JP2013097028A - Electromagnetic drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic drive device able to move a movable member in the axial direction of the movable member in a simple configuration and able to rotate and move the movable member around an axis perpendicular to the axis direction.SOLUTION: The electromagnetic drive device has electromagnetic drive means comprising: an even number of driving coils 141 to 144 wound around an axis perpendicular to a Z axis and arranged at even angle intervals around the Z axis; and driving magnets 151U to 154U (or 151D to 154D) arranged such that the respective magnetic faces are located opposite a side 14u (or a side 14d) extending in the direction in which the driving coils 141 to 144 are orthogonal to the Z axis and each pair of adjacent driving magnets are different from each other in polarity. Using the electromagnetic drive means, a lens holder 12, which is the movable member, is moved in the Z axis or rotated around the axis perpendicular to the Z axis with respect to a case, which is a fixed member.

Description

  The present invention relates to an electromagnetic drive device that can be applied to, for example, a camera shake suppression device or a lens drive device with a camera shake suppression function used in optical equipment for photographing.

In recent years, a camera mounted on a mobile phone or the like has increased in the number of pixels of an image sensor, and the quality of captured images has been improved. Along with this, the lens system to be mounted is also shifting from the conventional fixed focus lens driving device to the movable focus lens driving device. This is because a fixed-focus lens driving device is out of focus and cannot cope with the resolution of a high pixel count image sensor.
As a lens system driving method in a movable focus lens driving device, a voice coil motor type lens driving device as shown in FIG. 14 is often used (see, for example, Patent Document 1).
The lens driving device 50 includes a driving magnet 53 made of a cylindrical magnet that is magnetized in a radial direction with respect to the axis of the lens holder 52 in a case 51, and is wound around the optical axis of the lens 54. By attaching the driving coil 55 to the lens holder 52 and energizing the driving coil 55, a Lorentz force directed toward the subject is generated in the driving coil 55 indicated by an arrow in FIG. The lens 54 is moved to a predetermined position by moving it to a position balanced with the restoring force of the leaf springs 56A and 56B. In FIG. 14, reference numeral 57 denotes a magnetic yoke having a U-shaped cross section provided to guide the magnetic field generated by the driving magnet 53 to the driving coil 55.

JP 2004-280031 A

  However, in the conventional lens driving device 50, the lens holder 52, which is a movable member, can be moved in the optical axis direction of the lens 54, but it is necessary to rotate the lens holder 52 around an axis perpendicular to the lens optical axis. Separately, it is necessary to add a mechanism for swinging the lens holder 52, which is a movable member, with respect to the case 51, which is a fixed member.

  The present invention has been made in view of the conventional problems. The movable member can be moved in the axial direction of the movable member with a simple configuration, and the movable member has an axis perpendicular to the axial direction of the movable member. An object of the present invention is to provide an electromagnetic driving device capable of rotating around.

The invention according to claim 1 of the present application includes a fixed member, a columnar or cylindrical movable member, suspension means for swingably suspending the movable member on the fixed member, and the movable member on the fixed member. An electromagnetic drive device that swings relative to the Z-axis direction when the axial direction of the movable member is the Z-axis direction. And an even number of drive magnets arranged at equal angles around the Z-axis, and a drive coil arranged to face the drive magnet with a gap, and each of the drive magnets. Adjacent drive magnets have different polarities, and either one of the drive coil or the drive magnet is attached to the movable member, the other is attached to the fixed member, and Z of the drive coil The shaft and the magnetic pole surface of the drive magnet Energizing direction of the sides extending such a direction, characterized in that differently depending on the polarity of the drive magnet corresponding to the sides.
By adopting such a configuration, the movable member can be driven in a direction parallel to the Z axis, or can be driven to rotate around an axis perpendicular to the Z axis. A drive device can be obtained. Further, in the electromagnetic drive device according to the present invention, the drive magnet is disposed so as to face the side extending in the direction orthogonal to the Z axis of the drive coil with a gap therebetween, so that a magnetic field is effectively applied to the drive coil. it can. Therefore, an electromagnetic drive device with high drive efficiency can be obtained. Moreover, the electromagnetic drive device of the present invention can also be used only as a camera shake suppression device.
The invention according to claim 2 is the electromagnetic drive device according to claim 1, wherein the drive coil is wound around an axis perpendicular to the Z axis and the magnetic pole surface of the drive magnet. It consists of an even number of coils having sides extending in a direction perpendicular to.
Thus, if the drive coil is composed of a plurality of coils wound around an axis perpendicular to the Z axis, the side extending in the direction perpendicular to the Z axis of the drive coil and the drive magnet can be easily formed. Since they can face each other, a magnetic field for effectively driving the drive coil can be applied reliably.
The invention according to claim 3 is the electromagnetic drive device according to claim 1, wherein the drive coil includes at least one coil pair wound around the Z axis, and the coil pair The positions in the Z-axis direction of the two coils constituting the are switched according to the polarity of the driving magnet facing the coil pair.
By constructing the driving coil from such a pair of coils, a side extending in the direction perpendicular to the Z-axis facing the driving coil can be constructed with a small number of coils, so that driving efficiency can be improved. .

