JP6485727B2 - Blur correction device, lens unit, imaging device, and actuator - Google Patents

Description

  The present invention relates to an actuator for a shake correction device, a lens unit such as a video camera, a digital still camera, or a mobile device having a shooting function, and an imaging device including the shake correction device.

  Conventionally, in a shake correction device provided in a camera or the like, a camera shake detected by a camera shake detection circuit using an angular velocity sensor or the like is detected, and based on the detected amount, for example, a part of a photographing lens. A moving frame that holds a correction lens or an image sensor is shifted by an actuator, and image blurring is suppressed by relatively displacing the image sensor and the optical axis of the imaging optical system.

  In recent years, there is a tendency that a thinner body is desired from the viewpoint of improving the design of a camera or the like. Therefore, a more compact configuration is also required for the shake correction device mounted on such a camera or the like. On the other hand, Patent Document 1 discloses a shake correction apparatus having an actuator provided with a magnet in which three or more magnetic poles are magnetized.

JP 2012-120303 A

  The actuator disclosed in Patent Document 1 includes a magnet, a coil that is opposed to the magnet, and that moves relative to the magnet by a magnetic force generated by energization, and a position detection unit (Hall element) that detects the position of the magnet. And the magnet includes three or more magnetic pole portions on one side. By using a magnet having three or more magnetic pole portions in this way, there is an advantage that the degree of freedom in design layout of the coil and the Hall element is increased. In particular, when a so-called bent lens barrel is employed in order to realize a thin camera or the like, the space in the thickness direction is limited. Therefore, such an actuator is preferably used for a shake correction apparatus.

  However, the actuator disclosed in Patent Document 1 having a magnet having three or more magnetic pole portions on one side does not sufficiently consider leakage of magnetic flux in the magnetic pole portion, and diffusion to the outside increases. It has been found that there is a possibility that the position detection accuracy of the correction lens or the image sensor and the position control accuracy may be reduced by affecting the position detection means in the other axis movement direction.

  The present invention has been made in view of the above problems, and an object of the present invention is to obtain an actuator, a shake correction device, a lens unit, and an imaging device that can ensure shake correction control with high accuracy while having a compact configuration. .

The blur correction device according to claim 1 drives the moving frame holding the lens or the solid-state imaging device in a first direction and a second direction different from each other in a plane substantially orthogonal to the optical axis. A blur correction device that corrects blur during imaging,
A fixed frame, a movable frame that can move relative to the fixed frame, a first drive unit that moves the movable frame in the first direction relative to the fixed frame, and the movement relative to the fixed frame A second driving unit configured to move the frame in the second direction; first position detecting means for detecting a relative position of the moving frame with respect to the fixed frame; and the moving frame in the second direction with respect to the fixed frame. Second position detecting means for detecting a relative position;
It is possible to determine the amount of movement of the moving frame in the first direction based on the position detected by the first position detecting means,
The first drive unit includes a first coil provided on one of the fixed frame and the moving frame, and a three-pole magnetic pole part on at least one surface provided on the other of the fixed frame and the moving frame. 1 and a voltage applied to the first coil, the moving frame can be moved relative to the fixed frame in the first direction,
The first position detecting means detects a relative position in the first direction of the moving frame with respect to the fixed frame by detecting a magnetic field generated from the first magnet;
The first magnet has a central magnetic pole portion disposed in the center along the first direction, and end-side magnetic pole portions that are disposed on both sides thereof and have different polarities from the central magnetic pole portion, The width of the central magnetic pole portion in the first direction is larger than the width of the end magnetic pole portion in the first direction, and is 0.75 times the sum of the widths of the end magnetic pole portions in the first direction. Bigger than 1.75 times smaller,
On the one side of the first magnet, the sum of the total magnetic fluxes generated from all the N-pole magnetic pole portions and the sum of the total magnetic flux amounts generated from all the S-pole magnetic pole portions substantially coincide with each other.
The moving frame is provided with the first driving unit and the second driving unit on one side in the longitudinal direction with the lens or the solid-state imaging element interposed therebetween, and rotates around a rotation axis on the other side in the longitudinal direction. It is possible.

  In the first magnet having three or more magnetic poles on one side, there is a central magnetic pole part (central magnetic pole part) and both magnetic pole parts (end magnetic pole part), and the total magnetic flux amount of each magnetic pole part is If the sum does not substantially match, the magnetic flux is likely to leak to the outside of the magnet, so the leaked magnetic flux affects the second position detection means, and the position detection accuracy and position control accuracy of the correction lens or the image sensor are reduced. It turns out that there is a fear. According to the present invention, on the one surface of the first magnet, the sum of the total magnetic fluxes generated from all the N-pole magnetic poles and the sum of the total magnetic fluxes generated from all the S-pole magnetic poles are calculated. By approximately matching, the magnetic field in the first magnet can be balanced, leakage of magnetic flux to the outside can be reduced, and the second position for detecting the relative position in the second direction on the other axis side is detected. It is possible to provide a shake correction apparatus that can suppress the influence on the position detection means and has a low risk of reducing the position detection accuracy and the position control accuracy of the correction lens or the image sensor.

