JP2016035598A - Lens drive device, camera module, and camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress unnecessary resonance in the optical axis direction of a lens drive device.SOLUTION: A lens drive device has a camera shake correction part that includes: a fixing member that is arranged separated from an autofocus (AF) lens drive part in the optical axis direction; a suspension wire that has one end fixed at the periphery of the fixing member, extends along the optical axis to have the other end fixed to the AF lens drive part, and oscillatably supports the AF lens drive part in the direction orthogonal to the optical axis; a break prevention member for preventing the suspension wire from breaking; and a damper material that is disposed between the fixing member and the AF lens drive part to suppress unnecessary resonance in the optical axis direction of the AF lens drive part. The AF lens drive part includes, as a break prevention member, a wire fixing part of a first leaf spring to which the other end of the suspension wire is fixed, and includes, as a break prevention auxiliary member, a projection part that projects in the optical axis direction from a first end of a magnet holder to which the leaf spring is attached.SELECTED DRAWING: Figure 25

Description

  The present invention relates to a lens driving device, a camera module, and a camera, and in particular, a lens driving that can correct a camera shake (vibration) that occurs when a still image is captured with a small camera for a mobile phone and can capture an image without image blurring. The present invention relates to an apparatus, a camera module, and a camera.

  Various lens driving devices have been proposed in the art that prevent image blur on the image plane and enable clear shooting even when camera shake (vibration) occurs when shooting a still image.

  As camera shake correction methods, “optical methods” such as a sensor shift method and a lens shift method, and “software correction methods” for correcting camera shake by image processing by software are known. The camera shake correction method introduced in mobile phones mainly adopts the software correction method.

  The software correction method is disclosed in, for example, Japanese Patent Laid-Open No. 11-64905 (Patent Document 1). In the camera shake correction method disclosed in Patent Document 1, noise components are removed from the detection results of the detection means, and specific information necessary for correcting image blur due to camera shake of the imaging device is calculated from the detection signals from which the noise components have been removed. Thus, when the imaging apparatus is stationary and there is no camera shake, the captured image is also stationary.

  However, the camera shake correction method of the “software correction method” disclosed in Patent Document 1 has a problem that the image quality deteriorates as compared with the “optical type” described later. Further, the camera shake correction method of the software correction method has a drawback that it takes a long time since the imaging time includes software processing.

  For this reason, with the recent increase in the number of pixels, the demand for “optical” as a camera shake correction method is increasing. As “optical” image stabilization methods, “sensor shift method”, “lens shift method”, and “optical unit tilt method” are known.

  The sensor shift method is disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-274242 (Patent Document 2). The digital camera disclosed in Patent Document 2 has a configuration in which an image sensor (CCD) can be moved around a reference position (center) by an actuator. The actuator moves the CCD in accordance with the camera shake detected by the vibration sensor and corrects the camera shake. The CCD is disposed in the CCD moving unit. The CCD can be moved in the XY plane orthogonal to the Z axis by the CCD moving unit. The CCD moving unit mainly includes a base plate fixed to the housing, a first slider that moves in the X-axis direction with respect to the base plate, and a second slider that moves in the Y-axis direction with respect to the first slider. Consists of two members.

  However, in the “sensor shift method” as disclosed in Patent Document 2, the CCD moving unit (movable mechanism) becomes large. For this reason, it is difficult to adopt a sensor shift type camera shake correction device for a small camera for a mobile phone in terms of size (outer shape, height).

  Next, the lens shift method will be described.

  For example, Japanese Unexamined Patent Application Publication No. 2009-144771 (Patent Document 3) discloses an image shake correction apparatus including a shake correction unit that drives a correction lens. The shake correction unit includes a base plate that is a fixed member, a movable lens barrel that holds the correction lens movably, three spheres held between the base plate and the movable lens barrel, and the movable lens barrel with respect to the base plate. A plurality of elastic bodies to be elastically supported, two coils fixed to the base plate, and two magnets fixed to the movable barrel.

  Japanese Patent Laid-Open No. 2006-65352 (Patent Document 4) discloses a specific lens group (hereinafter referred to as “correction lens”) in a photographing optical system (imaging optical system) including a plurality of lens groups. Discloses an “image blur correction device” that corrects image blur by controlling movement in two directions perpendicular to each other in a plane perpendicular to the optical axis. In the image blur correction device disclosed in Patent Document 4, the correction lens is movable in the vertical direction (pitch direction) and the horizontal direction (yaw direction) with respect to the fixed frame via the pitching movement frame and the yawing movement frame. It is supported.

  Japanese Patent Application Laid-Open No. 2008-26634 (Patent Document 5) includes a correction optical member that corrects blurring of an image formed by the imaging optical system by moving in a direction intersecting the optical axis of the imaging optical system. An image stabilization unit is disclosed. In the correction optical member disclosed in Patent Document 5, the lens holding frame that holds the correction lens is supported so as to be movable in the pitch direction and the yaw direction with respect to the housing cylinder via the pitch slider and the yaw slider.

  Japanese Patent Laying-Open No. 2006-215095 (Patent Document 6) discloses an “image blur correction device” that can move a correction lens with a small driving force and can perform image blur correction quickly and with high accuracy. ing. An image blur correction device disclosed in Patent Document 6 includes a holding frame that holds a correction lens, a first slider that supports the holding frame so as to be slidable in a first direction (pitch direction), and a holding frame that has a first holding frame. A second slider that is slidably supported in two directions (yaw direction), a first coil motor that drives the first slider in the first direction, and a second slider that is driven in the second direction. And a second coil motor.

  Japanese Patent Laying-Open No. 2008-15159 (Patent Document 7) discloses a lens barrel provided with a blur correction optical system provided so as to be movable in a direction orthogonal to the optical axis. In the blur correction optical system disclosed in Patent Document 7, the movable VR unit arranged in the VR main body unit holds the correction lens (third lens group) and is movable in the XY plane orthogonal to the optical axis. Is provided.

  Japanese Patent Laid-Open No. 2007-212876 (Patent Document 8) makes it possible to move a correction lens held in a moving frame in first and second directions orthogonal to the optical axis of a lens system, and by driving means. An “image blur correction device” is disclosed in which image blur can be corrected by controlling the optical axis of the correction lens to coincide with the optical axis of the lens system.

  Japanese Patent Laying-Open No. 2007-17957 (Patent Document 9) discloses a correction lens for correcting blurring of an image formed by a lens system in a direction orthogonal to the optical axis of the lens system and first orthogonal to each other. An “image blur correction device” is disclosed that is driven by the operation of a lens driving unit in the first direction and the second direction to correct image blur. In the image blur correction apparatus disclosed in Patent Document 9, the lens driving unit is disposed on one side in a direction orthogonal to the optical axis of the correction lens.

  Japanese Patent Laid-Open No. 2007-17874 (Patent Document 10) moves a correction lens held in a moving frame in a first direction and a second direction that are orthogonal to the optical axis of the lens system and orthogonal to each other. An “image blur correction apparatus” is disclosed that enables image blur correction by controlling the optical axis of the correction lens to coincide with the optical axis of the lens system. The image blur correction device disclosed in Patent Document 10 includes a driving unit having a coil and a magnet that are relatively movable. One of the coil and the magnet is fixed to the moving frame, and the other is fixed to the support frame that supports the moving frame so as to be movable. Further, the image blur correction device disclosed in Patent Document 10 includes a first Hall element that detects position information related to the first direction of the correction lens by detecting the magnetic force of the magnet, and a second correction lens. And a second Hall element that detects position information by detecting the magnetic force of the magnet.

  Each of the “lens shift type” image blur correction devices (camera shake correction devices) disclosed in Patent Documents 3 to 10 described above has a structure in which the correction lens is moved and adjusted in a plane perpendicular to the optical axis. Yes. However, the image blur correction apparatus (camera shake correction apparatus) having such a structure has a problem that it has a complicated structure and is not suitable for downsizing. That is, in the same manner as the sensor shift type camera shake correction device, it is difficult to adopt the lens shift type camera shake correction device in a small camera for a mobile phone in terms of size (outer shape, height).

  In order to solve the above-described problems, camera shake correction is performed by correcting the camera shake (image blur) by swinging the lens module (camera module) itself that holds the lens and the image sensor (image sensor). An apparatus (image blur correction apparatus) has been proposed. Such a method is referred to herein as an “optical unit tilt method”.

  The “optical unit tilt method” will be described below.

  For example, Japanese Patent Laid-Open No. 2007-41455 (Patent Document 11) discloses a lens module that holds a lens and an image sensor, a frame structure that rotatably supports the lens module by a rotation shaft, and a rotation shaft. Driving means (actuator) for rotating the lens module with respect to the frame structure by applying a driving force to the driven part (rotor), and urging the driving means (actuator) to the driven part (rotor) of the rotating shaft An “image blur correcting device for an optical device” is disclosed that includes an urging means (plate spring). The frame structure is composed of an inner frame and an outer frame. The driving means (actuator) is disposed so as to come into contact with the driven portion (rotor) of the rotating shaft from a direction perpendicular to the optical axis. The driving means (actuator) includes a piezoelectric element and an action part on the rotating shaft side. The action portion drives the rotation shaft by longitudinal vibration and bending vibration of the piezoelectric element.

  However, in the “optical unit tilt type” image shake correction apparatus disclosed in Patent Document 11, it is necessary to cover the lens module with a frame structure including an inner frame and an outer frame. As a result, there is a problem that the image blur correction apparatus becomes large.

  Japanese Patent Application Laid-Open No. 2007-93953 (Patent Document 12) houses a camera module in which a photographing lens and an image sensor are integrated in a housing, and the camera module is orthogonal to the photographing optical axis and perpendicular to each other. The first and second axes intersecting with each other are pivotally attached to the housing, and the posture of the entire camera module is controlled inside the housing according to the shake of the housing detected by the hand shake sensor. Thus, there is disclosed a “camera shake correcting apparatus” that corrects camera shake during still image shooting. A camera shake correction device disclosed in Patent Document 12 includes an inner frame that supports an inner frame to which a camera module is fixed so as to be swingable from the outside around a first axis, and is fixed to the casing. The outer frame is supported from the outside so as to be swingable around the second axis, and the inner frame is incorporated in the middle frame in accordance with a camera shake signal from a camera shake sensor (first sensor module for detecting a camera shake in the pitch direction). The first driving means for swinging the frame around the first axis and the middle frame according to the camera shake signal from the camera shake sensor (second sensor module for detecting camera shake in the yaw direction) are incorporated in the outer frame. Second driving means for swinging around two axes. The first driving means includes a first stepping motor, a first reduction gear train for reducing the rotation of the first stepping motor, and a first cam follower provided on an inner frame that rotates integrally with the gear of the final stage. And a first cam for swinging the frame. The second drive means includes a second stepping motor, a second reduction gear train for reducing the rotation of the second stepping motor, and a second cam follower provided in the middle frame that rotates integrally with the final stage gear. And a second cam for swinging the frame.

  However, even in the “optical unit tilt type” camera shake correction apparatus disclosed in Patent Document 12, it is necessary to cover the camera module with the inner frame, the middle frame, and the outer frame. As a result, the camera shake correction apparatus becomes large. Furthermore, in the “optical unit tilt method”, since there is a rotation axis, there is a problem that friction occurs between the hole and the shaft, resulting in hysteresis.

