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 functions of taking pictures or recording videos. These electronic devices are increasingly popular and are developing towards convenient and thin designs to provide users with more choices.

[0003] Some electronic devices with the functions 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 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, wherein the optical element has an optical axis, the driving mechanism comprises a fixed part, a movable part and a driving assembly, the movable part is movably connected to the fixed part, 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 flat sliding member, the fixed part comprises a housing and a base connected to each other, and the movable part comprises a frame, wherein the sliding member is arranged on the frame and can slide relative to the base.

[0008] According to one embodiment of the present utility model, the sliding member is made of plastic steel.

[0009] According to one embodiment of the present utility model, the sliding member has a disc-shaped structure.

[0010] According to one of the embodiments of the utility model, the driving mechanism further comprises a spring sheet and a plurality of long strip-shaped elastic elements, and the movable part further comprises a bearing arranged inside the frame, wherein the spring sheet is connected to the bearing and the frame, and the plurality of elastic elements are connected to the spring sheet and the base along the optical axis direction.

[0011] According to one of the embodiments of the utility model, the driving mechanism further comprises a magnetic conducting element arranged on the base, and the driving assembly comprises a magnetic element and a first coil, wherein the first coil is arranged on the bearing, the magnetic element is arranged on the frame, and the magnetic conducting element is located below the magnetic element, wherein the magnetic conducting element and the magnetic element generate a magnetic attraction force, so that the sliding member and the base remain in contact.

[0012] According to one of the embodiments of the utility model, the driving mechanism further comprises a circuit board arranged on the base, and the driving assembly further comprises a second coil, which is arranged in the circuit board and corresponds to the magnetic element, wherein the circuit board is located between the magnetic conducting element and the magnetic element.

[0013] According to one of the embodiments of the utility model, the plurality of frames have a recess and a protrusion, the protrusion is located in the center of the recess, and the sliding member is fixed to the protrusion.

[0014] According to one of the embodiments of the utility model, the frame has a support leg, the recess and the protrusion are formed on the support leg, and the protrusion protrudes from a bottom surface of the support leg.

[0015] According to one of the embodiments of the utility model, the driving mechanism further comprises an adhesive element for bonding the sliding member and the frame.

[0016] According to one of the embodiments of the utility model, the driving mechanism further comprises a lubricating oil contained in the recess.

[0017] According to one of the embodiments of the utility model, the driving mechanism further comprises a support structure, and the base forms a groove, wherein the support structure is located in the center of the groove, and the sliding member slidably contacts the support structure.

[0018] According to one of the embodiments of the utility model, the hardness of the sliding member is less than the hardness of the support structure.

[0019] According to one of the embodiments of the utility model, the width of the sliding member is less than the width of the support structure.

[0020] According to one of the embodiments of the utility model, the width of the recess is less than the width of the groove.

[0021] According to one embodiment of the present invention, the support structure is made of metal.

[0022] According to one embodiment of the present invention, the driving mechanism includes four flat sliding members, the frame has four supporting feet, and the four sliding members are respectively fixed on the four supporting feet.

[0023] According to one embodiment of the present invention, a gap is formed between one of the four sliding members and the base.

[0024] According to one embodiment of the present invention, the driving mechanism further includes a support structure, and the base has a groove, wherein the support structure is located in the center of the groove and protrudes toward the frame, and the support structure is lower than an upper surface of the base.

[0025] According to one embodiment of the present invention, one of the four sliding members is formed with a curved surface facing the base, and a gap is formed between the curved surface and the base.

[0026] The beneficial effects of this utility model are that it uses a disc-shaped sliding member to contact the base, which can significantly reduce the overall height of the drive mechanism, thereby helping to achieve miniaturization of the drive mechanism. In addition, compared with the general technical solution of setting ball bearings between the frame and the base, the sliding member and the base of this utility model have a larger contact area, which can ensure the stability of both during sliding and avoid the problem of debris or structural damage caused by the small contact area when using ball bearings. Attached Figure Description

[0027] Figure 1 This is an exploded view of a drive mechanism according to an embodiment of the present invention.

[0028] Figure 2 express Figure 1 Another exploded view of the drive mechanism in the diagram.

[0029] Figure 3 express Figure 1 Another exploded view of the drive mechanism in the diagram.

[0030] Figure 4 express Figures 1-3 The drive mechanism is shown in the 3D diagram after assembly.

[0031] Figure 5 express Figure 4 A 3D view of the drive mechanism after the housing has been removed.

