An auto-focusing structure and an image pickup apparatus thereof

Abstract

The application relates to the field of camera technology, in particular to an automatic focusing structure and a camera device thereof, the automatic focusing structure comprising a lens seat, a ball seat, a sliding assembly, a magnetic guide assembly, a driving coil, a position sensor and a driving magnet, the lens seat being provided with an inner connecting plate; the ball seat is slidably arranged in the lens seat; the ball seat is provided with an outer connecting plate corresponding to the inner connecting wall; the sliding assembly is arranged between the inner connecting plate and the outer connecting plate; the magnetic guide assembly is arranged on the outer connecting plate; the driving coil is arranged on the outer connecting plate; the position sensor is arranged on the outer connecting plate; and the driving magnet is arranged on the inner connecting plate. The application has the advantages of compact structure, avoidance of mutual influence of different types of magnets and realization of a small-size automatic focusing structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of camera technology, in particular to an automatic focusing structure and a camera device thereof. BACKGROUND

[0002] The conventional ball motor adopts multiple balls. When the balls and the ball grooves have size errors or are worn due to friction, the lens optical axis is prone to tilt. Some automatic focusing ball motors adopt balls of different sizes. Only three to four balls are in close contact with the ball grooves during automatic ball movement, reducing the problem of the lens optical axis being prone to tilt. However, the use of balls of different sizes causes production difficulties, leading to an increase in production costs. On the other hand, due to the inconsistent normal force of the large balls in close contact with the ball grooves, the wear degree of the ball grooves caused by friction of the large balls is different, causing the lens optical axis to be prone to tilt after a long time of movement. SUMMARY

[0003] The purpose of the present application is to provide a structure that can achieve fast and accurate focusing, is compact, and can effectively reduce the problem of optical axis tilt and deviation caused by wear after multiple automatic focusing movements.

[0004] In order to achieve the above-mentioned purpose, the present application provides an automatic focusing structure, comprising:

[0005] a housing;

[0006] a lens seat mounted inside the housing, the lens seat having an external plate;

[0007] a coil seat mounted inside the housing, and the coil seat being provided with an internal plate corresponding to the external plate;

[0008] a drive coil mounted on the internal plate;

[0009] a drive magnet mounted on the external plate;

[0010] a sliding assembly provided between the internal plate and the external plate; the sliding assembly includes three balls, the three balls forming a triangular face, the triangular face having a first baseline; the first baseline connects two balls closest to each other among the three balls;

[0011] a magnetic guide assembly mounted on the internal plate; a magnetic attraction force is generated between the magnetic guide assembly and the drive magnet; the intersection of the magnetic attraction force and the triangular face is provided with a magnetic attraction force point; the magnetic attraction force point satisfies: e≤f×45%; wherein e is the minimum distance from the magnetic attraction force point to the first baseline, and f is the center of the ball farthest from the first baseline among the three balls;

[0012] A position sensor is mounted on the inner adapter plate.

[0013] Preferably, the outer adapter plate is provided with a first ball groove, a second ball groove and a third ball groove, the first ball groove and the second ball groove are arranged along the optical axis; the inner adapter plate is provided with a first sliding groove and a second sliding groove, the first sliding groove is arranged corresponding to the first ball groove and the second ball groove, and the second sliding groove is arranged corresponding to the third ball groove; the balls include a first ball, a second ball and a third ball; the first ball is mounted between the first ball groove and the first sliding groove; the second ball is mounted between the second ball groove and the first sliding groove; and the third ball is mounted between the third ball groove and the second sliding groove.

[0014] Preferably, the centers of the first ball, the second ball and the third ball are connected to form a triangular plane, and the first base line connects the centers of the first ball and the second ball.

[0015] Preferably, the horizontal cross sections of the first ball groove, the second ball groove, the third ball groove and the first sliding groove are V-shaped structures; and the horizontal cross section of the second sliding groove is a plane structure.

