JP2008058964A - Automatic focus adjustment structure for camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic focus adjustment structure for a camera, the structure being designed, such that a guide structure comprising a recess tank and a projection that is engaged with the recess tank is provided, and a lens is stably expanded/contracted. <P>SOLUTION: The automatic focus adjusting structure for the camera includes a lens module; a permanent magnet surrounding the lens module; at least one coil base set on one side of the permanent magnet; and a coil wound around the coil base. The lens module has a lens barrel and a lens mounted in the lens barrel, and between the lens barrel and coil base, the recess tank and the projection are formed so as to guide the lens to expand/contract. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an automatic focusing structure for a camera, and more particularly to a two-stage automatic focusing structure.

  With the development of digital technology, portable electronic devices such as mobile phones and PDAs (personal information terminals) are developing in the direction of miniaturization and multi-function. In order to reduce the size of the portable electronic device, the digital camera used for the portable electronic device and the lens module used for the digital camera need to be configured to be smaller.

  Current camera motors include a lens and a motor that drives the lens to move. The motor includes a permanent magnet and a power source, and a coil base on which a coil for electrical connection is wound. When the coil is energized, the focal point of the camera can be adjusted by moving the lens in a telescopic manner by the acting force between the magnetic field generated in the coil and the magnetic field of the permanent magnet. However, due to limitations in processing technology, the lens and motor cannot be processed into an absolute ideal shape, and when the lens is mounted in the motor, a gap is formed between the lens and the motor. It is inevitable. Therefore, in the process of moving the lens, a situation such as swinging or rotating occurs, and the lens cannot be moved stably. Therefore, the focus cannot be adjusted accurately, and the image of the camera may be affected.

  In view of the above problems, an object of the present invention is to provide a camera automatic focus adjustment structure having a structure for guiding a lens so as to extend and contract.

  In the automatic focusing structure for a camera, comprising: a lens module; a permanent magnet surrounding the lens module; at least one coil base installed on one side of the permanent magnet; and a coil wound around the coil base. The lens module includes a lens barrel and a lens mounted in the lens barrel, and a concave tank and a projection for guiding the lens to extend and contract are provided between the lens barrel and the coil base, respectively. Is formed.

  A seat, a lens barrel, a lens mounted in the lens barrel, a permanent magnet surrounding the outer peripheral surface of the lens barrel, and an upper coil base and a lower coil base respectively installed at both ends of the permanent magnet And an auto focus adjustment structure for a camera including an upper coil and a lower coil wound respectively on the upper coil base and the lower coil base, wherein the lower coil base is installed on the sheet, and the upper coil base or the Between the lower coil base and the lens barrel, at least one concave tank and a projection for guiding the lens to extend and contract along a straight line are formed.

  As described above, the automatic focusing structure for a camera according to the present invention guides the lens to move by the action force of the coil and the permanent magnet, and to move the lens between the lens barrel and the coil base. Since the concave tank and the concave tank are installed, the lens can be guided so as to expand and contract along the axial direction, and rotation or swinging of the lens can be prevented.

  Hereinafter, the configuration of a specific embodiment according to the present invention will be described in detail with reference to the drawings.

  Please refer to FIG. 1 and FIG. The automatic focus adjustment structure for a camera of the present invention can be used for equipment having a photographing lens such as a digital camera, a camera attached to a mobile phone, a photographing monitor, and the like. The automatic focusing structure for a camera includes a frame frame 1, a lens module 2 installed in the frame frame 1, a permanent magnet 3 surrounding the lens module 2, and both sides of the permanent magnet 3, respectively. The upper coil base 6a and the lower coil base 6b are installed, and the upper coil base 6a and the lower coil base 6b are wound around the upper coil base 6a and the lower coil base 6b, respectively, along a predetermined direction.

