KR20100068701A - Elastic member for lens actuator and lens actuator having the same - Google Patents

Elastic member for lens actuator and lens actuator having the same Download PDF

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Publication number
KR20100068701A
KR20100068701A KR1020080127151A KR20080127151A KR20100068701A KR 20100068701 A KR20100068701 A KR 20100068701A KR 1020080127151 A KR1020080127151 A KR 1020080127151A KR 20080127151 A KR20080127151 A KR 20080127151A KR 20100068701 A KR20100068701 A KR 20100068701A
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KR
South Korea
Prior art keywords
lens
elastic
driving
yoke
unit
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Application number
KR1020080127151A
Other languages
Korean (ko)
Inventor
김영준
이동락
Original Assignee
(주)차바이오앤디오스텍
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Priority to KR1020080127151A priority Critical patent/KR20100068701A/en
Publication of KR20100068701A publication Critical patent/KR20100068701A/en

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    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B7/00Mountings, adjusting means, or light-tight connections, for optical elements
    • G02B7/02Mountings, adjusting means, or light-tight connections, for optical elements for lenses
    • G02B7/04Mountings, adjusting means, or light-tight connections, for optical elements for lenses with mechanism for focusing or varying magnification
    • G02B7/08Mountings, adjusting means, or light-tight connections, for optical elements for lenses with mechanism for focusing or varying magnification adapted to co-operate with a remote control mechanism
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00Details of television systems
    • H04N5/222Studio circuitry; Studio devices; Studio equipment ; Cameras comprising an electronic image sensor, e.g. digital cameras, video cameras, TV cameras, video cameras, camcorders, webcams, camera modules for embedding in other devices, e.g. mobile phones, computers or vehicles
    • H04N5/225Television cameras ; Cameras comprising an electronic image sensor, e.g. digital cameras, video cameras, camcorders, webcams, camera modules specially adapted for being embedded in other devices, e.g. mobile phones, computers or vehicles
    • H04N5/2251Constructional details
    • H04N5/2254Mounting of optical parts, e.g. lenses, shutters, filters or optical parts peculiar to the presence or use of an electronic image sensor
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04NPICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00Details of television systems
    • H04N5/222Studio circuitry; Studio devices; Studio equipment ; Cameras comprising an electronic image sensor, e.g. digital cameras, video cameras, TV cameras, video cameras, camcorders, webcams, camera modules for embedding in other devices, e.g. mobile phones, computers or vehicles
    • H04N5/225Television cameras ; Cameras comprising an electronic image sensor, e.g. digital cameras, video cameras, camcorders, webcams, camera modules specially adapted for being embedded in other devices, e.g. mobile phones, computers or vehicles
    • H04N5/232Devices for controlling television cameras, e.g. remote control ; Control of cameras comprising an electronic image sensor
    • H04N5/23212Focusing based on image signals provided by the electronic image sensor
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00Metal working
    • Y10T29/49Method of mechanical manufacture
    • Y10T29/49609Spring making

Abstract

PURPOSE: An elastic member for a lens actuator and a lens actuator including the same are provided to set an initial driving location of a lens module by making possibly a preload without the member like a carrier. CONSTITUTION: A lens unit includes a lens unit. A driving unit(200) transfers the lens unit along an optical axis by a driving force by interaction of a magnet and a driving coil. Elastic bodies(310,320) are combined on the upper and lower of the driving unit and the lens unit. The lens unit includes a lens barrel for accepting the lens unit.

Description

Elastic member for Lens Actuator and Lens Actuator Having the Same}
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device, and more particularly, to an elastic member for a lens actuator adopted in a compact optical device and a lens actuator including the same.
The camera as a mechanical device capable of photographing a desired subject through the lens is provided with a plurality of lenses for focusing and / or zooming functions, and adjusts the focus by adjusting the relative distance between the lenses.
In recent years, with the rapid development of digital optical technology, a camera module is mounted on a small optical device such as a mobile communication device such as a digital camera or a mobile phone, so that a user can shoot a desired object at any time. It is spread to the public. However, the camera module mounted on such a small optical device is provided with various actuators as a driving means for zooming or auto-focusing, so that a lens formed inside the lens assembly is provided. The focus and / or magnification is adjusted by moving in the optical axis direction.
Conventionally, as an actuator for automatically adjusting a focus on a subject in a camera mounted on a compact optical device, a so-called rotary motor type mechanical device for changing a rotational motion of a motor by a gear into a linear motion has been widely used. However, in the case of a mechanical actuator, since the dynamic-static error due to friction, mechanical deformation, backlash, etc. accompanying the operation of the gear and the motor could not be avoided, fine control is virtually impossible, making it difficult to precisely adjust the focus. However, miniaturization was difficult due to the space problem occupied by each mechanical device. Therefore, there are many problems in mounting a mechanical actuator in a small optical device such as a mobile communication device.
Accordingly, in particular, in the camera module mounted on a mobile communication device such as a mobile phone and a PDA, many methods have been proposed to satisfy the miniaturization, light weight, and multifunctionality required by the mobile communication device. However, in order to clearly see a subject in an optical system of a camera module mounted on a gradually miniaturized mobile communication device, the subject is sharply imaged on an image sensor by adjusting a relative distance between a plurality of lenses and an image sensor or changing a lens curvature. It should be equipped with a focusing (focusing) function. In other words, since the position of the image of the subject imaged by the image sensor changes according to the position of the subject, in order to implement the focusing function for the subject thus changed, the position of the image is formed according to the distance between the subject and the lens. A focusing process is essential.
