the bending portion P2 along the Z-axis direction.

[0087] Specifically, a first coil PC1 and two second coils PC2 arranged along the Z-axis direction are provided inside the circuit substrate PC of the present embodiment, wherein the first and second coils PC1 and PC2 (for example, flat coils) at least partially overlap in the Z-axis direction, are electrically connected to the flexible circuit board P and are adjacent to the aforementioned first magnetic element M1.

[0088] The length of the first coil PC1 in the Y-axis direction is greater than the length of the second coil PC2 in the Y-axis direction; in addition, a position sensor HS (such as a Hall sensing element) is arranged on the flexible circuit board P and accommodated in a groove PC0 of the circuit substrate PC, wherein the position sensor HS is located between the two second coils PC2, and is used to sense the movement of the movable part relative to the fixed part in the X-axis direction.

[0089] It should be particularly noted that the aforementioned position sensor HS is slightly lower than the center of the first magnetic element M1 in the Z-axis direction, wherein the position sensor HS at least partially overlaps with the first magnetic element M1 in the X-axis direction, and the position sensor HS at least partially overlaps with the second coil PC2 in the Y-axis direction.

[0090] In addition, the second coil PC2 does not protrude from the first coil PC1 in the Y-axis direction, and the position sensor HS and the first coil PC1 do not overlap each other in the Y-axis direction. In addition, the position sensor HS and the first coil PC1 at least partially overlap in the Z-axis direction, and the position sensor HS and the second coil PC2 do not overlap each other in the Z-axis direction.

[0091] from Fig.10 It can be seen that the first magnetic element M1 includes a first magnetic unit m1 and a second magnetic unit m2 arranged along the Z-axis direction, wherein the first magnetic unit m1 at least partially overlaps with the first coil PC1 in the X-axis direction, and the second magnetic unit m2 at least partially overlaps with the second coil PC2 in the X-axis direction.

[0092] In addition, the second magnetic unit m2 and the position sensor HS at least partially overlap each other in the X-axis direction, while the first magnetic unit m1 and the position sensor HS do not overlap each other in the X-axis direction.

[0093] In this embodiment, the long axis of the first magnetic element M1 is parallel to the Y-axis direction (the first axial direction), and the circuit substrate PC and the first magnetic element M1 are separated by a distance in the X-axis direction (the second axial direction).

[0094] Please also refer to Fig.11 , Fig.12 ,in Fig.11 It is a cross-sectional view of the aforementioned driving mechanism 100 after removing the housing H, Fig.12 FIG. 4 is another cross-sectional view of the driving mechanism 100 with the housing H removed.

[0095] from Fig.11 It can be seen from the figure that a metal sheet T is disposed between the first magnetic unit m1 and the second magnetic unit m2, and the magnetic pole directions of the first magnetic unit m1 and the second magnetic unit m2 are different.

[0096] It should be understood that in this embodiment, a magnetic conductive sheet J ( Figure 1 ), wherein a magnetic attraction force can be generated between the magnetic conductive sheet J and the first magnetic element M1, so that the frame F can be stably suspended above the base B.

[0097] In this embodiment, the magnetic permeability of the magnetic conductive sheet J is higher than that of the metal sheet T, and the second magnetic unit m2 is located between the metal sheet T and the magnetic conductive sheet J after assembly.

[0098] Next, please refer to Fig.13 ,in Fig.13 A schematic diagram showing the conductive element K connecting the inner surface P11 of the body P1 of the flexible printed circuit P and the side surface PC3 of the circuit board PC.

[0099] from Fig.13 It can be seen that a conductive element K (such as solder) is applied to the inner surface P11 of the body P1 of the flexible circuit board P and the side surface PC3 of the circuit substrate PC to electrically connect the flexible circuit board P and the circuit substrate PC, wherein the inner surface P11 faces the circuit substrate PC, and the side surface PC3 is adjacent to the inner surface P11.

