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 utility model relates to a driving mechanism. More particularly, the present utility model relates to a driving mechanism for moving an optical element. BACKGROUND

[0002] With the development of technology, many electronic devices (such as smart phones or digital cameras) nowadays have the function of taking pictures or recording videos. The use of these electronic devices is becoming more and more popular, and is developing towards the direction of convenience and thinness, in order to provide users with more choices.

[0003] Some electronic devices with the function of taking pictures or recording videos are provided 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 optical element to form an image on a photosensitive element.

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

[0005] The present utility model aims to provide a driving mechanism to solve at least one of the above problems.

[0006] In view of the above known problems, an embodiment of the present utility model provides a driving mechanism for moving an optical element, which mainly comprises a fixed part, a movable part and a driving assembly. The movable part is movably connected to the fixed part, wherein the optical element is arranged on the movable part, and the driving assembly is used to drive the movable part to move relative to the fixed part.

[0007] In an embodiment, the driving mechanism further comprises a guide rod extending in a horizontal direction, and the fixed part has a housing and a base connected to each other, wherein the guide rod is fixed on the base, and the movable part is slidably arranged on the guide rod.

[0008] In an embodiment, the driving mechanism further comprises a circuit board, a magnetic scale and a sensor, the circuit board is fixed on the base, the magnetic scale is arranged on the movable part, and the sensor is arranged on the circuit board to sense the position change of the magnetic scale.

[0009] In an embodiment, the circuit board has a body and a bent part connected to each other, the body is perpendicular to a vertical direction, and the sensor is arranged on the body, wherein the sensor and the magnetic scale at least partially overlap in the vertical direction.

[0010] In one embodiment, the sensor and the guide rod do not overlap each other in the vertical direction.

[0011] In one embodiment, the optical element and the guide rod partially overlap in the vertical direction.

[0012] In one embodiment, the optical element and the guide rod do not overlap in the vertical direction, and the guide rod is located between the optical element and the sensor when viewed along the vertical direction.

[0013] In one embodiment, the driving mechanism further comprises two guide rods extending towards the horizontal direction, and the movable part is formed with two guide slots, wherein the guide rods extend through the guide slots.

[0014] In one embodiment, the sensor is located outside the guide rods.

[0015] In one embodiment, the driving mechanism further comprises a substrate fixed to the base, and the driving assembly comprises a magnetic element and a coil, wherein the magnetic element is disposed on the movable part, and the coil is disposed on the substrate and adjacent to the magnetic element.

[0016] In one embodiment, the magnetic element and the guide rod do not overlap each other in the vertical direction.

[0017] In one embodiment, the sensor, the magnetic scale, and the magnetic element at least partially overlap in the vertical direction.

[0018] In one embodiment, the substrate further has a recess for accommodating the bent portion of the circuit board.

[0019] In one embodiment, the driving mechanism further comprises a metal bracket embedded inside the substrate.

[0020] In one embodiment, the metal bracket has an H-shaped structure.

[0021] In one embodiment, the substrate has a plate structure and a protruding portion, the protruding portion protruding from the plate structure towards the magnetic element and passing through the coil, wherein the thickness of the protruding portion is greater than the thickness of the coil.

[0022] In one embodiment, the thickness of the plate structure is greater than or equal to 0.2 mm.

[0023] In one embodiment, the driving mechanism further comprises a wire, and the substrate further has a wire winding post protruding from the bottom side of the plate structure and having a T-shaped or L-shaped structure, the wire connecting the coil and being wound on the wire winding post.

[0024] In an embodiment, the plate-shaped structure abuts against a limiting surface of the base, and the winding post is adjacent to the limiting surface.

[0025] In an embodiment, the driving mechanism further comprises an electrically conductive member embedded inside the base and exposed on one side of the base, and the wire and the electrically conductive member are electrically connected to each other by welding. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 A perspective view of an optical system according to an embodiment of the present application is shown.

[0027] Figure 2 A sectional view of the optical system in Figure 1 is shown.

[0028] Figure 3 A perspective view of the driving mechanism in Figure 1 is shown.

[0029] Figure 4 A perspective view of another driving mechanism in Figure 1 is shown.

[0030] Figure 5 An exploded view of the driving mechanism in Figure 4 is shown.

[0031] Figure 6 A sectional view of the optical element and the driving mechanism after assembly is shown, and the housing is omitted in Figure 6 .