Invention of Claim 4 is an electromagnetic drive device in any one of Claims 1-3, Comprising: It is a side extended in the direction orthogonal to the Z-axis of each said coil, Comprising: A second magnet disposed so as to face a side different from the side facing the magnet, and a polarity of a magnetic pole surface, which is a surface facing the different side of the second magnet, of the driving magnet; It is different from polarity.
As a result, it is possible to generate a driving force (Lorentz force) on both the side located in front of the Z-axis direction and the side located in the rear in the Z-axis direction of each coil of the driving coil, so that the driving efficiency is further improved. .
A fifth aspect of the present invention is the electromagnetic drive device according to any one of the first to fourth aspects, further comprising current control means for controlling energization of each of the coils independently. .
In this way, if each coil of the drive coil is energized and controlled independently, the movable member can be efficiently rotated around an axis perpendicular to the Z axis.
The invention according to claim 6 is the electromagnetic drive device according to any one of claims 1 to 5, wherein the drive magnet or the drive magnet and the second magnet are used for the drive. A magnetic yoke is disposed on the surface of the coil opposite to the surface facing the drive coil of the drive magnet or the drive magnet and the second magnet.
Thereby, since the normal direction density of the magnetic flux applied to the drive coil can be increased, the movable member can be driven efficiently.

  The summary of the invention does not list all necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

It is the longitudinal cross-sectional view and top view which show the structure of the lens drive device with a camera-shake suppression function which concerns on embodiment of this invention. It is a disassembled perspective view of the lens drive device with a camera shake suppression function. It is a principal part perspective view of the lens drive device with a camera shake suppression function. It is a figure which shows an example of the magnetic field which a drive magnet produces (rectangular magnet). It is a figure which shows the relationship between the position of a drive coil, and the normal direction density of the magnetic flux which acts on a drive coil (rectangular magnet). It is a perspective view which shows the structure of the lens drive device with a camera-shake suppression function which has only a front side drive magnet. It is a figure which shows the structure of the camera-shake suppression apparatus by this invention. It is a figure which shows the structure of the lens drive device with a camera-shake suppression function using the drive magnet which consists of a triangular prism shaped magnet. It is a figure which shows an example of the magnetic field which a drive magnet produces (triangular prism magnet). It is a figure which shows the relationship between the position of a drive coil, and the normal direction density of the magnetic flux which acts on a drive coil (triangular prism magnet). It is a perspective view which shows the other structure of the drive part of the lens drive device with a camera-shake suppression function by this invention. It is a figure which shows the other structure of the drive coil of the lens drive device with a camera-shake suppression function by this invention. It is a figure which shows the other structure of the drive coil of the lens drive device with a camera-shake suppression function by this invention. It is a perspective view which shows the structure of the conventional lens drive device.

  Hereinafter, the present invention will be described in detail through embodiments, but the following embodiments do not limit the invention according to the claims, and all combinations of features described in the embodiments are included. It is not necessarily essential for the solution of the invention.

FIGS. 1 to 3 are diagrams showing an embodiment of the present invention. FIGS. 1A and 1B are a longitudinal sectional view showing a configuration of a lens driving device 10 with a camera shake suppression function as an electromagnetic driving device, respectively. FIG. 2 is an exploded perspective view, and FIG. 3 is a perspective view of a main part.
The lens driving device 10 with a camera shake suppressing function includes a case 11 as a fixed member, a lens holder 12 as a movable member, and front and rear spring members as suspension means for swinging the lens holder 12 to the case 11 so as to be swingable. 13A, 13B, four driving coils 141 to 144 mounted on the outer peripheral side of the lens holder 12, and a front side in which each magnetic pole surface extends in a direction perpendicular to the Z axis of each of the driving coils 141 to 144 In addition, the front drive magnets 151U to 154U as drive magnets and the rear side as second magnets are arranged to be spaced from the drive coils 141 to 144 so as to face the rear sides 14u and 14d, respectively. Driving magnets 151D to 154D and front and rear driving magnets 151U to 154U, 151D to 154D driving coils 141 to 1 4 to comprise a magnetic yoke 16 provided on the opposite side, a current control unit 17.
The front drive magnets 151 </ b> U to 154 </ b> U and the rear drive magnets 151 </ b> D to 154 </ b> D are attached to the inner peripheral side of the case 11 via the magnetic yoke 16.

The lens holder 12 is a cylindrical member having a square shape in plan view that holds a lens 18 formed of a combination of an objective lens and an eyepiece lens on the inner side. Hereinafter, the axial direction of the lens holder 12 indicated by an arrow in FIG. Two directions orthogonal to the Z axis and the Z axis are defined as an X axis and a Y axis, respectively.
Further, the subject direction when the lens 18 is mounted on the lens holder 12 is assumed to be the front of the Z axis. In this example, the lens holder 12 is arranged so that the two side surfaces 121 and 122 facing each other are perpendicular to the X axis. That is, the lens holder 12 includes a side surface 121 positioned in front of the X axis, a side surface 122 positioned in the rear of the X axis, a side surface 123 positioned in front of the Y axis, and a side surface 124 positioned in the rear of the Y axis.

