TWI676854B - Leaf spring type eccentric lens driving device - Google Patents

Abstract

A lens holder of a shrapnel type eccentric lens driving device is formed with a through hole for loading a lens. The central axis of the through hole coincides with the optical axis of the lens and is parallel to the physical central axis of the housing in the direction of the optical axis of the lens. The shell is defined. The direction of the physical axis of the body in the direction of the optical axis and the center axis of the through hole is an eccentric direction. The leaf spring of the shrapnel-type eccentric lens driving device is symmetrical about the first symmetrical axis and the second symmetrical axis that are perpendicular to each other, and the first symmetrical axis coincides with the eccentric direction, and the second symmetrical axis does not intersect the central axis of the through hole. . In this way, the shape of the leaf spring is easier to design and assemble, and the weight balance of the movable part of the lens driving device is easier to control, and it is not easy to twist during the lens driving process.

Description

Shrapnel type eccentric lens driving device

The invention relates to a lens driving device for driving a lens to realize automatic focusing, and in particular to a spring-type decentered lens driving device.

Currently, the proportion of screens of portable electronic devices equipped with camera modules is increasing, and the space available for camera module installation is becoming smaller and smaller. In particular, the application of curved screens further compresses the installation space of the camera module, and requires the lens center (optical axis) to be more inclined to the screen side (eccentricity) than the physical center of the camera module in order to achieve good driving. In the lens driving device with an eccentric structure, the installation space of the leaf spring near one side of the optical axis of the lens is reduced, so that the structural design of the leaf spring is difficult to meet the driving requirements and the design is difficult. Even if the design meets the requirements, the center of the lens holder is inconsistent with the physical center due to the eccentric design of the lens holder. During the driving process, the center-symmetric leaf spring is liable to slightly twist, resulting in unbalanced weight of the movable part and tilt, which affects the focus.

In view of this, our inventors are concentrating on further research and proceeding with research and development and improvement, with a better design to solve the above problems, and the invention came out after continuous testing and modification.

In view of this, it is necessary to provide a dome type decentered lens driving device capable of focusing well.

A shrapnel-type eccentric lens driving device includes a housing; a lens holder formed with a through hole for loading a lens, a central axis of the through hole coinciding with an optical axis of the lens, and a physical central axis of the housing in a direction of the optical axis of the lens Parallel, defines the direction of the physical center of the housing in the direction of the optical axis and the direction of the central axis of the through hole as an eccentric direction; a leaf spring for supporting the lens holder suspension in the housing; and a lens spring for driving the lens holder along the lens A drive mechanism that moves in the direction of the optical axis to achieve focusing. The leaf spring includes a fixing portion for connecting with the lens holder and the housing, and also includes an elastic arm connected between the fixing portions. The elastic arm is symmetrical about the first symmetry axis and the second symmetry axis that are perpendicular to each other. An axis of symmetry coincides with the eccentric direction, and a second axis of symmetry does not intersect the central axis of the through hole.

Preferably, when viewed from the direction of the optical axis of the lens, the second axis of symmetry passes through the center of gravity of the lens holder and the lens after being combined.

Preferably, in the eccentric direction, the outer surface of the lens holder is directly spaced from the inner surface of the housing, and the driving mechanism is fixed to the outer surfaces of the lens holder on both sides of the eccentric direction so that the thickness of the driving device Does not affect the distance between the lens holder and the housing in the eccentric direction.

As an embodiment, the driving mechanism includes spaced-apart coils and magnets, and the housing is generally a square shell; a physical central axis defining the housing in the optical axis direction is located behind the eccentric direction with respect to the central axis of the through hole. The magnet is fixed at four corners of the housing or only at two corners of the housing located on both sides in front of the eccentric direction, the coil is fixed on the outer surface of the lens holder, and is opposite to the magnet, and The winding direction of the coil is perpendicular to the optical axis of the lens, and the magnet is polarized away in the optical axis direction.