  A housing space (not shown) for housing the lens module 2, the permanent magnet 3, the upper coil 5a, the lower coil 5b, the upper coil base 6a, and the lower coil base 6b in the frame frame 1. Z). The frame 1 includes a frame 10 that is a hollow, substantially rectangular parallelepiped, a cover 12, and a sheet 14. The sheet 14 is a square frame provided with an opening (not shown) in the center. A circuit board 16 is installed below the sheet 14, and an image sensor (not shown) is installed on the circuit board 16.

  Four protrusions protruding upward are formed at the four corners of the sheet 14. A through hole 140 and a through hole 142 for accommodating the connecting terminal 144 and the connecting terminal 146 are provided in two projecting portions adjacent to each other. The connecting terminals 144 and 146 are Z-shaped bodies. The connecting terminals 144 and 146 are arranged on the upper surface of the projecting portion and are electrically connected to the upper coil 5a and the lower coil 5b, and are arranged on the lower surface of the projecting portion. A lower end portion that is electrically connected to the substrate; and a connecting portion that is accommodated in the through holes 140 and 142 and connects the upper end portion and the lower end portion so as to be perpendicular to the upper end portion and the lower end portion. A blind hole 141 for accommodating the connection terminal 148 is provided in the other protruding portion of the sheet 14. The connecting terminal 148 is an inverted L-shaped body, one end is inserted into the blind hole 141, the other end is formed in a fan shape, and is disposed on the upper surface of the protruding portion where the blind hole 141 is provided. The connection terminals 144, 146 and 148 are made of a conductive material.

  On the three projecting portions where the connecting terminals 144, 146 and 148 are disposed, step portions 145 are formed which are recessed from the outer edge. A guide notch angle 102 is formed at one corner of the frame body 10, and the guide notch angle 102 is engaged with a protruding portion of the sheet 14 where the connecting terminals 144, 146, 148 are not provided, A guide triangular protrusion 149 protruding upward is also formed. When the frame 10 is assembled to the seat 14, the flange portion of the frame 10 is supported by the stepped portion 145 of the seat 14, and the guide notch 102 abuts against the inner wall of the guide triangular protrusion 149 of the seat 14. . The cover 12 covers the upper end of the frame body 10. The size and shape of the cover 12 are substantially the same as the size and shape of the frame body 10, and a circular hole (not shown) used for expansion and contraction movement of the lens module 2 is provided at the center.

  The lens module 2 includes an annular lens barrel 20 and a lens 22 mounted in the lens barrel 20. The barrel 20 is provided with a cylindrical storage space 204 at the center. An inner thread 206 a is formed on the inner wall of the lens barrel 20, and an outer thread 206 b is formed on the outer surface of the lens 22. When the lens 22 is mounted in the lens barrel 20, the lens 22 is integrally fixed to the lens barrel 20 by screwing of the inner thread 206a and the outer thread 206b. The permanent magnet 3 is installed on the outer peripheral surface of the lens barrel 20 so as to surround the outer peripheral surface of the lens barrel 20. Below the permanent magnet 3, an annular projecting edge 208 is provided so as to project outward from the outer peripheral surface of the lens barrel 20. The projecting edge 208 supports the permanent magnet 3 and separates the permanent magnet 3 and the lower coil base 6b.

  Two rectangular recessed tanks 202 cut along the axial direction are formed at the lower end of the lens barrel 20 located below the permanent magnet 3. The two concave tanks 202 are arranged symmetrically and penetrate the lens barrel 20 along the radial direction of the lens barrel 20. An annular gasket 8 made of a nonmagnetic material such as copper is attached above the permanent magnet 3. The gasket 8 separates the permanent magnet 3 and the upper coil base 6a. That is, the gasket 8 is attached to the lens barrel 20 using an adhesive so that the gasket 8 and the projecting edge 208 are symmetrically disposed at both ends of the permanent magnet 3. Then, since the lens module 2, the permanent magnet 3, and the annular gasket 8 are fixed integrally, it is possible to realize the focus adjustment of the lens.

