JP2009230025A - Coil drive unit, blur correction mechanism and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve driving accuracy in a coil drive unit. <P>SOLUTION: The coil drive unit 520 is equipped with: a yoke 403 equipped with a pair of iron core parts 601a and 601b and a pair of iron core parts 602a and 602b respectively positioned on an inner periphery side and an outer periphery side of a coil 506 equipped with an air-core part inside a winding; a magnet 503 provided in either the iron core part 601b or 602a between the pair of iron core parts 601a and 601b and the pair of iron core parts 602a and 602b, and capable of displacing relatively to the coil 506 together with the yoke 403; a substrate 301 having a plane form part going along the inner peripheral surface of the coil 506 and attached to the coil 506 in such a state that the plane form part is made to abut on the inner peripheral surface of the coil 506; and a magnetic sensor 508 provided on the substrate 301 and detecting magnetic field strength of the magnet 503. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a coil drive unit that generates a driving force for moving a member to be driven in a predetermined direction, and vibration caused by camera shake or the like by moving the image sensor in a plane orthogonal to the optical axis using the coil drive unit. The present invention relates to a shake correction mechanism that reduces deterioration in image quality of a captured image, and an imaging apparatus that includes the shake correction mechanism.

  Conventionally, by using a magnetic sensor disposed on the inner peripheral portion of the drive coil, a magnetic field generated by the drive magnet disposed on one end side in the winding axis direction of the drive coil is detected, so that the relative relationship between the drive coil and the drive magnet is increased. There has been a technique for detecting the position (see, for example, Patent Document 1 below). In this technique, the magnetic sensor has a magnetic flux detection axis in a direction perpendicular to the winding axis of the drive coil, and the drive magnet magnetized by the two poles moves in the magnetization direction. A relative position between the drive coil and the drive magnet is detected by detecting a change in magnetic flux around the boundary.

  Conventionally, a technique in which a magnetic sensor is disposed on one surface of a yoke having drive coils mounted on both sides (see, for example, Patent Document 2 below), and a magnetic body in a direction parallel to the winding axis of the air core portion of the coil. There is a technique (see, for example, Patent Documents 3 and 4 below). Further, conventionally, there has been a technique in which the influence on the magnetic sensor due to the magnetic flux generated by the drive coil is corrected by a voltage applied to the drive coil (see, for example, Patent Document 5 below).

Japanese Patent Application Laid-Open No. 08-0505515 JP 2007-017874 A JP 09-244090 A Japanese Patent Laid-Open No. 07-181540 US Pat. No. 5,932,984

  However, in the technique of Patent Document 1 described above, the magnetic flux generated by the drive coil matches the detection direction of the magnetic sensor, so the magnetic flux of the drive coil affects the output of the magnetic sensor, and the magnetic flux of the drive magnet is good. There was a problem that it could not be detected. Further, in the technique of Patent Document 2 described above, since the drive coil and the magnetic sensor are provided on one side of the yoke, the magnetic flux of the drive coil affects the output of the magnetic sensor, and the magnetic flux of the drive magnet is improved. There was a problem that it could not be detected.

  Further, in the techniques of Patent Documents 3 and 4 described above, since the magnetic body enters and exits the air core portion of the drive coil, a magnetic sensor that detects a change in the movement amount by the magnetism of the drive magnet may be provided. There was a problem that it was difficult. As a countermeasure, it is conceivable to use an optical position sensor that is not affected by magnetism, but the optical sensor has more components than the magnetic detection generated by the drive magnet, and should be incorporated in a small space. Is difficult.

  Further, the technique disclosed in Patent Document 5 described above requires a circuit for correcting the voltage applied to the drive coil, which increases the number of components and complicates the structure. Furthermore, in the technique of Patent Document 5 described above, since the drive current is not constant and constantly changes, and the influence on the magnetic sensor is always changed, the voltage applied to the drive coil is corrected without delaying the change in the drive current. This is difficult, and there is a problem that it is difficult to accurately correct the influence of the magnetic flux generated by the drive coil on the magnetic sensor.

  In order to eliminate the above-described problems caused by the prior art, the present invention provides a coil drive unit capable of improving drive accuracy in a coil drive unit when relatively driving a yoke, a drive magnet, a coil, and a substrate, It is an object of the present invention to provide a shake correction unit including the coil drive unit and an imaging apparatus including the shake correction unit.

  In order to solve the above-described problems and achieve the object, a coil drive unit according to the present invention includes an air-core coil provided with an air-core portion inside a winding, an inner peripheral side and an outer peripheral side of the air-core coil. And a yoke provided with a pair of iron cores positioned on each of them, and provided between the pair of iron cores and on one of the iron cores, and is displaced relative to the air-core coil together with the yoke. A driving magnet and a planar shape portion along the peripheral surface of the air-core coil, and attached to the air-core coil in a state where the planar shape portion is in contact with the peripheral surface of the air-core coil It is provided with the board | substrate and the magnetic sensor which is provided in the surface by which the said drive magnet is arrange | positioned in the said board | substrate, and detects the magnetic field intensity of the said drive magnet.

  According to the present invention, it is possible to improve the accuracy of the mounting position of the substrate by using the peripheral surface of a coil that is generally manufactured by winding around a mold as a reference.

  The coil drive unit according to the present invention further includes an air core coil having an air core portion inside the winding, and a pair of iron core portions positioned respectively on the inner peripheral side and the outer peripheral side of the air core coil. Between the pair of iron cores and the one of the iron cores, a drive magnet that can be displaced relative to the air-core coil together with the yoke, and the air-core coil. A substrate having a planar shape portion along a peripheral surface, the substrate attached to the air core coil in a state where the planar shape portion is in contact with the peripheral surface of the air core coil, and the air core coil in the substrate; And a magnetic sensor provided on the opposite surface for detecting the magnetic field strength of the drive magnet.