[0032] Figure 7 A partial sectional enlarged view showing that the first end of the guide rod extends into the first opening of the first side wall is shown.

[0033] Figure 8 A partial sectional enlarged view showing that the second end of the guide rod extends into the second opening of the second side wall is shown.

[0034] Figure 9 A schematic view showing the relative position relationship of the circuit board, the substrate, the coil, the magnetic element, the guide rod and the carrier after combination is shown.

[0035] Figure 10 A schematic view showing that a curved surface and a recess are formed on the bump of the base is shown.

[0036] Figure 11 An exploded view of the substrate, the coil and a metal bracket before combination in Figure 5 is shown.

[0037] Figure 12 Another perspective exploded view of the substrate, the coil and a metal bracket before combination in Figure 5 is shown.

[0038] Figure 13 FIG. 9 shows a perspective view of the circuit board combined with the substrate.

[0039] Figure 14 FIG. 10 shows another perspective view of the circuit board combined with the substrate.

[0040] Figure 15 FIG. 11 shows a schematic diagram of the relative position relationship of the optical element, the guide rod, the circuit board, the substrate, and the coil after being combined.

[0041] Figure 16 FIG. 12 shows a schematic diagram of the driving mechanism after the shell is removed.

[0042] The reference signs are as follows:

[0043] 100: optical system

[0044] 10: driving mechanism

[0045] 11: circuit board

[0046] 20: driving mechanism

[0047] 21: circuit board

[0048] 211: body

[0049] 212: bent portion

[0050] 23: guide rod

[0051] 231: first end

[0052] 232: second end

[0053] 233: groove

[0054] B: base

[0055] BC: conductive member

[0056] BP: bump

[0057] BP1: curved surface

[0058] BP2: recess

[0059] BR: limiting surface

[0060] BW1: first side wall

[0061] BW2: second side wall

[0062] C: coil

[0063] D1: vertical direction

[0064] D2: horizontal direction

[0065] E: electronic element

[0066] H: housing

[0067] HM: magnetic scale

[0068] h1: first aperture

[0069] h11: groove

[0070] h2: second aperture

[0071] h21: first segment

[0072] h211: first inclined surface

[0073] h22: second segment

[0074] h221: second inclined surface

[0075] L1: optical element

[0076] L2: optical element

[0077] LH: carrier

[0078] LH1: guide groove

[0079] M: magnetic element

[0080] P: substrate

[0081] P1: plate structure

[0082] P2: protrusion

[0083] P3: winding post

[0084] P4: recess

[0085] R: optical element

[0086] S: sensor

[0087] T: metal bracket

[0088] T1: first thickness

[0089] T2: second thickness

[0090] U: metal plate DETAILED DESCRIPTION

[0091] The following describes the drive mechanism of the embodiments of the present application. However, it can be easily understood 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 used for illustration in a specific method using the present application, and are not intended to limit the scope of the present application.

[0092] 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.

[0093] The foregoing and other technical contents, features and effects of the present application will be more clearly understood from the following detailed description of a preferred embodiment taken in conjunction with the accompanying drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front or back, are only the directions of the accompanying drawings. Therefore, the directional terms used in the embodiments are used for illustration, not for limiting the present application.

[0094] First, refer to Figures 1 to 4 , wherein Figure 1 represents a perspective view of an optical system 100 according to an embodiment of the present application, Figure 2 represents Figure 1 a sectional view of the optical system 100 in Figure 3 represents Figure 1 a perspective view of a driving mechanism 10 in Figure 4 represents Figure 1 a perspective view of another driving mechanism 20 in

[0095] As shown in Figures 1 to 4 , the optical system 100 of the present embodiment can be installed inside a mobile phone or other portable electronic device, which mainly includes two interconnected driving mechanisms 10, 20 and several optical elements R, L1, L2. Specifically, the optical element R (such as a prism) is arranged inside the driving mechanism 10, and the optical elements L1, L2 (such as optical lenses) are arranged inside the driving mechanism 20.

[0096] In the present embodiment, the driving mechanisms 10, 20 are, for example, voice coil motors (VCMs), wherein the driving mechanism 10 can drive the optical element R to rotate, and the driving mechanism 20 can drive the optical element L2 to move along the X-axis direction, thereby achieving functions such as auto focusing (AF) or optical image stabilization (OIS).