  In order to strengthen the magnetic field generated in the upper coil 5a and the lower coil 5b, the upper coil base 6a and the lower coil base 6b are manufactured of a magnetic material such as iron. The upper coil base 6a includes a rectangular bottom plate 60a provided with a circular hole 62a in the center, an annular wall 64a formed by extending upward from an inner edge of the circular hole 62a of the rectangular bottom plate 60a, and the rectangular bottom plate. And terminals 602a and 604a formed on 60a. The lower coil base 6b includes a rectangular bottom plate 60b provided with a circular hole 62b at the center thereof, an annular wall 64b formed by extending upward from the inner edge of the circular hole 62b of the rectangular bottom plate 60b, and the bottom surface of the rectangular shape. And terminals 602b and 604b formed on 60b.

  The shape and size of the bottom plate 60a of the upper coil base 6a are substantially the same as the shape and size of the cover 12. The terminal 602a is an incoming terminal, the terminal 604a is an outgoing terminal, and is provided on a diagonal line of the bottom plate 60a of the upper coil base 6a. The size of the bottom plate 60 b of the lower coil base 6 b is the same as the size of the sheet 14. At the four corners of the lower coil base 6b, notches (not shown) having the same size and shape as the size and shape of the protruding portion of the sheet 14 are formed. That is, when the notch portion of the lower coil base 6 b is engaged with the four corners of the sheet 14, the lower coil base 6 b is fixed to the sheet 14. The terminal 602b is an incoming terminal, the terminal 604b is an outgoing terminal, provided at two adjacent corners of the bottom plate 60b, respectively, and the terminal 602a and the terminal 604a are the bottom surface 60a. The terminal 602b and the terminal 604b are formed to extend in a direction perpendicular to the bottom surface 60b.

  The upper coil 5a and the lower coil 5b are wound on the outer peripheral surfaces of the annular wall 64a and the annular wall 64b, respectively, along a predetermined direction. Both ends of the coil 5a are wound around the terminals 602a and 604a, respectively, and both ends of the coil 5b are wound around the terminals 602b and 604b, respectively.

  On the outer peripheral surface of the annular wall 64b, two rectangular concave tubs 202 formed by bending inward along the radial direction from the outer surface are provided. The two rectangular concave tanks 202 are installed so as to be symmetric with respect to the axial center of the annular wall 64b, and the size and position correspond to the two rectangular concave tanks 202 provided at the lower end of the lens barrel 20, respectively. When the protrusion 642 is engaged with the concave tank 202, the circumferential position of the lens module 2 is determined.

  As shown in FIGS. 3 and 4, when assembling the automatic focusing structure for a camera, the permanent magnet 3 is mounted on the middle of the outer surface of the lens barrel 20 so as to be placed on the protruding edge 208. The annular gasket 8 is placed on the upper end of the permanent magnet 3. Next, the permanent magnet 3, the annular gasket 8, and the lens module 2 are housed together in the housing space of the frame body 10.

  The upper coil base 6a and the lower coil base 6b are mounted on both ends of the lens module 2 so as to be positioned on both sides of the permanent magnet 3, respectively. The bottom plate 60b of the lower coil base 6b is engaged with the sheet 14, and the two rectangular protrusions 642 of the annular wall 64b of the lower coil base 6b are inserted into the rectangular concave tank 202 of the lens barrel 20. To do. The bottom plate 60a of the upper coil base 6a is positioned above the cover 12 so that the terminals 602b and 604b of the lower coil base 6b are respectively placed on the corners of the sheet 14 where the connecting terminals 144 and 148 are disposed. Attach to. Next, the upper coil base 6a is placed on the upper coil base 6a so that the terminals 602a and 604a of the upper coil base 6a are respectively placed on the corners of the sheet 14 where the connection terminals 146 and 148 are disposed. It is attached above. Next, the cover 12 is mounted on the bottom plate 60a of the upper coil base 6a.