  According to the present invention, the influence of the magnetic field of the air-core coil on the detection of the magnetic flux is detected by detecting the magnetic flux at a position where the magnetic flux of the air-core coil is sparser than when the magnetic sensor is provided on the same side as the air-core coil. Since the magnetic sensor and the drive magnet are positioned on the same side with respect to the substrate and the magnetic flux can be detected where the magnetic flux of the drive magnet is large, the magnetic flux of the drive magnet can be detected well.

  The coil drive unit according to the present invention is the coil drive unit according to the above-described invention, wherein the air-core coil includes a planar shape portion that intersects a radial direction of the air-core coil on at least a part of a circumferential surface, It is a flat member attached to the planar shape part of an air-core coil, It is characterized by the above-mentioned. According to this invention, it is possible to improve the accuracy of the mounting position of the substrate by attaching the flat substrate to the planar shape portion of the air-core coil, and to facilitate the mounting operation of the substrate.

  In the coil drive unit according to the present invention, in the above invention, the substrate has a shape in which the planar shape portion is along the inner peripheral surface of the air core coil, and the planar shape portion is formed on the air core coil. It is attached to the said air-core coil in the state contact | abutted to the internal peripheral surface.

  According to this invention, the accuracy of the mounting position of the substrate is improved by using the inner peripheral surface of the coil that is generally manufactured by winding around the formwork as a reference, and the case where the substrate is mounted on the outer peripheral side of the coil. In addition, the amount of deformation of the coil due to relative displacement with respect to the yoke and the drive magnet can be reduced by attaching the substrate at a position close to the center of the thrust generated in the axial direction of the coil.

  The coil drive unit according to the present invention is the air core coil according to the above invention, wherein the drive magnet causes the magnetic flux lines generated by the drive magnet to penetrate from the inner periphery side to the outer periphery side of the air core coil. It is provided in the inner peripheral side. According to this invention, the detection accuracy of magnetic flux can be improved by reducing the distance between the drive magnet and the magnetic sensor and detecting the magnetic flux where the magnetic flux of the drive magnet is large.

  The blur correction mechanism according to the present invention supports at least one of the image sensor and the substrate on which the image sensor is provided (hereinafter referred to as “element substrate”) and is capable of being displaced in a plane perpendicular to the optical axis direction. A correction member and the above-described coil drive unit that displaces the shake correction member are provided, and a substrate provided in the coil drive unit is attached to the shake correction member. According to this invention, the accuracy of the mounting position of the substrate can be improved by the coil driving unit, and the driving accuracy of the element substrate can be improved.

  According to another aspect of the present invention, there is provided an image pickup apparatus comprising: the shake correction mechanism described above; and an optical member that introduces external light into an image pickup element provided in the shake correction mechanism. According to the present invention, it is possible to improve the quality of an image to be captured by improving the driving accuracy of the element substrate.

  According to the coil drive unit according to the present invention, it is possible to improve the drive accuracy of the coil drive unit when the yoke, the drive magnet, the coil, and the substrate are relatively driven.

  Exemplary embodiments of a coil drive unit according to the present invention, a shake correction unit including the coil drive unit, and an imaging apparatus including the shake correction unit will be described below in detail with reference to the accompanying drawings.

(Embodiment 1)
First, the coil drive unit according to the first embodiment of the present invention, a shake correction unit including the coil drive unit, and an imaging device including the shake correction unit will be described. 1 and 2 are perspective views showing a shake correction unit including the coil drive unit according to the first embodiment of the present invention. In FIG. 1, the state which looked at the blurring correction unit provided with the coil drive unit of Embodiment 1 concerning this invention from the objective side is shown. In FIG. 2, the state which looked at the blurring correction unit provided with the coil drive unit of Embodiment 1 concerning this invention from the eyepiece side is shown.

  1 and 2, the blur correction unit 100 according to the first embodiment of the present invention includes a lens holding frame 102 that holds a lens 101. The lens holding frame 102 has a substantially cylindrical shape with the optical axis as the axial direction, and holds the lens 101 at the end on the objective side.

  On the eyepiece side of the lens holding frame 102, a lens barrel 103 and a rear cover 104 as a cover member are provided. The lens barrel 103 and the rear cover 104 are connected by a screw 201. 1 and 2, reference numerals 105 and 106 denote flexible substrates. The flexible substrates 105 and 106 have a long shape.

  The rear cover 104 is provided on the eyepiece side with respect to the lens barrel 103 in the optical axis direction, and covers a substrate (see reference numeral 301 in FIG. 3) on which an imaging element is mounted from the eyepiece side with respect to the lens barrel 103. The rear cover 104 includes a fixing portion 201 that fixes the other end portions of the flexible substrates 105 and 106. The other ends of the flexible substrates 105 and 106 are not limited to actual physical ends of the flexible substrates 105 and 106.

  The other end portions of the flexible substrates 105 and 106 may be an intermediate position in the longitudinal direction of the flexible substrates 105 and 106. In this case, the flexible substrates 105 and 106 are electrically connected from the substrate 301 side to the outside of the rear cover 104, and further extend (extend) to the outside of the rear cover 104.

  The flexible substrates 105 and 106 in the first embodiment are fixed to the fixing portion 201 at an intermediate position that is the other end. The fixing part 201 fixes both ends in the width direction of the flexible substrates 105 and 106 using screws. In addition, the fixing portion 201 may be fixed to the surface on the rear cover 104 side in the width direction of the flexible substrates 105 and 106 using a double-sided tape, an adhesive, or the like.

  The rear cover 104 is provided with a slit 202 that allows communication between the inner side and the outer side of the rear cover 104. The flexible boards 105 and 106 are electrically connected from the inner side of the rear cover 104 to the outer side through the slit 202, and are fixed to the rear cover 104 on the outer side of the rear cover 104.

  In the rear cover 104, the flexible substrate 105, 106 extending in the direction of one end of the flexible substrate 105, 106 from the fixed portion 201 is extended (expanded) in the flexible substrate 105 at both ends of the substrate (see reference numeral 301 in FIG. 3). The other end portions of the flexible substrates 105 and 106 are fixed so as to be in a direction opposite to the extending (extending) direction of.

