JP2014115450A - Position detector and photographing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a position detector that is able to detect a position highly accurately regardless of a change in the moved position of a correction moving body, and to provide a photographing apparatus that has this position detector.SOLUTION: A position detector YS comprises: a correction lens frame (correction moving body) 5 moved in a planer direction while supporting a correction lens used for making an image correction; and a base plate (fixed member) 4 arranged along the moving plane of the correction lens frame 5. The position detector YS supports a position detecting magnet 54y on the correction moving body 5, also supports a hole element 71y on the base plate 4, and detects the position of the correction lens frame 5 by using the position detecting magnet 54y and hole element 71y. The position detecting magnet 54y has a neutral area not magnetized by a spacer 54i inserted between the magnetic pole faces of a pair of magnets 54s and 54n. Yokes 58s and 58n of the same size as the corresponding magnetic pole faces are disposed on these magnetic pole faces.

Description

  The present invention relates to a position detection device for detecting the position of a component member in a correction optical device or the like for correcting image shake caused by camera shake occurring at the time of photographing, and a photographing device including the position detection device. It is.

  2. Description of the Related Art In recent photographing apparatuses represented by cameras, a camera shake correction device for correcting image blur caused by camera shake is performed. This camera shake correction device detects a camera shake vibration that occurs in the photographing apparatus during photographing, and drives the lens optical system and the image sensor of the photographing apparatus so as to cancel the vibration. A magnetic actuator composed of a magnet and a drive coil is used as a drive source for driving the element. Further, in order to properly drive the camera shake correction apparatus, it is preferable to detect the driving amount of the lens optical system and the image pickup device that is the driving target, that is, the movement amount, and a position sensor for that purpose is provided. As this position sensor, a sensor composed of a magnet for forming a magnetic field and a Hall element that outputs an electric quantity corresponding to the magnetic field strength is used. For example, in Patent Document 1, a magnet is supported on a fixed side member of a camera shake correction device, and a hall element is mounted on a stage plate that is disposed so as to face the magnet and can move in the XY directions. The position is detected by the output of the Hall element. Japanese Patent Application Laid-Open No. 2004-228561 has a configuration in which a magnet is supported on a lens frame of a camera shake correction lens, a Hall element is supported on a device fixing member facing the magnet, and a moving position of the lens frame is detected by the Hall element. ing. In either case, the Hall element relatively moves in the arrangement direction of the S-pole and N-pole of the magnet to detect the position in that direction.

JP 2007-25180 A Japanese Patent No. 3720473

  In the techniques of Patent Documents 1 and 2, a magnet in which a neutral region, that is, a region not magnetized does not exist between the S pole and the N pole is used. With this type of magnet, it is possible to increase the position detection accuracy in the region near the boundary between the S pole and the N pole. However, if the region is out of the region, the linearity of the detection characteristics is lost and the position detection accuracy is likely to be lowered. For this reason, as shown in FIG. 18 of Patent Document 2, a yoke is provided on the magnetic pole surface of the magnet to improve the linearity of the detection characteristics, and the position detection region with high detection accuracy is expanded. However, according to the inventor's view, in the configuration in which the yoke is disposed over the entire surface of the magnetic pole in this way, the detection accuracy in the position detection direction, that is, the arrangement direction of the S pole and the N pole is improved. As for the direction orthogonal to the arrangement direction of the N pole and the N pole, it has been found that the position detection accuracy varies at both ends of the magnet. For example, as shown in FIG. 12 of the drawings of the present specification, when the position of the Hall element 71 is detected by moving the Hall element 71 in the arrangement direction of the S pole and the N pole of the magnet 54, here, the Y direction, the Hall element 71 is detected. Is moved in the X direction of the magnet 54, as shown by the magnetic flux density T2 in the lower part of FIG. This is the same even when a yoke is formed only on part of the S and N poles of the magnet, as shown in FIG.

