JP2006276565A - Lens driving apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens driving apparatus which can be built in a small-sized optical apparatus such as a mobile phone camera. <P>SOLUTION: The lens driving apparatus includes a lens holder 1 for holding the lens 11 and a fixing member 2 for guiding the lens holder 1 in an optical axis direction. And, a coil 23 is fixed to one of the lens holder 1 and the fixing member 2, and a magnet 12 is fixed to the other, and in reply to the power supply to the coil 23, the lens holder 1 is moved in the direction of the optical axis 21 by the function of the specific interaction between the coil 23 and the magnetic field of the magnet 12. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lens driving device that drives a lens used in a camera or the like.

  Conventionally, a zoom mechanism has been employed in cameras. A general zoom mechanism of a camera lens has a cam groove provided in a lens barrel surrounding the lens. A key provided on the lens is inserted into the cam groove, and the lens barrel is rotated by a motor or the like, thereby moving the lens to the optical axis. It is configured to move in the direction.

  Since the zoom mechanism of such a camera lens is very difficult to miniaturize, for example, the zoom mechanism is almost adopted until several years ago in very small optical devices such as a camera for a mobile phone and an endoscope. It wasn't. However, recently, along with the downsizing of video cameras and still cameras, etc., a screw shaft with a screw groove is driven by a stepping motor, and the lens is driven by engaging the key part of the lens with the groove of the screw shaft. (See Patent Document 1). Also, in the field of mobile phones, a mechanism that has simplified and miniaturized the zoom mechanism of the camera lens has appeared (Patent Document 2).

JP-A-7-336938 (abstract) JP 2002-290523 (abstract, FIG. 5)

  Although the zoom mechanisms described in Patent Documents 1 and 2 are considerably downsized, they are not yet sufficient. This is because the zoom mechanism is still complex.

  Further, in the conventional zoom mechanism, the lens position is maintained on the wide-angle side or the telephoto side by continuing energization of the motor, resulting in a large current loss.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a lens driving device that can be incorporated into a small optical device such as a camera for a mobile phone. Another object of the present invention is to provide a lens driving device with little current loss during position holding.

  In order to solve the above-described problem, a lens driving device of the present invention includes a lens holder that holds a lens and a fixing member that guides the lens holder in the optical axis direction, and either the lens holder or the fixing member. The lens holder is moved in the direction of the optical axis by the action of interaction with the magnetic field of the magnet.

  In the present invention, when the coil is energized, a force is applied to drive the coil according to Fleming's left-hand rule, and the lens holder moves in the optical axis direction by the force or the reaction force of the force. Since the lens holder is driven by such a simple configuration and driving principle, a zoom mechanism having a small size can be easily obtained, and can be incorporated into a small or ultra-small optical apparatus.

  In addition to the lens driving device of the above-described invention, another invention is such that a magnetic material is fixed to either the lens holder or the fixing member, a magnet is fixed to the other, and the coil is not energized. The position is maintained by maintaining the state in which the lens holder is in contact with the abutting portion of the fixing member disposed on at least one side in the optical axis direction by magnetic attraction between the magnets. According to this configuration, in the non-energized state, the lens holder is held in position by the magnetic attractive force of the magnet, so that current loss is reduced.

  Furthermore, in another invention, in addition to the lens driving device of the above-described invention, a holding magnet made of a permanent magnet is arranged on the fixed member so as to sandwich the lens holder in the optical axis direction or on either side, and this holding is performed. The lens holder is held at a predetermined position by the magnetic force between the magnets for use. When this configuration is adopted, the lens holder is held in position by the magnetic force for the magnet in a non-energized state, so that current loss is reduced.

  In the present invention, a zoom mechanism having a small size can be easily obtained, and can be incorporated into a small or ultra-compact optical apparatus.

  Hereinafter, a lens driving device according to an embodiment of the present invention will be described with reference to the drawings. First, the lens driving device 10 according to the first embodiment will be described with reference to FIGS.