  Furthermore, Japanese Patent Laying-Open No. 2009-288770 (Patent Document 13) discloses a photographic optical apparatus in which the configuration of a photographic unit driving mechanism for correcting shaking with respect to a photographic unit can be improved so as to surely correct shaking. Disclosure. In the photographing optical device disclosed in Patent Document 13, a photographing unit (movable module) and a shake correction mechanism for performing shake correction by displacing the photographing unit are configured inside a fixed cover. The photographing unit is for moving the lens along the direction of the optical axis. The photographing unit includes a moving body that holds a lens and a fixed aperture inside, a lens driving mechanism that moves the moving body along the optical axis direction, and a support body on which the lens driving mechanism and the moving body are mounted. The lens driving mechanism includes a lens driving coil, a lens driving magnet, and a yoke. The photographing unit is supported on the fixed body by four suspension wires. At two locations on both sides of the optical axis between the two, a first photographing unit driving mechanism and a second photographing unit driving mechanism for shake correction that are paired with each other are provided. In these photographing unit driving mechanisms, a photographing unit driving magnet is held on the movable body side, and a photographing unit driving coil is held on the fixed body side.

  However, the “optical unit tilt type” photographing optical device disclosed in Patent Document 13 requires a photographing unit driving magnet in addition to the lens driving magnet. As a result, there is a problem that the photographing optical device becomes large.

  Japanese Patent Laying-Open No. 2011-107470 (Patent Document 14) discloses a lens driving device capable of driving a lens in the optical axis direction and correcting shaking. The lens driving device disclosed in Patent Document 14 includes a first holding body that holds a lens and is movable in the optical axis direction (Z direction), and a second holding that holds the first holding body so as to be movable in the Z direction. A body, a fixed body that movably holds the second holding body in a direction substantially perpendicular to the Z direction, a first drive mechanism for driving the first holding body in the Z direction, and a second holding body in the X direction And a third drive mechanism for driving the second holding body in the Y direction. The first holding body is supported by the second holding body so as to be movable in the Z direction by a first support member formed of an elastic material. The second holding body is supported by the fixed body so as to be movable in a direction substantially perpendicular to the Z direction by a second support member formed of an elastic material. The first drive mechanism includes a first drive coil and a first drive magnet, the second drive mechanism includes a second drive coil and a second drive magnet, and the third drive mechanism includes a third drive coil. A driving coil and a third driving magnet are provided.

  In the lens driving device disclosed in Patent Document 14, three types of driving mechanisms, that is, first to third driving mechanisms are required as driving mechanisms, and each of the first to third driving mechanisms includes a separate coil and magnet, respectively. There is a problem that the number of parts increases.

  Japanese Patent Application Laid-Open No. 2011-113209 (Patent Document 15) has a basic configuration similar to that of the lens driving device disclosed in Patent Document 14, and uses a plurality of wires as the second support member. The lens drive device provided with the buckling prevention member for preventing buckling of a wire is disclosed. The wire is formed in a straight line, and the second holding body is supported by the wire so as to be movable in a direction substantially perpendicular to the Z direction. The buckling prevention member is formed of an elastic member and elastically deforms in the Z direction with a force smaller than the buckling load of the wire. More specifically, the buckling prevention member is composed of a wire fixing portion formed on the leaf spring of the first support member. When a downward force is applied to the movable part such as the second holding body, the wire fixing portion is elastically deformed downward.

  Even in the lens driving device disclosed in Patent Document 15, there is a problem that the number of components increases as in the lens driving device disclosed in Patent Document 14. Further, the lens driving device disclosed in Patent Document 15 merely prevents the wire from buckling due to a force in the direction of compression applied to the wire. In other words, in the lens driving device disclosed in Patent Document 15, no consideration is given to the case where the wire is likely to break due to the force applied in the extending direction of the wire.

  Therefore, the present inventors (the present applicant) are able to reduce the size and height by using the permanent magnet for the autofocus (AF) lens driving device also as the permanent magnet for the camera shake correction device. A camera shake correction device that can be realized has been proposed (see Japanese Patent Application Laid-Open No. 2011-65140 (Patent Document 16)).

  The camera shake correction device disclosed in Patent Document 16 corrects camera shake by moving the lens barrel itself housed in the AF lens driving device, and is therefore referred to as a “barrel shift type” camera shake correction device. In addition, the “barrel shift type” camera shake correction apparatus is divided into a “moving magnet type” in which a permanent magnet moves (moves) and a “moving coil type” in which a coil moves (moves).

  In Patent Document 16, in the second embodiment, as a “moving magnet type” camera shake correction device, four pieces of first permanent magnet pieces and four pieces are arranged apart from each other in the optical axis direction. The second permanent magnet piece is provided with a permanent magnet, and a camera-shake correction coil is disposed between the upper four pieces of the first permanent magnet pieces and the lower four pieces of the second permanent magnet pieces. It is disclosed. That is, the second embodiment is a “moving magnet type” camera shake correction apparatus including permanent magnets composed of a total of eight permanent magnet pieces.

  In the camera shake correction device disclosed in Patent Document 16, the base is spaced from the bottom surface of the autofocus lens driving device, and one end of a plurality of suspension wires is fixed to the outer periphery of the base. Yes. The other ends of the plurality of suspension wires are firmly fixed to the autofocus lens driving device.

  Japanese Patent Laying-Open No. 2011-85666 (Patent Document 17) also discloses a lens driving device that combines an AF control magnet and a shake correction control magnet. The lens driving device disclosed in Patent Document 17 includes a lens holder that includes a first coil (AF coil) disposed on the outer periphery of a lens, and a magnet holder that fixes a magnet having a first surface facing the first coil. A spring that supports the member, the lens holder and the magnet holding member so as to be movable with respect to the magnet in the optical axis direction, and a second surface perpendicular to the first surface of the magnet. And a base member to which the second coil (blur correction coil) is fixed. A lens holding unit having a lens holder, a magnet, a magnet holding member, and a spring is held so as to be movable relative to the base member in a direction perpendicular to the optical axis.

  The lens driving device disclosed in Patent Document 17 discloses a sixth embodiment in which a position detection sensor is arranged in a gap between one wound correction coil. A Hall element is used as the position detection sensor. The lens holding unit is held by four suspension wires provided at the four corners of the fixed portion. That is, one end of the four suspension wires is fixed to the four corners of the fixing portion, and the other end of the four suspension wires is firmly fixed to the lens holding unit.

  On the other hand, Japanese Patent Laying-Open No. 2009-145771 (Patent Document 18) discloses an “image blur correction device” that can reduce the influence of unnecessary resonance. The image blur correction apparatus disclosed in Patent Document 18 includes a movable member that holds a correction unit for image blur correction, and a fixed member that supports the movable member so as to be movable in a plane orthogonal to the optical axis of the imaging optical system. And a driving means for changing the relative position of the movable member with respect to the fixed member in a plurality of directions, and an attenuating means disposed between the movable member and the fixed member. In this patent document 18, by arranging the attenuating means at an appropriate position, translational resonance which is movement in a plane orthogonal to the optical axis and resonance due to rotation around the optical axis are suppressed (attenuated).

JP-A-11-64905 JP 2004-274242 A JP 2009-144771 A JP 2006-65352 A JP 2008-26634 A JP 2006-215095 A JP 2008-15159 A JP 2007-212876 A JP 2007-17957 A JP 2007-17874 A JP 2007-41455 A JP 2007-93953 A JP 2009-288770 A (FIGS. 1 to 5) JP 2011-107470 A JP2011-113209A (paragraphs 0085 to 0088, FIG. 11) Japanese Patent Laying-Open No. 2011-65140 (paragraphs 0091 to 0149, FIGS. 5 to 11) JP 2011-85666 A (paragraph 0027, paragraphs 0050 to 0056, FIG. 7) JP 2009-144771 (paragraphs 0043, 0050, 0059, 0072, 0088)

  In the camera shake correction device disclosed in Patent Document 16, the autofocus lens driving device is swingably supported by a plurality of suspension wires. Therefore, there is a problem that the autofocus lens driving device resonates unnecessarily in the optical axis direction.

  Also in the lens driving device disclosed in Patent Document 17, the lens holding unit is swingably supported by four suspension wires. As a result, like the camera shake correction device disclosed in Patent Document 16, there is a problem that the lens holding unit resonates unnecessarily in the optical axis direction.

  Therefore, the devices disclosed in Patent Documents 16 and 17 cannot perform stable operation.

  On the other hand, as described above, the image shake correction apparatus disclosed in Patent Document 18 suppresses (attenuates) resonance due to motion (translation and rotation around the optical axis) on a plane orthogonal to the optical axis. Not too much.

  Therefore, a problem to be solved by the present invention is to provide a lens driving device, a camera module, and a camera that can perform a stable operation.

  Other objects of the invention will become apparent as the description proceeds.

According to the present invention, the autofocus lens driving section (20; 20A) for moving the lens barrel (12) along the optical axis (O) and the autofocus lens driving section on the optical axis (O). A lens driving device (10; 10A) having a camera shake correction unit that corrects camera shake by moving in a first direction (X) and a second direction (Y) that are orthogonal and orthogonal to each other. And the image stabilizer is
A fixing member (14, 18, 40, 44) disposed away from the autofocus lens driving unit (20; 20A) in the optical axis (O) direction;
A plurality of suspension wires (16) having one end fixed at the outer peripheral portion of the fixing member (14, 18, 40, 44), extending along the optical axis (O) and the other end for autofocusing A plurality of lenses fixed to the lens driving section (20; 20A) and supporting the autofocus lens driving section (20; 20A) so as to be swingable in the first direction (X) and the second direction (Y). Suspension wire (16) of
A breakage prevention member for preventing breakage of the plurality of suspension wires (16);
It is arranged between the fixing member (14, 18, 40, 44) and the autofocus lens driving section (20; 20A), and the fixing member (14, 18, 40, 44) and the autofocus lens driving section ( 20; 20A), a narrowing part (306a) for narrowing a part of the gap,
The autofocus lens drive unit (20; 20) is disposed in a narrowed part of the gap between the fixing member (14, 18, 40, 44) and the autofocus lens drive unit (20; 20A). 20A) a damper material (65) for suppressing unnecessary resonance in the optical axis (O) direction;
Have
The autofocus lens driver (20; 20A)
A lens holder (24) having a cylindrical portion (240) for holding the lens barrel (12);
A focus coil (26) fixed to the lens holder (24) so as to be positioned around the cylindrical portion (240);
A permanent magnet (28) disposed opposite the focus coil (26);
A magnet holder (30) disposed on the outer periphery of the lens holder (24) and holding the permanent magnet (28);
Attached to the first and second ends (30a, 30b) in the optical axis (O) direction of the magnet holder (30), respectively, with the lens holder (30) positioned in the radial direction, in the optical axis (O) direction. The first and second leaf springs (32, 34) that are displaceably supported are disposed at positions farther from the fixing member (14, 18, 40, 44) than the second leaf spring (34). From the first end (30a) of the magnet holder (30) to which the first leaf spring (32) is attached, it protrudes in the direction of the optical axis (O) and assists in preventing breakage of the plurality of suspension wires (16). A plurality of protrusions (308) to be a fracture prevention auxiliary member (308) to be
With
The other ends of the plurality of suspension wires (16) are fixed to the first leaf spring (32),
The first leaf spring (32) extends so as to bypass each of the plurality of protrusions (308), and the other end of each suspension wire (16) is fixed to a part of the first spring (32). The wire fixing part (328) is a breakage prevention member (328).
A lens driving device (10; 10A) is obtained.

  In the lens driving device (10; 10A) according to the present invention, the magnet holder (30) serves as the narrowing portion (306a) and includes at least one protrusion (14, 18, 40, 44) protruding toward the fixing member (14, 18, 40, 44). The damper material (65) may be disposed between the protrusion (306a) and the fixing member (14, 18, 40, 44). In the lens driving device (10; 10A) according to the present invention, the protrusion (306a) is fixed to the fixing member (14, 18, 40, 40) through the hole (344a) formed in the second leaf spring (34). 44).

