KR102636721B1 - Motor for actuating lens - Google Patents

Abstract

The embodiment includes a lens unit in which one or more lenses are accommodated, a bobbin for fixing the lens unit, a coil unit wound on an outer surface of the bobbin, a magnet unit positioned opposite the coil unit, and a yoke for fixing the magnet unit. An actuator unit including a unit, and a printed circuit board for applying power to the actuator unit, wherein the bobbin includes a body accommodating the lens unit, two or more straight parts formed on an outer surface of the body, and the straight circle. A lens driving motor is provided including a bending portion formed between the lines and a damping member applied to the front of the magnet portion facing the bobbin.

Description

Lens driving motor{MOTOR FOR ACTUATING LENS}

Embodiments of the present invention relate to a lens driving motor with an improved structure.

As various types of portable terminals become widespread and wireless Internet services become commercialized, consumer demands related to portable terminals are also diversifying. Accordingly, various types of additional devices are being installed on portable terminals.

Among them, a representative lens drive motor is one that can take a photo or video of a subject, store the image data, and then edit and transmit it as needed.

Recently, the demand for small lens drive motors is increasing for use in a variety of multimedia fields such as notebook-type personal computers, camera phones, PDAs, smart devices, and toys, and even for image input devices such as surveillance cameras and information terminals of video tape recorders. there is.

A conventional lens driving motor includes a lens unit and an actuator unit that moves the lens unit, and the actuator unit includes a bobbin that fixes the lens unit, a coil unit wound around the outer peripheral surface of the bobbin, and a magnet positioned opposite the coil unit. It includes a yoke portion that supports the magnet portion and the magnet portion.

However, during the manufacturing process, shape distortion may occur when the coil portion is wound on the bobbin, and this shape distortion reduces the reliability of precise image focus.

In addition, since the time required to return to the initial state after movement of the bobbin that fixes the lens unit, that is, the setting time, is rather long, rapid focus adjustment cannot be implemented.

(Patent Document 1) JP 2009-058601 A

The embodiment provides a lens drive motor that improves the reliability of the lens drive motor and can implement a quick image focus function.

The embodiment includes a lens unit in which one or more lenses are accommodated, a bobbin for fixing the lens unit, a coil unit wound on an outer surface of the bobbin, a magnet unit positioned opposite the coil unit, and a yoke for fixing the magnet unit. An actuator unit including a unit, and a printed circuit board for applying power to the actuator unit, wherein the bobbin includes a body accommodating the lens unit, two or more straight parts formed on an outer surface of the body, and the straight circle. A lens driving motor including a bending portion formed between line portions is provided.

Additionally, four straight parts are formed, and may be formed to be longer than the bent parts based on a direction perpendicular to the optical axis.

In addition, a lower protrusion is formed on the lower side of the straight portion and the bending portion to guide the winding of the coil portion, and a bending protrusion is formed on the upper side of the bending portion to guide bending of the coil portion, between the bending protrusion and the body. A groove may be formed in .

Additionally, the yoke portion may include a support portion for supporting the magnet portion, and a bent portion extending from an upper side of the support portion and positioned at a predetermined distance from the bottom surface of the groove.

In addition, it may further include a base mounted on the printed circuit board to support the lens unit and the actuator unit.

In addition, it may further include a housing that secures the magnet portion and the yoke portion and is fixed to the base.

In addition, it may further include an upper elastic member mounted on the upper side of the bobbin and a lower elastic member provided on the lower side of the bobbin.

In addition, it may further include an image sensor mounted on the printed circuit board to convert an optical signal incident from the lens unit into an electrical signal.

In addition, it may further include a damping member applied to the front of the magnet portion facing the bobbin.

In addition, the damping member is implemented with a magnetorheological fluid, and the magnetorheological fluid may be any one of a MR (magneto-rheological) fluid, an ER (electro-rheological) fluid, an EC (eletro conjugate) fluid, and a magnetic fluid. .

Meanwhile, the embodiment includes a lens unit in which one or more lenses are accommodated, a bobbin for fixing the lens unit, a coil unit wound on an outer surface of the bobbin, a magnet unit positioned opposite the coil unit, and a bobbin for fixing the lens unit. A lens driving motor is provided including an actuator unit including a yoke unit, a printed circuit board for applying power to the actuator unit, and a damping member applied to the front of the magnet unit facing the bobbin.