  The lens driving device 10 is used for a camera portion of a mobile phone, but can also be applied to other optical devices such as a camera or an endoscope attached around the display of a computer. The lens driving device 10 mainly includes a lens holder 1 and a cylindrical fixing member 2.

  The lens holder 1 has a substantially cylindrical shape as a whole and is made of a resin material. The lens holder 1 has a lens 11 such as a convex lens and a magnet 12 made of a cylindrical permanent magnet. The lens 11 is mounted and fixed below in FIG. 1 of a disk portion 14 having a light passage hole 13 that also functions as a diaphragm. The lens 11 is a plastic lens and an aspheric lens. In addition, it is good also as the lens holder 1 which has a some lens by making the lens holder 1 hold | maintain lenses other than the lens 11. FIG.

  The magnet 12 is disposed so as to be sandwiched between two holding portions 15 and 16 projecting in an annular shape on the outer periphery of the lens holder 1, and is fixed to the lens holder 1 with an adhesive or the like. The magnet 12 is configured so as to be circular as a whole by combining two to four arc-shaped members. The magnet 12 is magnetized so that the inner peripheral surface is an S pole and the outer peripheral surface is an N pole, and the magnetic flux crosses the magnet 12 in the radial direction. The magnet 12 as a whole may not be formed in a cylindrical shape, but may be formed so as to have a gap partially, such as a structure in which two magnets having a circumferential range of 120 degrees are opposed to each other with an interval of 60 degrees. .

  The fixing member 2 guides the lens holder 1 along the optical axis 21. In the first embodiment, the fixing member 2 has a large-diameter base 22 made of a resin material and a small-diameter bobbin made of a resin material that holds the coil 23. It consists of 24 two members. The fixing member 2 may be a single member in which the base 22 and the bobbin 24 are integrated instead of the two members. Note that the upper surface of the base 22 in FIG. 1 serves as an abutting portion 25 with which the lens holder 1 abuts.

  An annular and plate-shaped metal plate 31 made of a magnetic material is fixed to the cylindrical base 22 at a position overlapping the magnet 12 in the direction of the optical axis 21. A coil 23 is wound around the bobbin 24 so as to rotate around the optical axis 21 and is fixed to the bobbin 24. An annular and plate-shaped metal plate 32 made of a magnetic material is fixed to the upper surface of the bobbin 24 in FIG. 1 at a position overlapping the magnet 12 in the direction of the optical axis 21.

  A diaphragm (not shown) is arranged near the center of the base 22, and an image pickup device composed of a CCD is arranged on the back side (downward in FIG. 1) of the diaphragm. As a structure that is fixedly held on the base 22, one or more of a lens, an aperture, and an image sensor are selected according to the installed optical system, and sometimes the base 22 does not hold any of them. good.

  A circular abutting portion 34 serving as an abutting portion having a circular hole 33 is provided above the bobbin 24 in FIG. 1, and the lens holder 1 guided by the circular hole 33 moves back and forth in the direction of the optical axis 21. ing. The movable range of the lens holder 1 is between the state shown in FIG. 1 and the state where the holding portion 15 is in contact with the circular contact portion 34. That is, the state in which the holding portion 16 of the lens holder 1 is in contact with the abutting portion 25 which is the uppermost portion in FIG. 1 of the base 22 (FIG. 1) is the state in which the lens holder 1 has moved most to one side of the movable range. The state in which the holding portion 15 of the lens holder 1 is in contact with the circular contact portion 34 of the bobbin 24 is the state in which the lens holder 1 has moved most to the other side of the possible range.

  The base 22 and the bobbin 24 are bonded and fixed with an adhesive. This adhesion is performed by injecting an adhesive into a circular groove 35 provided on the outer periphery of the contact portion between the base 22 and the bobbin 24. Further, a part of the outer peripheral surface of the base 22 is notched, and a notch 36 (see FIG. 3) is provided. An FPC (flexible circuit board) 37 is disposed in the notch 36 so as to fit inside the outer peripheral surface of the base 22. The FPC 37 serves as a conductive portion that supplies current from the power source to the coil 23.