In the lens driving device (10; 10A) according to the present invention, the fixing member (14, 18, 40, 44) includes a base (14) for fixing (16) one end of the plurality of suspension wires at the outer peripheral portion. A coil substrate (40) fixed on the base and provided with a camera shake correction coil (18) of the camera shake correction unit may be provided. In this case, the damper material (65) is disposed between the protrusion (306a) and the coil substrate (40). In the lens driving device (10; 10A) according to the present invention, the permanent magnet (28) is composed of four pieces of permanent magnet pieces (282f, 282b, 282l, 282r), and four pieces of permanent magnet pieces (282f, 282b, 282l, and 282r) have a first surface facing the focus coil (26), and in the first direction (X) radially outward of the focus coil (26) with respect to the optical axis (O). The camera shake correction coil (18) is disposed opposite to the second direction (Y), and the second image stabilization coil (18) is perpendicular to the first surface of the four permanent magnet pieces (282f, 282b, 282l, 282r). It may consist of four camera shake correction coil portions (18f, 18b, 18l, 18r) disposed on the coil substrate (40) so as to face each other. The magnet holder (30) preferably has a guide groove (302a) for guiding a dispenser for applying the damper material (65).
Further, according to the present invention, the above-described lens driving device and the imaging substrate disposed on the opposite side of the autofocus lens driving unit (20; 20A) with respect to the fixing member (14, 18, 40, 44). A camera module having an image pickup device arranged is obtained.
In addition, according to the present invention, a camera having the camera module described above and a control unit that controls the camera module can be obtained.

  The reference numerals in the parentheses are given for ease of understanding, and are merely examples, and of course are not limited thereto.

  In the present invention, since the damper material is disposed between the fixing member and the autofocus lens driving unit, unnecessary resonance of the autofocus lens driving unit can be suppressed and stable operation can be performed. .

1 is an external perspective view of a lens driving device according to a first embodiment of the present invention. It is a fragmentary longitudinal cross-sectional view of the lens drive device shown in FIG. It is a disassembled perspective view which shows the lens drive device shown in FIG. It is a perspective view which shows the coil board | substrate used for the lens drive device shown in FIG. 1, and the coil for camera shake correction formed in it. It is a perspective view which shows the relationship between a related magnetic circuit and a Hall element. It is a longitudinal cross-sectional view which shows the relationship between a related magnetic circuit and a Hall element. It is a longitudinal cross-sectional view which shows the relationship between a related magnetic circuit when a AF unit is displaced to the front-back direction X, and a Hall element. It is a figure which shows the frequency characteristic of the front Hall element in a related magnetic circuit. The magnetic flux density a of the magnetic field B generated by the front permanent magnet piece and the magnetic field B _I1 generated by the first IS current I _IS1 flowing in the front camera shake correction coil in the regions I, II, and III of FIG. It is a figure which shows the magnitude | size and phase relationship of the magnetic flux density b and the total magnetic flux density (a + b) detected by a front Hall element. It is the figure which made the relationship of FIG. 9 a table. It is a perspective view which shows the relationship between the magnetic circuit used for the lens drive device shown in FIG. 1, and a Hall element. It is a longitudinal cross-sectional view which shows the relationship between the magnetic circuit shown in FIG. 11, and a Hall element. It is a longitudinal cross-sectional view which shows the relationship between the magnetic circuit shown in FIG. 11, and a Hall element when an AF unit is displaced to the front-back direction X. FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 13. It is a figure which shows the frequency characteristic of the front Hall element in the magnetic circuit shown in FIG. The magnetic field B _I1 generated by the magnetic flux density a of the magnetic field B generated by the front permanent magnet piece and the first IS current I _IS1 flowing in the front camera shake correction coil portion in the regions I, II, and III of FIG. It is a figure which shows the magnitude | size and phase relationship of the total magnetic flux density (a + b) detected by the magnetic flux density b of this, and a front side Hall element. It is the figure which made the relationship of FIG. 16 a table. FIG. 12 is a cross-sectional view showing a positional relationship between one permanent magnet piece of a permanent magnet and a focus coil and a camera shake correction coil portion arranged around the permanent magnet piece in the magnetic circuit shown in FIG. 11. It is a fragmentary perspective view which expands and shows the part which fixes the other end of a suspension wire to an upper leaf | plate spring used for the lens drive device shown in FIG. FIG. 20 is a partial cross-sectional view of a fixing portion shown in FIG. 19. It is the perspective view which looked at what combined the coil board | substrate and flexible printed circuit board (FPC) used for the lens drive device shown in FIG. 1 from the back surface side. FIG. 2 is a plan view showing a state in which a shield cover is omitted in the lens driving device shown in FIG. 1. In FIG. 22, it is a partial expansion perspective view which expands and shows the binding part of the terminal part of the wire which comprised the focus coil. FIG. 2 is a partial longitudinal sectional view showing a state in which a shield cover is omitted in the lens driving device shown in FIG. 1. It is the fragmentary perspective view which looked at the lens drive device shown in FIG. 24 from diagonally upward. In the lens drive device shown in FIG. 24, a part of upper leaf | plate spring (1st leaf | plate spring) is abbreviate | omitted and it is a top view which shows the arrangement position of a damper material. It is a figure which shows the frequency characteristic in the optical axis direction of the lens drive part for autofocus of the conventional lens drive device without a damper material. It is a figure which shows the frequency characteristic in the optical axis direction of the lens drive part for autofocus of the lens drive device which concerns on the 1st Embodiment of this invention. In the lens driving device according to the first modified example of the first embodiment, the shield cover is omitted, a part of the upper leaf spring (first leaf spring) is omitted, and the plane showing the arrangement position of the damper material FIG. In the lens driving device according to the second modification of the first embodiment, the shield cover is omitted, a part of the upper leaf spring (first leaf spring) is omitted, and the plane showing the arrangement position of the damper material FIG. In the lens driving device according to the third modified example of the first embodiment, the shield cover is omitted, a part of the upper leaf spring (first leaf spring) is omitted, and the plane showing the arrangement position of the damper material FIG. It is a fragmentary longitudinal cross-section which shows the state which excluded the shield cover in the lens drive device which concerns on the 4th modification of 1st Embodiment. It is a longitudinal cross-sectional view of the lens drive device which concerns on the 2nd Embodiment of this invention. It is a disassembled perspective view which shows the lens drive device shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment]
A lens driving device 10 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is an external perspective view of the lens driving device 10. FIG. 2 is a partial longitudinal sectional view of the lens driving device 10. FIG. 3 is an exploded perspective view showing the lens driving device 10.

  Here, as shown in FIGS. 1 to 3, an orthogonal coordinate system (X, Y, Z) is used. 1 to 3, in the orthogonal coordinate system (X, Y, Z), the X-axis direction is the front-rear direction (depth direction), the Y-axis direction is the left-right direction (width direction), and Z The axial direction is the vertical direction (height direction). In the example shown in FIGS. 1 to 3, the vertical direction Z is the optical axis O direction of the lens. In the second embodiment, the X-axis direction (front-rear direction) is also called a first direction, and the Y-axis direction (left-right direction) is also called a second direction.

  However, in the actual use situation, the optical axis O direction, that is, the Z-axis direction is the front-rear direction. In other words, the upward direction of the Z axis is the forward direction, and the downward direction of the Z axis is the backward direction.

  The illustrated lens driving device 10 includes an autofocus lens driving unit 20 which will be described later and a camera shake that corrects camera shake (vibration) generated in the autofocus lens driving unit 20 when a still image is taken with a small camera for a mobile phone. The apparatus includes a correction unit (described later) and can capture an image without image blur. The camera shake correction unit of the lens driving device 10 moves the autofocus lens driving unit 20 in a first direction (front-rear direction) X and a second direction (left-right direction) orthogonal to the optical axis O and orthogonal to each other. To correct camera shake.

  The autofocus lens driving unit 20 is for moving a lens barrel (not shown) along the optical axis O. A base 14 is disposed away from the bottom of the autofocus lens driving unit 20 radially outward. Although not shown, an image pickup device arranged on an image pickup substrate is mounted on the lower portion (rear portion) of the base 14. This image sensor picks up a subject image formed by the lens barrel and converts it into an electrical signal. The imaging device is configured by, for example, a CCD (charge coupled device) type image sensor, a CMOS (complementary metal oxide semiconductor) type image sensor, or the like. Therefore, a camera module is configured by a combination of the autofocus lens driving unit 20, the imaging substrate, and the imaging element.

  The base 14 has a quadrangular outer shape and a ring shape having a circular opening 14a inside.

  The camera shake correction unit of the lens driving device 10 is opposed to the four suspension wires 16 whose one ends are fixed at the four corners of the base 14 and the permanent magnet 28 of the autofocus lens driving unit 20 described later. It has a hand-shake correction coil 18 arranged.

  The four suspension wires 16 extend along the optical axis O and swing the entire autofocus lens driving unit 20 in the first direction (front-rear direction) X and the second direction (left-right direction) Y. Support as possible. The other ends of the four suspension wires 16 are fixed to the upper end of the autofocus lens driving unit 20 as described later.

  As described above, the four suspension wires 16 function as support members that support the autofocus lens driving unit 20 to be swingable in the first direction X and the second direction Y with respect to the base 14.

  As will be described later, the camera shake correction unit of the lens driving device 10 includes a single rectangular ring-shaped coil substrate 40 that is disposed so as to face and be separated from the permanent magnet 28. The coil substrate 40 is mounted on the base 14 with a flexible printed circuit board (FPC) 44 described later interposed therebetween. The hand-shake correction coil 18 is formed on the coil substrate 40.

  Next, the autofocus lens driving unit 20 will be described with reference to FIG. The autofocus lens driving unit 20 is also called an AF unit.

  The autofocus lens driving unit 20 includes a lens holder 24 having a cylindrical portion 240 for holding a lens barrel, and a focus coil 26 fixed to the lens holder 24 so as to be positioned around the cylindrical portion 240. The magnet holder 30 that holds the permanent magnet 28 disposed opposite to the focus coil 26 so as to face the focus coil 26, and the first and second ends 30a, 30b of the magnet holder 30 in the direction of the optical axis O are respectively attached. The first and second leaf springs 32 and 34 are provided.

  The first and second leaf springs 32 and 34 support the lens holder 24 so as to be displaceable in the optical axis O direction with the lens holder 24 positioned in the radial direction. In the illustrated example, the first leaf spring 32 is called an upper leaf spring, and the second leaf spring 34 is called a lower leaf spring.

  Further, as described above, in the actual use situation, the upward direction in the Z-axis direction (optical axis O direction) is the forward direction, and the downward direction in the Z-axis direction (optical axis O direction) is the backward direction. Accordingly, the upper leaf spring 32 is also referred to as a front spring, and the lower leaf spring 34 is also referred to as a rear spring.

  The magnet holder 30 has a substantially octagonal cylindrical shape. That is, the magnet holder 30 includes an octagonal cylindrical outer cylinder portion 302, a rectangular upper ring-shaped end portion 304 provided at an upper end (front end, first end) 30a of the outer cylindrical portion 302, and an outer cylindrical portion. It has an octagonal lower ring-shaped end portion 306 provided at the lower end (rear end, second end) 30b of 302. The upper ring-shaped end portion 304 has eight upper protrusions 304a that protrude upward at four corners, two at each corner. The lower ring-shaped end 306 has four lower protrusions 306a protruding downward at the four corners.