The above-mentioned spring-type eccentric lens driving device is eccentrically assembled between the lens holder and the housing, and the spring uses an axisymmetric plate spring. One of the symmetry axes is consistent with the eccentric direction of the lens holder, and the other does not pass through the center of the lens. The shape of the lens is easier to design and assemble, and the weight balance of the movable part of the lens driving device is easier to control, and it is not easy to twist during the lens driving process.

〔this invention〕

11‧‧‧ rear side mount

13‧‧‧ Front cover

15‧‧‧ the physical center axis of the shell

30‧‧‧ lens holder

31‧‧‧through hole

32‧‧‧ Central axis of through hole

33‧‧‧eccentric

41‧‧‧ leaf spring

43‧‧‧ leaf spring

431‧‧‧-Y side shrapnel

432‧‧‧ + Y side shrapnel

4321‧‧‧Fixed section

4322‧‧‧Fixed section

4323‧‧‧Fixed section

4324‧‧‧Elastic arm

45‧‧‧ first symmetry axis

47‧‧‧ second symmetry axis

50‧‧‧Drive mechanism

51‧‧‧coil

53‧‧‧Magnet

O‧‧‧ lens optical axis direction

X‧‧‧X axis

Y‧‧‧Y axis

FIG. 1 is an exploded view of a dome type eccentric lens driving device in an embodiment.

FIG. 2 is a plan view of the main part of the spring-type decentered lens driving device in FIG. 1. FIG.

Regarding the technical means of our inventors, several preferred embodiments are described in detail below in conjunction with the drawings, for the purpose of understanding and agreeing with the present invention.

The driving mechanism of the shrapnel decentered lens of the present invention will be further described in detail in combination with specific embodiments and drawings.

For the convenience of description, the subject is defined in front of the optical axis direction of the lens. The side of the subject is the front side of the optical axis direction O, and the side far from the subject is the rear side of the optical axis direction. Similarly, the optical axis direction is used as a reference. The relative positional relationship between the front and the back in the dome type eccentric lens driving device is described.

As shown in FIG. 1, in an embodiment, the shrapnel type eccentric lens driving device mainly includes a rear-side fixing frame 11 located rearward in the optical axis direction, a front-side cover 13 located in front of the optical axis direction, and used for holding not shown. Lens holder 30 of the lens, a plate spring for supporting the lens holder suspension in the housing The springs 41 and 43 and a driving mechanism 50 for driving the lens holder 30 to move in the direction of the optical axis of the lens to achieve focusing.

The lower end of the front cover 13 is connected to the rear fixing frame 11, and the two constitute a substantially rectangular shell. Viewed from the direction of the optical axis of the lens, the physical central axis of the housing is labeled 15 in the drawing. Here, the physical central axis is the central axis from the concept of geometry, regardless of quality. The outer shape of the shell is generally a symmetrical structure, and the physical central axis is an axis passing through the symmetrical center of two opposite faces of the shell. In this embodiment, when viewed from the direction of the optical axis of the lens, the housing is square, and the physical central axis 15 of the housing passes through the geometric center of the front cover 13 and the rear fixing frame 11 (the opposite sides of the four sides are at their midpoints. Even the resulting intersection point).

The lens holder 30 is cylindrical and has a circular through hole 31 in the optical axis direction for receiving and loading the lens. In this embodiment, when viewed from the direction of the optical axis, the outer shape of the lens holder 30 is substantially octagonal (that is, substantially, or can be recognized by a person with ordinary knowledge in the technical field to which the present invention pertains according to conventional thinking). The central axis 32 of the through hole 31 coincides with the optical axis O of the lens, and is parallel but not coincident with the physical central axis 15 of the housing in the lens optical axis direction, that is, the lens is eccentrically assembled on the lens holder 30. Here, the direction of the physical central axis 15 of the housing in the direction of the optical axis toward the central axis of the through hole is defined as the eccentric direction 33 (parallel to the X axis in the first figure). The eccentric direction 33 is perpendicular to one of the outer surfaces of the lens holder 30. The outer surface is parallel to and spaced apart from an inner side wall of the housing. Two outer surfaces adjacent to the outer surface are opposite to two corners of the housing, respectively. . In such a configuration, when viewed from the direction of the optical axis, four of the outer surfaces of the lens holder 30 are respectively opposed to the four inner sidewalls of the housing, and the remaining four outer surfaces are respectively oriented toward the four corners of the housing. In addition, in this embodiment, the physical central axis of the lens holder 30 in the optical axis direction is the same as the physical central axis 15 of the housing.