  Next, the operation of the lens driving device 10 configured as described above will be described.

  When a current flowing in one direction is supplied to the coil 23 from a power source (not shown), an interaction with the magnetic field of the magnet 12 works, and a downward driving force is generated in the magnet 12 in FIG. As a result, the lens holder 1 works downward in FIG. 1, hits the base 22, cannot move any more, and stops. Thereafter, the power supply to the coil 23 is stopped. Even when the power supply to the coil 23 is stopped, the lens holder 1 maintains the state shown in FIG. This is a result of magnetic attraction between the metal plate 31 and the magnet 12.

  Thereafter, when a current flowing in the other direction, which is the opposite direction to the previous direction, is applied to the coil 23, an interaction with the magnetic field of the magnet 12 acts, and an upward driving force acts on the magnet 12 in FIG. As a result, the lens holder 1 moves upward in FIG. 1, hits the circular abutting portion 34 of the bobbin 24, and stops there. Thereafter, the power supply to the coil 23 is stopped. Even when energization of the coil 23 is stopped, the lens holder 1 maintains a contact state with the circular contact portion 34. This is a result of the magnetic attractive force between the metal plate 32 and the magnet 12. In addition, although the energization to the coil 23 is stopped at both ends of the movable range, it is not necessary to make it zero, but a slight current may be passed to further secure the position.

  The lens driving device 10 is in a wide-angle photographing state in the state of FIG. 1 and is in a telephoto state when the lens holder 1 approaches the photographing object along the optical axis 21. As a result, a zoom operation with a predetermined magnification becomes possible. The lens driving device 10 is configured to switch between the two positions of the wide angle and the telephoto, but can be configured to switch to a three position by stopping in the middle of the zoom operation. For example, a metal plate made of an annular magnetic material is embedded substantially in the center in the direction of the optical axis 21 of the bobbin 24. When the lens holder 1 comes in the middle of the movable range, the energization is stopped, and the magnet 12 of the lens holder 1 and the bobbin 24 By adopting a configuration in which a magnetic attractive force is applied to the metal plate embedded in the center to maintain the intermediate position, a three-position switching configuration can be obtained.

  As described above, in the lens driving device 10, when the coil 23 is energized, a force is applied to drive the coil 23 according to Fleming's left-hand rule, but the coil 23 is fixed to the fixing member 2 and cannot move. Therefore, the reaction force is applied to the magnet 12, and the lens holder 1 to which the magnet 12 is fixed moves in the direction of the optical axis 21. Since the lens holder 1 operates with such a simple configuration and driving principle, a zoom mechanism with a small size can be easily obtained, and can be incorporated into an ultra-compact optical apparatus.

  Further, in the lens driving device 10, even when no current is supplied due to the magnetic attractive force between the magnetic material (metal plates 31, 32) and the magnet 12, which is a permanent magnet, the position can be reduced even if the current is reduced. Retention is ensured. For this reason, the current loss at the time of position holding is zero or very small.

  Since the lens driving device 10 according to the first embodiment has a configuration in which the coil 23 is wound around the outer periphery, the lens driving device 10 is a driving mechanism with good current efficiency. In addition, since the outer diameters of the metal plates 31 and 32 are smaller than the outer diameter of the coil 23, it is difficult to increase the size, and the configuration is suitable for miniaturization.

  Next, the lens driving device 40 according to Embodiment 2 will be described with reference to FIG.

  The lens driving device 40 is also used in the camera portion of a mobile phone, but can be applied to other uses such as binoculars. The lens driving device 40 has the same configuration as that of the lens driving device 10 except that the arrangement relationship between the magnet 12 and the coil 23 is reversed. For this reason, the same or similar parts as those of the lens driving device 10 are denoted by the same or similar symbols.

  In addition to the lens 11, the lens holder 1A includes a coil 23 and a washer 41 made of a magnetic material. On the other hand, the fixing member 2A includes a camera frame 42 and a cylindrical yoke 43 fixed to the frame 42 by insert molding.