  The focus coil 26 has an octagonal cylindrical shape that matches the shape of the octagonal cylindrical magnet holder 30. The permanent magnets 28 are arranged in four pieces on the outer cylindrical portion 302 of the magnet holder 30 that are spaced apart from each other in the first direction (front-rear direction) X and the second direction (left-right direction) Y. It consists of a rectangular permanent magnet piece 282. These four pieces of permanent magnet pieces 282 are arranged at a distance from the focus coil 26. In the illustrated embodiment, each permanent magnet piece 282 is magnetized to the N pole on the inner peripheral end side and magnetized to the S pole on the outer peripheral end side.

  The upper leaf spring (front spring) 32 is disposed on the upper side (front side) of the lens holder 24 in the optical axis O direction, and the lower leaf spring (rear side spring) 34 is disposed on the lower side (rear side) of the lens holder 24 in the optical axis O direction. Be placed.

  The upper leaf spring (front spring) 32 includes an upper inner peripheral end 322 attached to the upper end of the lens holder 24 as described later, and an upper attached to the upper ring-shaped end 304 of the magnet holder 30 as described later. And an outer peripheral end 324. A plurality of upper arm portions 326 are provided between the upper inner peripheral end 322 and the upper outer peripheral end 324. That is, the plurality of arm portions 326 connect the upper inner peripheral end 322 and the upper outer peripheral end 324.

  The cylindrical portion 240 of the lens holder 24 has four upper protrusions 240a protruding upward at the four corners at the upper end thereof. The upper inner peripheral end 322 has four upper holes 322a into which the four upper protrusions 240a are press-fitted (inserted). That is, the four upper protrusions 240 a of the cylindrical portion 240 of the lens holder 24 are press-fitted (charged) into the four upper holes 322 a of the upper inner peripheral side end 322 of the upper leaf spring 32, respectively.

  On the other hand, the upper outer peripheral end 324 has eight upper holes 324a into which the eight upper protrusions 304a of the magnet holder 30 are respectively inserted. That is, the eight upper protrusions 304 a of the magnet holder 30 are inserted into the eight upper holes 324 a of the upper outer peripheral end 324, respectively.

  The upper leaf spring (front spring) 32 further includes four arc-shaped extending portions 328 extending radially outward at the four corners of the upper outer peripheral end portion 324. Each of these four arc-shaped extending portions 328 has four wire fixing holes 328a into which the other ends of the four suspension wires 16 are inserted (inserted). The detailed structure of each arc-shaped extending portion 328 will be described later in detail with reference to FIG.

  The lower leaf spring (rear spring) 34 is provided at a lower inner peripheral end 342 attached to the lower end of the lens holder 24 as described later, and at a lower ring-shaped end 306 of the magnet holder 30 as described later. And a lower outer peripheral end 344 to be attached. A plurality of lower arm portions 346 are provided between the lower inner peripheral end portion 342 and the upper outer peripheral end portion 344. That is, the plurality of lower arm portions 346 connect the lower inner peripheral end portion 342 and the lower outer peripheral end portion 344.

  A spacer 36 having substantially the same outer shape is disposed below the lower leaf spring 34. More specifically, the spacer 36 includes an outer ring portion 364 having substantially the same shape as the lower outer peripheral end portion 344 of the lower plate spring 34, a lower inner peripheral end portion 342 of the lower plate spring 34, and a lower portion. An inner ring part 362 having a shape covering the side arm part 346.

  The cylindrical portion 240 of the lens holder 24 has four lower protrusions (not shown) protruding downward at the four corners at the lower end thereof. The lower inner peripheral end 342 has four lower holes 342a into which these four lower protrusions are press-fitted (inserted). That is, the four lower protrusions of the cylindrical portion 240 of the lens holder 24 are press-fitted (charged) into the four lower holes 342a of the lower inner peripheral end 342 of the lower leaf spring 34, respectively.

  On the other hand, the lower outer peripheral end 344 of the lower leaf spring 34 has four lower holes 344a into which the four lower protrusions 306a of the magnet holder 30 are respectively inserted. The outer ring portion 364 of the spacer 36 also has four lower holes 364a at which the four lower protrusions 306a of the magnet holder 30 are respectively pressed at positions corresponding to the four lower holes 344a. That is, the four lower protrusions 306 a of the magnet holder 30 are respectively connected to the four lower holes 364 a of the outer ring portion 364 of the spacer 36 via the four lower holes 344 a of the lower outer peripheral end portion 344 of the lower leaf spring 34. It is press-fitted into the side hole 364a and thermally welded at its tip.

  As is clear from FIG. 2, the four lower protrusions 306 a of the magnet holder 30 protrude so as to approach the coil substrate 40. In other words, the gap between the four lower protrusions 306a and the coil substrate 40 is narrower than the gap in the other region (that is, the gap between the spacer 36 and the coil substrate 40). You can see that

  The elastic member composed of the upper leaf spring 32 and the lower leaf spring 34 serves as a guide means for guiding the lens holder 24 so as to be movable only in the direction of the optical axis O. Each of the upper leaf spring 32 and the lower leaf spring 34 is made of beryllium copper, phosphor bronze, or the like.

  A female screw (not shown) is cut on the inner peripheral wall of the cylindrical portion 240 of the lens holder 24. On the other hand, a male screw to be screwed into the female screw is cut on the outer peripheral wall of the lens barrel. Therefore, in order to attach the lens barrel to the lens holder 24, the lens barrel is rotated around the optical axis O with respect to the cylindrical portion 240 of the lens holder 24 and screwed along the optical axis O direction. The barrel is accommodated in the lens holder 24 and joined to each other by an adhesive or the like.

  As will be described later, by passing an autofocus (AF) current through the focus coil 26, the lens holder 24 (lens barrel) is lighted by the interaction between the magnetic field of the permanent magnet 28 and the magnetic field due to the AF current flowing through the focus coil 26. It is possible to adjust the position in the direction of the axis O.

  As described above, the autofocus lens driving unit (AF unit) 20 includes the lens holder 24, the focus coil 26, the permanent magnet 28, the magnet holder 30, the upper leaf spring 32, the lower leaf spring 34, and the spacer 36. The

  Next, the camera shake correction unit of the lens driving device 10 will be described in more detail with reference to FIG.

  As described above, the camera shake correction unit of the lens driving device 10 is opposed to the four suspension wires 16 whose one ends are fixed at the four corners of the base 14 and the permanent magnet 28 of the autofocus lens driving unit 20. It has a hand-shake correction coil 18 arranged.

  The four suspension wires 16 extend along the optical axis O, and the entire autofocus lens driving unit (AF unit) 20 is moved in the first direction (front-rear direction) X and the second direction (left-right direction). Supports Y in a swingable manner. The other ends of the four suspension wires 16 are fixed to the upper end of the autofocus lens driving unit 20.

  More specifically, as described above, the four arc-shaped extending portions 328 of the upper leaf spring 32 each have four wire fixing holes 328a into which the other ends of the four suspension wires 16 are inserted (inserted). (See Fig. 3) The other ends of the four suspension wires 16 are inserted (inserted) into the four wire fixing holes 328a and fixed with an adhesive, solder, or the like.

  In the illustrated example, the extending portion 328 on each arc has an L shape, but it is needless to say that the present invention is not limited to this.

  Two of the four suspension wires 16 are also used to supply power to the focus coil 26.

  As described above, the permanent magnet 28 is composed of four pieces of permanent magnet pieces 282 arranged to face each other in the first direction (front-rear direction) X and the second direction (left-right direction) Y.

  The camera shake correction unit of the lens driving device 10 includes one ring-shaped coil substrate 40 that is inserted between the four permanent magnet pieces 282 and the base 14 and spaced apart. The coil substrate 40 has through holes 40a for inserting the four suspension wires 16 at the four corners. The hand movement correction coil 18 is formed on the single coil substrate 40.

  The combination of the base 14, the coil substrate 40, the camera shake correction coil 18, and the flexible printed circuit board (FPC) 44 is a fixed member (separated from the autofocus lens driving unit 20 in the optical axis O direction). 14, 40, 18, 44).

  Here, in the four pieces of permanent magnet pieces 282, the permanent magnet pieces arranged on the front side, the rear side, the left side, and the right side with respect to the optical axis O are respectively replaced with the front side permanent magnet piece 282f and the rear side permanent magnet. These will be referred to as a magnet piece 282b, a left permanent magnet piece 282l, and a right permanent magnet piece 282r.

  Referring also to FIG. 4, four camera shake correction coil portions 18 f, 18 b, 18 l and 18 r are formed on the coil substrate 40 as the camera shake correction coil 18.

  Two camera shake correction coil portions 18f and 18b arranged opposite to each other in the first direction (front-rear direction) X move the autofocus lens driving unit (AF unit) 20 in the first direction (front-rear direction) X. It is for moving (swinging). Such two camera shake correction coil portions 18f and 18b are called first-direction actuators. Here, the camera shake correction coil portion 18 f on the front side with respect to the optical axis O is referred to as “front camera shake correction coil portion”, and the camera shake correction coil portion 18 b on the rear side with respect to the optical axis O is referred to as “rear camera shake correction”. It will be referred to as a “coil section for use”.

  On the other hand, the two camera shake correction coil portions 18l and 18r arranged to face each other in the second direction (left-right direction) Y move the autofocus lens driving unit (AF unit) 20 in the second direction (left-right direction). ) For moving (swinging) to Y. Such two camera shake correction coil portions 18l and 18r are called second-direction actuators. Here, the camera shake correction coil portion 18l on the left side with respect to the optical axis O is referred to as a “left hand shake correction coil portion”, and the camera shake correction coil portion 18r on the right side with respect to the optical axis O is referred to as a “right hand shake correction coil portion”. Part ".

  As shown in FIG. 4, in the illustrated camera shake correction coil 18, the front hand shake correction coil portion 18f and the left hand shake correction coil portion 18l are respectively formed of the front permanent magnet piece 282f and the left permanent magnet piece 282l facing each other. It is divided into two coil portions so as to be separated at the center in the longitudinal direction. That is, the front-side camera shake correction coil portion 18f includes a left-side coil portion 18fl and a right-side coil portion 18fr. Similarly, the left hand shake correction coil portion 18l includes a front coil portion 18lf and a rear coil portion 18lb.

  In other words, each of the front-side image stabilization coil portion 18f and the left-side image stabilization coil portion 18l is composed of two loop portions, whereas the rear-side image stabilization coil portion 18b and the right-side image stabilization coil portion 18l. Each of the coil portions 18r is composed of one loop portion.

  Thus, among the four camera shake correction coil portions 18f, 18b, 181 and 18r, each of the two specific camera shake correction coil portions 18f and 18l arranged in the first direction X and the second direction is: It is divided into two coil portions 18fl, 18fr and 18lf, 18lb so as to be separated at the longitudinal center of the opposing permanent magnet pieces 282f and 282l.

  The four camera shake correction coil portions 18f, 18b, 18l, and 18r configured as described above cooperate with the permanent magnet 28 to move the entire autofocus lens driving unit (AF unit) 20 in the X-axis direction (first order). 1 direction) and Y-axis direction (second direction). The combination of the camera shake correction coil portions 18f, 18b, 18l, and 18r and the permanent magnet 28 functions as a voice coil motor (VCM).

  As described above, the camera shake correction unit of the illustrated lens driving device 10 moves the lens barrel itself housed in the autofocus lens driving unit (AF unit) 20 in the first direction (front-rear direction) X and the second direction. The camera shake is corrected by moving in the (left-right direction) Y direction. Therefore, the camera shake correction unit of the lens driving device 10 is called a “barrel shift type” camera shake correction unit.