  FIG. 3 is an explanatory diagram showing the flexible substrates 105 and 106. 3, the rear cover 104 in the shake correction unit 100 shown in FIG. 2 is indicated by a virtual line, and the flexible substrates 105 and 106 in a state where the rear cover 104 is attached are shown. In FIG. 3, the flexible substrates 105 and 106 are curved in an S shape inside the rear cover 104. The flexible substrates 105 and 106 are connected to the substrate 301 at one end in the longitudinal direction. Further, the other end portions of the flexible substrates 105 and 106 are fixed to the rear cover 104 by the fixing portion 201.

  4 is a cross-sectional view showing the shake correction unit 100, and FIG. 5 is an exploded perspective view showing a part of the shake correction unit 100. As shown in FIG. FIG. 4 shows a cross section of the blur correction unit 100 cut along a plane passing through the optical axis. FIG. 5 shows a state in which a part of the blur correction unit 100 is disassembled and viewed from the eyepiece side.

  4 and 5, a fixed frame 401 is provided on the inner peripheral side of the lens barrel 103. The fixed frame 401 includes a guide pole 501. The guide pole 501 is provided at a position retracted from the optical path with the first direction (see reference numeral X in FIG. 5) in the plane orthogonal to the optical axis as the axial direction. The guide poles 501 are provided at two locations with an optical path in between in a second direction (see reference numeral Y in FIG. 5) that intersects the first direction on a plane orthogonal to the optical axis.

  The fixed frame 401 includes a yoke support portion 402 that protrudes in the radial direction of a circle centered on the optical axis. The yoke support portion 402 is provided so as to protrude in two directions orthogonal to each other in a plane orthogonal to the optical axis. Specifically, one yoke support portion 402 is provided on a straight line passing through the optical axis in the first direction, and one on the straight line passing through the optical axis in the second direction. Each yoke support portion 402 supports the yoke 403.

  A magnet 503 is attached to each yoke 403. The yokes 403 are inserted into the air core portions of the coils 506 attached to the flexible substrate 505, respectively. The flexible substrate 505 is provided with a magnetic sensor 508 that detects the position of the substrate 301 in a plane orthogonal to the optical axis.

  In the first embodiment, a coil driving unit 520 is configured by the yoke 403, the flexible substrate 505, the magnet 503, the coil 506, and the magnetic sensor 508. In the first embodiment, a coil drive unit 520 that generates a driving force for moving a substrate 301 (an image sensor mounted on the substrate 301) in the first direction, and a substrate 301 (an image sensor mounted on the substrate 301). And a coil driving unit 520 that generates a driving force for moving the head in the second direction.

  The flexible substrate 505 is provided between the shake correction member 410 and the shake correction member 420. The blur correction member 410 is disposed to face the fixed frame 401 in the optical axis direction. The blur correction member 410 includes an opening 510 that opens an image sensor (not shown) provided on the substrate 301. In the first embodiment, an element substrate is realized by the substrate 301. The opening 510 includes a displacement range of the image sensor and opens so as to surround the displacement range from the outer peripheral side. A configuration in which the image sensor is displaced will be described later.

  In addition, the blur correction member 410 includes a guide portion 511 that engages with the guide pole 501, and is slidable along the guide pole 501 in a state where the guide portion 511 is in contact with the guide pole 501. . The shake correction member 410 can be displaced in the first direction on a plane orthogonal to the optical axis by sliding along the guide pole 501.

  In addition, the shake correction member 410 includes a guide pole 512. The guide pole 512 has a second direction as a longitudinal direction, and is provided at a position retracted from the optical path and on the outer peripheral side of the opening 510. The guide poles 512 are provided on both sides of the blur correction member 410 along the first direction in the plane orthogonal to the optical axis with the optical path in between.

  The blur correction member 420 supports the substrate 301. The blur correction member 420 includes a guide portion (not shown) that engages with the guide pole 512, and is provided to be slidable along the guide pole 512 in a state where the guide portion is in contact with the guide pole 512. Yes. The blur correction member 420 can be displaced in the second direction on a plane orthogonal to the optical axis by sliding along the guide pole 512.

  Further, since the shake correction member 420 is connected to the shake correction member 410, when the shake correction member 410 slides along the guide pole 501, it is also displaced in the first direction. In other words, the blur correction member 420 can be displaced in the first direction and the second direction in a plane orthogonal to the optical axis, whereby the image sensor mounted on the substrate 301 is in a plane orthogonal to the optical axis. It can be displaced to an arbitrary position.

  The substrate 301 has a flat plate shape that forms a plane orthogonal to the optical axis, and an image sensor is mounted at a substantially central portion of the substrate 301. The image sensor converts incident light into electricity and outputs an electric signal corresponding to the intensity of the incident light. The image pickup device can be realized by, for example, a CCD. Since the image pickup device is a known technique, description thereof is omitted.

  Since the substrate 301 is fixed to the shake correction member 420, it can be displaced in the same manner as the shake correction member 420. That is, the substrate 301 can be displaced to an arbitrary position in a plane orthogonal to the optical axis. One end of the flexible substrates 105 and 106 is connected to the substrate 301.

  The flexible substrates 105 and 106 are respectively connected to both ends of the substrate 301 in the first direction. The flexible substrates 105 and 106 have a long shape that extends (expands) with the first direction in the plane perpendicular to the optical axis as the longitudinal direction. The flexible substrates 105 and 106 are connected at one end where they are connected to the substrate 301 such that the extending (extending) direction from the substrate 301 is away from the optical axis.