That is, in order to realize a clear image in the image sensor in the optical device, at least one focusing lens should be able to move so as to change the relative position with respect to the image sensor according to the position of the subject. However, in order to realize a focusing function through such a focusing lens, an actuator as a driving source for moving the focusing lens in the optical axis direction according to the position of the subject is required. To date, a manual, step motor, piezoelectric element, and voice coil motor (Voice) A drive source using a coil motor (VCM) or the like has been proposed, and an actuator of a voice coil motor type is most widely used.
Here, the voice coil motor (VCM) or the voice coil actuator (VCA) method refers to an actuator that uses the Lorentz force generated by the induction magnetic force of the coil in a linear motion in a static magnetic field formed by a permanent magnet. It is very suitable for constructing a compact optical device that moves a relatively short distance precisely and linearly. The lens actuator of the conventional VCM method will be briefly described with reference to FIG. 1, which is a sectional view schematically showing a lens actuator of the VCM method applied to a conventional mobile communication device.
As shown, the conventional voice-coil motor-type lens actuator 1 is typically a lens barrel 2 as a lens assembly in which a plurality of focusing lenses are assembled, and a screw fastening method on the outer circumferential surface of the lens barrel 2. The carrier 3 is joined to the center is formed in the center. On the other hand, the magnet barrel 4 for generating magnetic force around the outer side of the hollow-shaped carrier 3 to which the lens barrel 2 is fastened therein and the upper end of the magnet 4 are provided to change the flow direction of the magnetic lines of force. And a hollow yoke 5 having a substantially " " shaped cross section to control and a top plate 6 provided at the bottom of the magnet 4 to support the magnet and to change the direction of the magnetic line flow in one direction. ) Is disposed, and the drive coil 7 is wound between the lower outer periphery of the carrier 3 and the inner peripheral surface of the top plate 6. That is, the magnet 4 generating the magnetic force in the lens actuator 1 using the VCM method and the driving coil 7 to which the electric current is applied are disposed to face each other, and the driving coil 7 in the magnetic force generated by the magnet 4. The lens barrel 2 and the carrier 3 receiving the same are driven in the optical axis direction by using the Lorentz force generated in the vertical direction of the current and the magnetic field, that is, in the optical axis direction, by the induced magnetic force caused by the interaction of h).
On the other hand, the upper cover 8 that provides the upper appearance of the lens actuator 1 at the upper end of the yoke 5, and the lower cover at which the upper plate 6 is seated and fixed at the lower end of the top plate 6 ( 9 is formed, and at the bottom of the carrier 3 and the lower cover 9, a base 10 is provided which provides the bottom appearance of the lens actuator 1. At this time, the upper spring 11 is seated on the upper end of the carrier 3 so as to minimize the inclination generated in the process of driving the carrier 3 and to return to the original position when the carrier 3 moves, the carrier ( The lower spring 12 is coupled to the lower end of the carrier 3 to return the position of the carrier 3 to the original position, respectively, to press the upper and lower ends of the carrier 3. In particular, looking at the arrangement of the upper spring 11 and the lower spring 12, the inner peripheral portion is configured such that its position or shape can be changed according to the linear movement of the carrier 3, while the outer peripheral portion of the upper spring 11 Is interposed between the upper cover 8 of the upper end and the yoke 5 of the lower end, and the outer periphery of the lower spring 12 also closely adheres between the lower cover 9 of the upper end and the base 10 of the lower end, It is interposed and is comprised so that the position or form may be fixed.
By the way, as described above, the upper spring 11 / lower spring 12 as a means for pressing the upper and lower ends of the carrier 3, even if the lens actuator 1 is driven, has an inner circumferential portion and an outer circumferential portion thereof. Rather than being arranged in parallel in the direction orthogonal to the optical axis, the inner circumferential portion is disposed obliquely upward to the fixed outer circumferential portion. By this arrangement, the inner circumferential portion of the upper spring 11 / lower spring 12 generates a repulsive force to return downward by elasticity, and the carrier 3 is driven by a driving force that overcomes this repulsive force in the actual driving process. Fine movement of the focus on the subject is possible by the linear movement along the optical axis.
As described above, when the camera module rotates 90 ° and / or 180 ° in the lens actuator 1 of the VCM method, the carrier 3 formed in the center of the lens actuator 1 constituting the camera module sags downward due to its own weight. In order to prevent this, the springs 11 and 12 are coupled to the upper and lower ends of the carrier 3, respectively, and the inner circumferential side thereof is inclined upward to press the carrier 3 by a predetermined repulsive force so as to press the carrier 3. It is necessary to set the position of, which is called the initial driving position of the carrier by 'pre-load' or 'posture'.
However, in the case of the lens actuator 1 employing the conventional VCM method, in order to apply a pre-load, i.e., an initial load, the lower end 3a of the carrier is set in contact with the upper end of the inner circumferential surface of the base 10, thereby providing an upper spring ( 11) and the inner circumference of the lower spring 12 are configured to be inclined. Therefore, in the conventional VCM-type lens actuator 1, the carrier 3 is fastened to the outer periphery of the lens barrel 2 in order to provide a pre-load, so in order to assemble the lens actuator 1 The fastening process of the lens barrel 2 and the carrier 3 must be accompanied, and there is no limit to reducing the size of the lens actuator 1. In addition, due to particles caused by continuous contact and impact of the lower end of the carrier 3a and the inner circumferential surface of the base 10, foreign matter is generated inside the lens actuator 1, causing focusing errors and poor resolution. Problems occur.
In addition, as the recent adoption of high resolution image sensors in small optical devices such as digital cameras, mobile communication devices, the lens module must also meet the requirements of miniaturization, light weight, and ultra-precision. However, in the case of the conventional VCM-type lens actuator (1) is formed integrally, as well as the difficulty in the assembly process, due to the fragility of the components, the instability of the drive in the process of being easily broken by the impact or performing the focusing function This problem has many problems in terms of reliability. In addition, since magnets, yokes, coils, and the like as the driving source are disposed along the outer periphery of the lens barrel, such a lens assembly may have a diameter at least as large as the diameter of the driving source is added to the outer diameter of the lens barrel. There was a limit to miniaturization.