In addition, the damping member is implemented with a magnetorheological fluid, and the magnetorheological fluid may be any one of a MR (magneto-rheological) fluid, an ER (electro-rheological) fluid, an EC (eletro conjugate) fluid, and a magnetic fluid. .

Additionally, the bobbin may include a body accommodating the lens unit, two or more straight portions formed on an outer surface of the body, and a bending portion formed between the straight circular portions.

Additionally, four straight parts are formed, and may be formed to be longer than the bent parts based on a direction perpendicular to the optical axis.

In addition, a lower protrusion is formed on the lower side of the straight portion and the bending portion to guide the winding of the coil portion, and a bending protrusion is formed on the upper side of the bending portion to guide bending of the coil portion, between the bending protrusion and the body. A groove may be formed.

Additionally, the yoke portion may include a support portion for supporting the magnet portion, and a bent portion extending from an upper side of the support portion and positioned at a predetermined distance from the bottom surface of the groove.

In addition, it may further include a base mounted on the printed circuit board to support the lens unit and the actuator unit.

In addition, it may further include a housing that secures the magnet portion and the yoke portion and is fixed to the base.

In addition, it may further include an upper elastic member mounted on the upper side of the bobbin and a lower elastic member provided on the lower side of the bobbin.

In addition, it may further include an image sensor mounted on the printed circuit board to convert an optical signal incident from the lens unit into an electrical signal.

According to an embodiment of the present invention, the structure of the bobbin can be improved to achieve excellent winding of the coil portion, and the upward movement of the bobbin can be restricted by the yoke portion.

In addition, the embodiment has a damping member to shorten the setting time, enabling rapid image focus adjustment.

1 is a side cross-sectional view of a lens driving motor according to an embodiment of the present invention.
Figure 2 is a perspective view of a bobbin according to an embodiment of the present invention.
Figure 3 is a diagram showing a yoke part wound on a bobbin according to an embodiment of the present invention.
Figure 4a is a diagram showing the setting time of a conventional lens drive motor.
Figure 4b is a diagram showing the setting time of the lens driving motor according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

Unless otherwise specified, all terms in this specification have the same general meaning as understood by those skilled in the art, and if a term used in this specification conflicts with the general meaning of the term, the definition used in this specification shall apply.

However, the invention described below is only for explaining embodiments of the present invention and is not intended to limit the scope of the present invention, and the same reference numbers used throughout the specification indicate the same elements.

Hereinafter, the lens driving motor of the embodiment will be described in detail with reference to the drawings.

Figure 1 is a side cross-sectional view of a lens driving motor according to an embodiment of the present invention, Figure 2 is a perspective view of a bobbin according to an embodiment of the present invention, and Figure 3 is a view of a yoke portion wound on a bobbin according to an embodiment of the present invention. am.

Referring to FIG. 1, the lens driving motor 100 largely includes a bobbin 121, a coil portion 122, a magnet portion 123, a base 130, an upper elastic member 142, a lower elastic member 144, It includes a yoke portion 124 and may further include a housing 150.

In addition, although not shown, the embodiment may further include a shield can, which accommodates the lens unit 110 and the actuator unit 120 and forms the exterior of the lens driving motor 100. . The shield can protects internal components from external impacts and has the function of preventing penetration of external contaminants. This shield can must also perform the function of protecting the components of the lens driving motor 100 from external radio wave interference caused by mobile phones, etc. Therefore, the shield can is preferably made of a metal material. Also, here, in the above embodiment, the yoke portion 124 can function as a shield can. At this time, the yoke part 124 may be referred to as a ‘shield can’. Furthermore, the yoke portion 124 may be referred to as 'yoke'.

In addition, although not shown, the embodiment may further include a printed circuit board below the base 130, which will be described later. The printed circuit board has an image sensor mounted on the central portion of the upper side, and various elements for driving the lens driving motor 100 can be mounted. Additionally, the printed circuit board may apply power to the actuator unit 120 to drive the actuator unit 120, which will be described later.

In addition, although not shown, the image sensor may be mounted on the central portion of the upper side of the printed circuit board so that it can be positioned along the optical axis direction with one or more lenses accommodated in the lens unit 110. This image sensor converts the optical signal of the object incident from the lens unit into an electrical signal.