  Next, the coil drive unit 520 will be described. FIG. 6 is a cross-sectional view showing the coil drive unit 520 of the first embodiment. FIG. 6 shows a state in which the coil drive unit 520 according to the first embodiment is cut in a plane passing through the optical axis and parallel to the optical axis. In FIG. 6, specifically, the coil drive unit 520 that generates a driving force for moving the substrate 301 (the image sensor mounted on the substrate 301) in the first direction passes through the optical axis and the first optical axis. The coil drive unit 520 that generates a driving force for moving the substrate 301 (the image sensor mounted on the substrate 301) in the second direction is cut through a plane parallel to the direction, and passes through the optical axis. The state cut | disconnected by the plane parallel to the direction of 2 is shown. The coil driving unit 520 that generates the driving force in any direction has the same structure, and the coil driving unit 520 will be described in FIG.

  In FIG. 6, a yoke 403 provided in the coil drive unit 520 has a plurality of (two in the first embodiment) yoke members 601 and 602, which are substantially U-shaped in cross section, stacked in the optical axis direction. The cross-sectional shape is a number 3 or a substantially E shape.

  The yoke members 601 and 602 each include a pair of iron core portions 601a and 601b, 602a and 602b that face each other in the optical axis direction. The pair of iron core portions 601a and 601b, 602a and 602b are connected at the end portions on the side away from the optical axis. The magnet 503 is provided between the pair of iron core portions 601a and 601b and 602a and 602b in the yoke members 601 and 602, respectively.

  The pair of iron core portions 601a and 601b, 602a and 602b has one iron core portion 601b and 602a positioned on the inner peripheral side of the coil 506 and the other iron core portion 601a and 602b positioned on the outer peripheral side of the coil 506, respectively. The magnet 503 is provided with iron core portions 601a and 602b located on the outer peripheral side of the coil 506, and is disposed in a state of facing the coil 506 therebetween.

  The magnet 503 and the coil 506 are in a non-contact state, and can be relatively displaced in the first direction or the second direction (the left-right direction in FIG. 6). The magnet 503 is provided on the outer peripheral side of the coil 506 so that the magnetic flux lines generated by each magnet 503 penetrate from the outer peripheral side of the coil 506 to the inner peripheral side.

  The substrate 301 is attached to the outer peripheral surface of the coil 506. The coil 506 is manufactured by winding a metal wire around a formwork. A mold used for manufacturing the coil 506 has a prismatic shape or an elliptical columnar shape, and a part of the outer peripheral surface is flat. The coil 506 is manufactured by winding a metal wire around a rectangular column-shaped or elliptical column-shaped mold, and thus has a planar shape portion that forms a plane intersecting the radial direction of the coil 506 on at least a part of the outer peripheral surface. ing. The substrate 301 is a flat member and is attached to the planar shape portion of the coil 506.

  By attaching the flat substrate 301 to the planar shape portion of the coil 506, the accuracy of the attachment position of the substrate can be improved and the attachment operation of the substrate can be facilitated. That is, by attaching the flat substrate 301 to the flat planar portion of the coil 506, the substrate mounting operation can be facilitated.

  The magnetic sensor 508 is provided on the substrate 301 and detects the magnetic field strength of the magnet 503. The magnetic sensor 508 is a surface of the substrate 301 on the magnet 503 side, and is provided outside the range where the iron core portions 601a and 601b and the iron core portions 602a and 602b face each other. The magnetic sensor 508 is provided on the surface of the substrate 301 opposite to the coil 506.

  Next, the magnetic flux generated by the magnet 503 will be described. FIG. 7 is an explanatory diagram showing the magnetic flux generated by the magnet 503. In FIG. 7, the magnet 503 attached to the iron core portion 601a generates magnetic flux lines from the magnet 503 through the coil 506 toward the iron core portion 601b opposite to the magnet 503. Magnetic flux lines are generated toward the nearby yoke member 601 without passing through the coil 506 at the end of the magnet 503 in the direction orthogonal to the facing direction of the iron core portions 601a and 601b.

  The magnet 503 attached to the iron core portion 602b generates magnetic flux lines from the magnet 503 through the coil 506 toward the iron core portion 602a opposite to the magnet 503. Magnetic flux lines are generated toward the end face of the nearby yoke member 602 without passing through the coil 506 at the end of the magnet 503 in the direction orthogonal to the facing direction of the iron core portions 602a and 602b.

  The magnetic flux lines generated by the magnet 503 have a lower density in the direction perpendicular to the facing direction of the iron core portions 602a and 602b as the end portion of the magnet 503 is located. The magnetic flux lines generated by the magnet 503 are higher on the magnet 503 side of the substrate 301 than on the magnet 503 side of the substrate 301. By providing the magnetic sensor 508 on the surface of the substrate 301 on the magnet 503 side, the magnetic field of the magnet 503 can be detected more than when the magnetic sensor 508 is provided on the surface of the substrate 301 opposite to the magnet 503. it can.

  Next, the magnetic flux generated by the coil 506 will be described. FIG. 8 is an explanatory diagram showing the magnetic flux generated by the coil 506. In FIG. 8, a coil 506 generates a magnetic flux that returns from the inner peripheral side of the coil 506 to the inner peripheral side through the outer peripheral side. The magnetic flux generated by the coil 506 passes through the yoke 403 and the magnet 503.

  The yoke 403 is excited by a magnet 503. For this reason, the magnetic flux does not easily pass through the yoke 403 closer to the magnet 503. The detection accuracy of the magnetic sensor 508 when installed on the same surface as the coil 506 with respect to the substrate 301 is more strongly affected by the magnetic field of the coil 506 than when the magnetic sensor 508 is installed on the surface opposite to the coil 506. receive.

  The amount of change in the magnetic field of the coil 506 is smaller on the surface of the substrate 301 opposite to the coil 506 than on the same surface of the substrate 301 as the coil 506. That is, when the magnetic sensor 508 is installed on the same surface as the coil 506 with respect to the substrate 301, the coil with respect to the magnetic sensor 508 is disposed on the surface opposite to the coil 506 with respect to the substrate 301. The influence of the magnetic field 506 is small.