  Therefore, when such a position sensor is incorporated in a stage that moves in the X and Y directions perpendicular to each other like an image stabilization device, the position in the Y direction is determined when the stage moves in the X direction. Since the Hall element of the position sensor to be detected is changed in position in the length region of the magnet in the X direction, it is difficult to detect the position in the Y direction with high accuracy due to the variation in the output as described above. The same applies to the position sensor that detects the position in the Y direction.

  Even when the object of the present invention is applied to a position sensor that detects the position of a correction moving body that moves in directions orthogonal to each other as in the XY directions, the position detection is performed with high control regardless of the change in the movement position of the correction moving body. The present invention provides a position detection device capable of performing the above and an imaging device including the position detection device.

The present invention includes a correction moving body that moves in the surface direction while supporting a correction lens or an image sensor for performing image correction, and a correction member that is disposed along the moving surface of the correction moving body, and performs correction movement. The position detection magnet is supported on one of the body and the fixed member, and the magnetic detection element disposed opposite to the magnetic pole surface of the position detection magnet is supported on the other, and the correction movement is configured by the position detection magnet and the magnetic detection element. A position detection device for detecting a position of a body, wherein the position detection magnet has a neutral region that is not magnetized between a pair of magnetic pole faces, and each magnetic pole face has substantially the same size as the magnetic pole face. A yoke is provided. Preferably, the position detection magnet is composed of two or more magnets, a single pole is magnetized in the longitudinal direction of the magnet, and the position detection magnet is magnetized between the magnetic pole surfaces of the magnets arranged in pairs. The position detection magnet is provided with a yoke of the same size in the longitudinal direction as the position detection magnet on the surface facing the magnetic detection element.

  As a preferred embodiment of the present invention, the correction moving body is movable in the X direction and the Y direction along the plane direction, and the position detection device detects the respective positions in the X direction and the Y direction. Consists of detection devices. In this case, the X position detection device has a pair of magnets arranged in the X direction with a neutral region in between, and the Y position detection device has a pair of magnets arranged in the Y direction with the neutral region in between.

  The configuration of the position detection magnet in the present invention is preferably as follows. The position detection magnet is composed of a pair of magnets in which the south pole face of the first magnet and the north pole face of the second magnet are arranged on the same plane, and between the first and second magnets. A neutral region that is not magnetized is formed by the spacer interposed between the two. The position detection magnet is internally supported in a frame provided on the correction movable body or the fixed member. Further, the first and second magnets are supported in a state of being sandwiched between the spacer and the inner surface of the frame by the spacer. Rails for forming a gap between the spacer and a pair of magnets are formed, and a jig for moving the yoke can be inserted into the gap. The rail is provided with a step for allowing the yoke to move toward the rail.

  The imaging device of the present invention includes the above-described position detection device according to the present invention in a camera lens or a camera body, and performs image capturing by correcting the position of the subject image based on the position of the correction moving body detected by the position detection device. It is characterized by performing.

  According to the present invention, by forming a pair of magnets spaced apart in one direction via a spacer to form a neutral region that is not magnetized between the two magnets, a region corresponding to the length of the neutral region is obtained. A linear region can be ensured in the magnetic flux density characteristics along the one direction, and accurate and highly accurate position detection is possible. In addition to this, by arranging a yoke of the same size on each magnetic pole face of a pair of magnets, the magnetic flux density formed by both magnets is made uniform in a direction perpendicular to one direction. Can do. Thereby, even when the correction moving body moves in a direction orthogonal to one direction, the position detection accuracy in the one direction is not lowered, and the position detection with high accuracy becomes possible.

  Further, according to the present invention, by providing a rail or a step on the spacer interposed between the pair of magnets, the magnet and the yoke can be accurately supported at a predetermined position. Accurate position detection is possible.

  In addition, the photographing apparatus of the present invention includes the position detection device of the present invention to detect the position of the correction moving body, that is, the movement position of the correction lens and the image sensor for correcting image shake with high accuracy. By controlling the movement position of the correction moving body with high accuracy, it is possible to realize an imaging apparatus that can obtain a high optical correction effect such as image blur correction.