  According to a second aspect of the present invention, there is provided the shake correction apparatus according to the first aspect of the present invention, wherein the sum of the total magnetic fluxes generated from all the N pole magnetic poles on one side of the first magnet is all the S poles. It is characterized by being larger than 0.8 times and smaller than 1.2 times the sum of the total magnetic fluxes generated from the magnetic pole portions.

  It is not necessary to make the sum of the total magnetic fluxes generated from all the N poles and the sum of the total magnetic fluxes generated from all the S poles completely, and it is generated from all the N poles. By making the sum of the total magnetic flux amounts to be larger than 0.8 times and smaller than 1.2 times the sum of the total magnetic flux amounts generated from the magnetic pole portions of all the S poles, magnetic flux leakage can be sufficiently reduced. Therefore, the influence on the second position detecting means can be suppressed.

  According to a third aspect of the present invention, there is provided the shake correction apparatus according to the second aspect of the invention, wherein the sum of the total magnetic fluxes generated from all the N-pole magnetic pole portions on one side of the first magnet is all the S-poles. It is characterized in that it is 0.85 times or more and 1.15 times or less of the sum of the total magnetic flux generated from the magnetic pole portions.

  More effectively by making the sum of the total magnetic fluxes generated from all the N-pole magnetic pole portions 0.85 to 1.15 of the sum of the total magnetic flux amounts generated from all the S-pole magnetic pole portions. The influence on the second position detecting means can be suppressed.

In order to make the sum of the total magnetic fluxes generated from all the N-pole magnetic poles close to the sum of the total magnetic fluxes generated from all the S-pole magnetic poles on the one side of the first magnet, The width of the central magnetic pole portion in the first direction and the width of the end magnetic pole portions on both sides thereof are not 1: 1, and it is necessary to further increase the width of the central magnetic pole portion. This is because the magnetic flux of the end side magnetic pole portion is more likely to wrap around from the side surface than the central magnetic pole portion. By spreading it, it is possible to suitably prevent the magnetic flux from wrapping around. More specifically, the width of the central magnetic pole portion in the first direction is set to be larger than 0.75 times the sum of widths of the end-side magnetic pole portions in the first direction and smaller than 1.75 times. Thus, the sum of the total magnetic fluxes generated from all the N-pole magnetic pole portions and the sum of the total magnetic flux amounts generated from all the S-pole magnetic pole portions can be substantially matched to the second position detecting means. The influence of can be suppressed.

The blur correction device according to claim 4 is the invention according to any one of claims 1 to 3 , wherein the width of the central magnetic pole portion in the first direction is the first direction of the end-side magnetic pole portion. It is characterized in that it is 0.8 times or more and 1.65 times or less of the sum of the widths.

  Thereby, the influence on said 2nd position detection means can be suppressed more effectively.

The blur correction device according to a fifth aspect of the present invention is the invention according to any one of the first to fourth aspects, wherein the second drive unit includes a second coil provided on one of the fixed frame and the movable frame. The second frame provided on the other of the fixed frame and the movable frame, and applying a voltage to the second coil, thereby moving the movable frame relative to the fixed frame to the second frame It is possible to move relative to the direction,
The second position detecting means detects a relative position in the second direction of the moving frame with respect to the fixed frame by detecting a magnetic field generated from the second magnet.

  As a result, the moving frame can be moved in the first direction and the second direction with respect to the fixed frame, and the relative positions of the first direction and the second direction can be detected. .

According to a sixth aspect of the present invention, there is provided a shake correction apparatus according to any one of the first to fifth aspects, wherein the moving frame guides the movable frame so as to be rotatable about an axis substantially parallel to the optical axis. A linear guide mechanism that guides the rotary guide mechanism so as to be movable in a straight direction that intersects the axis, wherein the first direction is the straight direction, and the second direction is about the axis. It is a rotation direction.

  Accordingly, the moving frame can be moved in the first direction and the second direction with respect to the fixed frame, and a relative position between the first direction and the second direction can be detected.

According to a seventh aspect of the present invention, there is provided a shake correcting apparatus according to the fifth aspect of the present invention, wherein the first magnet and the second magnet have at least one when viewed from the optical axis direction with a yoke interposed therebetween. The parts are arranged so as to overlap each other.