  The magnetic flux generated by the coil 506 is higher in density as it is closer to the coil 506, and is lower in density as it is separated from the coil 506. Further, the magnetic flux generated by the coil 506 has a higher density on the inner peripheral side of the coil 506, that is, on the iron core portions 601b and 602a side. Further, the magnetic flux generated by the coil 506 is high in the range where the iron core portions 601a and 601b and the iron core portions 602a and 602b face each other, and outside the range where the iron core portions 601a and 601b and the iron core portions 602a and 602b face each other. The further away from 506, the lower the density.

  The magnetic sensor 508 in the coil drive unit 520 of the first embodiment is a surface on the magnet 503 side of the substrate 301 and is provided outside the range where the iron core portions 601a and 601b and the iron core portions 602a and 602b face each other. Therefore, the magnetic flux of the magnet 503 can be detected at a position that is not easily affected by the magnetic flux generated by the coil 506.

  Next, the mounting position of the magnetic sensor 508 will be described. FIG. 9 and FIG. 10 are explanatory diagrams showing attachment positions of the magnetic sensor 508 in the coil drive unit 520 of the first embodiment. FIG. 9 shows a state in which the coil drive unit 520 according to the first embodiment is cut in a plane passing through the optical axis and parallel to the optical axis. FIG. 10 shows a state in which the coil drive unit 520 of the first embodiment is cut in a plane parallel to the optical axis and perpendicular to the radius of a circle centered on the optical axis.

  In FIG. 9, the magnetic sensor 508 is disposed at a distance D <b> 1 from the magnet 503 in the radial direction of a circle centered on the optical axis. The distance D1 is determined by the moving distance of the substrate 301 in the first direction or the second direction. The distance D1 is set so that the magnetic sensor 508 can maintain a state where it does not contact or collide with the magnet 503 when the substrate 301 moves in the first direction or the second direction.

  The closer the arrangement position of the magnetic sensor 508 is to the magnet 503, the higher the detection accuracy of the magnetic sensor 508 can be. The distance D1 in the first embodiment is such that the positional relationship between the magnetic sensor 508 and the magnet 503 is such that the magnetic sensor 508 does not contact or collide with the magnet 503 when the substrate 301 is moved, and the magnetic sensor 508 is not magnetized. It is determined to be a position that does not contact or collide even when it moves to the end on the 503 side.

  In FIG. 10, the magnetic sensor 508 is provided at the center position in the direction orthogonal to the moving direction of the substrate 301. Specifically, the magnetic sensor 508 that detects the position of the substrate 301 in the first direction is provided at the center position in the second direction. Further, the magnetic sensor 508 for detecting the position of the substrate 301 in the first direction is specifically provided on a straight line passing through the position and the optical axis that are the center of the magnet 503 in the second direction.

  Specifically, the magnetic sensor 508 for detecting the position of the substrate 301 in the second direction is provided at the center position in the first direction. In addition, the magnetic sensor 508 that detects the position of the substrate 301 in the second direction is specifically provided on a straight line passing through the position and the optical axis that are the center of the magnet 503 in the first direction.

  In the above configuration, when the coil 506 is energized, magnetic flux is generated from the energized coil 506, and the relative positional relationship between the coil 506 and the magnet 503 is changed in the plane orthogonal to the optical axis by the generated magnetic flux. Such electromagnetic force is generated. Then, the shake correction members 410 and 420 are displaced so that the relative positional relationship between the coil 506 and the magnet 503 changes according to the generated electromagnetic force. As a result, the substrate 301 moves in the first direction and the second direction.

  The coil drive unit 520 acquires the amount of movement of the substrate 301 in the first direction based on the strength of the magnetic flux detected by the magnetic sensor 508 provided on the straight line passing through the optical axis in the first direction. In addition, the coil drive unit 520 acquires the amount of movement of the substrate 301 in the second direction based on the strength of the magnetic flux detected by the magnetic sensor 508 provided on a straight line passing through the optical axis in the second direction.

  As described above, according to the coil drive unit 520 of the first embodiment of the present invention, the coil 506 as an example of an air core coil provided with an air core portion inside the winding, and the inner peripheral side of the coil 506 Between the pair of iron core portions 601a, 601b and 602a, 602b and the pair of iron core portions 601a, 601b and 602a, 602b, and one iron core portion 601b and 602a. And a magnet 503 as an example of a drive magnet that can be displaced relative to the coil 506 together with the yoke 403, and a planar portion along the peripheral surface of the coil 506. A substrate 301 attached to the coil 506 in contact with the peripheral surface of the substrate 506, and a magnet provided on the substrate 301; The magnetic sensor 508 for detecting the magnetic field strength of 03 is provided, so that the substrate 301 is attached by using the inner peripheral surface of the coil 506 that is generally manufactured by winding around a mold as a reference. The position accuracy can be improved. Accordingly, it is possible to improve the driving accuracy in the coil driving unit 520 when the yoke 403 and the magnet 503, the coil 506, and the substrate 301 are relatively driven.

  In addition, according to the coil drive unit 520 of the first embodiment of the present invention, the coil 506 includes a planar shape portion that intersects the radial direction of the coil 506 at least at a part of the peripheral surface, and the substrate 301 includes the coil 506. Since the flat plate-like member is attached to the flat shape portion of the coil 506, the flat plate-like substrate 301 is attached to the flat shape portion of the coil 506, thereby improving the mounting position accuracy of the substrate 301 and the substrate. The attachment work of 301 can be facilitated. As a result, it is possible to further improve the driving accuracy in the coil driving unit 520 when the yoke 403 and the magnet 503, the coil 506, and the substrate 301 are relatively driven.

  Further, according to the coil drive unit 520 of the first embodiment of the present invention, the magnetic sensor 508 is provided on the surface of the substrate 301 on the magnet 503 side, so that the magnetic flux generated by the coil 506 Since the direction of the magnetic field detected by the magnetic sensor 508 can be made different, the magnetic flux of the magnet 503 can be detected satisfactorily regardless of the energized state of the coil 506. As a result, it is possible to further improve the driving accuracy in the coil driving unit 520 when the yoke 403 and the magnet 503, the coil 506, and the substrate 301 are relatively driven.