The lens unit 110 is fixed to the bobbin 121, and the lens unit 110 may be a lens barrel, but is not limited to this and may include any holder structure that can support the lens. The embodiment will be described by taking the case where the lens unit is a lens barrel as an example.

The lens unit 110 is installed on the upper side of the printed circuit board and is placed at a position corresponding to the image sensor. This lens unit 110 accommodates one or more lenses (not shown).

Additionally, an infrared cut-off filter (IR filter) 135 may be provided between the image sensor and the lens unit 110, and the IR filter 135 may be provided as an infrared ray filter. Additionally, the IR filter 135 may be formed of, for example, a film material or a glass material, and an infrared blocking coating material may be disposed on a flat optical filter such as a cover glass for protecting the imaging surface.

In order to position the IR filter 135 and support the actuator unit 120 while performing the function of a sensor holder that protects the image sensor, a base 130 is provided between the actuator unit 120 and the printed circuit board. may be provided. In this case, the IR filter 135 may be mounted in a hollow portion formed in the center of the base 130. Here, the base 130 is mounted on the printed circuit board to support the lens unit 110 and the actuator unit 120, and is a component of the actuator unit 120. It may be formed integrally with the base, and a sensor holder, separate from the base, may be placed below the base to surround the image sensor.

In this way, a camera module can be constructed including the lens driving motor, lens unit, image sensor, and printed circuit board, and the camera module can be assembled into a mobile phone, etc. to form a digital device.

The lens unit 110 is fixed inside the bobbin 121, and the bobbin moves up and down to move the lens unit 110 fixed to the bobbin to adjust the focus of the image.

Specifically, the actuator unit 120 includes a bobbin 121 that is coupled to the outer peripheral surface of the lens unit 110 and fixes the lens unit 110, and a coil unit 122 provided on the outer peripheral surface of the bobbin 121. It includes a magnet portion 123 located opposite to the outer surface of the coil portion 122, and a yoke portion 124 that secures the magnet portion 123.

When power is applied to the coil unit 122 from the printed circuit board, the lens unit 110 is imaged in the optical axis direction by the electromagnetic force formed in the coil unit 122 and the magnetic force of the magnet unit 123. , ha is moved.

This actuator unit 120 may be equipped with an A.F. (Auto Focusing) actuator using a voice coil motor.

The upper and lower elastic members 142 and 144 may include leaf springs. Specifically, the lower elastic member 144 is coupled to the lower surface of the bobbin 121. The upper elastic member 142 is coupled to the upper surface of the bobbin 121.

The housing 150 secures the magnet portion 123 and the yoke portion 124 and is fixed on the base 130. Additionally, the magnet portion may be fixed to the yoke portion. That is, the magnet may be disposed at a corner or side of the yoke part, and the magnet may have a triangular pillar shape, a square pillar shape, a trapezoidal pillar shape, etc., and may include some curves in the prism shape. .

Referring to Figures 2 and 3, the bobbin 121 according to an embodiment of the present invention includes a body 121a that accommodates the lens unit 110, and two or more straight lines formed on the outer surface of the body 121a. It includes a portion 121b and a bending portion 121c formed between the straight portion 121b.

Four straight portions 121b are formed, and may be formed longer than the bent portion 121c based on the vertical direction of the optical axis. Therefore, by minimizing the portion where the coil portion 122 is placed in the bending portion, it is possible to prevent distortion of the coil portion 122. Due to this prevention of deformation, the lens drive motor 100 according to the embodiment is a product. In terms of productivity, the defect rate can be reduced. In this case, the magnet is placed on the side of the yoke part.

Additionally, when a magnet is placed at a corner of the yoke portion, the bent portion may be formed to be longer than the straight portion. This is to improve electromagnetic interaction between the magnet and the coil.

Meanwhile, in order to facilitate placement of the coil portion 122, a lower protrusion 121d is formed on the lower side of the straight portion 121b and the bent portion 121c to guide the position of the coil portion 122. . The lower protrusion 121d protrudes from the straight portion 121b and the bent portion 121c and may be formed as one piece.

A bending protrusion 121e is formed on the upper side of the bending portion 121c to guide the bending of the coil portion 122. Additionally, as shown, in order to more easily guide the arrangement of the coil portion 122, an upper protrusion 121f may be formed on the straight portion 121b.