[0032] Figure 6 Indicates along Figure 4a cross-sectional view of the line segment X1-X2 in

[0033] Figure 7 an enlarged view of the area A1 in Figure 6

[0034] Figure 8 a partial enlarged view showing the sliding member P in contact with the support structure.

[0035] Figure 9 an enlarged view of the area A2 in Figure 6

[0036] Reference signs are as follows:

[0037] 100: driving mechanism

[0038] A1: area

[0039] A2: area

[0040] B: base

[0041] B1: upper surface

[0042] BP: support structure

[0043] BP': support structure

[0044] BR: recess

[0045] BS: spring piece

[0046] C1: first coil

[0047] C2: second coil

[0048] d: width

[0049] D: width

[0050] F: frame

[0051] FC: circuit board

[0052] FL: support leg

[0053] FL1: bottom surface

[0054] FP: protrusion

[0055] FR: recess

[0056] FS: spring piece

[0057] g: distance

[0058] H: housing

[0059] K: magnetically conductive element

[0060] LH: carrier​​

[0061] M: magnetic element

[0062] O: optical axis

[0063] P: slider

[0064] PS: curved surface

[0065] P’: slider

[0066] T: adhesive element

[0067] W: elastic element DETAILED DESCRIPTION

[0068] 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 to illustrate the use of the present application in a specific manner and are not intended to limit the scope of the present application.

[0069] 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.

[0070] The foregoing and other technical contents, features and effects of the present application will be apparent from 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, 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.

[0071] First, please refer to Figures 1 to 4 wherein Figure 1 represents an exploded view of the drive mechanism 100 according to an embodiment of the present application, Figure 2 represents Figure 1 another exploded view of the drive mechanism 100 in Figure 3 represents Figure 1 another exploded view of the drive mechanism 100 in Figure 4 represents Figures 1-3 a perspective view of the drive mechanism 100 in Figure 5 represents Figure 4 a perspective view of the drive mechanism 100 in

[0072] As Figure 1、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 As shown in FIG. 1, 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 (e.g. an optical lens) to move, thereby achieving functions such as auto focusing (AF) or optical image stabilization (OIS).

[0073] The aforementioned driving mechanism 100 mainly includes a hollow housing H, at least one spring FS, a carrier LH, at least one spring BS, a plurality of long strip-shaped elastic elements W (e.g. metal rods), a quadrangular plastic frame F, a circuit board FC, and a base B.

[0074] In the present embodiment, the aforementioned housing H has a hollow structure and is combined with the base B, and the circuit board FC is fixed above the base B, wherein the housing H and the base B can jointly constitute a fixed part of the driving mechanism 100. In addition, an optical element (not shown) can be fixed in the carrier LH, wherein the aforementioned carrier LH and the frame F constitute a movable part which can move relative to the aforementioned fixed part (housing H and base B).

[0075] Specifically, the aforementioned frame F is movably accommodated in the housing H, and the aforementioned carrier LH is movably accommodated in the frame F. Wherein, the aforementioned carrier LH is connected to the frame F through the spring FS and the spring BS, and in addition, the four elastic elements W are connected to the spring FS and the base B along the Z-axis direction, so that the frame F, the carrier LH and the optical element arranged inside the carrier LH can be suspended inside the housing H.

[0076] 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 aforementioned light will pass through the optical lens and reach the image sensing element (not shown) located below the base B, thereby generating a digital image.

[0077] It should be particularly noted that the first coil C1 is arranged on both sides of the aforementioned carrier LH, and in addition, three magnetic elements M (e.g. magnets) are arranged on the frame F, the positions of the aforementioned magnetic elements M correspond to the three second coils C2 inside the circuit board FC, and two of the magnetic elements M are located below the aforementioned first coil C1. In the present embodiment, the aforementioned first and second coils C1, C2 and magnetic elements M can constitute a driving assembly, and the first coil C1 can be electrically connected to the metal circuit inside the circuit board FC or the base B through the spring FS and the elastic element W.

[0078] When a current signal is applied to the aforementioned first coil C1, the carrier LH and the optical element disposed inside the carrier LH can be driven to move relative to the frame F and the fixed portion (the base B and the housing H) along the optical axis O direction (Z-axis direction) by the magnetic force generated between the first coil C1 and the magnetic element M, thereby achieving the functions of auto focus (AF) or optical image stabilization (OIS).

[0079] In addition, when a current signal is applied to the aforementioned second coil C2, the frame F, the carrier LH and the optical element disposed inside the carrier LH can be driven to move relative to the fixed portion (the base B and the housing H) along a direction perpendicular to the optical axis O (X-axis or Y-axis direction) by the magnetic force generated between the second coil C2 and the magnetic element M, thereby achieving the function of optical image stabilization (OIS).