The case 11 includes an upper case 11A and a lower case 11B.
The upper case 11A is a square cylindrical member having an opening in the front of the Z-axis and the rear of the Z-axis being open, and the lower case 11B has a square plate-like base 11a having an opening 11h formed in the center. A support column 11b provided at the four corners of the pedestal 11a so as to protrude forward in the Z-axis, and a locking portion 11c that protrudes forward from the outer edge of the opening 11h in the Z-axis and contacts the rear end of the lens holder 12. And a restricting portion 11d for restricting the position of the outer edge portion of the outer frame 13a of the rear spring member 13B. The lower case 11B is disposed behind the upper case 11A in the Z axis. On the opening 11h side of the four support pillars 11b of the lower case 11B, mounting step portions 11k for mounting the magnetic yoke 16 are formed.

As shown in FIG. 2, the front and rear spring members 13A and 13B are each formed of four linear plates that connect a rectangular plate-like outer frame 13a and inner frame 13b, and the outer frame 13a and the inner frame 13b. The arm part 13c and the connection piece 13d which connects the arm part 13c and the outer frame 13a or the arm part 13c and the inner frame 13b are provided at both ends of each arm part 13c. The outer frame 13a of the rear spring member 13B is provided with cutout portions 13k at the four corners of the outer periphery in order to avoid the support pillar 11b provided on the lower case 11B.
The outer frame 13a of the front spring member 13A is fixed to the outer edge portion of the upper case 11A at the rear of the Z axis, and the inner frame 13b is fixed to the outer edge portion of the lens holder 12 at the front of the Z axis.
On the other hand, the outer frame 13a of the rear spring member 13B is fixed between the opening 11h of the pedestal 11a of the lower case 11B, the support pillar 11b, and the restricting portion 11d, and the inner frame 13b is the outer edge of the lens holder 12 at the rear of the Z axis. Fixed to the part.
The four arm portions 13c function as springs that suspend and support the lens holder 12 movably in the Z-axis direction on the case 11.
In this example, the lower case 11B is provided with a locking portion 11c that comes into contact with the rear end of the lens holder 12, and an offset is applied to each of the front and rear spring members 13A and 13B, so that the lens holder 12 is always rearward on the Z axis. I am trying to be energized.

  The driving coils 141 to 144 are formed by winding a coated conductor around the X axis or the Y axis. Specifically, the drive coils 141 to 144 extend in a direction orthogonal to the Z axis and are located in front of the Z axis in the front side 14u, and extend in a direction parallel to the side 14u and are positioned rearward in the Z axis direction. A rear side 14d and right and left sides 14r and 14l extending in a direction parallel to the Z-axis are provided, which are arranged on side surfaces 121 to 124 of the lens holder 12, respectively. That is, the driving coils 141 to 144 are wound around an axis perpendicular to the Z axis, respectively, and are equidistantly arranged on the side surfaces 121 to 124 of the lens holder 12 around the Z axis that is the central axis of the lens holder 12 ( 90 ° intervals).

The front drive magnets 151U to 154U and the rear drive magnets 151D to 154D are rectangular parallelepiped permanent magnets whose surface 15a on the lens holder 12 side is a magnetic pole surface, respectively. Driving magnets 151U to 154U are arranged behind the Z axis, and rear driving magnets 151D to 154D are arranged via the magnetic yoke 16, respectively.
The magnetic pole surfaces of the front driving magnets 151U to 154U are arranged so as to face the front side 14u of the driving coils 141 to 144 with a gap therebetween, and the magnetic pole surfaces of the rear driving magnets 151D to 154D are respectively The drive coils 141 to 144 are arranged so as to face the rear side 14d with a gap therebetween. That is, the front drive magnets 151U to 154U and the rear drive magnets 151D to 154D are equally spaced about the center axis of the lens holder 12 and about the Z axis (90, similarly to the drive coils 141 to 144D, respectively. Are arranged at intervals of °.
In this example, the front drive magnets 151U to 154U and the rear drive magnets 151D to 154D are arranged so that the drive magnets adjacent to each other in the Z axis direction and in the Z axis direction have different polarities. .
Specifically, if the polarity of the front drive magnet 151U on the drive coil 141 side is N pole, the polarity of the front drive magnet 152U on the drive coil 142 side is N pole and the front drive magnet 153U is used for driving. The front drive magnets 151U to 154U are arranged so that the polarity on the coil 143 side and the polarity on the drive coil 144 side of the front drive magnet 154U are S poles. On the other hand, the rear drive magnets 151D to 154D have a polarity on the drive coil 141 side of the rear drive magnet 151D and a polarity on the drive coil 142 side of the rear drive magnet 152D, and are for rear drive. The magnet 153D is arranged so that the polarity on the drive coil 143 side and the polarity on the drive coil 144 side of the rear drive magnet 154D are N poles.

The magnetic yoke 16 is a rectangular cylindrical member made of a soft magnetic material, and is in contact with the surface of the front drive magnets 151U to 154U and the rear drive magnets 151D to 154D opposite to the drive coils 141 to 144. Be placed.
The current control means 17 is electrically connected to the drive coils 141 to 144, respectively, and independently controls the magnitude of the current value supplied to each of the drive coils 141 to 144.