  By arranging the first magnet and the second magnet in this way, a compact shake correction apparatus can be provided. Further, although there is an increased risk that the second position detection means will be adversely affected by the magnetic field of the first magnet, the present invention can be preferably used because the influence on the second position detection means can be reduced. It is.

According to an eighth aspect of the present invention, in the blur correction device according to the fifth or seventh aspect , the first magnet, the second magnet, and a yoke are fixed to the moving frame, and the first coil and the The second coil is fixed to a fixed frame.

  Compared with the case where the coil is mounted on the moving frame, it is preferable because the wiring can be easily handled, the degree of freedom of design can be further secured, and the yoke can be shared.

According to a ninth aspect of the present invention, in the invention according to any one of the first to eighth aspects, the blur correction device is generated from a pair of N poles and S poles in the magnetic pole portion on one side of the first magnet. A magnetic field is detected by the first position detecting means and used to detect the position of the moving frame with respect to the fixed frame, and the magnetic field of another pair of N poles and S poles different from the one pair. Is used for driving the moving frame.

  By adopting the above configuration, the first position detecting means and the coil used for driving the moving frame can be arranged in the moving direction of the first driving unit, and therefore, it is preferably used when thinning in one axial direction. Can do. If the magnetic pole part on one side of the first magnet has three poles, among the three poles, the central magnetic pole is shared for position detection and driving, thereby reducing the size of the camera shake correction device. Can be achieved.

A lens unit according to a tenth aspect includes a blur correction device according to any one of the first to ninth aspects, an optical system including a plurality of lenses that guide subject light to the solid-state imaging device, and the plurality of lenses. And holding a lens barrel.

The lens unit according to an eleventh aspect is characterized in that, in the invention according to the tenth aspect , the optical system is a bent optical system including a reflecting member that bends the optical path.

  Although an imaging apparatus can be thinned by providing an optical system in which an optical path is bent by a reflecting member, that is, a so-called bending optical system, the space for installing the shake correction apparatus is limited. According to the present invention, it is possible to realize a shake correction device in a space where the thickness direction is limited by using the first magnet having at least three magnetic pole portions on one side. It is suitably used for an apparatus.

An imaging apparatus according to a twelfth aspect includes the lens unit according to the tenth or eleventh aspect and the solid-state imaging element.

According to a thirteenth aspect of the present invention, at the time of imaging by driving a moving frame holding a lens or a solid-state imaging device in a first direction and a second direction different from each other within a plane substantially orthogonal to the optical axis. An actuator used in a shake correction apparatus that corrects shake of
The blur correction device includes: a fixed frame; a movable frame that can move relative to the fixed frame; and a first position detection unit that detects a relative position of the movable frame with respect to the fixed frame in the first direction; Second position detecting means for detecting a relative position of the moving frame with respect to the fixed frame in the second direction;
It is possible to determine the amount of movement of the moving frame in the first direction based on the position detected by the first position detecting means,
The actuator includes a first drive unit that moves the moving frame in the first direction relative to the fixed frame, and a second drive unit that moves the movable frame in the second direction relative to the fixed frame. And comprising
The first drive unit includes a first coil provided on one of the fixed frame and the moving frame, and a three-pole magnetic pole part on at least one surface provided on the other of the fixed frame and the moving frame. 1 and a voltage applied to the first coil, the moving frame can be moved relative to the fixed frame in the first direction,
The first position detecting means detects a relative position in the first direction of the moving frame with respect to the fixed frame by detecting a magnetic field generated from the first magnet;
The first magnet has a central magnetic pole portion disposed in the center along the first direction, and end-side magnetic pole portions that are disposed on both sides thereof and have different polarities from the central magnetic pole portion, The width of the central magnetic pole portion in the first direction is larger than the width of the end magnetic pole portion in the first direction, and is 0.75 times the sum of the widths of the end magnetic pole portions in the first direction. Bigger than 1.75 times smaller,
On the one side of the first magnet, the sum of the total magnetic fluxes generated from all the N-pole magnetic pole portions and the sum of the total magnetic flux amounts generated from all the S-pole magnetic pole portions substantially coincide with each other.
The moving frame is provided with the first driving unit and the second driving unit on one side in the longitudinal direction with the lens or the solid-state imaging element interposed therebetween, and rotates around a rotation axis on the other side in the longitudinal direction. It is possible.

  According to the present invention, on the one surface of the first magnet, the sum of the total magnetic fluxes generated from all the N-pole magnetic poles and the sum of the total magnetic fluxes generated from all the S-pole magnetic poles are calculated. By approximately matching, the magnetic field in the magnet can be balanced, leakage of magnetic flux to the outside can be reduced, and the second position detecting means for detecting the relative position in the second direction on the other axis side. The influence of can be suppressed.