[0016] Preferably, the outer adapter plate is provided with a first ball groove and a second ball groove, the first ball groove extends along the optical axis direction, and the balls include a first ball, a second ball, a third ball and a fourth ball, the first ball, the second ball and the third ball are arranged corresponding to the first ball groove, and the fourth ball is arranged corresponding to the second ball groove.

[0017] Preferably, the second ball groove is provided with a clearance groove, and the clearance groove is arranged corresponding to the second ball.

[0018] Preferably, the shell includes a top shell and a bottom cover, the top shell is spliced with the bottom cover, and the bottom cover is provided with a dust ring.

[0019] Preferably, the lens seat is internally provided with a magnetic guide structure, and the magnetic guide structure is arranged corresponding to the driving magnet.

[0020] Preferably, the shell is made of a magnetic material.

[0021] The application also provides a camera device comprising the automatic focusing structure according to any one of the above.

[0022] The embodiments of the application have the following technical effects:

[0023] The automatic focusing structure of the present application sets a lens seat, the lens seat can move relative to the shell, and then drives the lens to move to realize focusing, wherein the lens seat and the coil seat are connected through balls, the magnetic conducting assembly is set on the coil seat, the size of the automatic focusing structure of the present application can be effectively reduced, and the magnetic attraction point of the magnetic conducting assembly passes through the triangular surface, and the distance to the first base line satisfies e≤f×45%, therefore, the positive force received by the three balls is relatively uniform, and a certain ball cannot be excessively worn to cause serious inclination or deviation. In addition, the automatic focusing structure of the present application supports the ball design, and the spring force does not need to be overcome by wasting current when fixing the lens, so that the effect of saving electricity can be achieved. BRIEF DESCRIPTION OF DRAWINGS

[0024] The present application is described in more detail below with the help of the drawings. The technical features shown in the drawings and / or described below are generally technical features of the present application and improve the present application accordingly, without depending on a particular combination of technical features.

[0025] It should be noted that the same reference numerals in different drawings represent the same or approximately the same components.

[0026] Figure 1 is a structural schematic view of the automatic focusing structure of the preferred embodiment of the present application;

[0027] Figure 2 is an exploded view of Figure 1 ;

[0028] Figure 3 is a front view of the lens seat of the preferred embodiment of the present application;

[0029] Figure 4 is a top view of the automatic focusing structure of the preferred embodiment of the present application;

[0030] Figure 5 is an A-A sectional view of Figure 4 ;

[0031] Figure 6 is a C-C sectional view of Figure 4 ;

[0032] Figure 7 is a horizontal sectional view of the first ball groove of the preferred embodiment of the present application;

[0033] Figure 8 is a structural schematic view of the magnetic conducting assembly of the preferred embodiment of the present application;

[0034] Figure 9 is another structural schematic view of the automatic focusing structure of the preferred embodiment of the present application;

[0035] Figure 10 is Figure 9exploded view;

[0036] Figure 11 is another front view of the lens holder of the preferred embodiment of the present application;

[0037] Figure 12 is a vertical sectional view of the auto-focusing structure of the preferred embodiment of the present application.

[0038] Explanation of Reference Numerals:

[0039] 1, lens holder; 1b, first ball groove; 1c, second ball groove; 1d, third ball groove; 1e, clearance groove;

[0040] 2, coil holder; 2b, first sliding groove; 2c, second sliding groove;

[0041] 3, sliding assembly; 3a, first ball; 3b, second ball; 3c, third ball; 3d, fourth ball;

[0042] 4, magnetic guiding assembly; 4a, magnetic attraction point;

[0043] 5, driving coil; 6, position sensor; 7, driving magnet;

[0044] 8, triangular surface; 8a, first base line;

[0045] 9, housing; 9a, top cover; 9b, bottom cover;

[0046] 10, dustproof ring. DETAILED DESCRIPTION

[0047] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application.