[0097] By the aforementioned mechanism configuration, external light rays can enter the optical element R of the driving mechanism 10 along a vertical direction D1 (-Z-axis direction), and then the light rays are reflected by the optical element R and sequentially pass through the optical elements L1 and L2 along a horizontal direction D2 (X-axis direction) in sequence, and then the light rays pass out of the optical system 100 to reach an image sensing element (not shown), thereby generating a digital image.

[0098] It can also be seen from Figures 1 to 4 that a circuit board 11, 21 is arranged at the bottom side of the driving mechanism 10, 20, respectively, and an external circuit can apply a current signal to the coil inside the driving mechanism 10, 20 through the aforementioned circuit board 11, 21, thereby generating an electromagnetic driving force, so as to drive the optical element R, L1, L2 inside the driving mechanism 10, 20 to move, so as to achieve functions such as Auto Focusing (AF) or Optical Image Stabilization (OIS).

[0099] Then, referring to Figures 5 to 6 together, Figure 5 , an exploded view of the driving mechanism 20 in Figure 4 is shown, Figure 6 , a cross-sectional view of the optical elements L1 and L2 and the driving mechanism 20 after assembly, and the housing H is omitted in Figure 6 .

[0100] As shown in Figures 5 to 6 , the driving mechanism 20 of an embodiment of the present application mainly comprises a circuit board 21, two guide rods 23 extending along the X-axis direction, a base B, a carrier LH, two magnetic elements M, two coils C, two substrates P, and a housing H.

[0101] Specifically, the housing H and the base B are combined with each other and constitute a fixed part of the driving mechanism 20, the carrier LH is movably arranged inside the base B and constitutes a movable part of the driving mechanism 20, wherein the two ends of the guide rod 23 are fixed in a first opening h1 of a first side wall BW1 and a second opening h2 of a second side wall BW2 of the base B, respectively, in addition, the guide rod 23 extends through the carrier LH, and the carrier LH can slide relative to the base B along the guide rod 23 in the X-axis direction.

[0102] In this embodiment, the optical element L1 is fixed to a first side wall BW1 of the base B, and the optical element L2 is arranged on the carrier LH, wherein the first side wall BW1 is adjacent to the aforementioned driving mechanism 10, and the carrier LH and the optical element L2 are adjacent to a second side wall BW2 of the base B.

[0103] The aforementioned magnetic element M (e.g. a magnet) is fixed to the outer surface of the carrier LH, and the aforementioned substrate P is fixed to the base B, wherein the coil C is disposed on the substrate P and adjacent to the aforementioned magnetic element M.

[0104] It is particularly noted that the aforementioned magnetic element M and the coil C constitute a driving assembly of the driving mechanism 20, and the aforementioned circuit board 21 is disposed on the bottom side of the base B and electrically connected to the coil C. When a current signal is applied to the aforementioned coil C through the aforementioned circuit board 21, the magnetic force generated between the coil C and the magnetic element M can be used to drive the carrier LH and the optical element L2 disposed inside the carrier LH to move relative to the base B along the X-axis direction, thereby achieving the functions of auto-focusing (AF) or optical image stabilization (OIS).

[0105] For example, the aforementioned circuit board 21 is a flexible circuit board (thickness of about 0.1 mm) and has a body 211 and a bending portion 212, wherein the aforementioned body 211 is perpendicular to the Z-axis direction, and an electronic element E (e.g. a control IC or other integrated circuit element) and a sensor S (e.g. a Hall effect sensor or other magnetic field sensing element) are disposed on the aforementioned body 211.

[0106] As shown in Figure 6 , the two ends of the guide rod 23 are respectively fixed in the first opening h1 of the first side wall BW1 and the second opening h2 of the second side wall BW2 of the base B, and the middle portion of the guide rod 23 is supported by a protrusion BP on the base B. Specifically, the aforementioned guide rod 23 extends through the carrier LH, wherein the aforementioned first side wall BW1 has a first thickness T1 in the X-axis direction, and the aforementioned second side wall BW2 has a second thickness T2 in the X-axis direction, wherein the aforementioned first thickness T1 is less than the aforementioned second thickness T2.

[0107] In addition, a metal plate U is embedded in the first side wall BW1 of the aforementioned base B, and the metal plate U and the base B made of plastic material can be made by insert molding, thereby improving the structural strength of the first side wall BW1 of the base B, and part of the metal plate U will be exposed to the aforementioned first opening h1 for connecting the aforementioned guide rod 23.