  “Total magnetic flux” refers to the total amount of magnetic flux generated from the magnetic pole part of the magnet. When there are a plurality of magnetic pole portions having the same polarity, the total magnetic flux amount of each magnetic pole portion is obtained. The total amount of magnetic flux can be measured by flux measurement using a search coil and a flux meter.

  In addition, when providing a lens in the shake correction apparatus, a single lens or a plurality of lenses may be used. Furthermore, the fixed frame and the moving frame may be a single component or a combination of a plurality of components.

  According to the present invention, it is possible to obtain an actuator, a shake correction device, a lens unit, and an image pickup device that can ensure shake correction control with high accuracy while having a compact configuration.

It is a front side perspective view of imaging device 10 of this embodiment. It is a back side perspective view of imaging device 10 of this embodiment. 2 is a perspective view illustrating a state in which a lens unit 50 is detached from the imaging device 10. FIG. It is the figure which cut | disconnected the structure of FIG. 3 by the surface containing an IV-IV line, and looked at the arrow direction. 1 is a perspective view of a shake correction apparatus 100. FIG. It is the figure which cut | disconnected the structure of FIG. 5 by the surface containing a VI-VI line and looked at the arrow direction. It is the figure which cut | disconnected the structure of FIG. 6 by the surface containing a VII-VII line, and looked at the arrow direction. 2 is a perspective view of a holder 101. FIG. 2 is a perspective view of a fixed frame 100. FIG. 3 is a perspective view of a magnet MG1 removed from a holder 101. FIG. It is r direction sectional drawing of the magnet MG1 concerning the comparative example 1, and the yoke YK1. It is r direction sectional drawing of the magnet MG1 concerning the comparative example 2, and the yoke YK1. It is r direction sectional drawing of the magnet MG1 concerning an Example, and the yoke YK1.

  An imaging apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front perspective view of an imaging apparatus 10 that is a digital still camera according to the present embodiment, and FIG. 2 is a rear perspective view of the imaging apparatus 10 of the present embodiment.

An imaging apparatus 10 that is a digital still camera has a housing 12 that forms an exterior.
As shown in FIGS. 1 and 2, the housing 12 is a flat, thin rectangle having a thickness in the front-rear direction, a height in the vertical direction larger than the thickness, and a width in the left-right direction larger than the height. It is formed in a plate shape.

  As shown in FIG. 1, an opening 12a is provided at a location near the right side of the front upper portion of the housing 12, and a first lens group of an imaging lens system, which will be described later, is provided facing the front through the opening 12a. ing. A cover member 14 capable of shielding the opening 12a is provided on the front surface.

  As shown in FIG. 2, on the back surface of the housing 12, a captured image (image data) is displayed, and a display 32 that displays an operation screen or a menu screen for performing various setting operations related to imaging and reproduction. Is provided. A display unit is constituted by the display 32. As the display 32, a conventionally known display device such as a liquid crystal display device or an organic EL display device can be adopted.

  A release button 34 and a power switch 36 are provided on the top surface of the housing 12. On the right side of the rear surface of the housing 12, a zoom operation switch 38 for adjusting the zoom ratio of the imaging lens system to the telephoto side (tele side) or the wide angle side (wide side), and switching between the imaging mode and the reproduction mode, etc. A plurality of operation switches 40 are provided for performing various operations, a selection operation of a selection item on a menu screen displayed on the display 32, a setting item setting operation, and the like.

  FIG. 3 is a perspective view illustrating a state where the lens unit 50 is detached from the imaging device 10. FIG. 4 is a diagram of the configuration of FIG. 3 cut along a plane including the IV-IV line and viewed in the direction of the arrow.

  As shown in FIG. 3, the lens unit 50 has a rectangular parallelepiped shape as a whole, and includes a lens barrel 51 and a shake correction device 52 that are connected to each other.

  In FIG. 4, the lens unit 50 has a bending imaging lens system OS. The imaging lens system OS includes a first lens unit L1, a second lens unit L2, a third lens unit L3, a fourth lens unit L4, a fifth lens unit L5, and an IR (not shown) in order from the object side. It consists of a cut filter. Although not shown, an imaging element is provided below the lens unit 50 via a fixed frame 100.

  The first lens unit L1 includes, in order from the object side, a concave lens L1a, a prism PZ as a reflecting member that bends the optical axis of the imaging lens system, and a convex lens L1b, which are attached to the lens barrel 51.

  The second lens group L2 is a lens group for zooming, and a concave lens L2a, a concave lens L2b, and a convex lens L2c, which are arranged in order from the object side, are integrally attached to the holder HLD1 and in the optical axis direction with respect to the lens barrel 51. It is supposed to move.