Thus, for example, Korean Patent Laid-Open Publication No. 2008-35601 proposes an imaging device that configures an effective diameter of a plurality of lenses differently and arranges an actuator around a lens having a minimum effective diameter. The assembly base for supporting the imaging lens and the actuator for driving the lens group are all molded in one piece. Therefore, in this publication, there are many difficulties in attaching or arranging an imaging lens, a movable barrel for accommodating the imaging lens, an actuator disposed outside the movable barrel, and an outer barrel configured at the bottom of the actuator, based on the focusing as described above. Instability of the drive in the process can be caused. In particular, in the case of such an integrated type, when a part of the component parts formed and mounted inside the base is damaged, the problem of inevitably replacing the whole is still not solved.
The present invention has been proposed to solve the above problems, and an object of the present invention is to be adopted in a compact optical device capable of pre-loading without a member, such as a carrier, which has been conventionally used to set the initial driving position of the lens module. An object of the present invention is to provide an elastic member for a lens actuator.
Another object of the present invention is to adopt an elastic member that can provide a pre-load by itself, thereby eliminating a part of the process for assembling a conventional lens actuator through the reduction of the components constituting the lens actuator. It is an object of the present invention to provide a lens actuator with improved convenience or economy.
Another object of the present invention is to provide a self-locking means in a part of the drive source for driving the lens in the optical axis direction, thereby reducing the overall size, while improving the ease of assembly process and stability of focusing It is to provide a lens actuator for.
Another object of the present invention is to suppress the generation of foreign matters due to collisions between components, and to provide an autofocus lens assembly for a small optical device, which does not require replacement of the entire component even if a part of the component is broken. I would like to.
Other advantages and objects of the present invention will become more apparent from the following detailed description of the invention and the accompanying drawings.
According to an aspect of the present invention having the above object, as an elastic member coupled to the lens actuator of the compact optical device, and composed of an outer peripheral portion and an inner peripheral portion, the inner peripheral portion so that the outer peripheral region can be inclined upward in the initial driving position An elastic member is provided in which the region extends downward.
In this case, preferably, the elastic member may have a leaf spring shape, and may have a wave-shaped curved portion between the outer peripheral portion and the inner peripheral portion.
On the other hand, according to another aspect of the invention, the lens unit is attached to the lens unit to enable the imaging of the subject; A driving unit for moving the lens unit along an optical axis direction by a driving force caused by interaction of a magnet and a driving coil disposed along an outer circumference of the lens unit; An elastic body coupled to an upper end and a lower end of the lens unit and the driving unit, and provides a lens actuator for a small optical device including an elastic body including the elastic member described above.
In this case, the lens unit may include a lens barrel accommodating the lens unit, and the lens barrel may include a plurality of diameter parts having different diameters, and at least one of the magnet and the driving coil may be the largest of the lens barrels. It may be arranged along the outer periphery of the diameter portion having no diameter.
On the other hand, the drive unit includes a yoke for controlling the magnetic force of the magnet, the yoke is a first yoke disposed on the upper end of the magnet, a second yoke extending downward from the outer peripheral surface of the magnet and the outer peripheral surface of the drive coil It includes.
At this time, a fastening portion is formed at an outer periphery of the second yoke, and the elastic body is in close contact with the first elastic body as the elastic member formed on the first yoke, the lower end of the lens barrel and the second yoke. It may be composed of a second elastic body.
In the present invention, in order to set the initial driving position of the voice-coil motor-type lens actuator constituting the camera module of a small optical device such as a mobile communication device, the elastic member that can be pre-loaded through its own unique shape without any additional configuration means Made possible. As a result, the number of components constituting the lens actuator adopting the elastic member can be reduced, so that economic efficiency or convenience can be achieved through the simplification of the assembly process.
In addition, in the lens actuator of the present invention, the fastening means is provided in the drive unit that participates in the focusing, so that the assembling process can be secured in comparison with the lens actuator, which has been conventionally molded in one piece.
In addition, in the case of a lens actuator that was manufactured as a single unit in the related art, even if a part of the component part is damaged, the entirety has to be replaced. Only replaceable components can be replaced.
In addition, the solid fastening of the drive source and the external base not only enables stable placement of components, but also prevents foreign substances from being generated due to contact and collision between the components in the process of setting initial driving positions. Stability and reliability can also be achieved.
In addition, by forming the upper end of the lens module constituting the lens actuator of the present invention to have a smaller diameter than other areas, and by arranging a drive around the upper end, it is possible to reduce the size of the entire autofocus lens assembly.
The inventors of the present invention change the shape of an elastic member coupled to a component of a voice-coil motor (VCM) type lens actuator in a small optical device such as a camera module mounted on a mobile communication device, The present invention has been completed by finding out that the above-mentioned problem can be solved by providing self-locking means in the drive unit for driving the optical axis in the actuator. Hereinafter, with reference to the accompanying drawings will be described a specific embodiment and driving mechanism of the present invention.
2 is an exploded perspective view schematically illustrating a coupling relationship between components constituting a voice-coil motor-type lens actuator constituting a small optical device such as a camera module mounted on a mobile communication device according to the present invention. 4 is a perspective view illustrating a state in which the lens actuator according to the present invention is assembled, and FIG. 4 is a plan view schematically showing an elastic member (first elastic member) coupled to the lens actuator according to the present invention, and FIG. 5 is V of FIG. 4. A cross-sectional view of the elastic member according to the present invention cut along the -V line, and FIG. 6 is a cross-sectional view showing a state before the lens actuator of the present invention cut along the VI-VI line of FIG.