[0048] The definitions of front, back, inner, outer, top and bottom are only used to conveniently describe the positional relationship or connection relationship between the components of the auto-focusing structure of the embodiments of the present application, and do not limit the embodiments of the present application.

[0049] It should be further noted that, for the same components in the embodiments of the present application, only one component or part may be labeled with a reference numeral in the drawings, and it should be understood that the reference numeral is also applicable to other same components or parts.

[0050] Meanwhile, the term "comprising" does not exclude other elements or steps, and "one" or "an" does not exclude a plurality.

[0051] It should also be noted that any single technical feature described or implied in the embodiments herein, or any single technical feature shown or implied in the drawings, can still be combined with other technical features (or their equivalents) to obtain other embodiments of the application not directly mentioned herein.

[0052] In addition, it should also be understood that the terms "first", "second" and the like are used herein to describe various information, but these information should not be limited to these terms, and these terms are only used to distinguish the same type of information from each other. For example, the "first" information can also be referred to as "second" information, and similarly, the "second" information can also be referred to as "first" information without departing from the scope of the application.

[0053] Referring to Figures 1-8 As shown in the drawings, the preferred embodiment of the application provides an automatic focusing structure, which comprises a shell 9, a lens seat 1, a coil seat 2, a sliding assembly 3, a magnetic guide assembly 4, a driving coil 5, a position sensor 6 and a driving magnet 7; the lens seat 1 is installed inside the shell 9, and the lens seat 1 has an external plate; the coil seat 2 is installed inside the shell 9, and the coil seat 2 is provided with an internal plate corresponding to the external plate; the sliding assembly 3 is arranged between the internal plate and the external plate; the sliding assembly 3 comprises three balls closely attached to the external plate and the internal plate, and the three balls form a triangular surface 8, and the triangular surface 8 has a first baseline 8a; the first baseline 8a connects two balls closest to each other among the three balls; the magnetic guide assembly 4 is installed on the internal plate; a magnetic attraction force is generated between the magnetic guide assembly 4 and the driving magnet 7; the magnetic attraction force and the intersection of the triangular surface are provided with a magnetic attraction point 4a, and the magnetic attraction point 4a is located on the triangular surface 8; the magnetic attraction point 4a satisfies: e≤f×45%; wherein e is the minimum distance from the magnetic attraction point 4a to the first baseline 8a, and f is the minimum distance from the first baseline 8a to the center of the ball farthest from the first baseline among the three balls; the driving coil 5 is installed on the internal plate; the position sensor 6 is installed on the internal plate; and the driving magnet 7 is installed on the external plate.

[0054] The use principle of the automatic focusing structure is that by changing the current of the driving coil 5, the electromagnetic force of the driving coil 5 and its direction can be changed, the lens seat 1 is driven to move along an axis of the lens optical axis, the distance between the image sensor and the lens located below the focusing structure is changed, and the automatic focusing effect is achieved.

[0055] By reading the output signal of the position sensor 6, the axial displacement of the position sensor 6 and the lens seat 1 can be calculated; according to the displacement and the change of the current of the driving coil 5, closed-loop control can be realized, faster focusing speed can be achieved, and the problem of resonance affecting image clarity can be avoided.

[0056] In some preferred embodiments of the present application, the driving magnet 7 is single-sided bipolar magnetized, the upper surface of the driving magnet 7 is the north pole, and the lower surface of the driving magnet 7 is the south pole. Therefore, the electromagnetic force of the driving coil 5 is approximately parallel to the optical axis.

[0057] In some preferred embodiments of the present application, the outer plate is provided with a first ball groove 1b, a second ball groove 1c, and a third ball groove 1d, and the first ball groove 1b and the second ball groove 1c are arranged along the optical axis; the inner plate is provided with a first sliding groove 2b and a second sliding groove 2c, the first sliding groove 2b is arranged corresponding to the first ball groove 1b and the second ball groove 1c, and the second sliding groove 2c is arranged corresponding to the third ball groove 1d; the balls include a first ball 3a, a second ball 3b, and a third ball 3c; the first ball 3a is installed between the first ball groove 1b and the first sliding groove 2b; the second ball 3b is installed between the second ball groove 1c and the first sliding groove 2b; and the third ball 3c is installed between the third ball groove 1d and the second sliding groove 2c.