  The upper coil 5a is wound around the outer peripheral surface of the annular wall 64a of the upper coil base 6a along a predetermined direction, one end of the upper coil 5a is wound around the incoming terminal 602a, and the other end is wound around the outgoing terminal 604a. Wrap. The lower coil 5b is wound around the outer peripheral surface of the annular wall 64b of the lower coil base 6b along a predetermined direction, one end of the lower coil 5b is wound around the incoming terminal 602b, and the other end is wound around the outgoing terminal 604b. Wrap. Thereafter, one end of the upper coil 5a wound around the incoming wire terminal 602a of the upper coil base 6a and one end of the lower coil 5b wound around the incoming wire terminal 602b of the lower coil base 6b are joined together in the blind hole of the seat 14. 141 is welded to the connecting terminal 148 installed. The other end of the upper coil 5a wound around the outgoing wire terminal 604a of the upper coil base 6a and the other end of the lower coil 5b wound around the outgoing wire terminal 604b of the lower coil base 6b are connected to the sheet 14 respectively. The terminal 144 and the connecting terminal 146 are welded. Then, as shown in FIG. 3, the upper coil 5a and the lower coil 5b constitute a series circuit, and constitute a power source and an electric circuit of the circuit board 16.

  As described above, since the connecting terminal 144, the connecting terminal 146, and the connecting terminal 148 are provided, the upper coil 5a and the lower coil 5b can be directly electrically connected to a power source. That is, since it is not necessary to electrically connect the coil to the power source with an external electric wire, the structure of the apparatus can be simplified. In addition, the gasket 8 is installed between the permanent magnet 3 and the upper coil 5a, and the protruding edge 20 is installed between the permanent magnet 3 and the lower coil 5b. The upper coil 5a or the lower coil 5b can be prevented from coming into direct contact with the permanent magnet 3. That is, it is possible to prevent the upper coil 5a or the lower coil 5b from being directly connected to the permanent magnet 3 and generating a large magnetic force.

  When using a digital camera, the lens 22 reciprocates between a far focus position and a near focus position. It is assumed that the upper side of the permanent magnet 3 is the N pole and the lower side is the S pole. Since the directions of the upper coil 5a and the lower coil 5b are different, magnetic fields (polarities) having different directions are generated in both. Before the lens 112 moves from the near focus position to the far focus position, the lens 112 is placed at the far focus position. At this time, the top end of the annular wall 64a of the upper coil base 6a contacts the annular gasket 8, and a certain gap is formed between the top end of the annular wall 64b of the lower coil base 6b and the protruding edge 208. .

  When the upper coil 5a and the lower coil 5b are energized, the upper side of the upper coil 5a becomes the S pole, the lower side becomes the N pole, the upper side of the lower coil 5b becomes the N pole, and the lower side becomes the S pole. . That is, the upper part of the upper coil base 6a becomes the S pole, the lower part becomes the N pole, the upper part of the lower coil base 6b becomes the N pole, and the lower part becomes the S pole.

  Since the lower end of the upper coil base 6a is N-pole and the upper end of the permanent magnet 3 is also N-pole, they repel each other. Since the lower end of the lower coil base 6b is an N pole and the upper end of the permanent magnet 3 is an S pole, both attract each other. The lens 112 and the permanent magnet 12 are moved from the far focus position to the near focus position by the repulsive and attractive action force. At this time, the top end of the annular wall 64b of the lower coil base 6b abuts the projecting edge 208, and a constant gap is formed between the top end of the annular wall 64a of the upper coil base 6a and the annular gasket 8. The

  Since the protrusion 642 on the inner surface of the lower coil base 6b is engaged in the concave tank 202 of the lens barrel 20, the rotation of the lens barrel 20 in the circumferential direction is restricted. That is, since the protrusion 642 is formed along the axial direction, the lens 22 can be guided so as to expand and contract along the axial direction, thereby preventing the lens from rotating or swinging.