  Further, according to the coil drive unit 520 of the first embodiment of the present invention, the coil 506 provided with the air core part inside the winding, and the pair positioned on the inner peripheral side and the outer peripheral side of the coil 506, respectively. Between the pair of iron core portions 601a, 601b and 602a, 602b and provided in one iron core portion 601b and 602a, together with the yoke 403, the coil 506 A magnet 503 as an example of a drive magnet that can be relatively displaced with respect to the inner surface of the coil 506, and a planar shape portion along the inner peripheral surface of the coil 506. The substrate 301 attached to the coil 506 in a state where the coil 506 is attached, and provided on the surface of the substrate 301 opposite to the coil 506, The magnetic sensor 508 for detecting the magnetic field strength of the coil 503 is provided. Therefore, the magnetic flux at the position where the magnetic flux of the coil 506 is sparser than when the magnetic sensor 508 is provided on the same side as the coil 506 is provided. Detecting and reducing the influence of the magnetic field of the coil 506 on detecting the magnetic flux, and detecting the magnetic flux where the magnetic flux of the driving magnet is large by positioning the magnetic sensor 508 and the magnet 503 on the same side with respect to the substrate 301. Therefore, the magnetic flux of the magnet 503 can be detected satisfactorily. As a result, it is possible to further improve the driving accuracy in the coil driving unit 520 when the yoke 403 and the magnet 503, the coil 506, and the substrate 301 are relatively driven.

  In addition, according to the shake correction unit 100 including the coil drive unit 520 according to the first embodiment of the present invention, the shake correction members 410 and 420 can be displaced with high accuracy, so that the shake of the image sensor is corrected well. can do.

  In addition, according to the blur correction unit 100 including the coil drive unit 520 of the first embodiment and the imaging device including the blur correction unit 100, it is possible to satisfactorily correct the blur of the image sensor. As a result, the quality of the image captured using the imaging device can be improved.

(Embodiment 2)
Next, a coil drive unit according to a second embodiment of the present invention, a shake correction unit including the coil drive unit, and an imaging apparatus including the shake correction unit will be described. In the second embodiment according to the present invention, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 11 is a sectional view showing a coil drive unit according to the second embodiment of the present invention. FIG. 11 shows a state in which the coil drive unit of the second embodiment is cut in a plane passing through the optical axis and parallel to the optical axis. In FIG. 11, specifically, a coil drive unit that generates a driving force for moving the substrate 301 (the image sensor mounted on the substrate 301) in the first direction passes through the optical axis and the optical axis and the first direction. And a coil drive unit that generates a driving force for moving the substrate 301 (the image sensor mounted on the substrate 301) in the second direction through the optical axis and the second axis. The state cut | disconnected by the plane parallel to a direction is shown. Coil drive units that generate drive force in any direction have the same structure.

  In FIG. 11, the magnet 503 provided in the coil drive unit 1100 is provided in the iron core portion 601 a of the yoke member 601 and the iron core portion 602 a of the yoke member 602. The coil 506 is positioned on the outer peripheral side of the core portions 601b and 602a and the iron core portion 602a so that the magnets 503 provided on the iron core portions 601b and 602a and the iron core portion 602a are positioned on the inner peripheral side.

  The substrate 301 is attached to the inner peripheral surface of the coil 506. The coil 506 is manufactured by winding a metal wire around a formwork. A mold used for manufacturing the coil 506 has a prismatic shape or an elliptical columnar shape, and a part of the outer peripheral surface is flat. The coil 506 is manufactured by winding a metal wire around a prismatic or elliptical cylinder-shaped formwork, so that a planar shape portion forming a plane intersecting the radial direction of the coil 506 is formed on at least a part of the inner peripheral surface. I have. The substrate 301 is a flat member and is attached to the planar shape portion of the coil 506.

  Since the coil 506 is formed by winding it around a mold, the shape and size of the air core in the coil 506 can be determined uniformly according to the outer shape of the mold, and the air core in the coil 506 is determined. It is possible to match the dimensional accuracy of the mold with the dimensional accuracy of the mold. In this way, by attaching the substrate 301 to the inner peripheral surface with reference to the inner peripheral surface of the coil 506 having high dimensional accuracy, the accuracy of the mounting position of the substrate 301 with respect to the coil 506 can be improved.

  Further, by attaching the flat substrate 301 to the planar shape portion of the coil 506, it is possible to improve the accuracy of the attachment position of the substrate and facilitate the operation of attaching the substrate. That is, by attaching a flat substrate to the flat planar portion of the coil 506, the attachment work of the substrate 301 can be facilitated.

  The thrust of the coil 506 is generated around the inside of the axial center of the coil, that is, the air core. By attaching the substrate 301 to the inner peripheral surface of the coil 506, the substrate 301 can be attached at a position closer to the center of the thrust than when the substrate is attached to the outer peripheral side of the coil 506. Thereby, the deformation amount of the coil 506 due to the substrate 301 being displaced relative to the yoke members 601 and 602 and the magnet 503 can be reduced.

  The magnetic sensor 508 is provided on the substrate 301 and detects the magnetic field strength of the magnet 503. The magnetic sensor 508 is a surface of the substrate 301 on the magnet 503 side, and is provided outside the range where the iron core portions 601a and 601b and the iron core portions 602a and 602b face each other.

  Next, the magnetic flux generated by the magnet 503 will be described. FIG. 12 is an explanatory diagram showing the magnetic flux generated by the magnet 503. In FIG. 12, the magnet 503 attached to the iron core portion 601a generates magnetic flux lines from the magnet 503 through the coil 506 toward the iron core portion 601b opposite to the magnet 503. Magnetic flux lines are generated toward the nearby yoke member 601 without passing through the coil 506 at the end of the magnet 503 in the direction orthogonal to the facing direction of the iron core portions 601a and 601b.