  The lens driving device 10 further includes a shield cover 42 that covers the autofocus lens driving unit (AF unit) 20. The shield cover 42 includes a square tube portion 422 that covers the outer peripheral side surface of the autofocus lens driving unit (AF unit) 20 and an upper end 424 that covers the upper surface of the autofocus lens driving unit (AF unit) 20. The upper end 424 has a circular opening 424 a concentric with the optical axis O.

  The camera shake correction unit of the illustrated lens driving device 10 further includes a position detection unit 50 for detecting the position of the autofocus lens driving unit (AF unit) 20 with respect to the base 14. The illustrated position detecting means 50 is composed of a magnetic position detecting means comprising two Hall elements 50 f and 50 l mounted on the base 14. As will be described later, these two Hall elements 50f and 50l are arranged so as to be spaced apart from two pieces of the four pieces of permanent magnet pieces 282, respectively. As shown in FIG. 2, the hall elements 50 f and 50 l are arranged so as to cross the direction from the north pole to the south pole in the permanent magnet piece 282.

  In the illustrated example, one Hall element 50f is called the front Hall element because it is arranged on the front side in the first direction (front-rear direction) X with respect to the optical axis O. Since the other Hall element 50l is arranged on the left side in the second direction (left-right direction) Y with respect to the optical axis O, it is called a left Hall element.

  The front Hall element 50f is disposed on the base 14 at a location where the two coil portions 18fl and 18fr of the front camera shake correction coil portion 18f having the two divided coil portions 18fl and 18fr are separated. Similarly, the left Hall element 50l is disposed on the base 14 at a location where the two coil portions 18lf and 18lb of the left hand shake correction coil portion 18l having the two divided coil portions 18lf and 18lb are separated. Yes.

  In this way, the two Hall elements 50f and 50l are divided into the two coil portions 18fl and 18fr of the specific two camera shake correction coil portions 18f and 18l having the two divided coil portions 18fl, 18fr and 18lf, 18lb. And 18 lf and 18 lb are separated on the base 14.

  The front Hall element 50f detects the first position associated with the movement (swing) in the first direction (front-rear direction) X by detecting the magnetic force of the front permanent magnet piece 282f facing the front Hall element 50f. The left Hall element 50l detects the second position associated with the movement (swing) in the second direction (left-right direction) Y by detecting the magnetic force of the left permanent magnet piece 282l facing the left Hall element 50l.

  Referring to FIGS. 5 to 7, in order to facilitate understanding of the lens driving device 10 according to the embodiment of the present invention, between the related magnetic circuit used in the related lens driving device and the Hall element. The relationship will be described. The relationship between the related magnetic circuit shown in the figure and the Hall element has the same configuration (relationship) as that disclosed in Patent Document 17 described above. FIG. 5 is a perspective view showing the relationship between the related magnetic circuit and the Hall element, FIG. 6 is a longitudinal sectional view showing the relationship between the related magnetic circuit and the Hall element, and FIG. 7 is an AF unit. It is a longitudinal cross-sectional view which shows the relationship between a related magnetic circuit and Hall element when 20 is displaced to the front-back direction X.

  The difference between the related magnetic circuit and the magnetic circuit used in the lens driving apparatus 10 according to the present embodiment is that the related magnetic circuit is for the four camera shake corrections constituting the camera shake correction coil 18 ′. The coil portions 18f ′, 18b ′, 18l ′ and 18r ′ are not divided into two loop portions. That is, in the conventional magnetic circuit, each of the four camera shake correction coil portions 18f ', 18b', 18l ', and 18r' is composed of only one loop portion.

  As described above, the four permanent magnet pieces 282f, 282b, 282l, and 282r are magnetized with the N pole on the inside and the S pole on the outside. An arrow B shown in FIG. 5 indicates the direction of magnetic flux generated by these permanent magnet pieces.

  Next, with reference to FIG. 5, the operation in the case of adjusting the position of the lens holder 24 (lens barrel) in the direction of the optical axis O using a related magnetic circuit will be described.

  For example, it is assumed that an AF current flows through the focus coil 26 counterclockwise. In this case, an upward electromagnetic force acts on the focus coil 26 in accordance with Fleming's left-hand rule. As a result, the lens holder 24 (lens barrel) can be moved upward in the optical axis O direction.

  Conversely, the lens holder 24 (lens barrel) can be moved downward in the direction of the optical axis O by causing the AF current to flow clockwise through the focus coil 26.

  Next, referring to FIG. 5 to FIG. 7, using the conventional magnetic circuit, the entire autofocus lens driving unit (AF unit) 20 is moved in the first direction (front-rear direction) X or the second direction. The operation when moving in the (left-right direction) Y will be described.

First, an operation when the entire autofocus lens driving unit (AF unit) 20 is moved to the rear side in the first direction (front-rear direction) X will be described. In this case, as shown in FIG. 5, a first camera shake correction (IS) current is caused to flow counterclockwise as shown by an arrow I _IS1 to the front camera shake correction coil portion 18f ′, thereby causing a rear camera shake. A second camera shake correction (IS) current is caused to flow clockwise through the correction coil portion 18b ′ as indicated by an arrow I _IS2 .

In this case, according to Fleming's left-hand rule, a forward electromagnetic force acts on the front-side camera shake correction coil portion 18f ′, and a forward electromagnetic force acts also on the rear-side camera shake correction coil portion 18b ′. However, since the camera shake correction coil portions 18f ′ and 18b ′ are fixed to the base 14, as a reaction thereof, the entire autofocus lens driving unit (AF unit) 20 includes the arrows _FIS1 and FIG. A backward electromagnetic force acts as shown in _FIS2 . As a result, the entire autofocus lens driving unit (AF unit) 20 can be moved backward.

  Conversely, the first IS current is caused to flow clockwise through the front camera shake correction coil portion 18f ′, and the second IS current is caused to flow counterclockwise through the rear hand shake correction coil portion 18b ′. The entire lens driving unit (AF unit) 20 can be moved in the forward direction.

  On the other hand, by driving a third IS current counterclockwise through the left hand shake correction coil portion 18l ′ and passing a fourth IS current clockwise through the right hand shake correction coil portion 18r ′, the lens drive for autofocus is driven. The entire unit (AF unit) 20 can be moved rightward.

  Further, a third IS current is passed clockwise through the left hand shake correction coil portion 18l ′, and a fourth IS current is passed counterclockwise through the right hand shake correction coil portion 18r ′, thereby driving an autofocus lens. The entire unit (AF unit) 20 can be moved leftward.

  In this way, camera shake can be corrected.

  Next, with reference to FIGS. 8 to 10 in addition to FIGS. 5 to 7, problems in the conventional lens driving device using the conventional magnetic circuit will be described in detail.

As described above, in order to move the entire autofocus lens driving unit (AF unit) 20 in the backward direction, as shown in FIG. 5, the front-side image stabilization coil unit 18f ′ is indicated by the arrow I _IS1. An example in which the first IS current is caused to flow counterclockwise and the second IS) current is caused to flow clockwise as indicated by the arrow I _IS2 through the rear image stabilization coil portion 18b ′. Will be described.

In this case, as shown in FIG. 7, the magnetic field B _I1 generated by the first IS current I _IS1 flowing in the front-side image stabilization coil portion 18f ′ and the magnetic field B generated by the moved front permanent magnet piece 282f It can be seen that are in the same phase. The magnetic flux density of the magnetic field B is represented by a, and the magnetic flux density of the magnetic field _BI1 is represented by b. Therefore, the front-side Hall element 50f is between the magnetic flux density b of the magnetic flux density a and a magnetic field B _I1 of the magnetic field B, it will detect the total magnetic flux density (a + b).

  Here, in order to detect the position of the autofocus lens driving unit (AF unit) 20 by the front Hall element 50f, the magnetic flux density a of the magnetic field B and the total magnetic flux density (a + b) are in phase. Note that it is necessary to be.

  FIG. 8 is a diagram showing the frequency characteristics of the front Hall element 50f in the related magnetic circuit. In FIG. 8, the horizontal axis represents frequency (Hz), the left vertical axis represents gain (dB), and the right vertical axis represents phase (deg). In FIG. 8, the solid line indicates the gain characteristic, and the alternate long and short dash line indicates the phase characteristic.

  As can be seen from FIG. 8, the frequency characteristics of the front Hall element 50f are divided into a region I, a region II, and a region III. Region I is a region having a low frequency in a band below the primary resonance of the actuator. Region II is a region having an intermediate frequency in a band equal to or higher than the primary resonance of the actuator. Region III is a region having a high frequency in a band equal to or higher than the primary resonance of the actuator.

FIG. 9 is generated by the magnetic flux density a of the magnetic field B generated by the front permanent magnet piece 282f and the first IS current I _IS1 flowing in the front camera shake correction coil 18f ′ in the regions I, II, and III. It illustrates magnetic flux density b, and the magnetic flux density of the total detected by the front-side Hall element 50f of (a + b) magnitude and phase relationships of the magnetic field B _I1. FIG. 10 is a table showing the relationship of FIG.

  The following can be understood from FIGS. 9 and 10.

In the band below the primary resonance that is the region I, the magnitude | a | of the magnetic flux density a of the magnetic field B is larger than the magnitude | b | of the magnetic flux density b of the magnetic field B _I1 (| a |> | b |), The magnetic flux density a of the magnetic field B, the magnetic flux density b of the magnetic field _BI1 , and the total magnetic flux density (a + b) are in phase. Accordingly, in the region I, the position of the autofocus lens driving unit (AF unit) 20 can be detected by the front Hall element 50f.

On the other hand, in the actuator of the primary resonance or the motion of the front permanent magnet pieces 282f is a first phase and 180 ° shifts for IS current I _IS1 caused to flow to the front image stabilizer coil 18f ', the opposite phase.

In the region II in the region II that is higher than the primary resonance, the magnitude | a | of the magnetic flux B of the magnetic field B is larger than the magnitude | b | of the magnetic flux density b of the magnetic field B _I1 (| a |> | b |). The magnetic flux density a of the magnetic field B and the total magnetic flux density (a + b) are in phase. Therefore, in the region II, the position of the autofocus lens driving unit (AF unit) 20 can be detected by the front Hall element 50f.

However, in the band of the primary resonance or higher in the region III, the magnitude | a | of the magnetic flux density a of the magnetic field B is smaller than the magnitude | b | of the magnetic flux density b of the magnetic field B _I1 (| a | <| b |). Therefore, the magnetic flux density a of the magnetic field B and the total magnetic flux density (a + b) are in opposite phases. As a result, in the area III, the position of the autofocus lens driving unit (AF unit) 20 cannot be detected by the front Hall element 50f. That is, the output of the Hall element has a resonance point.

  Therefore, it can be seen that if the Hall element is arranged between (inside) one loop portion of the coil, the position of the autofocus lens driving unit (AF unit) 20 cannot be detected in the region III above the primary resonance. . In other words, the hose elements 50f and 50l are adversely affected by the magnetic field generated by the currents flowing through the camera shake correction coils 18f 'and 18l', respectively.

  Next, the relationship between the magnetic circuit according to the present embodiment used in the lens driving apparatus 10 according to the embodiment of the present invention and the Hall element will be described with reference to FIGS. FIG. 11 is a perspective view showing the relationship between the magnetic circuit and the Hall element according to the present embodiment, and FIG. 12 is a longitudinal sectional view showing the relationship between the magnetic circuit and the Hall element according to the present embodiment. FIG. 13 is a longitudinal sectional view showing the relationship between the magnetic circuit and the Hall element according to the present embodiment when the AF unit 20 is displaced in the front-rear direction X, and FIG. It is sectional drawing in line XIV-XIV.