[0080] It should be particularly noted that support feet FL are formed at the four corners of the frame F in the embodiment, and a sticking element T and a flat sliding member P are respectively arranged on the bottom side of each support foot FL. The sliding member P can be fixed on the bottom side surface of the support foot FL by the sticking element T (such as double-sided tape), and after the driving mechanism 100 is assembled, three sliding members P will contact the support structure BP at the corners of the base B in a slidable manner, and the other sliding member P' will maintain a gap (as shown in Figure 9 ).

[0081] That is, only three sliding members P will contact the support structure BP at the corners of the base B after the four sliding members P in the embodiment are assembled, thereby allowing the dimensional tolerance between the base B and the sliding member P to be generated.

[0082] For example, the aforementioned sliding member P can contain polyoxymethylene (POM) or other polymer materials, but is not limited to the ones disclosed in the embodiment of the utility model.

[0083] On the other hand, it can be seen from Figure 1 that a magnetic conducting element K is additionally arranged on different sides of the base B. The position of the aforementioned magnetic conducting element K is below the aforementioned magnetic element M, and the circuit board FC is located between the magnetic conducting element K and the magnetic element M. It should be understood that the magnetic attraction force parallel to the optical axis O direction (Z-axis direction) can be generated between the aforementioned magnetic conducting element K and the magnetic element M, so as to enable the aforementioned sliding member P to maintain contact with the support structure BP, thereby greatly improving the stability of the driving mechanism 100 during operation.

[0084] In one embodiment, the aforementioned magnetic conductive element K can also not be provided, and only the elastic element W extending towards the Z-axis direction is used to connect the spring FS and the base B, thereby providing a clamping force between the frame F and the base B, and also maintaining the contact between the sliding member P and the support structure BP, so as to greatly improve the stability of the driving mechanism 100 during operation.

[0085] From Figure 1 and Figure 2 it can be seen that a groove BR is formed at each corner of the aforementioned base B, wherein the aforementioned support structure BP is located at the center of the groove BR, and the aforementioned support structure BP protrudes from the bottom side of the aforementioned groove BR towards the support leg FL.

[0086] On the other hand, from Figure 3 it can be seen that a recess FR and a protrusion FP are formed at the bottom side of each support leg FL of the aforementioned frame F, wherein the aforementioned protrusion FP is located at the center of the recess FR, and the protrusion FP protrudes from the bottom side of the groove BR towards the base B.

[0087] During the assembly of the driving mechanism 100, the sliding member P can be adhered and fixed to the surface of the protrusion FP at the bottom side of the support leg FL by using the adhesive element T, and three of the aforementioned sliding members P are respectively in contact with the support structure BP on the base B. When a current signal is applied to the aforementioned second coil C2, the magnetic force generated between the second coil C2 and the magnetic element M can drive the frame F, the carrier LH and the optical element arranged inside to move relative to the fixed part (the base B and the housing H) along the direction perpendicular to the optical axis O (the X-axis or Y-axis direction), and at this time the sliding member P slides along the surface of the support structure BP of the base B, so as to achieve the function of optical image stabilization (OIS).

[0088] In this embodiment, by arranging the sliding member P at the bottom side of the support leg FL of the frame F and making it in contact with the support structure BP on the base B, not only can the frame F, the carrier LH and the optical element arranged inside be effectively supported in the direction of the optical axis O (Z-axis direction), but also the collision of the frame F, the carrier LH and the optical element arranged inside to the circuit board FC and the base B below due to external force can be effectively prevented.

[0089] On the other hand, when the frame F, the carrier LH and the optical element arranged inside move along the horizontal direction (X-axis or Y-axis direction), the sliding member P is in slidable contact with the support structure BP on the base B, which can more accurately guide the stability of the frame F, the carrier LH and the optical element arranged inside when moving along the horizontal direction, so as to greatly improve the positioning accuracy and stability of the entire driving mechanism 100.

[0090] Then please refer to Figure 6 andFigure 7 ,in Figure 6 Indicates along Figure 4 A sectional view of line segment X1-X2 in the diagram. Figure 7 express Figure 6 A magnified view of region A1 in the image.

[0091] like Figure 7 As shown, located Figure 6 A recess FR is formed on the bottom side of the support leg FL of the frame F in the right region A1, and a protrusion FP protruding towards the base B is formed in the center of the recess FR, wherein the aforementioned protrusion FP protrudes slightly beyond the bottom surface FL1 of the support leg FL; correspondingly, a groove BR is formed on the aforementioned base B, and a support structure BP protruding towards the support leg FL is provided in the center of the groove BR, wherein the sliding member P can be glued and fixed below the aforementioned protrusion FP by the connecting element T.