[0108] Please also refer to Figure 6 and Figure 7 , wherein Figure 7 represents a partial cross-sectional enlarged view of the first end 231 of the guide rod 23 extending into the first opening h1 of the first side wall BW1.

[0109] As shown in Figure 7As shown, the first end 231 of the guide rod 23 extends into the first opening h1 of the first side wall BW1, and is welded with the metal plate U exposed at the first opening h1. In addition, a groove h11 is formed inside the first side wall BW1, wherein the groove h11 is adjacent to the metal plate U and communicates with the first opening h1. The groove h11 is beneficial for the assembly of the guide rod 23, and can avoid damaging the first side wall BW1 when welding the first end 231 of the guide rod 23 to the metal plate U.

[0110] In the present embodiment, the first end 231 of the guide rod 23 does not completely pass through the first opening h1 and protrude from the outer surface of the base B, and after welding the first end 231 of the guide rod 23 to the metal plate U, glue can be applied in the first opening h1. The groove h11 can be used to hold the glue, thereby improving the adhesion strength between the guide rod 23, the base B and the metal plate U.

[0111] Please refer to Figure 6 and Figure 8 together. Figure 8 Figure 7 shows a partial cross-sectional enlarged view of the second end 232 of the guide rod 23 extending into the second opening h2 of the second side wall BW2.

[0112] As shown in Figure 8 , the second end 232 of the guide rod 23 extends into the second opening h2 of the second side wall BW2, and glue can be applied in the second opening h2 during assembly, so that the second end 232 of the guide rod 23 can be fixedly bonded in the second opening h2.

[0113] Specifically, the second opening h2 includes a first section h21 and a second section h22, wherein the first section h21 is formed with a first inclined surface h211 tapering towards the horizontal direction (X-axis direction), and the second section h22 is formed with a second inclined surface h221 tapering towards the horizontal direction (X-axis direction), wherein the included angle (acute angle) between the first inclined surface h211 and the X-axis direction is greater than the included angle (acute angle) between the second inclined surface h221 and the X-axis direction.

[0114] It should be particularly noted that the guide rod 23 extends towards the -X-axis direction through the second section h22 and reaches the first section h21, wherein the guide rod 23 does not completely pass through the first section h21 and protrude from the outer surface of the base B, and the length of the first section h21 in the X-axis direction is less than the length of the second section h22 in the X-axis direction.

[0115] On the other hand, as can be seen from Figure 8 , a ring-shaped groove 233 is formed on the guide rod 23, which is adjacent to the second end 232 of the guide rod 23 and located in the second section h22 of the second opening h2.

[0116] In one embodiment, when the second end 232 of the guide rod 23 is fixed in the second opening h2 of the base B, glue can be applied in the second opening h2, wherein the glue can flow into the second section h22 and the groove 233 of the guide rod 23 through the first section h21 of the second opening h2, thereby effectively improving the adhesion strength between the guide rod 23 and the base B.

[0117] Referring back to Figure 9 , wherein Figure 9 indicates a schematic diagram of the relative position relationship of the combination of the circuit board 21, the substrate P, the coil C, the magnetic element M, the guide rod 23, and the carrier LH.

[0118] As Figure 9 shown, the bottom side of the carrier LH forms a guide groove LH1 for accommodating the guide rod 23, wherein the guide rod 23 passes through the guide groove LH1 of the carrier LH along the X-axis direction, so that the carrier LH can slide relative to the base B along the guide rod 23 in the X-axis direction.

[0119] In the present embodiment, the body 211 of the circuit board 21 is fixed to the bottom side of the base B, and the bent portion 212 of the circuit board 21 is fixed to the substrate P, wherein the sensor S on the circuit board 21 is located outside the two guide rods 23, and the sensor S and the guide rod 23 do not overlap each other in the vertical direction (Z-axis direction), and the magnetic element M and the guide rod 23 also do not overlap each other in the vertical direction (Z-axis direction).

[0120] On the other hand, it can also be seen from Figure 9 that a magnetic scale HM is additionally provided on the bottom side of the carrier LH, wherein the sensor S on the circuit board 21 and the magnetic scale HM and the magnetic element M at least partially overlap each other in the vertical direction (Z-axis direction). It should be understood that the present embodiment can detect the position change of the magnetic scale HM by providing the magnetic scale HM on the bottom side of the carrier LH and using the sensor S on the circuit board 21, thereby being able to know the movement of the carrier LH and the optical element L2 relative to the base B in the horizontal direction (X-axis direction).