  The magnet 503 attached to the iron core part 602a generates magnetic flux lines from the magnet 503 through the coil 506 toward the iron core part 602b opposite to the magnet 503. Magnetic flux lines are generated toward the nearby yoke member 602 without passing through the coil 506 at the end of the magnet 503 in a direction orthogonal to the facing direction of the iron core portions 602a and 602b.

  The magnetic flux lines generated by the magnet 503 have a lower density in the direction perpendicular to the facing direction of the iron core portions 602a and 602b as the end portion of the magnet 503 is located. The magnetic flux lines generated by the magnet 503 are higher on the coil 506 side of the substrate 301 than on the magnet 503 side of the substrate 301. By providing the magnetic sensor 508 on the surface of the substrate 301 on the magnet 503 side, the magnetic field of the magnet 503 can be detected more than when the magnetic sensor 508 is provided on the surface of the substrate 301 opposite to the magnet 503. it can.

  Next, the magnetic flux generated by the coil 506 will be described. FIG. 13 is an explanatory diagram showing the magnetic flux generated by the coil 506. In FIG. 13, the coil 506 generates a magnetic flux that returns from the inner peripheral side of the coil 506 to the inner peripheral side through the outer peripheral side. The magnetic flux generated by the coil 506 passes through the yoke 403 and the magnet 503.

  The yoke 403 is excited by a magnet 503. For this reason, the magnetic flux does not easily pass through the yoke 403 closer to the magnet 503. The detection accuracy of the magnetic sensor 508 when installed on the same surface as the coil 506 with respect to the substrate 301 is more strongly affected by the magnetic field of the coil 506 than when the magnetic sensor 508 is installed on the surface opposite to the coil 506. receive.

  The amount of change in the magnetic field of the coil 506 is smaller on the surface of the substrate 301 opposite to the coil 506 than on the same surface of the substrate 301 as the coil 506. That is, when the magnetic sensor 508 is installed on the same surface as the coil 506 with respect to the substrate 301, the coil with respect to the magnetic sensor 508 is disposed on the surface opposite to the coil 506 with respect to the substrate 301. The influence of the magnetic field 506 is small.

  The magnetic flux generated by the coil 506 is higher in density as it is closer to the coil 506, and is lower in density as it is separated from the coil 506. Further, the magnetic flux generated by the coil 506 has a higher density on the inner peripheral side of the coil 506, that is, on the iron core portions 601b and 602a side. Further, the magnetic flux generated by the coil 506 is high in the range where the iron core portions 601a and 601b and the iron core portions 602a and 602b face each other, and outside the range where the iron core portions 601a and 601b and the iron core portions 602a and 602b face each other. The further away from 506, the lower the density.

  The magnetic sensor 508 in the coil drive unit 520 of the second embodiment is a surface on the magnet 503 side of the substrate 301 and is provided outside the range where the iron core portions 601a and 601b and the iron core portions 602a and 602b face each other. Therefore, the magnetic flux of the magnet 503 can be detected at a position that is not easily affected by the magnetic flux generated by the coil 506.

  Next, the mounting position of the magnetic sensor 508 will be described. FIG. 14 and FIG. 15 are explanatory diagrams showing attachment positions of the magnetic sensor 508 in the coil drive unit 1100 of the second embodiment. FIG. 14 shows a state in which the coil drive unit 1100 according to the second embodiment is cut in a plane passing through the optical axis and parallel to the optical axis. FIG. 15 shows a state in which the coil drive unit 1100 of the first embodiment is cut along a plane parallel to the optical axis and perpendicular to the radius of a circle centered on the optical axis.

  In FIG. 14, the magnetic sensor 508 is disposed at a distance D2 from the magnet 503 in the radial direction of a circle centered on the optical axis. The distance D2 is determined by the moving distance of the substrate 301 in the first direction or the second direction. The distance D2 is set so that the magnetic sensor 508 can maintain a state where it does not contact or collide with the magnet 503 when the substrate 301 moves in the first direction or the second direction.

  The closer the arrangement position of the magnetic sensor 508 is to the magnet 503, the higher the detection accuracy of the magnetic sensor 508 can be. The distance D2 in the second embodiment is such that the positional relationship between the magnetic sensor 508 and the magnet 503 is such that the magnetic sensor 508 does not contact or collide with the magnet 503 when the substrate 301 is moved. It is determined to be a position that does not contact or collide even when it moves to the end on the 503 side.

  In FIG. 15, the magnetic sensor 508 is provided at the center position in the direction orthogonal to the moving direction of the substrate 301. Specifically, the magnetic sensor 508 that detects the position of the substrate 301 in the first direction is provided at the center position in the second direction. Further, the magnetic sensor 508 for detecting the position of the substrate 301 in the first direction is specifically provided on a straight line passing through the position and the optical axis that are the center of the magnet 503 in the second direction.

  Specifically, the magnetic sensor 508 for detecting the position of the substrate 301 in the second direction is provided at the center position in the first direction. In addition, the magnetic sensor 508 that detects the position of the substrate 301 in the second direction is specifically provided on a straight line passing through the position and the optical axis that are the center of the magnet 503 in the first direction.

  As described above, according to the coil drive unit 1100 of the second embodiment of the present invention, the substrate 301 has a planar shape portion that follows the inner peripheral surface of the coil 506, and the planar shape portion serves as the coil 506. Since it is attached to the coil 506 in contact with the inner peripheral surface of the substrate, the inner peripheral surface of the coil 506, which is generally manufactured by winding around a mold, is used as a reference for the substrate. In addition to improving the accuracy of the attachment position, the substrate is attached to a position closer to the center of the thrust generated in the axial direction of the coil 506 than when the substrate 301 is attached to the outer peripheral side of the coil 506, whereby the yoke 403 and the magnet 503 are attached. Therefore, the amount of deformation of the coil 506 due to relative displacement can be reduced. As a result, the durability of the coil drive unit 520 can be improved, and the drive accuracy of the coil drive unit 520 can be further improved.