[0058] In some preferred embodiments of the present application, the centers of the first ball 3a, the second ball 3b, and the third ball 3c are connected to form a triangular surface 8, and a first baseline 8a connects the centers of the first ball 3a and the second ball 3b; the first ball 3a and the second ball 3b are the two closest balls among the three balls; the third ball 3c is the ball farthest from the first baseline; and the magnetic attraction point 4a satisfies e≤f×45%; wherein e is the minimum distance from the magnetic attraction point 4a to the first baseline 8a, and f is the minimum distance from the first baseline 8a to the center of the third ball 3c.

[0059] In some preferred embodiments of the present application, the horizontal cross-sections of the first ball groove 1b, the second ball groove 1c, the third ball groove 1d, and the first sliding groove 2b are V-shaped structures; and the horizontal cross-section of the second sliding groove 2c is a flat structure. In this way, the first ball groove 1b, the second ball groove 1c, the third ball groove 1d, and the first sliding groove 2b are designed in a V shape, each V-shaped groove is tightly connected to two surfaces of a ball; the second sliding groove 2c is designed in a flat shape and is tightly connected to only one surface of the third ball 3c. Since the first ball 3a and the second ball 3b are tightly connected to the four V-shaped grooves, the movement of the lens seat 1 relative to the shell 9 in the Rx, Ry, x, and y directions can be effectively limited; since the third ball 3c is tightly connected to the flat second sliding groove 2c and the V-shaped third ball groove 1d, the movement of the lens seat 1 relative to the shell 9 in the y direction can be effectively limited; therefore, the movement of the lens seat 1 in the Rx, Ry, Rz, x, and y directions can be effectively limited, and only the degree of freedom in the z direction is provided. The z direction is approximately parallel to the optical axis of the lens.

[0060] Referring to Figures 9-12As shown, in some preferred embodiments of the present application, the outer plate is provided with a first ball groove 1b and a second ball groove 1c, the first ball groove 1b extends along the optical axis direction, and the balls include a first ball 3a, a second ball 3b, a third ball 3c and a fourth ball 3d, the first ball 3a, the second ball 3b and the third ball 3c are arranged correspondingly to the first ball groove 1b, and the fourth ball 3d is arranged correspondingly to the second ball groove 1c.

[0061] In some preferred embodiments of the present application, the first ball groove 1b is provided with a clearance groove 1e, and the clearance groove 1e is arranged correspondingly to the second ball 3b.

[0062] In some preferred embodiments of the present application, the shell 9 includes a top shell 9a and a bottom cover 9b, the top shell 9a is spliced with the bottom cover 9b, and the bottom cover 9b is provided with a dust ring 10. The dust ring 10 can reduce the risk of dust falling on the image sensor below the lens.

[0063] In some preferred embodiments of the present application, the inside of the lens seat 1 is provided with a magnetic guide structure, and the magnetic guide structure is arranged correspondingly to the driving magnet 7. The magnetic guide structure can strengthen the magnetic field strength of the driving coil 5, and reduce the power consumption. In addition, the magnetic guide structure and the driving magnet 7 generate magnetic attraction force, which facilitates the assembly of the magnet and reduces the risk of the magnet falling off when falling.

[0064] In some preferred embodiments of the present application, the shell 9 is made of a magnetic material. The shell 9 can reduce the magnetic interference of external magnets on the magnet and the position sensor 6, and reduce the influence on the auto-focusing closed-loop control.