The driving mechanism 50 is used to drive the lens holder 30 to move along the optical axis direction of the lens to achieve focusing. The driving mechanism 50 is fixed to the outer surfaces of the lens holder 30 facing the four corners of the housing (that is, the outer surfaces on both sides of the eccentric direction, rather than the outer surfaces through which the eccentric direction 33 passes) so that the thickness of the driving device does not change. The distance between the lens holder 30 and the housing in the eccentric direction 33 is affected. In the eccentric direction 33, the outer surface of the lens holder 30 and the inner surface of the housing are directly opposed to each other.

In this embodiment, the driving mechanism 50 includes four sets of coils 51 and four sets of magnets 53 opposed to each other in space. The coil 51 is fixed on the outer surface of the lens holder, and the magnets 53 opposed to it are fixed at the four corners of the housing. The winding direction of the coil 51 is perpendicular to the optical axis of the lens, and the magnets are polarized away in the optical axis direction. In this way, when the coil 51 is energized, the Lorentz force generated in the magnetic field of the magnet will drive the lens holder 30 in the direction of the optical axis.

In other embodiments, the driving mechanism may include only two sets of coils and two sets of magnets. For the convenience of description, the physical central axis 15 of the housing in the optical axis direction is defined behind the eccentric direction 33 of the through-hole central axis 32, then these two sets of coils and two sets of magnets can be respectively fixed in the housing in front of the eccentric direction 33 (Or rear) at two corners on either side.

In other embodiments, the driving mechanism may be replaced by a piezoelectric device or a shape memory alloy device.

As described above, the leaf springs 41 and 43 are used to support the lens holder 30 in the housing. In particular, the leaf springs 41 and 43 each include a fixing portion for connecting with the lens holder 30 and the housing, and also include an elastic arm connected between the fixing portions, wherein the elastic arms are aligned with the first symmetrical axis 45 (parallel to each other) (On the X axis) and the second symmetry axis 47 (parallel to the Y axis) are axisymmetric, and when viewed from the direction of the lens optical axis, the first symmetry axis 45 coincides with the eccentric direction 33, and the second symmetry axis 47 and the central axis of the through hole 32 does not intersect, but passes through the center of gravity of the lens holder 30 and the lens combination (also the physical central axis 15 in this embodiment). So leaf spring The shape of the lens is easier to design and assemble, and the weight balance of the movable part of the lens driving device is easier to control, and it is not easy to twist during the lens driving process.

Specifically, the leaf spring 41 is connected to a position where the front end surface of the lens holder 30 and the inner side of the front side cover 13 are upward, and the leaf spring 43 is connected between the rear end surface of the lens holder 30 and the rear fixing frame. The leaf spring 43 includes a -Y side spring piece 431 and a + Y side spring piece 432 with the eccentric direction 33 as a symmetry axis (mirror axis), and both the -Y side spring piece 431 and the + Y side spring piece 432 are symmetrical about the second symmetry axis 47 (mirror image symmetry). Here, the + Y side elastic piece 432 is described as an example. The + Y side elastic piece 432 includes a fixing portion 4321, 4322, 4323, and an elastic arm 4324. Among them, the fixing portions 4321 and 4322 are generally L-shaped, and the longer side is fixed to the casing (for the + Y-side elastic piece 432, it is fixed to the rear fixing frame 11), which is parallel to one side wall of the casing. Both ends of the elastic arm 4324 are integrally connected to the ends of the shorter sides of the fixing portions 4321 and 4322. The elastic arm 4324 can have at least two bends and turns to have a preset elastic deformation and recovery capability, and most of it should be suspended between the lens holder 30 and the housing, and the lens holder 30 is suspended in the housing. The fixing portion 4323 extends integrally from the side of the elastic arm 4324 facing the optical axis, and is used for fixed connection with the lens holder 30.