  The third lens unit L <b> 3 includes a single convex lens and is attached to the lens barrel 51. The fourth lens unit L4 is a lens unit for zooming and focusing, and a concave lens L4a and a convex lens L4b, which are arranged in order from the object side, are integrally attached to the holder HLD2, and are arranged in the optical axis direction with respect to the lens barrel 51. It is supposed to move.

  The fifth lens unit L5 includes, in order from the object side, a concave lens L5a held by the lens barrel 51, a convex lens L5b held by the holder 101 (moving frame), and a concave lens L5c held by the fixed frame 100.

  The blur correction device 52 of the present embodiment will be described. 5 is a perspective view of the blur correction device 52, FIG. 6 is a view of the configuration of FIG. 5 cut along a plane including the VI-VI line and viewed in the direction of the arrow, and FIG. FIG. 8 is a perspective view of the holder 101 in which the configuration is cut along a plane including the line VII-VII and viewed in the direction of the arrow. FIG. 9 is a perspective view of the fixed frame 100. FIG. 10 is a perspective view of the magnet MG1 removed from the holder 101, and is partially shown schematically.

  6 and 8, the holder 101 accommodated in the shake correction device 52 is an elongated plate extending in the direction perpendicular to the optical axis of the convex lens L5b, holding the convex lens L5b on one end side, and plate-like on the other end side. The yokes YK1 and YK2 are stacked and held. A linear drive magnet MG1 is attached to the holder 101 adjacent to the object-side yoke YK1. Above the magnet MG1, a straight driving coil CL1 fed from the outside and a sensor (Hall element) S1 for detecting a straight driving position are attached to the fixed frame 100. The magnet MG1, the yokes YK1, YK2, and the coil CL1 constitute a first drive unit.

The magnet MG1 will be described. In FIG. 10 where the upper side is the object side and the lower side is the image side, the magnet MG1 is magnetized with three poles on one side. Specifically, the magnet MG1 has three magnetic pole portions MG1a, MG1b, and MG1c (arrangement of N poles, S poles, and N poles as viewed from the image side, but may be arrangement of S poles, N poles, and S poles). These are provided side by side along a direction (r direction) orthogonal to the axis AX of the rotation shaft 53. An unmagnetized portion MG1d having no polarity is formed between the magnetic pole portions MG1a and MG1b, and an unmagnetized portion MG1e having no polarity is formed between the magnetic pole portions MG1b and MG1c, which are parallel to each other. It extends in the tangential direction of the concentric circle of the axis AX. Here, when the width of the magnetic pole part MG1a along the r direction is A, the width of the magnetic pole part MG1b is B, and the width of the magnetic pole part MG1c is C, the following expression is found.
0.75 < B / (A + C) <1.75 (1)
More preferably, the following expression is satisfied.
0.8 ≦ B / (A + C) ≦ 1.65 (1 ′)

  As shown in FIG. 6, the coil CL1 is arranged on the object side of the magnet MG1 so as to straddle the magnetic pole portions MG1a and MG1b so that the unmagnetized portion MG1d comes to the center. A certain sensor S1 is arranged on the object side of the magnet MG1 so that the non-magnetized portion MG1e comes to the center so as to straddle the magnetic pole portions MG1b and MG1c.

  Although not visible in FIG. 6, a rotation direction driving magnet MG <b> 2 (see FIG. 7) is attached to the holder 101 adjacent to the image pickup device side yoke YK <b> 2. Below the magnet MG2, a rotation direction driving coil CL2 fed from the outside and a rotation direction position detection sensor (Hall element) S2 are attached to the fixed frame 100. The magnet MG2, the yokes YK1, YK2, and the coil CL2 constitute a second drive unit.

  In the cross section of FIG. 7, the coil CL2 is disposed so as to straddle both poles on the image side of the magnet MG2. The magnet MG1 and the magnet MG2 are arranged so as to overlap in the optical axis direction. As shown in FIG. 6, the sensor S2, which is the second position detection means, is disposed on the image side of the magnet MG2 and adjacent to the coil CL2 and overlapping the magnets MG1 and MG2.

  6, slits 101a, 101b, 101c, and 101d extending in the left-right direction in FIG. 6 are formed on both end surfaces of the holder 101 (see FIG. 8). A rotating shaft 53 extending in a vertical direction (a direction substantially parallel to the optical axis) from the fixed frame 100 is engaged in the slit 101d constituting the rectilinear guide mechanism. As a result, the holder 101 can move in the extending direction of the long hole 101d with respect to the rotation shaft 53 constituting the rotation guide mechanism, and can rotate about the rotation axis AX (see FIG. 5) of the rotation shaft 53. It has become.