  As described above, the four permanent magnet pieces 282f, 282b, 282l, and 282r are magnetized with the N pole on the inside and the S pole on the outside. An arrow B shown in FIG. 11 indicates the direction of the magnetic flux generated by these permanent magnet pieces.

  Next, with reference to FIG. 11, the operation in the case of adjusting the position of the lens holder 24 (lens barrel) in the direction of the optical axis O using the magnetic circuit according to the present embodiment will be described.

  For example, it is assumed that an AF current flows through the focus coil 26 counterclockwise. In this case, an upward electromagnetic force acts on the focus coil 26 in accordance with Fleming's left-hand rule. As a result, the lens holder 24 (lens barrel) can be moved upward in the optical axis O direction.

  Conversely, the lens holder 24 (lens barrel) can be moved downward in the direction of the optical axis O by causing the AF current to flow clockwise through the focus coil 26.

  Next, referring to FIG. 11 to FIG. 14, the entire autofocus lens driving unit (AF unit) 20 is moved in the first direction (front-rear direction) X or by using the magnetic circuit according to the present embodiment. An operation when moving in the second direction (left-right direction) Y will be described.

First, an operation when the entire autofocus lens driving unit (AF unit) 20 is moved to the rear side in the first direction (front-rear direction) X will be described. In this case, as shown in FIG. 11, each of the two coil portions 18fl and 18fr of the front-side image stabilization coil portion 18f has a first image stabilization (counterclockwise as indicated by an arrow I _IS1 ). IS) current is passed, and the second hand shake correction (IS) current is passed clockwise through the rear hand shake correction coil portion 18b as shown by the arrow I _IS2 .

In this case, in accordance with Fleming's left-hand rule, a forward electromagnetic force acts on the front camera shake correction coil portion 18f, and a forward electromagnetic force also acts on the rear hand shake correction coil portion 18b. However, since the camera shake correction coil portions 18f and 18b are fixed to the base 14, as a reaction thereof, the entire autofocus lens driving unit (AF unit) 20 has arrows F _IS1 and F _{IS2 in} FIG. A backward electromagnetic force as shown in FIG. As a result, the entire autofocus lens driving unit (AF unit) 20 can be moved backward.

  Conversely, a first IS current is passed clockwise through each of the two coil portions 18fl and 18fr of the front-side camera shake correction coil portion 18f, and a second IS current is supplied counterclockwise through the rear-side camera shake correction coil portion 18b. , The entire autofocus lens driving unit (AF unit) 20 can be moved in the forward direction.

  On the other hand, a third IS current is caused to flow counterclockwise through each of the two coil portions 18lf and 18lb of the left hand shake correction coil portion 18l, and a fourth IS current is caused to flow clockwise through the right hand shake correction coil portion 18r. Thus, the entire autofocus lens driving unit (AF unit) 20 can be moved rightward.

  Further, a third IS current is passed clockwise through each of the two coil portions 18lf and 18lb of the left hand shake correction coil portion 18l, and a fourth IS current is passed counterclockwise through the right hand shake correction coil portion 18r. Thus, the entire autofocus lens driving unit (AF unit) 20 can be moved in the left direction.

  In this way, camera shake can be corrected.

  Next, the advantages of the lens driving device 10 using the magnetic circuit according to the present embodiment will be described in detail with reference to FIGS. 15 to 17 in addition to FIGS.

As described above, in order to move the entire autofocus lens driving unit (AF unit) 20 in the backward direction, as shown in FIG. 11, the two coil portions 18fl and 18fr of the front camera shake correction coil unit 18f are moved. A first IS current is caused to flow counterclockwise as indicated by an arrow I _IS1 , and a second IS is applied clockwise to the rear image stabilization coil portion 18b as indicated by an arrow I _IS2. A case where a current is passed will be described as an example.

In this case, as shown in FIGS. 13 and 14, the magnetic field B _I1 generated by the first IS current I _IS1 passed through the front-side image stabilization coil portion 18f and the magnetic field generated by the moved front-side permanent magnet piece 282f. It can be seen that B is in the opposite phase. The magnetic flux density of the magnetic field B is represented by a, and the magnetic flux density of the magnetic field _BI1 is represented by b. Therefore, the front-side Hall element 50f is between the magnetic flux density b of the magnetic flux density a and a magnetic field B _I1 of the magnetic field B, it will detect the total magnetic flux density (a + b).

  As described above, in order to detect the position of the autofocus lens driver (AF unit) 20 by the front Hall element 50f, the magnetic flux density a of the magnetic field B and the total magnetic flux density (a + b) are in phase. Note that it is necessary to be.

  FIG. 15 is a diagram illustrating frequency characteristics of the front Hall element 50f in the magnetic circuit according to the present embodiment. In FIG. 15, the horizontal axis represents frequency (Hz), the left vertical axis represents gain (dB), and the right vertical axis represents phase (deg). In FIG. 15, the solid line indicates the gain characteristic, and the alternate long and short dash line indicates the phase characteristic.

  As can be seen from FIG. 15, the frequency characteristics of the front Hall element 50f are divided into a region I, a region II, and a region III in order from the lowest frequency. Region I is a region having a low frequency in a band below the primary resonance of the actuator. Region II is a region having an intermediate frequency in a band equal to or higher than the primary resonance of the actuator. Region III is a region having a high frequency in a band equal to or higher than the primary resonance of the actuator.

FIG. 16 is generated by the magnetic flux density a of the magnetic field B generated by the front permanent magnet piece 282f and the first IS current I _IS1 flowing through the front camera shake correction coil portion 18f in the regions I, II, and III. It illustrates magnetic flux density b, and the magnetic flux density of the total detected by the front-side Hall element 50f of (a + b) magnitude and phase relationships of the magnetic field B _I1. FIG. 17 is a table showing the relationship of FIG.

  The following can be understood from FIGS. 16 and 17.

In the band below the primary resonance that is the region I, the magnitude | a | of the magnetic flux density a of the magnetic field B is larger than the magnitude | b | of the magnetic flux density b of the magnetic field B _I1 (| a |> | b |), The magnetic flux density a of the magnetic field B and the magnetic flux density b of the magnetic field _BI1 are in opposite phases, but the magnetic flux density a of the magnetic field B and the total magnetic flux density (a + b) are in phase. Accordingly, in the region I, the position of the autofocus lens driving unit (AF unit) 20 can be detected by the front Hall element 50f.

On the other hand, in the actuator of the primary resonance or the motion of the front permanent magnet pieces 282f becomes the first IS current I _IS1 the same phase flows in front image stabilizer coil portion 18f.

In the region II in the region II that is higher than the primary resonance, the magnitude | a | of the magnetic flux B of the magnetic field B is larger than the magnitude | b | of the magnetic flux density b of the magnetic field B _I1 (| a |> | b |). The magnetic flux density a of the magnetic field B and the total magnetic flux density (a + b) are in phase. Therefore, in the region II, the position of the autofocus lens driving unit (AF unit) 20 can be detected by the front Hall element 50f.

On the other hand, in the band of the primary resonance in region III, the magnitude | a | of the magnetic flux density a of the magnetic field B is smaller than the magnitude | b | of the magnetic flux density b of the magnetic field B _I1 (| a | <| b |) However, since the magnetic flux density a of the magnetic field B and the total magnetic flux density (a + b) are in phase, both the magnetic flux density a of the magnetic field B and the total magnetic flux density (a + b) are in phase. As a result, also in the region III, the position of the autofocus lens driving unit (AF unit) 20 can be detected by the front Hall element 50f. That is, resonance does not occur in the output of the Hall element.

  Therefore, it can be seen that the position of the autofocus lens driving unit (AF unit) 20 can be detected in the entire frequency range by arranging the Hall element between the two loop portions of the coil. In other words, the Hall elements 50f and 50l can be prevented from being adversely affected by the magnetic field generated by the current flowing through the camera shake correction coil portions 18f and 18l, respectively.

  FIG. 18 is a cross-sectional view showing the positional relationship between one permanent magnet piece 282 of the permanent magnet 28, the focus coil 26 and the camera shake correction coil 18 arranged around the permanent magnet piece 28 in the magnetic circuit.

  The height of the focus coil 26 is lower than the height of the permanent magnet piece 282. Thereby, the stroke in the case of adjusting the position of the lens holder 24 (lens barrel) in the optical axis O direction can be increased.

  Further, the permanent magnet piece 282 and the camera shake correction coil 18 are arranged so that the edge in the radial direction of the permanent magnet piece 282 falls within the radial cross-sectional width of the camera shake correction coil 18. Thereby, the sensitivity of the driving force for moving the entire autofocus lens driving unit (AF unit) 20 in the direction orthogonal to the optical axis O can be increased.

  By the way, in the lens driving device 10 having such a configuration, there is a possibility that the four suspension wires 16 may be broken by applying a force in the extending direction to the four suspension wires 16 due to a drop impact or the like. The lens driving device 10 according to the embodiment includes a breakage prevention member that prevents breakage of the four suspension wires 16 as described later.

  With reference to FIGS. 19 and 20, the fracture preventing member according to the present embodiment will be described in detail. FIG. 19 is an enlarged partial perspective view showing a portion for fixing the other end of the suspension wire 16 to the upper leaf spring 32, and FIG. 20 is a partial cross-sectional view of the portion to be fixed.

  As described above, the upper leaf spring 32 includes only four arc-shaped extensions 328 extending outward in the radial direction at the four corners of the upper outer peripheral end 324 (in FIG. 19, only one arc-shaped extension 328 is provided. As shown). Each of the four arc-shaped extending portions 328 has four wire fixing holes 328a (see FIG. 3) into which the other ends of the four suspension wires 16 are inserted (inserted). The other ends of the four suspension wires 16 are inserted into the four wire fixing holes 328a and fixed by soldering 60 or an adhesive (not shown).

  Therefore, the four arc-shaped extending portions 328 serve as wire fixing portions that fix the other ends of the four suspension wires 16.

  In the lens driving device 10 having such a configuration, even when a force in a direction away from the base 14 is applied to the autofocus lens driving unit (AF unit) 20 due to a drop impact or the like, the other ends of the four suspension wires 16A are not connected. The autofocus lens driving unit (AF unit) 20 is raised while the four arcuate extension portions 328 are elastically deformed while being fixed to the four arcuate extension portions 328 of the upper leaf spring 32. Become.

  As a result, the four suspension wires 16 can be prevented from breaking. Accordingly, the four arc-shaped extending portions 328 function as breakage prevention members that prevent the breakage of the four suspension wires 16.

  On the other hand, as shown in FIG. 19, the magnet holder 30 has four upper stoppers 308 (only one upper stopper 308 is shown in FIG. 19) protruding upward at the four corners of the upper ring-shaped end 304. Each upper stopper 308 protrudes from an opening 32 a formed between the upper outer peripheral side end portion 324 of the upper leaf spring 32 and each arc-shaped extension portion 328.

  In other words, the four upper stoppers 308 protrude from the magnet holder 30 toward the inner wall surface of the shield cover 42.

  These four upper stoppers 308 restrict the upward movement of the autofocus lens driving unit (AF unit) 20 as shown in FIG. In other words, when the autofocus lens driving unit (AF unit) 20 moves upward, the four arc-shaped extending portions 328 are elastically deformed, but before the four arc-shaped extending portions 328 are bent. The four upper stoppers 308 of the magnet holder 30 come into contact with the inner wall surface of the upper end 424 of the shield cover 42 before the breaking force is applied to the four suspension wires 16.

  That is, the four upper stoppers 308 function as breakage prevention auxiliary members that assist in preventing breakage of the four suspension wires 16.