[0065] In some preferred embodiments of the present application, the magnetic guide assembly 4 is made of a conductive material and is provided with two terminals, the two terminals are electrically connected with the driving coil 5; the coil seat 2 and the magnetic guide assembly 4 can support automatic winding of the coil on the two terminals, and the coil and the terminals are electrically connected through an automatic soldering process, thereby improving the production efficiency and reliability.

[0066] In some preferred embodiments of the present application, the terminal and the optical axis are not parallel, and the included angle is more than 5°. This design can support automatic winding and improve the design flexibility of the magnetic guide assembly 4 and the coil seat 2, and reduce the size of the automatic focusing ball voice coil motor in the present application.

[0067] In some preferred embodiments of the present application, a driving chip including the position sensor 6 can be used.

[0068] The preferred embodiments of the present application also provide a camera device including the automatic focusing structure according to any one of the above.

[0069] Finally, it should be noted that the above-described embodiments are merely specific embodiments of the present application, which are used to illustrate the technical solutions of the present application, but not to limit the same. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that any person skilled in the art can make modifications or easily think of changes to the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some of the technical features within the technical scope disclosed by the present application. The modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An autofocus structure, characterized in that, include: shell; Lens mount, the lens mount being installed inside the housing, the lens mount having an external plate; A coil holder is installed inside the housing, and the coil holder is provided with an inner plate corresponding to the outer plate; A driving magnet, the driving magnet being mounted on the outer plate; A drive coil, which is mounted on the inner plate; A sliding assembly is disposed between the inner plate and the outer plate; the sliding assembly includes three balls that are in close contact with the outer plate and the inner plate, the three balls forming a triangular surface, the triangular surface having a first baseline, the first baseline connecting the two balls that are closest to each other among the three balls; A magnetic guide assembly is mounted on the inner plate; a magnetic attraction force is generated between the magnetic guide assembly and the driving magnet; a magnetic attraction point is provided at the intersection of the magnetic attraction force and the triangular surface; the magnetic attraction point satisfies: e ≤ f×45%; where e is the minimum distance from the magnetic attraction point to the first baseline, and f is the minimum distance from the first baseline to the center of the ball furthest from the first baseline among the three balls; A position sensor, which is mounted on the inner board; The outer plate has a first bead groove, a second bead groove, and a third bead groove, with the first and second bead grooves spaced apart along the optical axis; the inner plate has a first sliding groove and a second sliding groove, with the first sliding groove corresponding to the first and second bead grooves, and the second sliding groove corresponding to the third bead groove; the ball includes a first ball, a second ball, and a third ball; the first ball is installed between the first bead groove and the first sliding groove; the second ball is installed between the second bead groove and the first sliding groove; and the third ball is installed between the third bead groove and the second sliding groove. The centers of the first ball, the second ball, and the third ball are connected to form a triangular surface, and the first baseline connects the centers of the first ball and the second ball, respectively. The first bead groove, the second bead groove, the third bead groove, and the first sliding groove have a V-shaped horizontal cross-section; the second sliding groove has a planar horizontal cross-section. The second ball groove is provided with a clearance groove, which is correspondingly provided with the second ball.

2. The autofocus structure according to claim 1, characterized in that, The outer plate is provided with a first ball groove and a second ball groove. The first ball groove extends along the optical axis. The ball includes a first ball, a second ball, a third ball, and a fourth ball. The first ball, the second ball, and the third ball are correspondingly arranged with the first ball groove, and the fourth ball is correspondingly arranged with the second ball groove.

3. The autofocus structure according to claim 1, characterized in that, The outer casing includes a top shell and a bottom cover, the top shell and the bottom cover are joined together, and the bottom cover is provided with a dustproof ring.

4. The autofocus structure according to claim 1, characterized in that, The lens mount has a magnetically conductive structure inside, which is correspondingly arranged with the driving magnet.

5. The autofocus structure according to claim 1, characterized in that, The outer shell is made of a magnetically conductive material.

6. A camera device, characterized in that, Includes the autofocus structure as described in any one of claims 1-5.

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