  The coil 23 is arranged in an air-core shape on the step portion 51 on the outer periphery of the lens holder 1A. The washer 41 is formed in a C-shape, and is incorporated so as to contact the lower side of the lens 11 in FIG. When the washer 41 is assembled, the diameter of the washer 41 is increased, and the washer 41 is strongly fixed to the lens holder 1A by an elastic force. On the back side of the lens holder 1A, a truncated cone-shaped slope portion 52, a ring-shaped butting step portion 53, a ring-shaped step portion 51, and a contact portion 54 serving as an end portion on the back side of the lens holder 1A. Are sequentially provided toward the back side.

  The frame 42 is a part of the camera casing. The yoke 43 is made of a magnetic material and serves as a magnetic flux path for the magnet 12. Unlike Embodiment 1, the magnet 12 is magnetized so that the inner peripheral surface is an N pole and the outer peripheral surface is an S pole. The magnet 12 is preferably a rare earth magnet, but may be other types of magnets such as ferrite. Moreover, although the magnet 12 is a fixed magnet, it may be a bonded magnet. An isotropic magnet may be used, but an anisotropic magnet is more preferable. The magnet 12 is arranged so as to be concentric with the coil 23 (the optical axis 21 is the same center) and to surround the coil 23 radially outward so that the magnetic flux emitted from the N pole crosses the coil 23.

  The yoke 43 has a cylindrical outermost peripheral portion 61 having a minimum diameter, a cylindrical innermost peripheral portion 62 having a minimum diameter, and a disk-shaped connecting portion 63 that connects the two. . The magnet 12 is fixed to the inner peripheral surface of the outermost peripheral portion 61 of the yoke 43 with an adhesive. An inclined surface portion 64 is provided on the inner peripheral side of the innermost peripheral portion 62 so as to contact the slope portion 52 of the lens holder 1A. Further, the tip end of the innermost peripheral portion 62 is an abutting portion 65 that abuts against the abutting step portion 53 of the lens holder 1A.

  The innermost peripheral portion 62 of the yoke 43 does not extend to the center of the magnet 12 in the optical axis 21 direction, and more than half of the inner side of the magnet 12 does not face the innermost peripheral portion 62. ing. As a result, the magnetic flux emitted from the magnet 12 on the subject side is caught by the yoke 43 and returns to the S pole side of the magnet 12 via the yoke 43, but the magnetic flux emitted from the back side of the magnet 12 is perfect. However, a part of the magnetic flux is not captured by the yoke 43 and becomes a leakage magnetic flux and goes toward the optical axis 21 side.

  The operation of the lens driving device 40 configured as described above will be described below.

  When a current flowing in one direction is supplied to the coil 23 from a power source (not shown), an interaction with the magnetic field of the magnet 12 works, and a downward driving force is generated in the coil 23 in FIG. As a result, the lens holder 1 </ b> A works downward in FIG. 4, the abutting portion 54 strikes against the abutting portion 25 on the upper surface of the frame 42, and cannot move any more and stops. Thereafter, the power supply to the coil 23 is stopped. Even when the power supply to the coil 23 is stopped, the lens holder 1A maintains the state shown in FIG. This is a result of the magnetic attraction between washer 41 and magnet 12.

  The magnetic attractive force between the washer 41 and the magnet 12 is generated because the leakage magnetic flux from the magnet 12 acts on the washer 41. The leakage magnetic flux is a magnetic flux mainly generated from the back half of the magnet 12 and is a force for driving the washer 41 to the back side (downward in FIG. 4). For this reason, the lens holder 1A is held in the state shown in FIG.

  Thereafter, when a current flowing in the other direction, which is the opposite direction to the previous direction, is applied to the coil 23, an interaction with the magnetic field of the magnet 12 acts, and an upward driving force acts on the coil 23 in FIG. As a result, the lens holder 1A moves upward in FIG. 4, and the slope portion 52 of the lens holder 1A hits the inclined surface portion 64 of the yoke 43 and stops there. At this time, the abutting step portion 53 abuts against the abutting portion 65. One or both of the two bumps occur, but preferably the bump at the slope portion 52 should occur.