  As shown in FIG. 2, there is almost no clearance (gap) between the fixing member (14, 40, 18, 44) and the autofocus lens driving unit (AF unit) 20. Therefore, even if a force in the direction approaching the base 14 is applied to the autofocus lens driving unit (AF unit) 20 due to a drop impact or the like, the autofocus lens driving unit (AF unit) 20 immediately becomes fixed to the fixing member (14, 40, 18, and 44), the four suspension wires 16 are bent but not plastically deformed.

  A flexible printed circuit board (FPC) 44 disposed between the base 14 and the coil substrate 40 and a mounting method thereof will be described with reference to FIG. 21 in addition to FIGS. FIG. 21 is a perspective view of a combination of a coil substrate 40 and a flexible printed circuit board (FPC) 44 as viewed from the back side.

  As shown in FIG. 3, the base 14 has four positioning protrusions 142 protruding upward on a diagonal line on the radially outer side near the circular opening 14a. On the other hand, as shown in FIG. 4, the coil substrate 40 has four positioning holes 40b into which the four positioning protrusions 142 are respectively inserted. As shown in FIG. 21, the flexible printed circuit board (FPC) 44 also has four positioning hole portions 44a at positions corresponding to these four positioning hole portions 40b. Therefore, the four positioning protrusions 142 of the base 14 are inserted into the four positioning hole portions 40 b of the coil substrate 40 through the four positioning hole portions 44 a of the flexible printed circuit board (FPC) 44, respectively.

  As shown in FIG. 21, two Hall elements 50 f and 50 l are mounted on the back surface of the flexible printed circuit board (FPC) 44. On the other hand, as shown in FIG. 2, the base 14 is formed with a hole 14b into which the two Hall elements 50f and 50l are inserted.

  Further, as shown in FIG. 4, the coil substrate 40 is configured to supply current to the four camera shake correction coil portions 18f, 18b, 18l, and 18r along the circular opening 40c at the center thereof. Six lands 18a are formed. On the other hand, as shown in FIG. 21, the flexible printed circuit board (FPC) 44 has six notches 44b formed at positions corresponding to the six lands 18a. Therefore, by placing a solder paste on these six cutouts 44b and reflowing the solder, the internal wiring (not shown) of the flexible printed circuit board (FPC) 44 and the six lands 18a of the coil board 40 are electrically connected. Can be connected.

  As shown in FIG. 21, a control unit 46 is mounted on the back surface of the flexible printed circuit board (FPC) 44. The control unit 46 controls the current flowing through the focus coil 16 and cancels the shaking detected based on two directional gyros (not shown) based on the position detection signals detected by the two Hall elements 50f and 50l. As described above, the currents supplied to the four camera shake correction coil portions 18f, 18b, 18l, and 18r are controlled.

  A method for supplying power to the focus coil 26 will be described with reference to FIGS. FIG. 22 is a plan view of the lens driving device 10 with the shield cover 42 omitted. FIG. 23 is a partially enlarged perspective view showing, in an enlarged manner, the binding portion of the end portion of the wire constituting the focus coil 26 in FIG.

  As shown in FIG. 22, the lens holder 24 has first and second protrusions 241 and 242 that protrude from the upper end in a direction away from each other in the left-right direction Y (radially outward). In the example shown in the drawing, the first protrusion 241 protrudes to the right and is therefore referred to as the right protrusion, and the second protrusion 242 protrudes to the left and is therefore referred to as the left protrusion.

  On the other hand, the wire constituting the focus coil 26 has first and second end portions 261 and 262. As shown in FIG. 23, the first end portion 261 of the wire rod of the focus coil 26 is entangled with the first protrusion (right protrusion) 241 of the lens holder 24. Similarly, the second end portion 262 of the wire rod of the focus coil 26 is entangled with the second protrusion (left protrusion) 242 of the lens holder 24. Accordingly, the first and second end portions 261 and 262 are also referred to as first and second binding portions, respectively.

  On the other hand, as shown in FIG. 22, the first leaf spring (upper leaf spring) 32 includes first and second leaf spring pieces 32-1 and 32-2 that are electrically insulated from each other. Yes. The first and second leaf spring pieces 32-1 and 32-2 have a rotationally symmetric shape around the optical axis O of the lens. The first leaf spring piece 32-1 is disposed substantially on the rear side and the right side on the first end (upper end) of the magnet holder 30, and the second leaf spring piece 32-2 is a magnet. On the first end (upper end) of the holder 30, the holder 30 is disposed substantially on the front side and the left side.

  The upper inner peripheral end 322 on the right side of the first leaf spring piece 32-1 is a position corresponding to the first protrusion (right protrusion) 241 of the lens holder 24, and is on the right (radially outward). It has the 1st U-shaped terminal part 322-1 which protruded in the side. Similarly, the upper inner peripheral side end 322 on the left side of the second leaf spring piece 32-2 is at a position corresponding to the second protrusion (left protrusion) 242 of the lens holder 24, and is on the left (radius) A second U-shaped terminal portion 322-2 protruding outward (in the direction). The first U-shaped terminal portion 322-1 is also referred to as a right-side U-shaped terminal portion, and the second U-shaped terminal portion 322-2 is referred to as a left-side U-shaped terminal portion.

  A first U-shaped terminal portion (right U-shaped terminal portion) 322-1 is a first protrusion (right protruding portion) 241 of the lens holder 24, and a first terminal portion (first first) of the focus coil 26. 261) and a solder (not shown). Similarly, the second U-shaped terminal portion (left U-shaped terminal portion) 322-2 is the second protrusion (left protruding portion) 242 of the lens holder 24, and the second end portion of the focus coil 26. (Second binding portion) 262 is electrically connected with solder (not shown).

  Further, as described above, the other ends of the two suspension wires 16 (in the example of FIG. 22, right back and left front) of the four suspension wires 16 are arc-shaped by the solder 60 through the wire fixing holes 328a. The extension portion 328 is fixed. The other ends of the remaining two suspension wires 16 (in the example of FIG. 22, left rear and right front) are fixed to the arc-shaped extension 328 by the adhesive 62 through the wire fixing holes 328a.

  Accordingly, the single suspension wire 16 at the right back includes the first leaf spring piece 32-1 of the first leaf spring (upper leaf spring) 32 and the first U-shaped terminal portion (right U-shaped terminal portion). ) It is electrically connected to the first end portion (first binding portion) 261 of the focus coil 26 via 322-1. Similarly, the left front suspension wire 16 includes a second leaf spring piece 32-2 of the first leaf spring (upper leaf spring) 32 and a second U-shaped terminal portion (left U-shaped terminal portion). ) It is electrically connected to the second end portion (second binding portion) 262 of the focus coil 26 via 322-2.

  In this way, power is supplied from the suspension wire 16 to the focus coil 26 via the first leaf spring 32.

  Next, a method for assembling the lens driving device 10 will be described.

  First, the lens holder 24, the focus coil 26, the permanent magnet 28, the magnet holder 30, the upper leaf spring 32, the lower leaf spring 34, and the spacer 36 are combined to produce the autofocus lens driving unit (AF unit) 20. To do.

  On the other hand, an assembly of the coil substrate 40 and the flexible printed circuit board (FPC) 44 is produced by the above-described solder reflow as shown in FIG. The assembly is mounted on the base 14 to which one end of the four suspension wires 16 is fixed.

  The autofocus lens driving unit (AF unit) 20 is mounted on the base 14 via the assembly, and the other ends of the four suspension wires 16 are passed through the wire fixing holes 328a to be bonded to the solder 60 or the like. The agent 62 is fixed to the arc-shaped extension 328.

  The first and second U-shaped terminal portions 322-1 and 322-2 of the first leaf spring (upper leaf spring) 32 are soldered to the first and second ends of the focus coil 26, respectively. Connected to the sections 261 and 262.

  Finally, the shield cover 42 is covered so as to cover the autofocus lens driving unit (AF unit) 20, and the lower end of the shield cover 42 is fixed to the base 14.

  In this way, the lens driving device 10 can be easily assembled.

  The dimension of the lens driving device 10 assembled in this way is 11 mm × 11 mm × 4.2 mm.

  Referring to FIGS. 24 to 26, in the lens driving device 10, the mounting method and arrangement of the damper material 65 for suppressing unnecessary resonance in the optical axis O direction of the autofocus lens driving unit (AF unit) 20 The position will be described.

  FIG. 24 is a partial front view showing the lens driving device 10 with the shield cover 42 omitted. FIG. 25 is a partial perspective view of the lens driving device 10 shown in FIG. 24 as viewed obliquely from above. FIG. 26 is a plan view showing an arrangement position of the damper member 65 in the lens driving device 10 in a state where the shield cover 42 is omitted and a part of the upper leaf spring (first leaf spring) 32 is omitted.

  The damper material 65 is disposed between the four lower protrusions 306 a of the magnet holder 30 and the coil substrate 40. The outer cylindrical portion 302 of the magnet holder 30 has four guide grooves 302 a for guiding a dispenser (not shown) for applying the damper material 65. Accordingly, the damper material 65 can be easily applied to the gap between the four lower protrusions 306a and the coil substrate 40 using a dispenser. As described above, the gap between the four lower protrusions 306a and the coil substrate 40 is narrower than the gaps in other regions. Therefore, when the damper material 65 is applied in the vicinity of the four lower protrusions 306a using the dispenser inserted along the guide groove 302a, the applied damper material 65 is naturally separated by the four lower protrusions due to the surface tension. It collects in the gap between 306a and the coil substrate 40.

  In the illustrated example, an ultraviolet curable silicone gel having a viscosity of 90 Pa · s, which is TB3168E manufactured by ThreeBond, is used as the damper material 65.

  Therefore, as described above, after the damper material 65 is applied to the gap between the four lower protrusions 306a of the magnet holder 30 and the coil substrate 40, the damper material 65 is irradiated with ultraviolet rays to cure the damper material 65. Let

  With reference to FIGS. 27 and 28, the frequency characteristics when there is no damper material 65 (conventional example) and when there is a damper material 65 (first embodiment) will be described. FIG. 27 shows the frequency characteristics in the optical axis O direction of the autofocus lens driving unit (AF unit) 20 of the conventional lens driving device without the damper material 65, and FIG. 28 shows the frequency characteristics with the damper material 65. The frequency characteristic in the optical axis O direction of the lens drive part (AF unit) 20 for autofocus of the lens drive device 10 by 1st Embodiment is shown. In each of FIGS. 27 and 28, the horizontal axis indicates the frequency [Hz], and the vertical axis indicates the gain [dB].

  As can be seen from FIG. 27, in the conventional lens driving device without the damper material 65, resonance (high-order resonance mode) occurs in the direction of the optical axis O at a frequency of about 400 Hz.

  On the other hand, as is apparent from FIG. 28, in the lens driving device 10 according to the first embodiment having the damper material 65, such resonance in the optical axis O direction (high-order resonance mode) occurs. You can see that it is suppressed.

  Therefore, in the lens driving device 10 according to the first embodiment, it is possible to perform a stable control operation for camera shake correction.

  Further, since the damper material 65 is disposed so as to support the autofocus lens driving unit (AF unit) 20 which is a movable portion on the camera shake correction side, the autofocus lens driving unit is dropped when the lens driving device 10 is dropped. There is also an effect that the impact on the (AF unit) 20 can be reduced.

  The lens driving device 10 according to the first embodiment of the present invention as described above has the following effects.

  First, the two Hall elements 50f and 50l are arranged on the base 14 at the place where the two coil portions 18fl, 18fr and 18lf, 18lb of the specific two image stabilization coil portions 18f and 18l are separated. Therefore, it is possible to avoid an adverse effect caused by the magnetic field generated by the currents flowing through the two hall-shake correction coil portions 18f and 18l by the two Hall elements 50f and 50l.