The voice-coil motor-type lens actuator 100 according to the present invention includes a lens unit 110 as a lens module having a hollow area to accommodate a plurality of focusing lenses L1 to L4, and the lens unit 110. The driving unit 200 is disposed along the outer periphery of the casing, and the casing members 410, 420, and 430 are formed to enclose the components for driving the lens actuator and the driving unit 200 from the outside.
The lens unit 110 includes a lens unit 120 composed of one or more lenses L1, L2, L3, and L4 whose diameters and curvatures are not equal to each other, and the lens unit 120 therein. It includes a lens barrel 130 having a different diameter of the top and bottom to accommodate in. In this case, the lens unit 120 may be mounted and mounted in the lens barrel 130 in a form in which the lens holder assembly or each lens is assembled to match the optical axis, and the number of lenses forming the lens unit 120 may be As shown in the figure, the lens is not composed of only four lenses, and the number and shape of the lenses can be arbitrarily adjusted as necessary. In particular, the plurality of lenses L1, L2, L3, and L4 constituting the lens unit 120 may have a difference in curvature or the like, but, for example, the first lens L1 and the second lens positioned close to the subject ( The outer diameter of L2) can be made small, and the outer diameter of the remaining lenses L3, L4 can be made larger. The lens unit 120 is assembled inside the lens barrel 130 made of metal or plastic, which may be manufactured through, for example, a press molding method.
In particular, in the present invention, as the outer diameter of the lens constituting the lens unit 120 is configured not to be the same, the cross section of the lens barrel 130 for accommodating the lens unit 120 is also not a simple cylindrical shape, the upper and lower ends thereof are It consists of parts with different diameters. That is, as can be seen in the cross-sectional view of Figure 6, the lens barrel 130 according to the present embodiment has a relatively small minimum diameter to accommodate the first lens (L1) and the second lens (L2) on the top And a second diameter portion 134 having a relatively large maximum diameter so as to accommodate the third lens L3 and the fourth lens L4.
In order to be accommodated in the lens barrel 130 having such a cross-sectional shape, the first lens L1 and the second lens L2 accommodated in the first diameter portion 132 have substantially the same outer diameters. The outer diameter of the third lens L3 and the fourth lens L4 accommodated in the second diameter portion 134 is substantially the same. Meanwhile, according to the present invention, the flange portion 136 protrudes outward from the middle portion of the second diameter portion 134 constituting the lower end of the lens barrel 130, and is driven to the upper surface of the flange portion 136. The coil 230 is configured to be seated and disposed. At this time, while shielding the transmitted light to the periphery of the lens unit 120 composed of one or more lenses, each lens is assembled and arranged stably in the lens barrel 130, and the interval between each lens is adjusted. Means for doing so may be provided.
Meanwhile, the magnet 210, the yoke 220, and the driving coil 230, which are the driving unit 200, may move the lens unit 110 in the optical axis direction to adjust the focus on the photographed subject. It is arranged along the outer periphery. That is, according to the present invention, the magnet 210 is in close contact with and disposed on the outer circumference of the first diameter portion 132 of the upper end having a relatively small minimum diameter among the lens barrel 130, and is generated from the magnet 210. The yoke 220 is disposed at the top and the outside of the magnet 210 to control the flow of magnetic force (magnetic flux). On the other hand, the drive coil 230 is electrically connected to the external power source so that a predetermined current is applied to interact with the magnetic field generated by the magnet 210 to generate the Lorentz force, that is, the driving force. Opposed to the inner circumferential surface of the two yokes 224, the lens barrel 130 is staked out in a form wound around the outer periphery of the second diameter portion 134 of the lower end having a relatively large maximum diameter.
At this time, the magnet 210 forming the magnetic field in the lens actuator 100 of the VCM method according to the present invention may be a permanent magnet used in the voice coil motor (VCM) method, as shown in FIG. If the S pole is located and disposed so that the N pole is positioned at the bottom, the driving force may be improved as described below. However, the present invention is not limited thereto, and may have polarities of the upper N pole and the lower S pole, for example. In this case, according to the present invention, it is preferable that the magnets 210 have different polarities arranged in the optical axis direction. When the two poles are configured as dipoles, a single pole is divided into upper and lower poles or a single magnet that is magnetized into two poles. It can be configured as a magnet.
According to the present invention, the inner circumferential surface of the magnet 210 is in close contact with the outer circumference of the first diameter portion 132 whose diameter is relatively small among the lens barrel 130. The magnet 210 according to the present invention is preferably a ring shape having a hollow substantially the same as or slightly larger than the outer diameter of the first diameter portion 132 of the upper end of the lens barrel 130.
 As described above, since the magnet 210 is closely adhered to and arranged around the outer circumference of the first diameter portion 132 having a relatively small diameter among the lens barrels 130, the inner diameter of the magnet 210 is determined in the lens barrel 130. It becomes smaller than the outer diameter of the 2nd diameter part 134 which has a largest diameter. Accordingly, in the case of the lens actuator adopting the conventional VCM method, the lens barrel 130 according to the present invention is compared with the size of the horizontal direction in which the width between the inner and outer diameters of the magnet is added to at least the maximum outer diameter of the lens portion. By using the relative diameter difference between the minimum diameter and the maximum diameter of the magnet 210 as a drive source can be reduced the overall size of the lens actuator (100).
Meanwhile, in the present invention, in order to control the magnetic flux generated from the magnet 210 to flow only in a predetermined direction, for example, in the horizontal axis direction of the lens unit 110, the upper and outer sides of the magnet 210 are respectively made of a conductive material. A yoke 220 composed of a first yoke (upper yoke 222) and a second yoke (side yoke 224) to be made is arranged. Yoke 220 according to the present invention is a ring shape having a constant hollow, it can be made of a conductive material such as, for example, iron, cold rolled steel or nickel having excellent magnetic permeability to efficiently control the magnetic flux.