  When it is desired to move the lens 22 of the digital camera from the near focus position to the far focus position, the current direction of the upper coil 5a and the lower coil 5b is changed. Then, a polarity opposite to the original polarity is generated in the upper coil 5a and the lower coil 5b. However, since the direction of the magnetic field of the permanent magnet 3 is not changed, the lens module 2 can move from the near focus position to the far focus position together with the permanent magnet 3. Since the protrusion 642 on the inner surface of the lower coil base 6b engages in the concave tank 202 of the lens barrel 20, the rotation of the lens barrel 20 in the circumferential direction is restricted. In other words, since the protrusion 642 is formed along the axial direction, the lens 22 is guided so as to expand and contract along the axial direction, thereby preventing the lens from rotating or swinging.

  After the lens module 2 reaches the far focus position or the near focus position, when the electricity to the upper coil 5a and the lower coil 5b is cut off, the magnetic fields of the upper coil base 6a and the lower coil base 6b disappear. However, since the upper coil base 6a and the lower coil base 6b are made of a magnetic material, the permanent magnet 3 attracts the upper coil base 6a or the lower coil base 6b. That is, even if no power is supplied to the lens module 2, the power can be saved because the lens module 2 is still placed at the far focus position or near focus position.

  The annular gasket 8 is installed between the permanent magnet 3 and the upper coil base 6a, and the protruding edge 20 is installed between the permanent magnet 3 and the lower coil base 6b. The upper coil base 6a or the lower coil base 6b can be prevented from coming into direct contact with the permanent magnet 3. That is, it can be prevented that the upper coil base 6a or the lower coil base 6b is directly connected to the permanent magnet 3 to generate a large magnetic force.

  In the embodiment of the present invention, since the concave tank 202 at the bottom end of the lens barrel 20 and the protrusion 642 of the lower coil base 6b are engaged with each other, the rotation of the lens module 2 is restricted and the lens is stably expanded and contracted. Can be guided to make the focus adjustment accurate. Thus, the positions of the concave tank 202 and the protrusion 642 can be exchanged. That is, the concave tank 202 can be provided on the lower coil base 6 b and the protrusion 642 can be provided on the lens barrel 20.

  Alternatively, the protrusion 642 and the concave tank 202 may be provided between the upper end portion of the lens barrel 20 and the upper coil base 6a, or may be provided between the lower end portion of the lens barrel 20 and the lower coil base 6b. it can. The protrusion 642 may be provided integrally with the lens barrel 20 or the coil bases 6a and 6b. The quantity and shape of the protrusion 642 and the concave tank 202 can be freely determined according to the difference in the automatic focusing structure for a camera. For example, it can be provided in a cylindrical shape, a semi-cylindrical shape or the like.

It is a three-dimensional exploded view of one embodiment of the automatic focusing structure for a camera according to the present invention. FIG. 3 is a three-dimensional assembly diagram of the automatic focusing structure for a camera shown in FIG. 1. FIG. 3 is a perspective view of the internal structure of the automatic focusing structure for a camera shown in FIG. 2. It is sectional drawing of the automatic focus adjustment structure for cameras shown in FIG. It is an enlarged view of the ellipse V part shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Frame frame 2 Lens module 3 Permanent magnet 5a Upper coil 5b Lower coil 6a Upper coil base 6b Lower coil base 8 Annular gasket 10 Frame 12 Cover 14 Sheet 16 Circuit board 20 Lens barrel 22 Lens 60a Bottom surface 60b Bottom surface 62a Circular hole 62b Circular hole 64a Annular wall 64b Annular wall 102 Guide cutout part 140 Through hole 141 Blind hole 142 Through hole 144 Connecting terminal 145 Stepped part 146 Connecting terminal 148 Connecting terminal 149 Stepped part 202 Recessed tank 204 Housing space 206a Screw thread 206b Screw thread 206 Edge 602a terminal 602b terminal 604a terminal 604b terminal 642 protrusion

Claims (16)