  As shown in FIG. 9, holes 100a and 100b (not visible but opposed to 100a), 100c and 100d are formed in opposing side walls of the fixed frame 100, and pins 54, 55 and 56 are formed here. (FIG. 5) is inserted in parallel. The pin 54 extends through the fixed frame 100 and engages with the slit 101 a of the holder 101. Each of the pins 55 and 56 extends inward from both side walls of the fixed frame 100, and the tip of the pin 55 engages with the slit 101 b of the holder 101, and the tip of the pin 56 is the holder 101. Is engaged with the slit 101c. With such a configuration, the holder 101 is slidably held in a plane orthogonal to the optical axis by the pins 54, 55, and 56.

  The operation of the shake correction device 52 will be described. When it is detected that an image blur occurs by an acceleration sensor or the like provided in the imaging apparatus, the blur correction is performed by moving the holder 101 together with the convex lens L5b. Specifically, when driving the convex lens L5b in the rotational direction, a magnetic force is applied to the magnet MG2 by energizing the coil CL2 for driving the rotational direction, and in FIG. The convex lens L5b rotates around the rotation axis AX of the rotation shaft 53 (the θ direction as the second direction) together with the holder 101 guided by 56, and its position is obtained by detecting the magnetic field of the magnet MG2 with the Hall element S2. Feedback control is performed.

  On the other hand, when the convex lens L5b is to be driven in the straight direction, a magnetic force is applied to the magnet MG1 by energizing the coil CL1 for driving in the straight direction, and guides to the pins 54, 55, and 56 in FIG. The convex lens L5b is moved in the direction orthogonal to the axis AX of the rotation shaft 53 (the r direction as the first direction) together with the holder 101, and the position thereof is obtained by detecting the magnetic field of the magnet MG1 with the Hall element S1, Feedback control is performed. Accordingly, the convex lens L5b can be shifted to an arbitrary position in the direction orthogonal to the optical axis with respect to the imaging element. Here, in the magnetic pole part on one side of the magnet MG1, the magnetic field generated from the pair of N pole and S pole magnetic poles MG1b and MG1c is detected by the Hall element S1, and the position of the moving frame relative to the fixed frame is detected. The function is shared so that the magnetic fields of another pair of N and S poles MG1a and MG1b different from the one pair are used for driving the moving frame.

  Here, in order to realize accurate position control of the holder 101, it is desired to suppress the influence of the magnetic field of the magnet MG1 on the sensor S2. Therefore, in the present embodiment, the sum of the total magnetic flux amounts generated from all the N pole parts by adjusting the size and magnetic force of the magnet on the surface of the magnet MG1 facing the yoke YK1, The total amount of magnetic flux generated from the magnetic pole portions is larger than 0.8 times and smaller than 1.2 times. More preferably, in magnet MG1, the sum of the total magnetic fluxes generated from all the N-pole magnetic poles is greater than 0.85 times the sum of the total magnetic fluxes generated from all the S-pole magnetic poles. Make it smaller than twice. That is, the sum of the total magnetic fluxes generated from all the N-pole magnetic poles is made substantially equal to the sum of the total magnetic fluxes generated from all the S-pole magnetic poles. As a result, the amount of magnetic flux leaking to the outside of the magnet MG1 can be reduced, so that the influence of the magnetic field of the magnet MG1 can be prevented from reaching the sensor S2, and deterioration of position detection accuracy and position control accuracy can be prevented. it can.

  Hereinafter, simulation results performed by the present inventors will be described. 11 to 13 are cross-sectional views in the r direction of the magnet MG1 and the yoke YK1 with different specifications, and are shown together with the generated magnetic flux. Here, the width in the r direction (left and right direction) of the magnetic pole part MG1a of the magnet MG1 is A, the width in the r direction (left and right direction) of the magnetic pole part MG1b is B, and the width in the r direction (left and right direction) of the magnetic pole part MG1c is C. And

In the magnet MG1 having the specifications shown in FIG. 11, since A = B = C, B / (A + C) = 0.5 , which is below the lower limit of the expression (1). As shown in FIG. 11, the amount of magnetic flux leaking to the outside of the magnetic pole portions MG1a and MG1c at both ends increases, and the magnetic flux spills down to the lower side of the yoke YK1, adversely affecting the sensor S2, and the position detection accuracy and position control accuracy. There is a risk of worsening.

In the magnet MG1 having the specifications shown in FIG. 12, B / (A + C) = 2 , which exceeds the upper limit of the expression (1). As shown in FIG. 12, the amount of magnetic flux generated from the upper surface (N pole) of the central magnetic pole portion MG1b increases, and cannot be absorbed by the upper surfaces (S poles) of the magnetic pole portions MG1a and MG1c at both ends, and is below the yoke YK1. May cause adverse effects on the sensor S2, and may cause deterioration in position detection accuracy and position control accuracy.