After this abutment occurs, the lens holder 1 </ b> A cannot move in the direction perpendicular to the optical axis 21. This is because the conical slope portion 52 fits into the inclined surface portion 64 having the same shape (conical shape). As a result, the lens 11 is held without vibration. In this state, in order to maintain the position in the direction of the optical axis 21, it is necessary to keep a slight current flowing through the coil 23.

  The lens driving device 40 is in a wide-angle shooting state in the state of FIG. 4, and is in a telephoto state when the lens holder 1A approaches the shooting object along the optical axis 21. As a result, a zoom operation with a predetermined magnification becomes possible. The lens driving device 40 is configured to switch between the two positions of the wide angle and the telephoto. However, the lens driving device 40 can be configured to have a plurality of switching configurations such as three positions and four positions by stopping in the middle of the zoom operation.

  As described above, in the lens driving device 40, when the coil 23 is energized, a force to drive the coil 23 according to Fleming's left-hand rule works, and the lens holder 1A to which the coil 23 is fixed moves in the direction of the optical axis 21. Moving. Since the lens holder 1A operates with such a simple configuration and driving principle, it is possible to easily obtain a zoom mechanism of a small size and to be incorporated into an ultra-small optical apparatus.

  Further, in the lens driving device 40, the position on one side is reliably maintained even when no current is applied by the magnetic attraction between the washer 41 and the magnet 12 which is a permanent magnet. For this reason, the current loss at the time of position holding is zero or very small.

  Since the lens driving device 40 according to this embodiment can suppress the vibration (lateral vibration) of the lens 11 on the telephoto side, it is easy to use. In other words, the camera shake on the telephoto side compared to the wide-angle side is very difficult to see visually, and blurring tends to occur during photographing. In addition, since the lens driving device 40 is fixed to the lens holder 1A is the coil 23, the lens driving device 40 is lighter and more responsive than that fixing the magnet 12.

  Next, a modified example of the lens driving device 40 will be described with reference to FIG.

  FIG. 5 is an enlarged view of a portion corresponding to the slope portion 52 and the inclined surface portion 64 of the lens driving device 40. The innermost peripheral portion 62A of the yoke 43 of the lens driving device 40 is not cylindrical, and three projections are extended from the connecting portion 63 in the axial direction at intervals of 180 degrees. On the other hand, the slope portion 52A has three second slope surfaces that gradually increase in the circumferential direction in addition to the radial inclination. Each of the second slope surfaces is formed over a range of 180 degrees in the circumferential direction.

  When a current is passed through the coil 23 of the lens driving device 40 having such a configuration, the lens holder 1 </ b> A moves back and forth along the optical axis 21 while rotating in the circumferential direction around the optical axis 21.

  This will be described below. First, in a state where the lens holder 1A is in contact with the frame 42 (FIG. 5A), the three inclined surface portions 64 of the yoke 43 are formed on the wide-angle holding portion 71 which is the highest vicinity in the second slope surface. The lens holder 1A is held in position so that it does not move laterally. At this time, the lens holder 1A is located on the farthest side.

  Thereafter, when an electric current is applied to drive the lens holder 1A toward the subject, the lens holder 1A is blocked from advancing as it is by the inclined surface portion 64. Since the lens holder 1 </ b> A has a margin to move forward by rotating, the lens holder 1 </ b> A moves forward (moves toward the subject) while rotating in the circumferential direction while contacting the inclined surface portion 64. When the telephoto side reaches the telephoto side, the inclined surface portion 64 abuts on the telephoto holding portion 72 which is the lowest position in the second slope surface, and the lens holder 1A is held in a position so as not to move laterally at that position. At the same time, the abutting step portion 53 abuts against the abutting portion 65 and the forward movement is prevented.