[0121] Referring back to Figure 6 and Figure 10 , wherein Figure 10 indicates a schematic diagram of the convex block BP of the base B formed with a curved surface BP1 and a recess BP2.

[0122] As Figure 6 and Figure 10As shown, in order to provide stable support for the guide rod 23, a protrusion BP is formed on the bottom side of the base B, wherein the protrusion BP is located between the first side wall BW1 and the second side wall BW2, and a curved surface BP1 is formed on the protrusion BP to support the guide rod 23.

[0123] In this embodiment, the curvature radius of the curved surface BP1 is greater than the curvature radius of the guide rod 23, and in addition, a recess BP2 is further formed in the center of the curved surface BP1 to accommodate glue, thereby improving the bonding strength between the guide rod 23 and the base B.

[0124] Next, please refer to Figure 11 , Figure 12 , Figure 13 and Figure 14 , wherein Figure 11 represents an exploded view of the substrate P, the coil C and a metal bracket T before being combined in Figure 5 , Figure 12 represents another perspective exploded view of the substrate P, the coil C and a metal bracket T before being combined in Figure 5 , Figure 13 represents a perspective view of the circuit board 21 after being combined with the substrate P, Figure 14 represents another perspective view of the circuit board 21 after being combined with the substrate P.

[0125] As shown in Figure 11 , Figure 12 , Figure 13 and Figure 14 , the substrate P in this embodiment has a plate structure P1, a protruding portion P2 and two winding posts P3, wherein the thickness of the plate structure P1 is greater than or equal to 0.2 mm (for example, 0.3 mm), the protruding portion P2 protrudes from the center of the plate structure P1 towards the magnetic element M, and the winding posts P3 protrude from the bottom side of the plate structure P1 towards the -Z axis. During assembly, the coil C can be wound on the protruding portion P2, and the coil C and the winding posts P3 can be connected by wires (not shown). Then, the wires on the winding posts P3 can be welded to conductive members on the base B, and the conductive members can be electrically connected to external circuits through the circuit board 21.

[0126] It should be particularly noted that in order to improve the structural strength of the plastic substrate P, a H-shaped metal bracket T can be inserted into the substrate P by insert molding, thereby avoiding deformation and damage of the substrate P due to external forces.

[0127] In addition, from Figure 12 and Figure 14As can be seen, a recessed portion P4 is formed on the substrate P to accommodate and fix the bent portion 212 of the circuit board 21, so as to achieve the miniaturization of the driving mechanism 20.

[0128] Referring again to Figure 15 , wherein Figure 15 schematic diagram of the relative positions of the optical elements L1, L2, the guide rods 23, the circuit board 21, the substrate P, and the coil C after assembly.

[0129] As shown in Figure 15 , the optical elements L1, L2 partially overlap the guide rods 23 in the vertical direction (Z-axis direction) after the driving mechanism 20 of the present embodiment is assembled. However, the optical elements L1, L2 and the guide rods 23 can also not overlap in the vertical direction (Z-axis direction) after assembly, but the optical elements L1, L2 are positioned between the two guide rods 23, and one of the guide rods 23 is positioned between the sensor S and the optical elements L1, L2.

[0130] In addition, as can be seen from Figure 15 , the protruding portion P2 protrudes from the center of the plate-shaped structure PI toward the magnetic element M and passes through the coil C, and the thickness of the protruding portion P2 in the Y-axis direction is greater than the thickness of the coil in the Y-axis direction, so as to avoid the coil C directly colliding with the magnetic element M on the carrier LH when the driving mechanism 20 is impacted by external force, thereby causing damage to the structure.

[0131] Referring again to Figure 16 , wherein Figure 16 schematic diagram of the driving mechanism 20 after removal of the housing H.

[0132] As shown in Figure 16 , the substrate P is fixed to the base B during assembly, and the plate-shaped structure PI of the substrate P abuts against a limiting surface BR of the base B; in addition, the winding post P3 below the substrate P can have a T-shaped or L-shaped structure, and the wire (not shown) wound on the winding post P3 can be welded to the conductive member BC exposed on the side of the base B during assembly, so that the coil C can be electrically connected to the external circuit in sequence through the wire, the conductive member BC, and the circuit board 21 below the base B.