At this time, the first yoke 222 disposed on the magnet 210 has a hollow substantially the same as the magnet 210, whereas the second yoke (22) preferably spaced apart from the outer peripheral surface of the magnet 210 to a certain degree ( The 224 may be configured to be interviewed with the outer bottom surface of the first yoke 222 to improve and improve the magnetic transmittance generated from the magnet 210. As illustrated, the second yoke 224 may include the second diameter portion 132 of the bottom of the lens barrel 130 as well as the first diameter portion 132 of the upper end of the lens barrel 130 from the outer bottom surface of the first yoke 222. 134 extends in the vertical direction. In the drawing, the second yoke 224 disposed in close contact with the outer periphery of the magnet 210 and the first yoke 222 disposed on the upper end of the magnet are separately configured, but the first yoke 222 and the second yoke are separately constructed. 224 can be configured integrally.
In particular, according to the present invention is provided with a fastening means to the outer periphery of the yoke constituting the drive unit 200. That is, the yoke fastening portion 226, which preferably has a threaded shape, is formed from approximately interrupted to the lower end of the second yoke 224, which is staked to extend vertically along the outer periphery of the lens barrel 130. In addition, a base fastening part 432 corresponding to the yoke fastening part 226, preferably having a thread shape, is formed on the inner circumferential surface of the base 430 that supports and accommodates the driving part 200 and the lens part 200. have. Accordingly, in the process of accommodating and assembling the lens unit 110 in which the driving unit 200 and the related driving components are closely arranged and coupled to the base 430, the driving unit 200 and the driving unit 200 are vertically extended along the outer periphery of the lens barrel 130. 2 yoke fastening portion 226 formed on the outer circumferential surface of the yoke 224 is combined with the base fastening portion 432 of the inner circumferential surface of the base 430, thereby stably securing the lens unit 110, the driving unit 200, and the like to the base 430. ) Can be assembled inside.
As described above, in the present invention, since the yoke 220 constituting the driving unit 200 includes a self-fastening means, no additional fastening means is required to assemble the lens actuator 100, thereby achieving efficiency of the manufacturing process. have. In addition, the conventional auto focus lens assembly for compact optical instruments is integrally formed with a lens unit / actuator / housing, etc., and therefore, the entire auto focus lens assembly must be replaced when a specific part is damaged during the assembly process or the use process. However, the present invention has the advantage of replacing only a specific broken part through a method of releasing the fastening between the base 430 and the second yoke 224. In addition, compared to the case of the VCM-type lens actuator assembled through a conventional one-piece molding process, in the present invention, preferably, the drive unit disposed on the lens unit 110 and its outer periphery through a rigid fastening means such as a screw unit ( Since the driving parts including the 200 may be stably assembled into the base 430, the stability of the focusing process may also be improved.
Meanwhile, according to the present invention, the driving coil 230 is electrically connected to an external power supply means to drive the lens unit 110 including the lens barrel 130 along the optical axis. It is arranged in the form that is wound along the outer periphery of the second diameter portion 134 having a large maximum diameter.
In particular, according to the present invention, approximately the middle portion of the second diameter portion 134 constituting the lower end of the lens barrel 130 protrudes outward so that the position of the driving coil 230 with respect to the lens barrel 130 can be fixed. The flange portion 136 is formed. The driving coil 234 is seated on the upper surface of the flange portion 136, the flange portion 136 is able to function as a kind of driving coil 230 support means. This drive coil 230 also has a disk-shaped ring shape as a whole.
In addition, according to the present invention, the outer periphery, the top, and the bottom of the lens barrel 130 may be arranged in a mounted form of various components for controlling and assisting the driving of the driving unit 200 of the above-described VCM method. For example, the driving coil 230, which is staked while being supported at the outer periphery of the second diameter portion 134 of the lens barrel 130 constituting the lens unit 110, is arranged along the optical axis to adjust focusing on the photographed subject. The magnet 210 and the yoke 220 which function as a movable part which repeats the up and down reciprocating motion and are disposed on the outer periphery of the first diameter part 132 on the upper end of the lens barrel 130 are fixed parts whose positions are fixed. Function.
Accordingly, in order to adjust the focus on the subject, it is necessary to fasten the movable part and the fixing part and simultaneously apply a predetermined current to the driving coil 230 according to the image of the subject. The elastic bodies 310 and 320 are firmly coupled to the top and bottom of the bottom, respectively. The elastic bodies 310 and 320 supply current to both ends of the driving coil 230, and give a restoring force as the lens unit 110 moves in the optical axis direction, thereby determining the relative position of the lens unit 110. It is configured to be. To this end, the elastic bodies 310 and 320 may have an upper end of the movable part and the fixed part so as to elastically connect the lens part 110-the driving coil 230 as the movable part and the magnet 210-the yoke 220 as the fixed part. And it is preferable to be installed in the vicinity of the coupling of the lower end.
By the way, in the present invention, the shape of the first elastic body 310 seated on the upper end of the lens unit 110 of the above-mentioned elastic body, for example, there is a significant difference compared to the conventional, the first elastic body (elastic member, 310) This will be described in more detail with reference to FIGS. 4, 5 and 6.
According to the present invention, the elastic member 310 may be, for example, a first elastic body disposed on the upper surface of the lens actuator 100. The elastic member 310 may be in close contact with and interposed between the upper end of the first yoke 222 and the lower end of the upper cover 410 to be described later, and the lens 110 may pass through the outer peripheral part 312 where the position is fixed. A hollow is formed and consists of an inner circumferential portion 318 seated to the upper end of the lens barrel 130, a constant elastic force adjacent to the outer circumferential portion 312 in the region between the outer circumferential portion 312 and the inner circumferential portion 318 The wave-shaped curved portion 314 is formed so as to constitute a kind of tension bar so as to provide a. In particular, the movable part 316 near the inner peripheral part 318 inside this curved part 314 is comprised so that it may protrude downward and extend compared with the outer peripheral part 312 and the curved part 314 (refer FIG. 5).