  That is, regardless of the position of the magnet 503 with respect to the coil 506, depending on the position of the coil 506 and the magnet 503 with respect to the substrate 301 and the position of the magnetic sensor 508 with respect to the substrate 301, the magnetic field is opposite to the coil 506 on the substrate 301. By providing the sensor 508, it is possible to improve the driving accuracy in the coil driving unit 1100 when the yoke 403, the magnet 503, the coil 506, and the substrate 301 are relatively driven.

  Further, according to the coil drive unit 520 of the second embodiment of the present invention, the magnet 503 has the inner circumference of the coil 506 so that the magnetic flux lines generated by the magnet 503 penetrate from the inner circumference side of the coil 506 to the outer circumference side. Since the distance between the magnet 503 and the magnetic sensor 508 is reduced and the magnetic flux is detected where the magnetic flux of the magnet 503 is large, the detection accuracy of the magnetic flux can be improved. it can. As a result, it is possible to further improve the driving accuracy in the coil driving unit 520 when the yoke 403 and the magnet 503, the coil 506, and the substrate 301 are relatively driven.

  As described above, according to the first and second embodiments, it is possible to improve the driving accuracy in the coil driving unit when the yoke, the magnet, the coil, and the substrate are relatively driven.

  As described above, the coil drive unit according to the present invention, the shake correction unit including the coil drive unit, and the image pickup apparatus including the shake correction unit can move the image pickup device in a plane orthogonal to the optical axis. It is useful in reducing image quality degradation of captured images due to vibrations such as camera shake, and in particular to detect the amount of movement of the image sensor in order to improve drive accuracy in the coil drive unit, the coil drive unit and the coil drive unit And an image pickup apparatus including the shake correction unit.

It is a perspective view (the 1) which shows the blurring correction unit provided with the coil drive unit of Embodiment 1 concerning this invention. It is a perspective view (the 2) which shows the blurring correction unit provided with the coil drive unit of Embodiment 1 concerning this invention. It is explanatory drawing which shows a flexible substrate. It is sectional drawing which shows a blurring correction unit. It is a disassembled perspective view which shows a part of shake correction unit. FIG. 3 is a cross-sectional view showing the coil drive unit of the first embodiment. It is explanatory drawing which shows the magnetic flux which a magnet generate | occur | produces. It is explanatory drawing which shows the magnetic flux which a coil generate | occur | produces. FIG. 6 is an explanatory diagram (No. 1) showing a mounting position of the magnetic sensor in the coil drive unit according to the first embodiment. FIG. 6 is an explanatory diagram (No. 2) illustrating the attachment position of the magnetic sensor in the coil drive unit according to the first embodiment. It is sectional drawing which shows the coil drive unit of Embodiment 2 concerning this invention. It is explanatory drawing which shows the magnetic flux which a magnet generate | occur | produces. It is explanatory drawing which shows the magnetic flux which a coil generate | occur | produces. FIG. 9 is an explanatory diagram (No. 1) showing a mounting position of a magnetic sensor in the coil drive unit according to the second embodiment. FIG. 10 is an explanatory diagram (No. 2) showing a mounting position of the magnetic sensor in the coil drive unit according to the second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Shake correction unit 301 Board | substrate 410,420 Shake correction member 502 Yoke 503 Magnet 506 Coil 508 Magnetic sensor 520 Coil drive unit 601, 602 Yoke member 601a, 601b, 602a, 602b Iron core part 1100 Coil drive unit

Claims (7)

An air core coil with an air core inside the winding;
A yoke provided with a pair of iron cores positioned on the inner peripheral side and the outer peripheral side of the air-core coil,
A drive magnet provided between any of the pair of iron cores and disposed on any one of the iron cores and capable of being displaced relative to the air-core coil together with the yoke;
A substrate attached to the air-core coil in a state of having a planar shape portion along the circumferential surface of the air-core coil and contacting the planar shape portion with the circumferential surface of the air-core coil;
A magnetic sensor provided on a surface of the substrate on which the driving magnet is disposed to detect a magnetic field strength of the driving magnet;
A coil drive unit comprising: An air core coil with an air core inside the winding;
A yoke provided with a pair of iron cores positioned on the inner peripheral side and the outer peripheral side of the air-core coil,
A drive magnet provided between any of the pair of iron cores and disposed on any one of the iron cores and capable of being displaced relative to the air-core coil together with the yoke;
A substrate attached to the air-core coil in a state of having a planar shape portion along the circumferential surface of the air-core coil and contacting the planar shape portion with the circumferential surface of the air-core coil;
A magnetic sensor provided on a surface of the substrate opposite to the air-core coil to detect a magnetic field strength of the drive magnet;
A coil drive unit comprising: The air-core coil includes a planar shape portion that intersects the radial direction of the air-core coil on at least a part of the peripheral surface,
The coil drive unit according to claim 1, wherein the substrate is a flat plate member attached to a planar shape portion of the air-core coil.   The substrate is attached to the air-core coil in a state where the planar shape portion is formed along the inner peripheral surface of the air-core coil and the planar shape portion is in contact with the inner peripheral surface of the air-core coil. The coil drive unit according to any one of claims 1 to 3, wherein the coil drive unit is provided.   The said drive magnet is provided in the inner peripheral side of the said air-core coil so that the magnetic flux line which the said drive magnet generate | occur | produces may penetrate from the inner peripheral side of the said air-core coil to the outer peripheral side. 5. The coil drive unit according to 4. A blur correction member that supports at least one of the image sensor or the substrate on which the image sensor is provided (hereinafter referred to as “element substrate”) and is displaceable in a plane perpendicular to the optical axis direction;
The coil drive unit according to any one of claims 1 to 5, wherein the blur correction member is displaced,
With
A shake correction mechanism, wherein the substrate provided in the coil drive unit is attached to the shake correction member. The blur correction mechanism according to claim 6;
An optical member for introducing outside light into the image sensor provided in the blur correction mechanism;
An imaging apparatus comprising:

Images