[0100] Please see again Fig.14 ,in Fig.14 A schematic diagram showing a protruding structure B1 of a base B and a flexible printed circuit board P connected to a component G.

[0101] from Figure 8 , Fig.14 As can be seen in FIG. 1 , the base B has four protruding structures B1 extending in the Z-axis direction. In addition, two bonding elements G (such as glue) are respectively applied to two of the protruding structures B1 ( Figure 8 ), for bonding and fixing the flexible circuit board P to the base B, wherein the protruding structure B1 and the circuit substrate PC do not overlap in the X-axis direction. In this embodiment, the bonding element G further contacts the circuit substrate PC, the protruding structure B1 and the flexible circuit board P at the same time ( Fig.14 ) so that the above three can be firmly connected to each other.

[0102] On the other hand, Figure 5 As shown, at least one buffer element FR (such as rubber or soft plastic block) is further provided on the plastic block F1 of the frame F. Thus, when the movable portion moves to an extreme position relative to the fixed portion along the X-axis direction, the buffer element FR will contact the circuit substrate PC to prevent the first magnetic element M1 from directly hitting the circuit substrate PC and causing damage to its structure.

[0103] In this embodiment, the hardness of the buffer element FR is smaller than the hardness of the plastic block F1 of the frame F and the base B. In addition, the hardness of the plastic block F1 is smaller than the hardness of the base B.

[0104] On the other hand, from Fig.12 It can be seen that the positioning column Q1 passes through the horizontal coil C2, wherein the distance between the positioning column Q1 and the second magnetic element M2 is smaller than the distance between the horizontal coil C2 and the second magnetic element M2. In this way, when the frame F moves in the Z-axis direction relative to the base B, the positioning column Q1 will contact the second magnetic element M2, thereby preventing the second magnetic element M2 from directly colliding with the horizontal coil C2 and causing damage to its structure.

[0105] In this embodiment, the top end of the positioning post Q1 can be bonded to the housing H during assembly to enhance the overall structural strength and reliability of the driving mechanism 100 .

[0106] In addition, from Figure 8 It can be seen that the bending portion P2 of the flexible circuit board P can be bonded to the top surface of the protruding structure B1 through a first adhesive G1, and the body P1 of the flexible circuit board P can be bonded to the outer side surface of the protruding structure B1 through a second adhesive G2, wherein the first and second adhesives G1 and G2 are separated from each other and do not contact each other.

[0107] Based on the above configuration, the carrier LH and the frame F can share the first magnetic element M1, so that the overall structure size is reduced and the function of autofocus or optical image stabilization can be achieved. In addition, the arrangement of the first electronic element E1 corresponding to the second magnetic element M2 can also reduce the number of induction magnets, so that the drive mechanism 100 can achieve the purpose of miniaturization and lightness. In addition, the position sensor HS is arranged between the second coil PC2, which can also reduce the crosstalk sensing effect caused by rotation, thereby achieving the purpose of improving the sensing accuracy.

[0108] Although the embodiments of the present invention and their advantages have been disclosed above, it should be understood that those skilled in the art may make changes, substitutions and modifications without departing from the spirit and scope of the present invention. In addition, the scope of protection of the present invention is not limited to the processes, machines, manufacturing, material compositions, devices, methods and steps in the specific embodiments described in the specification. Any technician in the relevant technical field can understand from the disclosure of the present invention that the processes, machines, manufacturing, material compositions, devices, methods and steps currently or in the future can be used according to the present invention as long as they can implement substantially the same functions or obtain substantially the same results in the embodiments described herein.

[0109] Therefore, the protection scope of the present invention includes the above-mentioned processes, machines, manufactures, material compositions, devices, methods and steps. In addition, each claim constitutes a separate embodiment, and the protection scope of the present invention also includes the combination of various claims and embodiments.

[0110] Although the present invention has been disclosed above in terms of preferred embodiments, they are not intended to limit the present invention. Those skilled in the art may make slight changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A driving mechanism for driving an optical element to move, wherein the optical element has an optical axis, the driving mechanism comprising: a fixing portion; a movable portion movably connected to the fixed portion, wherein the optical element is disposed on the movable portion; as well as A driving assembly is used to drive the movable part to move relative to the fixed part.