Next, the magnetic field applied to the driving coils 141 to 144 will be described.
FIGS. 4A and 4B show a case where four rectangular parallelepiped permanent magnets 14a to 14d having a width a = 5 mm, a length b = 0.5 mm, and a thickness 1 mm are arranged in a square shape in the XY plane. FIG. 6 is a diagram showing an example of a magnetic field created by permanent magnets 14a to 14d, and the distance between opposing permanent magnets 14a and 14c and permanent magnets 14b and 14d is 7 mm.
(A) The figure is an example in which the polarities of the permanent magnets 14a to 14d are all arranged so as to face the inner side of the square formed by the permanent magnets 14a to 14d. In addition, the permanent magnets 14a to 14d are arranged such that the polarities of the permanent magnets adjacent to each other around the Z axis are different from each other.
The square ABCD indicated by the alternate long and short dash line in FIGS. (A) and (b) is the inner side of the square surrounded by four straight lines parallel to the inner peripheral side of the permanent magnets 14a to 14d (for example, 0.2 mm inside). And it is a square containing the position in which the drive coils 141-144 are arrange | positioned. Comparing the magnetic field on the side AB of the square ABCD, in FIG. 5A, not only the magnetic flux density crossing the side AB is low, but also the magnetic field component orthogonal to the side AB is small, whereas FIG. Then, it can be seen that the magnetic flux density intersecting with the side AB is high and the lines of magnetic force are almost perpendicular to the side AB. The same applies to the side BC, the side CD, and the side DA.

FIG. 5 is a diagram showing the magnitude of the magnetic field crossing the sides AB and BC of the square ABCD, where the horizontal axis is the position [mm] on the broken line ABC, and the vertical axis is the normal direction density [T] of the magnetic flux. is there. The solid line in the figure shows the density in the normal direction of the magnetic flux when the permanent magnets 14a to 14d are arranged so that the polarities of the adjacent permanent magnets are different from each other, and the broken lines indicate that the polarities of the permanent magnets 14a to 14d are all inside. It is a normal direction density of magnetic flux when arranged so as to face. Since the direction and magnitude of the magnetic field on the polygonal line CDA are the same as the direction and magnitude of the magnetic field on the polygonal line ABC, the relationship between the position [mm] on the polygonal line CDA and the normal direction density [T] of the magnetic flux is This is the same as FIG.
As is clear from FIGS. 4A, 4B, and 5, when the permanent magnets 14a to 14d are arranged so that all the polarities face inward, the magnetic flux density of the normal density of the magnetic flux itself is low. In addition, it can be seen that the region where the magnetic flux flow is reversed (reversal magnetic field region) is wide. When the reversal magnetic field region is wide, a magnetic field cannot be effectively applied to the driving coils 141 to 144. On the other hand, when the polarities of adjacent permanent magnets are different from each other, the magnetic flux density in the normal direction density of the magnetic flux is high and the switching field region is narrow.
Therefore, like the lens driving device 10 with the hand movement suppressing function of this example, the front driving magnets 151U to 154U and the rear driving magnets 151D to 154D are arranged so that the polarities of the adjacent permanent magnets are different from each other. Then, a magnetic field in a direction orthogonal to the extending direction of the sides 14u and 14d and the Z-axis can be effectively applied to the front side 14u and the rear side 14d of the driving coils 141 to 144. confirmed.

Next, the operation of the lens driving device with a camera shake suppression function 10 will be described.
First, a case of so-called autofocus driving in which the lens holder 12 is moved in the subject direction (Z-axis direction) will be described with reference to FIG.
Specifically, when the current control means 17 causes a current I counterclockwise in the X-axis direction as shown by an arrow in the drawing to flow through the driving coil 141 mounted on the side surface 121 of the lens holder 12, the driving coil Since a magnetic field in the −X-axis direction from the front drive magnet 151U is acting on the front side 14u of 141, the Lorentz force F directed in the + Z direction indicated by the upward arrow in FIG. Occurs. The direction of the current flowing through the rear side 14d is the direction opposite to the front side 14u (the −Y axis direction), and the magnetic field in the + X axis direction from the rear drive magnet 151D is applied to the rear side 14d. As a result, the Lorentz force F directed in the + Z direction is also generated on the rear side 14d. Since the magnetic field acting on the left and right sides 14r and 14l has almost no component orthogonal to the direction of current, no Lorentz force is generated.
Therefore, when a current I counterclockwise in the X-axis direction is supplied to the driving coil 141, a force for moving the driving coil 141 in the + Z direction acts on the driving coil 141.
Further, when a current (in the clockwise direction of the X axis) I in the direction opposite to that of the driving coil 141 is passed through the driving coil 142 mounted on the side surface 122 opposite to the side surface 121, the driving coil 142 (not shown) is illustrated. A magnetic field in the + X-axis direction from the front drive magnet 152U acts on the front side 14u of the front side, and a magnetic field in the −X-axis direction from the rear drive magnet 152D acts on the rear side 14d. A Lorentz force F directed in the + Z direction is generated on each of the front side 14u and the rear side 14d. As in the case of the drive coil 141, no Lorentz force is generated on the left and right sides 14r, 14l.
Therefore, the current control means 17 causes the driving coil 141 to pass a current I counterclockwise in the X-axis direction, and causes the driving coil 142 to apply a current I having the same magnitude as the current flowing to the driving coil 141 to the X-axis direction clock. If it is made to flow around, the lens holder 12 can be moved to the + Z side. The lens holder 12 moves to a position where the Lorentz force and the restoring force of the spring members 13A and 13B are balanced.
In order to move the lens holder 12 to the −Z side, if a current I that is clockwise in the X-axis direction is supplied to the driving coil 141 and a current I that is counterclockwise in the X-axis direction is supplied to the driving coil 142. Good. In this case as well, it goes without saying that the magnitude of the current flowing through the driving coil 141 and the magnitude of the current flowing through the driving coil 142 are the same.