[0092] In this embodiment, the aforementioned base B contains plastic material, while the aforementioned support structure BP contains metal material. The aforementioned support structure BP can be integrated into the base B by insert molding to contact the sliding member P, thereby providing sufficient support for the frame F and significantly improving the stability and reliability of the drive mechanism 100.

[0093] It should be noted that in this embodiment, both the slider P and the support structure BP have a disc-shaped structure, and the width of the slider P in the horizontal direction (X-axis or Y-axis direction) (approximately 0.75 to 1 mm) is smaller than the width of the support structure BP in the horizontal direction (X-axis or Y-axis direction) (approximately 1.5 mm), so as to facilitate the slider P to slide on the surface of the support structure BP; in addition, the hardness of the slider P is less than the hardness of the support structure BP, so as to avoid the generation of debris due to friction during the sliding process of the slider P and the support structure BP, thereby preventing damage to the internal components of the drive mechanism 100 and improving its service life.

[0094] In one embodiment, the aforementioned support structure BP may also be made of the same material as the base B (e.g., an integrally molded plastic material), and the hardness of the sliding member P is less than that of the support structure BP. However, the aforementioned support structure BP and base B may still be adjusted according to design requirements and are not limited to those disclosed in the embodiments of this utility model.

[0095] On the other hand, by Figure 7As can be seen, the recess FR on the bottom side of the support leg FL of the frame F has a width d in the horizontal direction (Y-axis direction), while the groove BR on the base B has a width D in the horizontal direction (Y-axis direction), wherein the aforementioned width D is greater than the width d; in addition, there is a distance g between the bottom surface FL1 of the aforementioned support leg FL and the upper surface B1 of the aforementioned base B, wherein the aforementioned distance g is approximately 0.1 mm, however, the aforementioned distance g can still be adjusted according to the design requirements of the mechanism, and is not limited to the embodiments disclosed in this utility model.

[0096] During the assembly of the aforementioned drive mechanism 100, lubricating oil can be applied between the base B and the support leg FL of the frame F. At this time, the lubricating oil will penetrate into the contact surface between the sliding member P and the support structure BP, thereby significantly reducing the friction between the sliding member P and the support structure BP during sliding. In addition, the aforementioned lubricating oil can further flow into and be stored in the recess FR on the bottom side of the support leg FL and the groove BR on the surface of the base B. This not only prevents the lubricating oil from overflowing to other areas, but also ensures that the sliding member P and the support structure BP can maintain lubrication for a long time and reduce wear, thereby improving the performance of the drive mechanism 100 and significantly increasing its service life.

[0097] Please see again Figure 8 ,in Figure 8 This is a magnified view showing the contact between the sliding member P and the supporting structure BP.

[0098] like Figure 8 As shown, in this embodiment, the recess FR, the slider P, the groove BR, and the support structure BP all have a circular structure. The support structure BP protrudes from the bottom side of the groove BR toward the slider P, and the width of the slider P in the horizontal direction is smaller than the width of the support structure BP in the horizontal direction.

[0099] Please refer to the following: Figure 9 ,in Figure 9 express Figure 6 A magnified view of region A2 in the image.

[0100] from Figure 9 As can be seen from this, located Figure 6 A recess FR is formed on the bottom side of the support leg FL of the frame F in the left region A2, and a protrusion FP protruding towards the base B is formed in the center of the recess FR, wherein the aforementioned protrusion FP protrudes slightly beyond the bottom surface FL1 of the support leg FL; correspondingly, a groove BR is formed on the aforementioned base B, and a support structure BP' protruding towards the support leg FL is provided in the center of the groove BR, wherein the sliding member P' can be glued and fixed to the aforementioned protrusion FP by the bonding element T.

[0101] Figure 9 The sliding member P' and the supporting structure BP' shown are...Figure 7 The main difference between the sliding member P and the support structure BP shown in the figure is that: Figure 9 The sliding member P' and the support structure BP' in the figure are not in contact with each other, wherein the height of the support structure BP' is slightly lower than the upper surface B1 of the base B, and a gap is formed between the sliding member P' and the support structure BP'.

[0102] It should be noted that, Figure 9 The sliding member P' in the figure mainly serves as an auxiliary support, and it can prevent the frame F from overturning and generating an excessive inclination angle relative to the base B. In this embodiment, a smooth curved surface PS is formed on the bottom side of the sliding member P', and a gap is formed between the curved surface PS and the support structure BP'; in this way, when the frame F is inclined relative to the base B and causes the sliding member P' to contact the support structure BP', the edge of the sliding member P' and the support structure BP' can be effectively prevented from being damaged due to contact collision.