2. The driving mechanism of claim 1, wherein the driving assembly comprises: A first coil is disposed on the fixing portion; a second coil disposed on the fixing portion, wherein the first coil and the second coil at least partially overlap in the direction of the optical axis; as well as A first magnetic element is disposed on the movable portion and is adjacent to the first coil and the second coil. 3 . The driving mechanism as claimed in claim 2 , wherein a length of the first coil in a first axial direction is greater than a length of the second coil in the first axial direction, and the first axial direction is perpendicular to the optical axis.

4. The driving mechanism as described in claim 3, wherein the driving mechanism also includes a position sensor for sensing the movement of the movable part, wherein the position sensor and the first magnetic element at least partially overlap in a second axial direction, and the second axial direction is perpendicular to the optical axis and the first axial direction. 5 . The driving mechanism of claim 4 , wherein the position sensor and the second coil at least partially overlap in the first axial direction. 6 . The driving mechanism of claim 5 , wherein the driving component further comprises two second coils, and the position sensor is disposed between a plurality of the second coils. 7 . The driving mechanism of claim 6 , wherein the plurality of second coils do not protrude from the first coil in the first axial direction. 8 . The driving mechanism of claim 5 , wherein the position sensor and the first coil do not overlap in the first axial direction. 9 . The driving mechanism of claim 5 , wherein the position sensor and the first coil at least partially overlap in the direction of the optical axis. 10 . The driving mechanism of claim 5 , wherein the position sensor and the second coil do not overlap in the optical axis direction.

11. The driving mechanism of claim 5, wherein the position sensor is offset from a center of the first magnetic element in the direction of the optical axis. 12 . The driving mechanism of claim 5 , wherein the position sensor senses movement of the movable portion relative to the fixed portion in the second axial direction.

13. A driving mechanism as described in claim 5, wherein the first magnetic element includes a first magnetic unit and a second magnetic unit arranged along the optical axis direction, the first magnetic unit and the first coil at least partially overlap in the second axial direction, and the second magnetic unit and the second coil at least partially overlap in the second axial direction. 14 . The driving mechanism of claim 13 , wherein the second magnetic unit and the position sensor at least partially overlap in the second axial direction. 15 . The driving mechanism of claim 14 , wherein the first magnetic unit and the position sensor do not overlap in the second axial direction. 16 . The driving mechanism as claimed in claim 13 , wherein the driving mechanism further comprises a metal sheet disposed between the first magnetic unit and the second magnetic unit, and the magnetic poles of the first magnetic unit and the second magnetic unit are axially different. 17 . The driving mechanism as claimed in claim 16 , wherein the driving mechanism further comprises a magnetic conductive sheet disposed on the base, and the second magnetic unit is located between the metal sheet and the magnetic conductive sheet.

18. The driving mechanism of claim 17, wherein the magnetic permeability of the magnetic conductive sheet is higher than the magnetic permeability of the metal sheet.

19. The driving mechanism as claimed in claim 5, wherein the driving mechanism further comprises a circuit substrate, and the first coil and the second coil are disposed in the circuit substrate.

20. The driving mechanism of claim 19, wherein the circuit substrate is formed with a groove for accommodating the position sensor.

21. The driving mechanism as claimed in claim 19, wherein the driving mechanism further comprises a flexible circuit board electrically connecting the first coil and the second coil, the circuit substrate is disposed on the flexible circuit board, and the thickness of the flexible circuit board is smaller than the thickness of the circuit substrate.

22. The driving mechanism as claimed in claim 21, wherein the driving mechanism further comprises a conductive element, the flexible printed circuit board has an inner surface facing the circuit substrate, and the circuit substrate has a side surface adjacent to the inner surface, wherein the conductive element connects the inner surface and the side surface.

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