A lens module;
A permanent magnet surrounding the lens module;
At least one coil base installed on one side of the permanent magnet;
In the automatic focusing structure for a camera, including a coil wound around the coil base,
The lens module is
A lens barrel,
A lens mounted in the lens barrel,
An automatic focus adjustment structure for a camera, wherein a concave tub and a projection for guiding the lens to extend and contract are formed between the lens barrel and the coil base, respectively.   2. The automatic focusing structure for a camera according to claim 1, wherein the protrusion is formed on the coil base, and the concave tank is formed on the lens barrel.   2. The automatic focusing structure for a camera according to claim 1, wherein the concave tank is formed on the coil base and the protrusion is formed on the lens barrel. The at least one coil base includes an upper coil base and a lower coil base installed on both sides of the permanent magnet,
The automatic focusing structure for a camera according to claim 1, wherein an upper coil and a lower coil are wound around the upper coil base and the lower coil base, respectively.   5. The automatic focusing structure for a camera according to claim 4, wherein the protrusion and the concave tank are respectively formed on the upper coil base and an upper end portion of the lens barrel on which the upper coil base is disposed.   5. The automatic focusing structure for a camera according to claim 4, wherein the protrusion and the concave tank are respectively formed on the lower coil base and a lower end portion of the lens barrel on which the lower coil base is disposed.   The protrusion and the concave tub are formed on the upper coil base and an upper end portion of the lens barrel on which the upper coil base is arranged, and the lower coil base and the lens barrel on which the lower coil base is arranged. 5. The automatic focusing structure for a camera according to claim 4, wherein the structure is also formed at a lower end portion.   2. The automatic focusing structure for a camera according to claim 1, wherein the protrusion is formed integrally with the lens barrel or the coil base, and the concave tank penetrates the coil base or the lens barrel in a radial direction. .   2. The automatic focusing structure for a camera according to claim 1, wherein the projection and the concave tank are a rectangular body, a cylindrical body, or a semi-cylindrical body formed by extending in the axial direction. The automatic focusing structure for a camera further includes a frame frame for accommodating the lens module, the permanent magnet, and a coil base on which a coil is wound,
The frame frame includes a frame body and a sheet that engages with the frame body,
The camera automatic focusing structure according to claim 1, wherein a connecting terminal for electrically connecting the coil to the sheet is installed.   11. The automatic focusing structure for a camera according to claim 10, wherein the connecting terminal is formed in a Z-shaped body or an L-shaped body. Two guide terminals for guiding both ends of the coil are formed on the coil base,
11. The automatic focusing structure for a camera according to claim 10, wherein both ends of the coil are wound around the guide terminal and are electrically connected to a connecting terminal installed on the sheet. Sheet,
A lens barrel,
A lens mounted in the barrel;
A permanent magnet surrounding the outer peripheral surface of the lens barrel;
An upper coil base and a lower coil base respectively installed at both ends of the permanent magnet;
In the automatic focusing structure for a camera, including an upper coil and a lower coil wound respectively on the upper coil base and the lower coil base,
The lower coil base is installed on the seat;
The camera is characterized in that at least one concave tank and a projection are formed between the upper coil base or the lower coil base and the lens barrel to guide the lens so as to extend and contract along a straight line. Automatic focus adjustment structure. The sheet is provided with a first series connection terminal and a second connection terminal that are electrically connected to both poles of the power source,
14. The automatic focusing structure for a camera according to claim 13, wherein one end of the upper coil and one end of the lower coil are electrically connected to the first series connection terminal and the second connection terminal, respectively. Two guide terminals for guiding both ends of the upper coil are formed on the upper coil base,
Both ends of the upper coil are respectively wound around two guide terminals of the upper coil base,
Two guide terminals for guiding both ends of the lower coil are formed on the lower coil base,
15. The automatic focusing structure for a camera according to claim 14, wherein both ends of the lower coil are wound around two guide terminals of the lower coil base, respectively. A third connecting terminal is provided on the sheet;
The first connection terminal is electrically connected to one end of the lower coil;
The second connecting terminal is electrically connected to one end of the upper coil,
16. The automatic focusing structure for a camera according to claim 15, wherein the third connecting terminal is electrically connected to the other ends of the upper coil and the lower coil.

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