Similarly, when a clockwise current I in the Y-axis direction is passed through a driving coil 143 (not shown) mounted on the side surface 123 of the lens holder 12, a front side 14u and a rear side 14d of the driving coil 143 are connected to each other. A Lorentz force F directed in the + Z direction is generated, and the drive coil 144 mounted on the side surface 124 opposite to the side surface 123 has a current in the direction opposite to that of the drive coil 143 (current in the Y-axis direction counterclockwise). ) When I is applied, Lorentz force F directed in the + Z direction is generated on the front side 14u and the rear side 14d of the driving coil 144, respectively.
Accordingly, if the current control means 17 causes the current I to flow in the Y-axis direction clockwise through the driving coil 143 and the current I in the Y-axis direction counterclockwise to flow through the driving coil 144, the lens holder 12 can be removed. It can be moved to the + Z side. The lens holder 12 moves to a position where the Lorentz force and the restoring force of the spring members 13A and 13B are balanced.
When trying to move the lens holder 12 to the −Z side, a current I counterclockwise in the Y-axis direction is supplied to the driving coil 143 and a current I clockwise in the Y-axis direction is supplied to the driving coil 144. You can do it.
Therefore, the lens holder 12 can be moved in the Z-axis direction by supplying the currents having the same magnitude and direction to each of the driving coils 141 to 144.

Next, the case where camera shake is suppressed will be described.
First, whether or not camera shake has occurred in the lens 18 is detected by, for example, an angular velocity sensor (not shown) attached to the lens holder 12. When camera shake has occurred, the magnitude and direction of camera shake detected by the angular velocity sensor are sent to the current control means 17. The current control means 17 controls the amount and direction of current supplied to the drive coils 141 to 144 according to the detected magnitude and direction of the camera shake, and swings the lens holder 12 to suppress the camera shake. To do.
For example, when a camera shake that causes the lens holder 12 that holds the lens 18 to rotate clockwise about the Y-axis occurs, a current I ₁ that is counterclockwise in the X-axis direction is supplied to the drive coil 141 and the drive coil 142 is supplied. A current I ₂ clockwise in the X-axis direction is allowed to flow, and the magnitude of the current I ₁ may be made larger than the magnitude of the current I ₂ (| I ₁ |> | I ₂ |).
Since the relationship between the direction of the current flowing through the driving coils 141 to 144 and the Lorentz force acting on the driving coils 141 to 144 is the same as in the above-described autofocus driving, the Lorentz in the + Z direction acting on the driving coil 141. The force F ₁ is larger than the + Z direction Lorentz force F ₂ acting on the drive coil 142. As a result, the lens holder 12 can be rotated to the left around the Y axis while being moved to the + Z side, so that camera shake that causes the lens holder 12 to rotate to the right around the Y axis can be suppressed.
In order to rotate the lens holder 12 to the -Z side and rotate counterclockwise around the Y axis, a current I ′ ₁ clockwise in the X-axis direction is passed through the drive coil 141, and the magnitude of the current I is increased in the drive coil 142. It suffices to pass a current I ′ ₂ that is counterclockwise in the X-axis direction and is larger than the magnitude of “ _1” .
In addition, when a camera shake that causes the lens holder 12 to rotate leftward around the Y axis while moving in the Z axis direction, the magnitudes of the currents I ₁ and I ₂ that flow through the driving coils 141 and 142 are set. By reversing, the lens holder 12 may be rotated to the right around the Y axis.
In addition, in order to rotate the lens holder 12 counterclockwise around the Y axis without moving in the Z axis direction, a current counterclockwise in the X axis direction is passed through the driving coil 141 and the driving coil 142 to move around the Y axis. In order to rotate clockwise, a current clockwise in the X-axis direction is passed through the drive coil 141 and the drive coil 142.