  In the lens driving device 40 shown in FIG. 5, since the three inclined surface portions 64 are always in contact with the slope portion 52A of the lens holder 1A, vibration of the lens holder 1A can be suppressed. In addition, since the optical axis 21 of the lens holder 1A is not shifted left and right or diagonally by the three inclined surface portions 64, the optical axis 21 of the optical system is always held at a constant position. The innermost peripheral portion 62A may be two, or four or more. In that case, it is preferable to adjust the number of second slope surfaces in accordance with the number of innermost peripheral portions 62A.

  Further, instead of holding the position at the slope portion 52 and the inclined surface portion 64 of the lens driving device 40 and holding the position at the inclined surface portion 64 and the second slope surface of the innermost peripheral portion 62A, as shown in FIG. The position may be maintained (vibration prevention). That is, as shown in FIG. 6 (A), an elastic member 81 such as a rubber member is provided so as to cover the slope portion 52, and the elastic member 81 is moved to the innermost peripheral portion 62 immediately after the lens holder 1A moves to the subject side. You may make it contact | abut to the inclined surface part 64 and aim at vibration prevention.

  In the case of FIG. 6 (A), the lens holder 1A can move further within a predetermined range after contact with the inclined surface portion 64 by the deflection (dent) of the elastic member 81. During the predetermined range, the lens holder 1A The optical axis 21 is held at a fixed position. Further, as shown in FIG. 6B, a curved slope portion 52A and a curved inclined surface portion 64A may be used. Further, only one of them may be a curved surface.

  Next, a lens driving device 90 according to Embodiment 3 will be described with reference to FIG.

  The lens driving device 90 is also used for the camera portion of the cellular phone, but can be applied to other purposes. The lens driving device 90 has the same arrangement relationship between the magnet 12 and the coil 23 as the lens driving device 10, but the magnet 12 is magnetized and the fixing member is different. Except for these differences, the configuration is the same, and the differences will be mainly described. For this reason, the same or similar parts as those of the lens driving device 10 are denoted by the same or similar symbols.

  The lens holder 1 </ b> B has a lens 11 and a coil 23. On the other hand, the fixing member 2B has ring-shaped magnets 91 and 92 made of permanent magnets instead of the magnetic material.

  Unlike the first embodiment, the magnet 12 is NS magnetized in the direction of the optical axis 21 such that the side facing the holding part 15 of the lens holder 1 is the S pole and the side facing the holding part 16 is the N pole. Magnetized. The magnet 12 is preferably a rare earth magnet, but may be other types of magnets such as ferrite. The magnet 91 is provided so as to face the holding portion 15 of the lens holder 1 </ b> B, and the magnet 92 is provided so as to face the holding portion 16. The magnet 91 is magnetized on the side facing the holding portion 15 to the same polarity as the opposing magnetic pole of the magnet 12, for example, the S pole. The magnet 92 is magnetized so that the side facing the holding portion 16 is the same polarity as the opposing magnetic pole of the magnet 12, for example, N pole.

  When the coil 23 is not energized, the lens driving device 90 configured as described above is stopped in a state where the lens holder 1B is floated between the magnets 91 and 92 due to the magnetic repulsion of the three magnets 12, 91 and 92. (See FIG. 7). In the state of FIG. 7, when the coil 23 is energized, the lens holder 1 </ b> B is driven up or down in FIG. 7 along the optical axis 21. Further, when a current flowing in the opposite direction to the energization is supplied to the coil 23, the lens holder 1B is driven to one of the other.

  In the lens driving device 90, three positions can be switched, and energization is not necessary at the intermediate position. Further, the driving amount of the lens holder 1B can be changed according to the magnitude of the current flowing through the coil 23, and stepless and smooth zooming is also possible.

  One of the magnets 91 and 92 of the lens driving device 90, for example, the magnet 92 may be removed, and the lens holder 1B may be kept in contact with the abutting portion 25 due to the repulsion between the magnet 91 and the magnet 12. That is, at the time of de-energization, the lens holder 1B may abut against the abutting portion 25 and stop there, and the lens holder 1B may move to the circular contact portion 34 side by energizing the coil 23. In the case of a structure in which any one of the magnets 91 and 92 is removed, the magnet 12 can be configured to have an attractive relationship rather than a repulsion. In the case of this lens driving device 90 that magnetizes the magnet 12 in the optical axis direction, considering the flow of magnetic flux, the coil 23 has two winding phases like a PM type two-phase stepping motor, If they are arranged side by side in the direction of the optical axis 21 and the direction of the flowing current is reversed, it becomes easy to obtain the driving force of the lens holder 1B.