[0133] In the present embodiment, the conductive member BC can be embedded inside the plastic base B and exposed on one side of the base B by insert molding, and the positions of the conductive member BC and the winding post P3 are adjacent to the limiting surface BR of the base B.

[0134] Although the embodiments and advantages of the present application have been disclosed as above, it should be understood that those skilled in the art can make modifications, substitutions and embellishments without departing from the spirit and scope of the present application. In addition, the protection scope of the present application is not limited to the processes, machines, manufactures, compositions of matter, devices, methods and steps in the specific embodiments described in the specification. 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 perform substantially the same function or obtain substantially the same result in the embodiments described herein. Therefore, the protection scope of the present application includes the above processes, machines, manufactures, compositions of matter, devices, methods and steps. In addition, each claim constitutes an individual embodiment, and the protection scope of the present application also includes the combination of each claim and embodiment.

[0135] Although the present application has been disclosed with preferred embodiments, it is not intended to limit the present application, and those skilled in the art can make some modifications and embellishments without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application is defined by the appended claims.

Claims

1. A drive mechanism for driving an optical element, characterized by The application relates to a driving mechanism for an optical element, comprising: a fixed part having a housing and a base connected to each other; a movable part movably connected to the fixed part, wherein the optical element is arranged on the movable part; a guide rod fixed to the base and extending in a horizontal direction, wherein the movable part is slidably arranged on the guide rod; and a driving assembly for driving the movable part to move relative to the fixed part.

2. The drive mechanism of claim 1, wherein, The driving mechanism further comprises a circuit board fixed to the base, a magnetic scale arranged on the movable part, and a sensor arranged on the circuit board for sensing the position change of the magnetic scale.

3. The drive mechanism of claim 2, wherein, The circuit board has a body and a bent part connected to each other, the body is perpendicular to a vertical direction, and the sensor is arranged on the body, wherein the sensor and the magnetic scale at least partially overlap in the vertical direction.

4. The drive mechanism of claim 3, wherein, The sensor and the guide rod do not overlap each other in the vertical direction.

5. The drive mechanism of claim 3, wherein, The optical element and the guide rod partially overlap in the vertical direction.

6. The drive mechanism of claim 3, wherein, The optical element and the guide rod do not overlap in the vertical direction, and the guide rod is located between the optical element and the sensor when viewed along the vertical direction.

7. The drive mechanism of claim 3, wherein, The driving mechanism further comprises two guide rods extending in the horizontal direction, and the movable part is formed with two guide grooves, wherein the guide rods extend through the guide grooves.

8. The drive mechanism of claim 7, wherein, The sensor is located outside the guide rods.

9. The drive mechanism of claim 3, wherein, The driving mechanism further comprises a base plate fixed to the base, and the driving assembly comprises a magnetic element arranged on the movable part and a coil arranged on the base plate and adjacent to the magnetic element.

10. The drive mechanism of claim 9, wherein, The magnetic element and the guide rod do not overlap each other in the vertical direction.

11. The drive mechanism of claim 9, wherein, The sensor, the magnetic scale and the magnetic element at least partially overlap in the vertical direction.

12. The drive mechanism of claim 9, wherein, The base plate further has a recess for accommodating the bent part of the circuit board.

13. The drive mechanism of claim 9, wherein, The driving mechanism further comprises a metal bracket embedded in the base plate.

14. The drive mechanism of claim 13, wherein, The metal bracket has an H-shaped structure.

15. The drive mechanism of claim 9, wherein, The base plate has a plate structure and a protruding part, the protruding part protrudes from the plate structure towards the magnetic element and passes through the coil, wherein the thickness of the protruding part is greater than the thickness of the coil.

16. The drive mechanism of claim 15, wherein, The thickness of the plate structure is greater than or equal to 0.2 mm.

17. The drive mechanism of claim 15, wherein, The driving mechanism further comprises a wire, and the base plate further has a wire winding column protruding from the bottom side of the plate structure and having a T-shaped or L-shaped structure, the wire is connected to the coil and wound on the wire winding column.

18. The drive mechanism of claim 17, wherein, The plate structure abuts against a limiting surface of the base, and the wire winding column is adjacent to the limiting surface.

19. The drive mechanism of claim 17, wherein, The driving mechanism further comprises a conductive part embedded in the base and exposed on one side of the base, and the wire and the conductive part are electrically connected to each other by welding.

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