Further, when a camera shake that causes the lens holder 12 to rotate clockwise around the X axis occurs, a current I ₃ that is clockwise in the Y-axis direction is passed through the drive coil 143 and the Y-axis direction is counterclockwise through the drive coil 144. Current I ₄ and the magnitude of the current I ₃ may be made smaller than the magnitude of the current I ₄ (| I ₃ | <| I ₄ |). As a result, the lens holder 12 can be rotated counterclockwise around the X axis while moving to the + Z side, so that camera shake that causes the lens holder 12 to rotate clockwise around the X axis can be suppressed.
In addition, in order to rotate the lens holder 12 counterclockwise around the X axis while moving to the −Z side, a current I ′ ₃ counterclockwise in the Y-axis direction is supplied to the driving coil 143, and the driving coil 144 has a magnitude. A current I ′ ₄ clockwise in the Y-axis direction that is smaller than the magnitude of the current I ′ ₃ may be supplied.
In addition, when a camera shake that causes the lens holder 12 to rotate leftward around the X axis while moving in the Z-axis direction, the magnitudes of the currents I ₃ and I ₄ that flow through the driving coils 143 and 144 are set. Just reverse.
In addition, in order to rotate the lens holder 12 counterclockwise around the X axis without moving in the Z axis direction, a current counterclockwise in the Y axis direction is passed through the driving coil 143 and the driving coil 144 to rotate around the X axis. In order to rotate clockwise, a current clockwise in the Y-axis direction is passed through the driving coil 143 and the driving coil 144.
Further, if the rotation around the X axis and the rotation around the Y axis are combined, the lens holder 12 is driven in the Z axis direction or is not moved in the Z axis direction, but is arbitrary to the Z axis. Since it can be rotated around the axis, camera shake around an arbitrary axis perpendicular to the Z axis generated in the lens 18 can be suppressed.

In the above-described embodiment, the front drive magnets 151U to 154U and the rear drive magnets 151D to 154D are arranged on the front side in the Z axis direction and the rear side in the Z axis direction, respectively. However, as shown in FIG. Only the use magnets 151U to 154U may be arranged, or only the rear drive magnets 151D to 154D may be arranged. In this case, the driving force is smaller than in the above embodiment, but there is an advantage that the number of parts can be reduced.
When only the front drive magnets 151U to 154U are disposed, the front drive magnets 151U to 154U are disposed so as to face the front side 14u of the drive coils 141 to 144, respectively, for rear drive. When only the magnets 151D to 154D are arranged, it is important to arrange the rear driving magnets 151D to 154D so as to face the rear sides 14d of the driving coils 141 to 144, respectively. When the magnets 151U to 154U or the front drive magnets 151U to 154U are arranged between the side 14u and the side 14d, the magnetic field component perpendicular to the surfaces of the driving coils 141 to 144 applied to the side 14u and the side 14d Therefore, it is difficult to move or rotate the lens holder 12 as in the present embodiment.

In the above example, the electromagnetic driving device is the lens driving device 10 with a camera shake suppression function. However, as shown in FIGS. 7A and 7B, the lens holder 12 which is a movable body is not a lens having a rotation function. If the case 11 as a fixing member is replaced with the fixed body 31 that holds the lens driving device, the camera shake suppressing device 40 that suppresses the camera shake of the lens driving device 20 can be configured.
That is, the lens driving device 20 is suspended swingably on the fixed body 31 by the front and rear spring members 13A and 13B, and the driving coils 141 to 144 are mounted on the outer peripheral side of the lens driving device 20, and the fixed body 31 is mounted. Each of the driving coils 141 to 141 has a magnetic pole face facing the front and rear sides 14 u and 14 d extending in a direction perpendicular to the Z axis of the driving coils 141 to 144. The front drive magnets 151U to 154U and the rear drive magnets 151D to 154D may be disposed with a gap from the 144. In this case, since there is no need to offset the front and rear spring members 13A and 13B, the lower fixed body 31B having the same configuration as that obtained by omitting the locking portion 11c of the lower case 11B is used. Further, as the upper fixed body 31A, a cylindrical member that can fix the outer frame 13a of the front spring member 13A may be used. Or you may abbreviate | omit upper fixing body 31A and attach to the edge part of the Z-axis front side of the support pillar which the lower fixing body 31B does not illustrate.
When suppressing camera shake, for example, the amount of current supplied to the drive coils 141 to 144 and the direction of application according to the magnitude and direction of camera shake detected by an angular velocity sensor (not shown) attached to the lens driving device 20 are determined. The lens driving device 20 may be controlled to rotate in the direction opposite to the camera shake detected around an arbitrary axis perpendicular to the Z axis.
The method for suppressing camera shake is the same as that in the case of the camera shake suppression in the lens driving device 10 with the camera shake suppression function described above, and a description thereof will be omitted.

In the above example, the drive coils 141 to 144 are mounted on the lens holder 12 side which is a movable member, and the front drive magnets 151U to 154U and the rear drive magnets 151D to 154D are placed on the case 11 side which is a fixed member. The same effect can be obtained by attaching the driving coils 141 to 144 to the case 11 side and attaching the front driving magnets 151U to 154U and the rear driving magnets 151D to 154D to the lens holder 12 side. Can do.
In the above example, four front drive magnets 151U to 154U and rear drive magnets 151D to 154D are arranged around the Z axis. However, the number of drive magnets is not limited to this, It may be an even number such as six or eight. However, in the case of two, there is no problem with auto-focus driving, but since rotation is possible only around one axis, the number of driving magnets is preferably an even number of four or more. Further, when the driving magnets are arranged in the front and rear in the Z-axis direction, the number of driving magnets arranged in the front in the Z-axis direction is the same as the number of driving magnets arranged in the front and rear in the Z-axis direction. It is preferable for control.