The leaf spring 43 needs to be used as the conductive path of the coil 51, so it needs to be made of conductive metal, and it needs to be cut into two parts that are independent of each other. The leaf spring 41 may not be limited to a conductive metal material, and may be formed in a single piece. In this embodiment, the difference between the leaf spring 41 and the leaf spring 43 is that the leaf spring 41 is an integrated leaf spring. The free ends of the fixing portion 4321 of the -Y side elastic piece 431 and the + Y side elastic piece 432 are integrally connected, and the free ends of the fixing portion 4322 are integrally connected to form a plate spring 41, which is not described herein again.

In this embodiment, the leaf springs 41 and 43 are all based on the first symmetry axis 45 and the second symmetry axis 47. Since the key part of its elastic support is the elastic arm, in other embodiments, the shape of the fixed portion of the leaf spring can be adjusted according to the actual situation, as long as the elastic arm has a first symmetrical axis 45 and a second symmetrical axis 47 which are perpendicular to each other. Symmetry is fine.

In other embodiments, when viewed from the direction of the optical axis of the lens, the second symmetry axis 47 does not intersect the central axis 32 of the through hole, and may be closer to the back or front of the eccentric direction than the center of gravity of the lens holder 30 and the lens combination.

In summary, the technical means disclosed in the present invention can effectively solve problems such as knowledge, and achieve the intended purpose and effect. It has not been published in publications before application, has not been publicly used, and has long-term progress. The invention referred to in the Patent Law is correct, and he filed an application in accordance with the law. He earnestly hopes that Jun will give him a detailed review and grant a patent for the invention.

However, the above are only a few preferred embodiments of the present invention. When the scope of implementation of the present invention cannot be limited in this way, that is, equivalent changes and modifications made according to the scope of the patent application and the content of the invention specification of the present invention are all It should still fall within the scope of the invention patent.

Claims (4)

A shrapnel-type eccentric lens driving device includes: a housing; a lens holder formed with a through hole for loading a lens, a central axis of the through hole coinciding with an optical axis of the lens, and a physical center of the housing in a direction of the optical axis of the lens The axes are parallel, defining the physical center of the housing in the direction of the optical axis and the direction of the central axis of the through-hole is an eccentric direction; a leaf spring for supporting the lens holder suspension in the housing; and for driving the lens holder along the lens A driving mechanism that moves in the direction of the optical axis to achieve focusing; the improvement is that the leaf spring includes a fixing portion for connecting with the lens holder and the housing, and also includes an elastic arm connected between the fixing portions, and the elastic arms are connected to each other The vertical first symmetry axis and the second symmetry axis are axially symmetric, and the first symmetry axis coincides with the eccentric direction, and the second symmetry axis does not intersect the central axis of the through hole. According to the bullet-type eccentric lens driving device described in item 1 of the patent application scope, wherein the second axis of symmetry passes through the center of gravity of the lens holder and the lens when viewed from the direction of the optical axis of the lens. According to the bullet-type eccentric lens driving device described in item 2 of the patent application scope, in the eccentric direction, the outer surface of the lens holder is directly spaced from the inner surface of the housing, and the driving mechanism is fixed to the lens holder at The two sides of the eccentric direction are on the outer surface so that the thickness of the driving device does not affect the distance between the lens holder and the housing in the eccentric direction. As described in item 2 of the patent application scope, the shrapnel type eccentric lens driving device, wherein the driving mechanism includes spaced-apart coils and magnets, and the housing is generally a square shell; defines the housing in the direction of the optical axis. The physical central axis is located behind the eccentric direction with respect to the central axis of the through hole. The magnet is fixed at the four corners of the housing or only at the two corners of the housing at the two sides in front of the eccentric direction. The coil is fixed to the lens holder. On the outer surface, the magnet is opposed to the magnet, the winding direction of the coil is perpendicular to the optical axis of the lens, and the magnet is polarized away in the optical axis direction.