As described above, in the elastic member 310 of the present invention, the movable portion 316 of the region near the inner circumference 318 extends downward, compared to the region near the outer circumference 312, so that the outer circumferential portion of the elastic member 310 is assembled in the process of assembling the lens actuator 100. 312 As the end is in close contact with and fixed between the first yoke 222 and the upper cover 410, the outer peripheral portion (3) without a separate means due to the step between the bottom of the outer peripheral portion 312 and the bottom of the movable portion 316 ( An inner region of 312, that is, a rectilinear outer region of the movable portion 316, may be arranged in a bent shape toward its upper end (see FIG. 6). Accordingly, the elastic member of the present invention can be formed with a repulsive force to provide a pre-load, that is, an initial load without a separate component.
Meanwhile, in the case of the second elastic body 320 disposed at the lower ends of the lens barrel 130 and the second yoke 224, the outer circumferential portion thereof is disposed at the upper end of the bottom surface of the second yoke 224 and the upper end of the inner circumferential surface of the base 430. By being interposed between the covers 420, the position is fixed, but the inner circumference thereof is coupled to the lower end of the lens barrel 130 spaced a predetermined distance from the upper end of the inner circumferential surface of the base 430 by bonding or thermal caulking. It is. Accordingly, the second elastic body 320 may be disposed in an inclined shape between the outer circumference and the inner circumference toward the upper end even in the initial driving position to provide a pre-load (see FIG. 6). In order to fix and support the second elastic body 320, a lower cover 420 corresponding to the upper cover 410 may be seated and formed at the upper end of the inner circumferential surface of the base 430.
When a voltage is applied to the driving coil 230 through the above-described method, when the lens unit 110 including the lens barrel 130 performs linear movement in the optical axis direction, the outer circumferential region of the first elastic body 310 is While being compressed and fixed to a specific position by the upper cover 410, the inner circumferential region of the first elastic body 310 may change its position according to the elastic force in response to the movement of the lens barrel 130. On the other hand, the outer circumferential region of the second elastic body 320 is compressed by the lower end of the second yoke 224, while the inner circumferential region is not fixed by a specific coupling means, so that the lens barrel 130 performs linear motion. In this case, the outer circumferential region of the second elastic body 320 is fixed in position, but the inner circumferential region is configured such that its position can be elastically changed in response to the movement of the lens barrel 130.
At this time, between the first elastic body 310 and the upper cover 410 may be fixed by bonding adhesion and / or thermal caulking, and also between the second elastic body 320 and the lens barrel 130 bottom / base 430 It may be fixed by bonding adhesion and / or thermal caulking or the like.
Accordingly, since the elastic bodies 310 and 320 are arranged to exert a constant elastic restoring force even in the initial driving position, a vertical direction in which the current is orthogonal to the magnetic flux generated from the magnet 210 by applying a current to the driving coil 230. Even if the driving force is generated by applying a current of a predetermined size or more to increase the magnetic force, the lens unit 110 is moved in the optical axis direction only when the elastic restoring force of the elastic body (310, 320) is overcome. In other words, since a pre-load, i.e., an initial load is applied to the elastic bodies 310 and 320, the posture difference when the lens unit 110 including the lens barrel 130 rotates by 90 ° and / or 180 ° or more. The initial driving position is set so as not to be moved by its own weight. In the present invention, for example, the first elastic body 310 may be configured to apply an initial load by itself, thereby including the lens barrel 130. The lens unit 110 can be prevented from sagging.
As described above, according to the present invention, the elastic bodies 310 and 320 respectively coupled to the upper and lower ends of the lens actuator 100 are in contact with the lens barrel 130 in which a plurality of lenses are accommodated and elastically contact the lens barrel 130. In order to pressurize, after the linear movement of the lens unit 110 by the above-described driving unit 200, it may be made of a conductive material having a suitable modulus of elasticity to return to its original position. However, when the general coil spring is adopted as the elastic bodies 310 and 320 according to the present invention, the spring should be fixed at two points outside the lens barrel 130 and a separate guide should be installed for safety. The surface of the barrel 130 has a relatively small occupied area and is in surface-contact, and a leaf spring shape is useful for miniaturization and miniaturization due to uniform elasticity. In addition, in the case of applying these leaf spring-type elastic bodies 310 and 320, it is advantageous because it can be used as a signal terminal and a ground terminal necessary for the operation of the lens actuator 100. To this end, the elastic bodies 310 and 320 may be made of steel or a copper alloy.
That is, the first elastic body 310 and the second elastic body 320, which are uniquely shaped elastic members according to the present invention, are configured to apply a predetermined external voltage to the driving coil 230, respectively. However, since the magnet 210, the yoke 220, and the like that form the driving unit are all made of a magnetic material, the first elastic body 310 and the second elastic body 320 fastened to the upper and lower ends of the second yoke 224, respectively. An electrical short may occur when a voltage is applied. Therefore, in order to prevent such an electrical short, an insulating material (not shown) may be formed between the upper end of the first yoke 222 and the bottom of the first elastic body 310. In this case, even if the first elastic body 310 collides with the first yoke 222 while the lens unit 110 is driven, the impact amount may be reduced due to the insulating material interposed therebetween.