  In the above example, the front drive magnets 151U to 154U and the rear drive magnets 151D to 154D have a rectangular parallelepiped shape. However, as shown in FIG. 8, the shape of the lens holder 12 is changed to a triangular prism shape. If the shape is an octagonal prism, the lens driving device 10 with a camera shake suppression function can be reduced in size. It should be noted that most of the front side 14u and most of the rear side 14d of the drive coils 141 to 144 are the front drive magnets 151U to 154U and the rear drive among the side surfaces of the octagonal columnar lens holder 12. Needless to say, the magnets 151D to 154D need to be disposed on the side surface facing the magnets 151D to 154D.

9A and 9B, four triangular prism-shaped permanent magnets 14p to 14s having a length of 2.5 mm, a width of 2.5 mm, and a thickness of 1 mm are arranged in a frame of 8 mm × 8 mm on the XY plane. It is a figure which shows an example of the magnetic field which the permanent magnets 14p-14s make.
(A) The figure shows an example in which the polarities of the permanent magnets 14p to 14s are all oriented toward the inside of the frame. (B) The figure shows the permanent magnets 14p to 14s, and the polarities of the permanent magnets adjacent around the Z axis are different from each other. This is an example in which the polarities are arranged.
A polygonal line DEFGHI shown by a one-dot chain line in FIGS. 5A and 5B is located at a position where the drive coils 141 and 143 are disposed inside (for example, 0.2 mm inside) the inclined surfaces of the permanent magnets 14p to 14s. A broken line including the line segment EF and the line segment GH, the start point D is the midpoint of the permanent magnet 14s and the permanent magnet 14p, and the end point I is the midpoint of the permanent magnet 14q and the permanent magnet 14r. Comparing the magnetic field on the line segment EF and the line segment GH, the magnetic field component orthogonal to the line segment EF and the line segment GH is small in FIG. It can be seen that it is orthogonal to the minute GH.

FIG. 10 is a diagram showing the magnitude of the magnetic field crossing the polygonal line DEFGHI. The horizontal axis represents the position [mm] of the polygonal line DEFGHI, and the vertical axis represents the magnetic flux density [T] of the normal direction density of the magnetic flux. The solid line in the figure is the magnetic flux density when the permanent magnets 14p to 14s are arranged so that the adjacent permanent magnets have different polarities, and the broken lines are arranged so that the polarities of the permanent magnets 14p to 14s all face inward. Is the magnetic flux density.
As is clear from FIGS. 9A, 9B, and 10, when the permanent magnets 14p to 14s are arranged so that all the polarities face inward, the magnetic flux density of the normal density of the magnetic flux itself is low. In addition, the area where the magnetic flux flow is reversed (reversal magnetic field area) is wide, but when the adjacent permanent magnets have different polarities, the magnetic flux density in the normal direction of the magnetic flux is high and the magnetic flux is reversed. It can be seen that the magnetic field region is narrow.
Therefore, even when the triangular prism-shaped permanent magnets 14p to 14s are used, if the driving coils 141 and 143 are arranged on the line segment EF and the line segment GH, the front side 14u and the rear side of the driving coils 141 and 143 are arranged. It was confirmed that a magnetic field perpendicular to the extending direction of the sides 14u and 14d and the Z axis can be effectively applied to the side 14d.
Further, since the magnetic fields generated by the triangular prism-shaped permanent magnets 14p to 14s are the same in the upper half and the lower half of FIGS. 9A and 9B, the front side 14u and the rear side of the drive coils 142 and 144 are the same. Needless to say, a magnetic field perpendicular to the extending direction of the sides 14u and 14d and the Z-axis can be effectively applied to 14d.

In the above example, the shape of the lens holder 12 is a cylindrical member having a square shape in plan view. However, the shape is not limited to this, and may be an octagonal prism shape as shown in FIG. Also in this case, as in the case of FIG. 8, most of the front side 14 u and most of the rear side 14 d of the driving coils 141 to 144 are the front side of the side surface of the octagonal columnar lens holder 12. The drive magnets 151U to 154U and the rear drive magnets 151D to 154D are disposed on the side surfaces facing each other.
Alternatively, as shown in FIG. 12, the shape of the lens holder 12 may be cylindrical. In this case, it is preferable that the front drive magnets 151U to 154U and the rear drive magnets 151D to 154D are arc columnar permanent magnets, respectively.

  In the above example, the lens holder 12 is suspended and supported by the case 11 using the front and rear spring members 13A and 13B. However, the lens holder 12 is extended to the lens holder 12 in the axial direction of the lens holder 12. Other support means such as providing a guide hole penetrating, standing a guide pin penetrating the guide hole in the base 11a of the case 11, and moving the lens holder 12 along the guide pin in the Z-axis direction, etc. The lens holder 12 may be supported by the case 11 so as to be movable.