Additionally, a groove 121g may be formed between the bending protrusion 121e and the body 121a. Referring again to FIG. 1, the groove may be formed at a corner of the bobbin. In addition, the yoke portion 124 includes a support portion 124a for supporting the magnet portion 123, and extends from the upper side of the support portion 124a and is positioned at a predetermined distance from the bottom surface of the groove 121g. It may include a bent portion 124b. In this case, the bent portion 124b limits the upward movement of the bobbin 121 by the spaced distance, thereby preventing the bobbin 121 from being separated from impact.

In addition, due to the structural feature that the straight portion 121b is formed longer than the bent portion 121c, the length of the groove 121g in the optical axis direction becomes longer, so that the bent portion 124b and the coil portion ( 122) can prevent contact.

Meanwhile, referring to FIG. 1, the embodiment of the present invention further includes a damping member 160 applied to the magnet portion 123 facing the bobbin 121. The damping member 160 may include a first damping member 161 and a second damping member 162 as shown in FIG. 1 . The first damping member 161 and the second damping member 162 may be spaced apart from each other. The second damping member 162 may be disposed on the first damping member 161. The first damping member 161 may connect the magnet portion 123 and the coil portion 122. The first damping member 161 may be connected to the coil portion 122. The first damping member 161 may be disposed between the support portion 124a of the coil portion 122 and the yoke portion 124 in a direction perpendicular to the optical axis direction. The first damping member 161 may be disposed between the upper plate and the base 130 of the yoke portion 124 in the optical axis direction. The second damping member 162 may connect the magnet portion 123 and the bobbin 121. The second damping member 162 may be connected to the bobbin 121. The second damping member 162 may be disposed between the bobbin 121 and the support portion 124a of the yoke portion 124 in a direction perpendicular to the optical axis direction. The second damping member 162 may be disposed between the upper plate and the base 130 of the yoke portion 124 in the optical axis direction.

This damping member 160 can be implemented with a magnetorheological fluid. The damping member 160 is applied to the magnet portion 123, and when the magnetic field of the magnet portion 123 is formed, the magnet portion 123 ), where the magnetism is concentrated the most. Typically, the place in the magnet unit 123 where the magnetic field is most concentrated is the edge area of the magnet unit 123. When the magnetorheological fluid is concentrated in this way, the height increases toward the optical axis like a water drop shape as shown, and comes into contact with the outer surface of the bobbin to provide friction. This magnetorheological fluid is a viscous sol or gel-like liquid and can be any one of MR (magneto-rheological) fluid, ER (electro-rheological) fluid, EC (eletro conjugate) fluid, and magnetic fluid.

That is, the magnetorheological fluid interferes with the bobbin when the magnetic field of the magnet portion 123 is formed and acts as a damper. Let's look at this in detail as follows.

FIG. 4A is a diagram showing the setting time of a conventional lens driving motor, and FIG. 4B is a diagram showing the setting time of the lens driving motor 100 according to an embodiment of the present invention.

From a dynamic perspective, the conventional lens driving motor is a one-degree-of-freedom (1-DOF) system consisting of only one mass called a bobbin in which the lens unit is accommodated and an elastic member that elastically supports the mass.

Here, the 1-DOF system has the formula F=ma + bv + kx, where m is the mass, a is the acceleration, b is the damping coefficient, v is the speed, k is the spring constant of the elastic member, x represents the deforming displacement.

That is, the conventional lens driving motor does not have a system that acts as a damper, so b = 0 in the above formula. Due to these conditions, the setting time, which is the time for the bobbin to return to its original state after moving, becomes long, as shown in Figure 4a.

However, the embodiment of the present invention includes a magnetorheological fluid, so that the b value exists in the formula of the 1-degree-of-freedom (1-DOF) system. This makes it possible to implement a fast setting time as shown in Figure 4b.

In short, the embodiment of the present invention has a bobbin 121 and a yoke portion 124 with an improved structure, thereby reducing distortion that occurs when arranging the coil portion 122 and improving reliability accordingly, and the damping member 160 It is possible to implement a lens drive motor that enables fast image focus adjustment.

From the above description, those skilled in the art will be able to see that various changes and modifications can be made without departing from the technical spirit of the present invention, and the technical scope of the present invention is not limited to the contents described in the embodiments, but rather the patent claims. It must be determined by the scope and equivalent scope.