  Secondly, since the breakage preventing member 328 is provided, the four suspension wires 16 can be prevented from being broken, and the impact resistance of the lens driving device 10 can be improved.

  Third, since the notch 44b is formed in the flexible printed circuit board (FPC) 44 at a position corresponding to the plurality of lands 18a formed on the coil substrate 40, solder reflow causes the flexible printed circuit board (FPC) 44 to The internal wiring and the plurality of lands 18a of the coil substrate 40 can be electrically connected.

  Fourthly, since the height of the focus coil 26 is made lower than the height of the permanent magnet piece 282, the stroke for adjusting the position of the lens holder 24 (lens barrel) in the optical axis O direction can be increased. .

  Fifth, since the permanent magnet piece 282 and the camera shake correction coil portion 18 are arranged so that the radial edge of the permanent magnet piece 282 falls within the radial coil cross-sectional width of the camera shake correction coil portion 18, The sensitivity of the driving force that moves the entire focusing lens driving unit (AF unit) 20 in the direction orthogonal to the optical axis O can be increased.

  Sixth, since the damper member 65 is disposed between the fixing member (14, 40, 18, 44) and the autofocus lens driving unit 20, unnecessary resonance can be suppressed and stable operation can be performed. be able to.

  Seventh, since the damper member 65 is disposed between the fixing member (14, 40, 18, 44) and the autofocus lens driving unit 20, it is possible to improve the yield strength when dropped.

[Modification]
Next, a modified example of the lens driving device 10 according to the first embodiment will be described.

  In the lens driving device 10 according to the first embodiment described above, as shown in FIG. 26, the damper members 65 are provided at four locations. However, the number of the damper members 65 and the arrangement positions thereof are the same for the present invention. It is not important, and it is important that the damper material 65 is disposed between the movable part (autofocus lens driving part) 20 and the fixed member (14, 40, 18, 44).

  For example, as shown in FIG. 29, the damper member 65 may be provided only in one place as in the lens driving device 10 according to the first modification. Moreover, you may provide the damper material 65 in three places like the lens drive device 10 which concerns on a 2nd modification as shown in FIG. Furthermore, as shown in FIG. 31, damper materials 65 may be provided at eight locations as in the lens driving device 10 according to the third modification.

  As described above, even when the damper material 65 is provided at one place or at many places, the same effect as in the first embodiment can be obtained.

  Further, in the lens driving device 10 according to the first embodiment described above, a guide groove 302a is formed in the magnet holder 30 in order to make it easy to apply the damper material 65, as shown in FIGS. ing. However, the guide groove 302a may be omitted as in the lens driving device 10 according to the fourth modified example as shown in FIG.

  Furthermore, in the lens driving device 10 according to the first embodiment, an infrared curable silicone gel is used as the damper material 65. However, the material of the damper material 65 is not limited thereto, and a material having a damper effect. Any one may be used.

[Second Embodiment]
With reference to FIGS. 33 and 34, a lens driving apparatus 10A according to a second embodiment of the present invention will be described. FIG. 33 is a longitudinal sectional view of the lens driving device 10A. FIG. 34 is an exploded perspective view showing the lens driving device 10A.

  Here, as shown in FIGS. 33 and 34, an orthogonal coordinate system (X, Y, Z) is used. 33 and FIG. 34, in the orthogonal coordinate system (X, Y, Z), the X-axis direction is the front-rear direction (depth direction), the Y-axis direction is the left-right direction (width direction), and Z The axial direction is the vertical direction (height direction). In the examples shown in FIGS. 33 and 34, the vertical direction Z is the direction of the optical axis O of the lens. In the second embodiment, the X-axis direction (front-rear direction) is also called a first direction, and the Y-axis direction (left-right direction) is also called a second direction.

  However, in the actual use situation, the optical axis O direction, that is, the Z-axis direction is the front-rear direction. In other words, the upward direction of the Z axis is the forward direction, and the downward direction of the Z axis is the backward direction.

  The illustrated lens driving device 10A includes an autofocus lens driving unit 20A and a camera shake correction unit that corrects camera shake (vibration) generated in the autofocus lens driving unit 20A when a still image is captured by a small camera for a mobile phone. Is a device that can take an image without image blur.

  The illustrated lens driving device 10A has a structure that is substantially upside down from the lens driving device 10 according to the first embodiment described above. Therefore, “upper” may be read as “lower” and “lower” may be read as “upper”. For simplification of description, the same reference numerals are given to components having the same functions as those of the lens driving device 10 according to the first embodiment, and only differences will be described below.

  The lens barrel 12 has a bell shape. Instead of the shield cover 42, a square cylindrical shield wall 422A and a second base (cover) 424A are used. In the autofocus lens driving unit (AF unit) 20A, the spacer 36A is attached to the lower leaf spring 32 that is the first leaf spring.

  Other structures are the same as those of the lens driving device 10 according to the first embodiment described above.

  In other words, a damper material (not shown) is disposed between the fixed member (14, 40, 18, 44) and the autofocus lens driving unit (AF unit) 20A which is a movable unit.

  Therefore, the lens driving device 10A according to the second embodiment of the present invention also has the same effects as the lens driving device 10 according to the first embodiment described above.

  The present invention has been described above with reference to the embodiment, but the present invention is not limited to the above embodiment. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention. For example, in the above-described embodiment, four suspension wires are used as a support member that swingably supports the autofocus lens driving unit with respect to the fixed member, but the number of suspension wires is four. It is not limited to, and it is sufficient if there are a plurality. Further, in the embodiment described above, the projection 306a is provided on the magnet holder 30, but instead, a concave or convex portion is provided on the coil substrate 40 and the damper material is fastened at this place. Good.

DESCRIPTION OF SYMBOLS 10,10A Lens drive device 12 Lens barrel 14 Base 14a Circular opening 14b Hole 142 Positioning protrusion 16 Suspension wire 18 Camera shake correction coil 18a Land 18f Front side shake correction coil part 18fl Left side coil part 18fr Right side coil part 18b Rear side camera shake correction Coil part 18l Left hand shake correction coil part 18lf Front coil part 18lb Rear coil part 18r Right hand shake correction coil part 20, 20A Autofocus lens drive part (AF unit)
24 lens holder 240 cylindrical portion 240a upper protrusion 241 first protrusion (right protrusion)
242 Second protrusion (left protrusion)
26 Focus coil 261 1st terminal part (1st binding part)
262 second end (second binding portion)
28 Permanent magnet 282 Permanent magnet piece 282f Front permanent magnet piece 282b Rear permanent magnet piece 282l Left permanent magnet piece 282r Right permanent magnet piece 30 Magnet holder 30a First end 30b Second end 302 Outer cylinder portion 302a Guide groove 304 Upper Ring-shaped end portion 304a Upper projection 306 Lower ring-shaped end portion 306a Lower projection 308 Stopper (Break prevention auxiliary member)
32 First leaf spring (upper leaf spring)
32-1 First Plate Spring Piece 32-2 Second Plate Spring Piece 32a Opening 322 Upper Inner Side End 322-1 First U-shaped Terminal (Right U-shaped Terminal)
322-2 Second U-shaped terminal (left U-shaped terminal)
322a Upper hole 324 Upper outer peripheral side end 324a Upper hole 326 Upper arm 328 Arc-shaped extension (breakage prevention member, wire fixing part)
328a Wire fixing hole 34 Second leaf spring (lower leaf spring)
342 Lower inner peripheral edge 342a Lower hole 344 Lower outer peripheral edge 344a Lower hole 346 Lower arm 36, 36A Spacer 362 Inner ring 364 Outer ring 364a Lower hole 40 Coil substrate 40a Through hole 40b Positioning hole 40c Circular opening 42 Shield cover 422 Square tube 422A Shield wall 424 Upper end 424A Second base (cover)
424a Circular opening 44 Flexible printed circuit board (FPC)
44a Positioning hole 44b Notch 46 Control unit 50 Position detecting means (Hall element)
50f Front Hall element 50l Left Hall element 60 Solder 62 Adhesive 65 Damper material O Optical axis X First direction (front-rear direction)
Y Second direction (left-right direction)

Claims (8)

An autofocus lens driving unit that moves the lens barrel along the optical axis, and the autofocus lens driving unit are moved in a first direction and a second direction that are orthogonal to the optical axis and orthogonal to each other. Thus, a lens driving device having a camera shake correction unit adapted to correct camera shake, the camera shake correction unit,
A fixing member disposed away from the autofocus lens driving unit in the optical axis direction;
A plurality of suspension wires having one end fixed at an outer peripheral portion of the fixing member, extending along the optical axis and having the other end fixed to the autofocus lens driving unit; A plurality of suspension wires that support a drive unit in a swingable manner in the first direction and the second direction;
A breakage preventing member for preventing breakage of the plurality of suspension wires;
A narrowing portion that is disposed between the fixing member and the autofocus lens driving unit and that partially narrows a gap between the fixing member and the autofocus lens driving unit;
A damper material disposed in a narrowed part of the gap between the fixing member and the autofocus lens driving unit, and suppressing unnecessary resonance in the optical axis direction of the autofocus lens driving unit;
Have
The autofocus lens driving unit is:
A lens holder having a cylindrical portion for holding the lens barrel;
A focus coil fixed to the lens holder so as to be positioned around the cylindrical portion;
A permanent magnet disposed opposite the focus coil;
A magnet holder disposed on the outer periphery of the lens holder to hold the permanent magnet;
First and second leaf springs that are attached to the first and second ends of the magnet holder in the optical axis direction, respectively, and support the lens holder so that the lens holder can be displaced in the optical axis direction while being positioned in the radial direction. And projecting in the optical axis direction from the first end of the magnet holder to which the first plate spring disposed at a position farther from the fixing member than the second plate spring is attached. A plurality of protrusions serving as breakage prevention auxiliary members that assist in preventing breakage of the plurality of suspension wires;
With
The other ends of the plurality of suspension wires are fixed to the first leaf spring,
The first leaf spring includes a wire fixing portion that extends to bypass each of the plurality of protrusions and to which the other end of each suspension wire is fixed. It is a fracture prevention member,
Lens drive device. The magnet holder has at least one protrusion protruding toward the fixing member as the narrowing portion,
The lens driving device according to claim 1, wherein the damper material is disposed between the protrusion and the fixing member.   The lens driving device according to claim 2, wherein the protrusion protrudes toward the fixing member through a hole formed in the second leaf spring. The fixing member is
A base for fixing one end of the plurality of suspension wires at the outer periphery;
A coil substrate fixed on the base and formed with a camera shake correction coil of the camera shake correction unit;
With
The lens driving device according to claim 2, wherein the damper material is disposed between the protrusion and the coil substrate. The permanent magnet is composed of four permanent magnet pieces, each of the four permanent magnet pieces having a first surface facing the focus coil, and a radius of the focus coil with respect to the optical axis. Arranged on the outer side in the direction facing the first direction and the second direction,
The camera shake correction coil includes four camera shake correction coil portions disposed on the coil substrate so as to face the second surface perpendicular to the first surface of the four permanent magnet pieces, respectively. The lens driving device according to claim 4.   The lens driving device according to claim 2, wherein the magnet holder has a guide groove that guides a dispenser for applying the damper material. A lens driving device according to any one of claims 1 to 6,
An image sensor disposed on an imaging substrate disposed on the opposite side of the autofocus lens driving unit with respect to the fixing member;
Having a camera module. A camera module according to claim 7;
A control unit for controlling the camera module;
Having a camera.

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