On the other hand, in the magnet MG1 having the specification shown in FIG. 13, B / (A + C) = 1.0, which satisfies the expression (1). As a result, the sum of the total magnetic fluxes generated from the N-pole magnetic pole portions and the sum of the total magnetic flux amounts generated from all the S-pole magnetic pole portions substantially coincide with each other. Therefore, as shown in FIG. 13, the magnetic flux generated from the upper surface (N pole) of the central magnetic pole portion MG1b and the magnetic flux to the upper surfaces (S pole) of the magnetic pole portions MG1a and MG1c at both ends are balanced. Since the amount of magnetic flux below YK1 is greatly reduced, it can be avoided that the sensor S2 is adversely affected, and deterioration in position detection accuracy and position control accuracy can be prevented.

  In addition, assuming that the magnet MG1 has a rectangular plate shape with a vertical and horizontal thickness and a constant thickness dimension, the value in the width direction of the magnetic pole part is defined. However, when the magnet MG1 has a different shape, the dimension of the magnetic pole part is , (1) or (1 ′) may be exceeded. However, even in such a magnet, the sum of the total magnetic fluxes generated from all the N-pole magnetic poles and the sum of the total magnetic fluxes generated from all the S-pole magnetic poles substantially coincide on one side. In some cases, it should be understood to be within the scope of the present invention.

  The present invention is not limited to the embodiment described above. For example, a solid-state imaging device may be mounted on the holder 101 and moved in two directions orthogonal to the optical axis. Further, a magnetic pole portion having three or more poles may be provided on one side of the magnet MG2. Further, it may be a moving coil type blur correction device that drives a coil instead of a moving magnet type that drives a magnet.

DESCRIPTION OF SYMBOLS 10 Image pick-up device 12 Case 12a Opening 14 Cover member 32 Display 34 Release button 36 Power switch 38 Zoom operation switch 40 Operation switch 50 Lens unit 51 Lens barrel 52 Shake correction device 53 Rotating shaft 54, 55, 56 Pin 100 Fixed frame 100a Hole 100b hole 100c hole 100d hole 101 holder 101a slit 101b slit 101c slit 101d slit

AX Rotation axis CL1 Coil CL2 Coil HLD1 Holder HLD2 Holder L1-L5 Lens group MG1 Magnet MG2 Magnet PZ Prism S1 Sensor (Hall element)
S2 sensor (Hall element)
YK1 Yoke YK2 Yoke

Claims (13)