  In the above example, the magnetic yoke 16 is provided on the surface opposite to the driving coil 14 of the front driving magnets 151U to 154U and the rear driving magnets 151D to 154D, but the magnetic yoke 16 is used as the driving coil 141. ˜144 may be arranged on the inner peripheral side. Alternatively, the magnetic yoke 16 is provided on both the surface of the front drive magnets 151U to 154U and the rear drive magnets 151D to 154D opposite to the drive coil 14 and the inner peripheral side of the drive coils 141 to 144. Also good. The magnetic yoke 16 is not an essential element of the present invention and may be omitted. However, by providing the magnetic yoke 16, the front drive magnets 151U to 154U that act on the drive coils 141 to 144 and the rear are provided. Since the normal direction density of the magnetic flux from the side drive magnets 151D to 154D increases, it is preferable to provide the magnetic yoke 16 as in this example.

  In the above example, the coated conductor is formed by winding around the X axis or the Y axis and using the driving coils 141 to 144. However, as shown in FIG. Two drive coils 146 and 147 may be used. In this case, as shown in the development view of FIG. 13B, the driving coil 146 and the driving coil 147 are switched so that the position in the Z-axis direction is switched between the front side and the rear side every 90 °. The front drive magnets 151U to 154U are arranged so as to face the side located in front of the Z axis among the sides of the drive coils 146 and 147, and the rear drive magnets 151D to 154D are arranged as drive coils. It arrange | positions so that the edge | side located behind Z-axis among the edges of 146,147 may be opposed. If the energizing directions of the drive coils 146 and 147 are reversed, the Lorentz force directed to the front of the Z axis or the Lorentz force directed to the rear of the Z axis is all applied to each side of the drive coils 146 and 147. As a result, the lens holder 12 can be moved along the Z-axis.

In the above-described embodiment, the front side 14u of the driving coil 141 faces the N pole that is the magnetic pole surface of the driving magnet 151U, and the rear side 14d is the S pole that is the magnetic pole surface of the driving magnet 151D. Although the front side 14u of the driving coil 143 adjacent to the Z axis is opposed to the S pole which is the magnetic pole surface of the driving magnet 153U, the rear side 14d is the magnetic pole of the driving magnet 153D. It faces the N pole, which is the surface. As shown in FIG. 3, the energizing direction of the front side 14u of the driving coil 141 is clockwise in the Z-axis direction and the energizing direction of the rear side 14d is counterclockwise in the Z-axis direction. The energization direction of the front side 14u of the coil 143 is counterclockwise in the Z-axis direction, and the energization direction of the rear side 14d is clockwise in the Z-axis direction. The same applies to the driving coil 143 and the driving coil 142 adjacent to the Z axis, the driving coil 142 and the driving coil 144, and the driving coil 144 and the driving coil 141.
Therefore, also in the above-described embodiment, as in FIGS. 13A and 13B, the energization direction of the sides extending in the direction perpendicular to the Z axis and the magnetic pole surface of the driving magnet among the sides of the driving coil. However, the sides in the same energizing direction are switched between the front side and the rear side every 90 ° in the Z-axis direction.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the embodiment. It is apparent from the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

10 Lens drive device with camera shake suppression function, 11 case, 11A upper case,
11B Lower case, 12 Lens holder, 121-124 Side surface of lens holder,
13A, 13B Spring member, 141-144 Driving coil,
151U to 154U Front drive magnet, 151D to 154D Rear drive magnet,
16 Magnetic yoke, 17 Current control means, 18 Lens.

Claims (6)

A fixed member; a columnar or cylindrical movable member; suspension means for suspending the movable member on the fixed member in a swingable manner; and electromagnetic drive means for swinging the movable member with respect to the fixed member. An electromagnetic drive device,
When the axial direction of the movable member is the Z-axis direction,
The electromagnetic driving means is arranged to have an even number of driving magnets having a magnetic pole surface perpendicular to the Z-axis direction and arranged at equal angles around the Z-axis, and to face the driving magnet with a gap. And a drive coil
The drive magnets adjacent to each other among the drive magnets have different polarities,
Either one of the driving coil and the driving magnet is attached to the movable member, and the other is attached to the fixed member,
The electromagnetic current characterized in that the energizing direction of the side extending in the direction perpendicular to the Z axis and the magnetic pole surface of the driving magnet of the driving coil differs depending on the polarity of the driving magnet corresponding to the side. Drive device.   The drive coil comprises an even number of coils having a Z axis wound around an axis perpendicular to the Z axis and sides extending in a direction perpendicular to the magnetic pole surface of the drive magnet. Item 2. The electromagnetic drive device according to Item 1.   The driving coil includes at least one coil pair wound around the Z axis, and the positions of the two coils constituting the coil pair in the Z axis direction are opposite to the polarity of the driving magnet. The electromagnetic drive device according to claim 1, wherein the electromagnetic drive device is switched in accordance with.   A second magnet arranged to face a side that extends in a direction perpendicular to the Z-axis of each of the coils and is different from a side that faces the drive magnet; 4. The electromagnetic driving device according to claim 1, wherein a polarity of a magnetic pole surface that is a surface facing the different side of the magnet is different from a polarity of the driving magnet. 5.   The electromagnetic drive device according to any one of claims 1 to 4, further comprising a current control unit that controls energization of each of the coils independently.   2. The magnetic yoke is disposed on a surface of the driving magnet or on a surface opposite to the surface of the driving magnet and the second magnet facing the driving coil. The electromagnetic drive device according to claim 5.

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