On the other hand, as described briefly above, when the elastic bodies 310 and 320 serve as terminals, it is necessary to electrically connect between the elastic bodies 310 and 320 and the driving coil 230. To this end, one end of the driving coil 230 extends downward along the outer periphery of the second diameter portion 134 of the lens barrel 130 to be connectable with the second elastic body 320, and the second elastic body 320. Is electrically connected to an external positive power supply through an external terminal (not shown). On the other hand, the other end of the drive coil 230 is extended upward along the outer periphery of the second diameter portion 134 and the first diameter portion 132 of the lens barrel 130 can be connected to the first elastic body 310, The first elastic body 310 is electrically connected to an external (-) power source through an external terminal (not shown). For the electrical connection between the drive coil 230 and the elastic bodies 310 and 312, a separate buried groove (not shown) is formed at the outer periphery of the lens barrel 130, and both ends of the drive coil 230 are The buried groove may be configured to be electrically connected to each of the elastic bodies 310 and 320. As such, for example, the elastic bodies 310 and 320 having a leaf spring shape press the lens unit 110 to set the initial driving position of the lens actuator 310, and at the same time, a terminal for adjusting focusing by the driving unit 200. It also functions as.
In addition, in the lens actuator 100 of the present invention, the lens 200 is mounted to engage with the driving unit 200 and the focusing unit capable of moving the lens unit 200 in the optical axis direction around the lens unit 200 as the lens module described above. The casing members 410, 420, and 430 for accommodating the various parts to be assembled are molded.
In detail, the upper cover 410 is formed at the upper end of the first elastic body 310 to fix the outer circumferential portion 312 of the first elastic body 310. At this time, the upper cover 410 that provides the top shape of the lens actuator 100 is formed in the center of the hollow to accommodate the lens unit 110 and the driving unit 200, the magnet 210 is inserted therein In order to prevent the yoke 220 from being separated, the outer circumference of the yoke 220 may be extended downward.
In addition, the lower cover 420 is formed to be seated on the upper end of the inner circumferential surface of the base 430 so that the size and shape of the lower cover 420 can correspond to the shape of the second elastic body 320 disposed on the upper end. In this way, the lower cover 420 is in contact with the lower end surface of the second elastic body 320, thereby pressing the second elastic body 320 to be firmly fixed in the substantially horizontal direction.
In addition, the base 430 provides the bottom shape of the lens actuator 100, and a hollow enough to accommodate the lens barrel 120 and the second yoke 224 is formed, and the outer circumferential surface is a square and is substantially hexahedral. It has a shape. The base 430 is preferably coupled through the outer periphery of the second yoke 224 to accommodate at least a portion of the lens unit 110 and the driving unit 200 disposed at the outer periphery thereof.
On the other hand, although not shown in the drawings, a filter for controlling the amount of light by blocking a portion of the incident light entering through the lens to the hollow portion of the inner flange area formed on the lower inner peripheral surface of the base 430 is disposed, the lower end of the base 430 As an inner circumferential surface, for example, an image sensor such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) type sensor is mounted above the substrate bonded through a bonding agent. .
As a result, in the present invention, various components including the driving unit 200 as well as the lens unit 110 are provided through the self-locking means 226 formed on the outer circumference of the second yoke 224, for example. Tightly fastened inside. That is, the lens barrel 130 constituting the lens unit 110 attaches at least one lens constituting the lens unit 120 at the center thereof, and the base 430 is mounted at the center thereof. ) And a plurality of parts for controlling the operation of the driving unit 200 and the driving unit 200 to control the auto-focusing (AF) process along the outer periphery of the lens barrel 130 as appropriate. I assemble it firmly while being arranged.
In addition, as described above, the magnet 210 is disposed around the outer periphery of the first diameter portion 132 having a relatively small diameter among the lens barrel 130, and the outside of the bottom of the second yoke 224 that forms the outermost portion. By configuring the lens barrel 130 to be directly received into the base 430 through a fastening means such as a thread formed in the periphery, the overall size of the lens actuator 100 may be reduced.
In the lens actuator 100 disposed as described above, the magnetic field generated by the magnet 210 passes through the driving coil 230 disposed in the form of being wound along the outer periphery of the lens barrel 130. The lens barrel 130 and the lens unit housed inside the lens barrel 130 are configured to support the driving coil 230 and the driving coil 230 by the electromagnetic force due to the interaction of the electric field, that is, the Lorentz force. The entire lens unit 110 including the 120 is driven. That is, when a current is applied to the driving coil 230 which is disposed adjacent to the winding of the outer diameter of the second diameter portion 134 of the lens barrel 130 according to the present invention, it is opposed to the driving coil 230. The induced magnetic force of the driving coil 230 by the interaction with the magnetic field uttered from the magnet 210 formed by the acts as a Lorentz force, causing a linear motion in the optical axis direction of the lens barrel 120, FIGS. 6 and 7. Explain while referring to.
According to the present invention, if an image of a subject passing through the center of the lens unit 120 composed of a plurality of focusing adjusting lenses L1, L2, L3, and L4 is transmitted to the image sensor via a filter, the image is an electrical signal. The focusing is performed while being converted to and transmitted to the control unit provided in the camera module main body. In this process, the driving coil 230 disposed as being supported by the lens barrel 130 as well as the lens unit 110 is an optical axis. It can move forward and backward along. As such, the lens unit 110 including the lens barrel 130 accommodating the lens unit 120 moves in the optical axis direction, thereby enabling focusing, that is, auto focusing, on the subject.
At this time, in order to clearly capture the subject, the optical image of the subject formed on the image sensor should be focused. In other words, in order to focus the optical image on the subject with the image sensor, the lens unit 110 must move in the direction of the optical axis to adjust the focal length. In this embodiment, a voice coil motor type actuator is used as a driving source. Specifically, auto focusing generates the autofocusing data by data-contrast the captured image, and adjusts the focus by positioning the lens at the largest position. If the subject is in focus, the shape of the subject is clear and contrasted. Since the distinction is clear, the autofocusing data is utilized.