  As described above, the lens driving devices 10, 40, and 90 according to the respective embodiments are preferred examples of the present invention, but various modifications can be made without departing from the gist of the present invention. For example, the lens driving devices 10, 40, and 90 are illustrated as having a single lens 11, but the lens 11 mounted on the lens holders 1, 1 </ b> A, and 1 </ b> B serving as a movable portion may be a single lens, but is a composite lens. It may be used as a part of a lens.

  In each of the above-described embodiments, the lens holders 1, 1A, 1B are cylindrical. However, the lens 11 may be circular, and the outer shape of the lens holders 1, 1A, 1B surrounding the lens 11 may be rectangular, such as a square. good. This also applies to the fixing members 2, 2A, 2B. That is, the outer shape of the fixing members 2, 2A, 2B may be rectangular instead of columnar.

  Furthermore, although the lens driving devices 10, 40, and 90 of the above-described embodiments have been described as zoom mechanisms for the camera portion of a mobile phone, they can be applied to small and ultra-small ordinary cameras such as digital cameras and surveillance cameras. Applicable. The lens driving device of the present invention can also be applied to switching between normal shooting and macro shooting in a mobile phone camera or other cameras. Furthermore, the lens driving device of the present invention can be applied to all optical devices that use lenses, such as endoscopes and binoculars, in addition to cameras.

It is sectional drawing of the lens drive device which concerns on Embodiment 1 of this invention. It is a perspective view of the lens drive device of FIG. It is a rear view of the lens drive device of FIG. 1, and is a figure which shows the state which the lens holder advanced slightly. It is sectional drawing of the lens drive device which concerns on Embodiment 2 of this invention. FIG. 5A is a diagram illustrating a modification of the lens driving device in FIG. 4, and FIG. 5A is a partially enlarged view illustrating an enlarged slope portion and an inclined surface portion when the lens holder is located on the innermost side, and FIG. It is the elements on larger scale which expand and show a slope part and an inclined surface part when a lens holder approaches the subject side most. FIG. 5 is a view showing a further modification of the lens driving device of FIG. 4, (A) is a partially enlarged view showing an example in which an elastic member is attached to the slope portion, and (B) is an example in which the slope portion and the inclined surface portion are curved surfaces. FIG. It is sectional drawing of the lens drive device which concerns on Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1A, 1B Lens holder 2,2A, 2B Fixing member 10 Lens drive device 11 Lens 12 Magnet 21 Optical axis 22 Base 23 Coil 24 Bobbin 25 Butting part 31 Metal plate (magnetic material)
32 Metal plate (magnetic material)
34 Circular contact part (butting part)
40 Lens drive device
41 Washer (magnetic material)

Claims (3)

A lens holder that holds the lens, and a fixing member that guides the lens holder in the optical axis direction,
A coil is fixed to one of the lens holder and the fixing member, a magnet is fixed to the other, and the lens holder is moved in the optical axis direction by the interaction with the magnetic field of the magnet by energizing the coil. A lens driving device. A magnetic material is fixed to either the lens holder or the fixing member, and the magnet is fixed to the other,
When the coil is not energized, the lens holder is kept in contact with the abutting portion of the fixing member arranged on at least one side in the optical axis direction by magnetic attraction between the magnetic material and the magnet. The lens driving device according to claim 1, wherein the position is held.   A holding magnet made of a permanent magnet is arranged on the fixing member so as to sandwich the lens holder in the optical axis direction, and the lens holder is configured by a magnetic force between the holding magnet and the magnet. The lens driving device according to claim 1, wherein the lens driving device is held at a predetermined position.

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