[0103] As mentioned above, in this embodiment, only three sliding members P will be in contact with the support structures BP at the corners of the base B after assembly, and a gap will be formed between one sliding member P' and the corresponding support structure BP'. Figure 9 In this way, the base B can provide sufficient support to the frame F through three-point contact, while avoiding assembly problems between the base B and the sliding member P due to dimensional tolerance, thereby greatly improving the stability and reliability of the driving mechanism 100.

[0104] Since the sliding member and the base of the present application are in contact, the overall height of the driving mechanism can be greatly reduced, thereby helping to achieve the miniaturization of the driving mechanism. In addition, compared with the technical solution of generally setting a ball between the frame and the base, since the contact area between the sliding member and the base of the present application is larger, the stability of the two during sliding can be ensured, and the problem of generating debris or causing structural damage due to small contact area when using a ball can be avoided.

[0105] 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, manufacturing, material compositions, 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, manufacturing, material compositions, 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, manufacturing, material compositions, 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.

[0106] 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 driving mechanism for driving the movement of an optical element, characterized in that, The optical element has an optical axis, and the driving mechanism includes: A fixing part includes a housing and a base that are interconnected; A movable part is movably connected to the fixed part and includes a frame, wherein the optical element is disposed on the movable part; A flat slider is disposed on the frame and is slidable relative to the base; and A drive assembly is used to drive the moving part to move relative to the fixed part.

2. The driving mechanism as described in claim 1, characterized in that, The slider is made of plastic steel.

3. The driving mechanism as described in claim 1, characterized in that, The slider has a disc-shaped structure.

4. The driving mechanism as described in claim 1, characterized in that, The drive mechanism also includes a spring and a plurality of elongated elastic elements, and the movable part also includes a support member disposed inside the frame, wherein the spring connects the support member and the frame, and the plurality of elastic elements connect the spring and the base along the optical axis.

5. The driving mechanism as described in claim 4, characterized in that, The drive mechanism also includes a magnetic element disposed on the base, and the drive assembly includes a magnetic element and a first coil, wherein the first coil is disposed on the support member, the magnetic element is disposed on the frame, and the magnetic element is located below the magnetic element, wherein the magnetic element and the magnetic element generate a magnetic attraction, thereby keeping the slider in contact with the base.

6. The driving mechanism as described in claim 5, characterized in that, The drive mechanism also includes a circuit board disposed on the base, and the drive assembly further includes a second coil disposed within the circuit board and corresponding to the magnetic element, wherein the circuit board is located between the magnetic element and the magnetic element.

7. The driving mechanism as described in claim 1, characterized in that, The plurality of said frames have a recess and a protrusion, the protrusion being located in the center of the recess, and the slider being fixed to the protrusion.

8. The driving mechanism as described in claim 7, characterized in that, The frame has a support leg, the recess and the protrusion are formed on the support leg, and the protrusion protrudes from the bottom surface of the support leg.

9. The driving mechanism as described in claim 7, characterized in that, The drive mechanism also includes a bonding element that attaches the slider and the frame.

10. The driving mechanism as described in claim 7, characterized in that, The drive mechanism also includes a lubricating oil contained within the recess.

11. The driving mechanism as described in claim 7, characterized in that, The drive mechanism also includes a support structure, and the base is formed with a groove, wherein the support structure is located in the center of the groove, and the slider contacts the support structure in a slidable manner.

12. The driving mechanism as described in claim 11, characterized in that, The hardness of the sliding component is less than that of the supporting structure.

13. The driving mechanism as described in claim 11, characterized in that, The width of the slider is smaller than the width of the support structure.

14. The driving mechanism as described in claim 11, characterized in that, The width of the recess is smaller than the width of the groove.

15. The driving mechanism as described in claim 11, characterized in that, The support structure is made of metal.

16. The driving mechanism as described in claim 1, characterized in that, The drive mechanism includes four flat sliders, the frame has four support feet, and the four sliders are respectively fixed to the four support feet.

17. The driving mechanism as described in claim 16, characterized in that, A gap is formed between one of the four sliding members and the base.

18. The drive mechanism as described in claim 17, characterized in that, The drive mechanism also includes a support structure, and the base has a groove, wherein the support structure is located in the center of the groove and protrudes toward the frame, and the support structure is lower than an upper surface of the base.

19. The driving mechanism as described in claim 16, characterized in that, One of the four sliders has a curved surface facing the base, and a gap is formed between the curved surface and the base.

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