100: Lens driving motor 110: Lens unit
120: Actuator unit 121: Bobbin
121a: body 121b: straight part
121c: bending portion 121d: lower protrusion
121e: bending protrusion 121f: upper protrusion
121g: Groove 122: Coil portion
123: Magnet part 124: York part
124a: support part 124b: bent part
130: Base 160: Damping member

Claims (20)

Base;
a shield can disposed on the base;
A bobbin disposed within the shield can;
a coil disposed on the bobbin;
A magnet disposed between the coil and the shield can; and
Includes a damping member disposed on the coil,
The bobbin includes a groove formed concavely on an upper surface of the bobbin,
The shield can includes at least a portion of a bent portion disposed in the groove of the bobbin,
A lens driving motor in which at least a portion of the bent portion is disposed between a portion of the bobbin and another portion of the bobbin in a direction perpendicular to the optical axis and outward from the optical axis. According to paragraph 1,
The shield can includes a top plate and a support portion extending from the top plate and disposed on the base,
A lens driving motor wherein the bent portion of the shield can extends from the upper plate of the shield can. According to paragraph 2,
The damping member is a lens driving motor disposed between the coil and the support portion of the shield can in a direction perpendicular to the optical axis. According to paragraph 1,
A lens driving motor in which at least a portion of the bent portion overlaps the portion of the bobbin and the other portion of the bobbin in the direction perpendicular to the optical axis and outward from the optical axis. According to paragraph 1,
A lens driving motor including an additional damping member spaced apart from the damping member and disposed on the bobbin. According to paragraph 1,
The coil is a lens driving motor disposed between the damping member and the bobbin. According to paragraph 1,
The damping member is a lens driving motor in contact with the coil. According to paragraph 1,
The damping member is a lens driving motor in a gel state. According to paragraph 1,
A lens driving motor wherein the bent portion does not overlap the coil in a direction perpendicular to the optical axis. According to paragraph 1,
A lens driving motor where the lower end of the bent portion is disposed higher than the upper end of the coil. According to paragraph 1,
The bobbin includes a body and a protrusion formed in a corner area of the upper surface of the body,
The groove of the bobbin is formed between the body and the protrusion,
The body of the bobbin includes the portion of the bobbin,
A lens driving motor wherein the protrusion of the bobbin includes the other part of the bobbin. According to paragraph 1,
The bent portion includes an inner surface facing the optical axis and an outer surface opposite to the inner surface,
A lens driving motor wherein each of the inner and outer surfaces of the bent portion is disposed to face the bobbin. According to paragraph 1,
The coil is disposed on the outer peripheral surface of the bobbin,
A lens driving motor in which the groove of the bobbin is spaced apart from the coil. According to paragraph 1,
The damping member is formed of magnetorheological fluid,
The magnetorheological fluid is a lens driving motor provided with any one of MR (magneto-rheological) fluid, ER (electro-rheological) fluid, EC (eletro conjugate) fluid, and magnetic fluid. According to paragraph 1,
A lens driving motor including an upper elastic member coupled to the upper part of the bobbin and a lower elastic member coupled to the lower part of the bobbin. Base;
A shield can including a top plate and a support portion disposed on the base;
A bobbin disposed within the shield can;
a coil and a magnet disposed within the shield can and moving the bobbin in the optical axis direction; and
Includes a damping member in contact with the coil,
The bobbin includes a groove that opens toward the upper plate of the shield can,
The shield can includes a bent portion extending from the upper plate, at least a portion of which is disposed in the groove of the bobbin,
A lens driving motor in which at least a portion of the bent portion is disposed between a portion of the bobbin and another portion of the bobbin in a direction perpendicular to the optical axis and outward from the optical axis. According to clause 16,
A lens driving motor in which at least a portion of the bent portion overlaps the portion of the bobbin and the other portion of the bobbin in the direction perpendicular to the optical axis and outward from the optical axis. According to clause 16,
A lens driving motor including an additional damping member spaced apart from the damping member and in contact with the bobbin. printed circuit board;
an image sensor disposed on the printed circuit board;
The lens driving motor of any one of claims 1 to 18; and
A camera module including a lens coupled to the bobbin of the lens driving motor and disposed at a position corresponding to the image sensor. A portable terminal including the camera module of claim 19.