A blur correction device that corrects blur at the time of imaging by driving a moving frame holding a lens or a solid-state imaging device in a first direction and a second direction different from each other in a plane substantially orthogonal to the optical axis Because
A fixed frame, a movable frame that can move relative to the fixed frame, a first drive unit that moves the movable frame in the first direction relative to the fixed frame, and the movement relative to the fixed frame A second driving unit configured to move the frame in the second direction; first position detecting means for detecting a relative position of the moving frame with respect to the fixed frame; and the moving frame in the second direction with respect to the fixed frame. Second position detecting means for detecting a relative position;
It is possible to determine the amount of movement of the moving frame in the first direction based on the position detected by the first position detecting means,
The first drive unit includes a first coil provided on one of the fixed frame and the moving frame, and a three-pole magnetic pole part on at least one surface provided on the other of the fixed frame and the moving frame. 1 and a voltage applied to the first coil, the moving frame can be moved relative to the fixed frame in the first direction,
The first position detecting means detects a relative position in the first direction of the moving frame with respect to the fixed frame by detecting a magnetic field generated from the first magnet;
The first magnet has a central magnetic pole portion disposed in the center along the first direction, and end-side magnetic pole portions that are disposed on both sides thereof and have different polarities from the central magnetic pole portion, The width of the central magnetic pole portion in the first direction is larger than the width of the end magnetic pole portion in the first direction, and is 0.75 times the sum of the widths of the end magnetic pole portions in the first direction. Bigger than 1.75 times smaller,
On the one side of the first magnet, the sum of the total magnetic fluxes generated from all the N-pole magnetic pole portions and the sum of the total magnetic flux amounts generated from all the S-pole magnetic pole portions substantially coincide with each other.
The moving frame is provided with the first driving unit and the second driving unit on one side in the longitudinal direction with the lens or the solid-state imaging element interposed therebetween, and rotates around a rotation axis on the other side in the longitudinal direction. A blur correction device characterized in that it is possible.   On one side of the first magnet, the sum of the total magnetic fluxes generated from all the N-pole magnetic poles is greater than 0.8 times the sum of the total magnetic fluxes generated from all the S-pole magnetic poles. The blur correction apparatus according to claim 1, wherein the blur correction apparatus is smaller than two times.   On one side of the first magnet, the sum of the total magnetic fluxes generated from all the N-pole magnetic poles is 0.85 times or more the sum of the total magnetic fluxes generated from all the S-pole magnetic poles; The blur correction device according to claim 2, wherein the blur correction device is 15 times or less. The width of the central magnetic pole portion in the first direction is 0.8 times or more and 1.65 times or less of a sum of widths of the end-side magnetic pole portions in the first direction. The blur correction apparatus according to any one of 1 to 3 . The second driving unit includes a second coil provided on one of the fixed frame and the moving frame, and a second magnet provided on the other of the fixed frame and the moving frame, By applying a voltage to the coil of 2, it is possible to move the moving frame relative to the fixed frame in the second direction,
The said 2nd position detection means detects the relative position in the said 2nd direction of the said moving frame with respect to the said fixed frame by detecting the magnetic field which generate | occur | produces from the said 2nd magnet. 5. The blur correction device according to any one of 4 above. A rotation guide mechanism that guides the moving frame so as to be rotatable about an axis substantially parallel to the optical axis, and a rectilinear guide mechanism that guides the movement frame so as to be movable in a straight direction intersecting the axis of the rotation guide mechanism. a, the first direction is the rectilinear direction, the second direction blur correction device according to any one of claims 1 to 5, characterized in that a rotational direction of the axis line. Said first magnet and said second magnet, through the yoke between, when viewed in the optical axis direction, according to claim 5, characterized in that it is disposed so that they at least partially overlap Blur correction device. Said first magnet and said second magnet and the yoke is fixed to the movable frame, according to claim 5 or 7 wherein the first coil and the second coil is characterized in that it is fixed to the fixed frame The image stabilizer according to 1. In the magnetic pole part on one side of the first magnet, a magnetic field generated from a pair of N pole and S pole magnetic poles is detected by the first position detecting means, and the position of the moving frame relative to the fixed frame is detected. use to, according to the magnetic field of the magnetic poles of N and S poles of the other pair different from the pair to any one of claims 1 to 8, characterized in that used for driving the moving frame Blur correction device. A blur correction apparatus according to any one of claims 1 to 9 , an optical system including a plurality of lenses for guiding subject light to a solid-state imaging device, and a lens barrel that holds the plurality of lenses. Lens unit to be used. The lens unit according to claim 10 , wherein the optical system is a bent optical system including a reflecting member that bends an optical path. An image pickup apparatus comprising the lens unit according to claim 10 and a solid-state image pickup device. A blur correction device that corrects blur at the time of imaging by driving a moving frame holding a lens or a solid-state imaging device in a first direction and a second direction different from each other in a plane substantially orthogonal to the optical axis An actuator for use in
The blur correction device includes: a fixed frame; a movable frame that can move relative to the fixed frame; and a first position detection unit that detects a relative position of the movable frame with respect to the fixed frame in the first direction; Second position detecting means for detecting a relative position of the moving frame with respect to the fixed frame in the second direction;
It is possible to determine the amount of movement of the moving frame in the first direction based on the position detected by the first position detecting means,
The actuator includes a first drive unit that moves the moving frame in the first direction relative to the fixed frame, and a second drive unit that moves the movable frame in the second direction relative to the fixed frame. And comprising
The first drive unit includes a first coil provided on one of the fixed frame and the moving frame, and a three-pole magnetic pole part on at least one surface provided on the other of the fixed frame and the moving frame. 1 and a voltage applied to the first coil, the moving frame can be moved relative to the fixed frame in the first direction,
The first position detecting means detects a relative position in the first direction of the moving frame with respect to the fixed frame by detecting a magnetic field generated from the first magnet;
The first magnet has a central magnetic pole portion disposed in the center along the first direction, and end-side magnetic pole portions that are disposed on both sides thereof and have different polarities from the central magnetic pole portion, The width of the central magnetic pole portion in the first direction is larger than the width of the end magnetic pole portion in the first direction, and is 0.75 times the sum of the widths of the end magnetic pole portions in the first direction. Bigger than 1.75 times smaller,
On the one side of the first magnet, the sum of the total magnetic fluxes generated from all the N-pole magnetic pole portions and the sum of the total magnetic flux amounts generated from all the S-pole magnetic pole portions substantially coincide with each other.
The moving frame is provided with the first driving unit and the second driving unit on one side in the longitudinal direction with the lens or the solid-state imaging element interposed therebetween, and rotates around a rotation axis on the other side in the longitudinal direction. An actuator characterized in that it is possible.