That is, when a user of a mobile communication device or a digital camera equipped with a small optical device adopting the lens actuator 100 according to the present invention presses a recording button, an image sensor is operated to display a subject located in front of the lens actuator 100. After passing through the hollow lens unit 110 and the filter is converted into an electrical signal from the image sensor is transmitted to a control unit (not shown) in the camera module. If the image signal of the subject transmitted from the controller to the image sensor is blurred, it is determined that there is a focusing error of the lens assembly, and currents for moving the lens unit 110 in the optical axis direction are respectively transmitted via the elastic bodies 310 and 320. It is applied to the drive coil 230 having both ends electrically connected to the elastic body of.
When a predetermined current is applied to the driving coil 230 in this manner, a magnetic field is generated in the driving coil 230, and the Lorentz force is generated by the repulsive force or the attraction force with the magnetic flux transmitted from the magnet 210. The driving force protrudes outward from the lens barrel 130, the lens unit 110 including the lens unit 120 accommodated in the lens barrel 130, and the second diameter portion 134 of the lens barrel 130 by the driving force. The driving coil 230 disposed while being supported by the flange portion 136, which is configured to overcome the elastic force due to the pre-load provided by itself in the process of assembling the first elastic body 310 and the second elastic body 320, has an optical axis. The reciprocating motion in the direction becomes possible. At this time, the control unit in the camera module can realize the focusing to sharpen the image of the subject captured by the image sensor by moving the lens unit 110 up and down on the optical axis in a method of changing the direction of the current. If the current is supplied to the driving coil 230 in the opposite direction, the lens unit 110 may be moved downward.
In the above, a preferred embodiment of the present invention has been described, but it is only presented to help those skilled in the art for the sake of understanding only, and the present invention is not limited thereto. Rather, it will be apparent to those skilled in the art that various modifications and variations can be made easily from the above-described embodiments and the accompanying drawings. However, it will be more apparent from the following claims that such modifications and variations fall within the scope of the present invention without departing from the spirit of the present invention.
1 is a schematic cross-sectional view of an auto focus lens assembly that has been mounted in a miniature optical instrument such as a mobile device.
Figure 2 is an exploded perspective view schematically showing the coupling relationship between the components constituting the lens actuator of the VCM system employing the elastic member according to the present invention.
3 is an overall perspective view of a lens actuator in which an elastic member according to the present invention is formed.
4 is a plan view schematically showing an elastic member (first elastic body) coupled to a lens actuator according to the present invention;
5 is a cross-sectional view of the elastic member according to the present invention cut along the line V-V of FIG.
FIG. 6 is a cross-sectional view showing a state before driving the lens actuator of the present invention cut along the VI-VI line of FIG. 3; FIG.
7 is a cross-sectional view showing a state in which the lens actuator of the present invention is driven.
<Explanation of symbols for the main parts of the drawings>
100: lens actuator 110: lens unit (lens module)
120 lens unit 130 lens barrel
200: drive unit 210: magnet
220: York 222: First York
224: second yoke 230: drive coil
310: elastic member (first elastic body) 312: outer peripheral portion
314: curved portion 316: movable portion
318: inner peripheral portion 320: second elastic body
410: upper cover 420: lower cover
430 base

Claims (9)

  1. An elastic member coupled to a lens actuator of a compact optical device, the elastic member including an outer circumference and an inner circumference, wherein the inner circumference region extends downward so that the outer circumference region can be bent upward at an initial driving position.
  2. The method of claim 1,
    The elastic member has a leaf spring shape, the elastic member having a wave-shaped curved portion between the outer peripheral portion and the inner peripheral portion.
  3. A lens unit to which a lens unit is mounted to allow imaging of a subject;
    A driving unit for moving the lens unit along an optical axis direction by a driving force caused by interaction of a magnet and a driving coil disposed along an outer circumference of the lens unit;
    An elastic body that is coupled to the upper and lower ends of the lens unit and the driving unit, the elastic body comprising the elastic member described in claim 1
    Lens actuator for a small optical device comprising a.
  4. The method of claim 3, wherein
    The lens unit includes a lens barrel for receiving the lens unit, the lens barrel comprises a plurality of diameter portions having different diameters.
  5. The method of claim 4, wherein
    At least one of the magnet and the drive coil is disposed along the outer periphery of the diameter portion of the lens barrel does not have a maximum diameter.
  6. The method of claim 4, wherein
    The driving unit includes a yoke for controlling the magnetic force of the magnet.
  7. The method of claim 6,
    The yoke includes a first yoke disposed on an upper end of the magnet, and a second yoke extending downwardly opposite to an outer circumferential surface of the magnet and an outer circumferential surface of the driving coil.
  8. The method of claim 7, wherein
    And a fastening portion is formed at an outer periphery of the second yoke.
  9. The method of claim 7, wherein
    And the elastic body is composed of a first elastic body serving as the elastic member formed on the first yoke, and a second elastic body in close contact with the lower end of the lens barrel and the second yoke.
KR1020080127151A 2008-12-15 2008-12-15 Elastic member for lens actuator and lens actuator having the same KR20100068701A (en)

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Application Number Priority Date Filing Date Title
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20130085928A (en) * 2011-12-08 2013-07-30 엘지이노텍 주식회사 Camera module
KR101896991B1 (en) 2017-06-09 2018-09-12 (주)알비케이이엠디 Camera apparatus with plate spring

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20130085928A (en) * 2011-12-08 2013-07-30 엘지이노텍 주식회사 Camera module
KR101896991B1 (en) 2017-06-09 2018-09-12 (주)알비케이이엠디 Camera apparatus with plate spring

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