The conceptual block diagram of the camera provided with the correction | amendment optical apparatus of this invention. The external appearance perspective view of the whole structure of a correction | amendment optical apparatus. The partial exploded perspective view of a correction | amendment optical apparatus. The front view of a correction lens frame. Sectional drawing in a post. Sectional drawing of a ball retainer. The partially broken perspective view and bb line expanded sectional view of a magnetic actuator. The disassembled perspective view of a part of correction | amendment optical apparatus for XY guide part explaining. The partial exploded perspective view of a Y position sensor. Sectional drawing of a part of Y position sensor. The whole Y position sensor sectional view. The figure which shows the position detection characteristic of a position sensor. The rear view for demonstrating operation | movement of a lock ring.

  Next, embodiments of the present invention will be described with reference to the drawings. In this embodiment, the position detection device of the present invention is incorporated in a camera shake correction device built in a camera lens of a camera. FIG. 1 is a conceptual configuration diagram of the camera CAM, which includes a camera body CB and a camera lens CL formed integrally with or removable from the camera body CB. An image sensor IS for capturing a subject image formed by the lens CL is provided. The camera lens CL is internally provided with an imaging optical system OL for imaging a subject in a lens barrel, and correction optics for correcting camera shake of a subject image formed by the imaging optical system OL. The device ROD is internally furnished. This correction optical device ROD is installed in the camera lens CL and detects each hand vibration in the X direction (left and right direction in FIG. 1) and Y direction (up and down direction in FIG. 1) generated in the camera body CB or the camera lens CL at the time of shooting. On the basis of detection signals from vibration detection means (gyro sensors) XG and YG, the subject image is displaced in the X and Y directions perpendicular to the optical axis so as to cancel the vibration. In order to perform this correction, the correction optical device ROD includes a correction lens RL disposed on the optical path of the imaging optical system OL, and X, X, Y for driving the correction lens RL in the X and Y directions. Magnetic actuators XM and YM having Y voice coil configurations and X and Y position sensors XS and YS for detecting positions in the X and Y directions associated with driving of the correction lens RL are provided.

  FIG. 2 is an external perspective view of the correction optical device ROD, that is, the camera shake correction device as seen from the camera body side. The camera shake correction device ROD is assembled mainly with a fixed frame 1 having a shape close to a short cylinder, and the fixed frame 1 is fixedly supported in the lens barrel of the camera lens CL in FIG. FIG. 3 is a partially exploded perspective view of the camera shake correction apparatus ROD, as viewed from the front side of the camera lens CL, that is, from the subject side. In the following description, the front side is the subject side and the rear side is the camera body side. 2 and 3 together, a rear yoke 2, a front yoke 3, and a base plate 4 are fixedly supported on the front side of the fixed frame 1 in a state of being arranged in the optical axis direction. Further, a correction lens frame 5 supporting the correction lens RL is disposed between the rear yoke 2 and the front yoke 3 in the optical axis direction. The correction lens frame 5 is located with respect to the fixed frame 1. It is supported so as to be movable in the aforementioned X and Y directions. On the other hand, a lock ring 6 is supported on the rear side of the fixed frame 1, that is, the surface on the camera body side so as to be rotatable at a required angle in the circumferential direction.

  The fixed frame 1 is formed in a short cylindrical container shape in which a part of a circumferential wall is notched and opened in the center, and the upper part of the front surface that is the bottom surface in the cylinder when the fixed frame 1 is viewed from the subject side. A rear ball retainer 8A, which will be described in detail later, is disposed at three locations, the lower right portion and the lower left portion (hereinafter, the directions seen from the front side in the left, right, and upper and lower directions). Further, a lock motor 10 whose details will be described later is mounted on the fixed frame 1, and a Y guide portion 11 whose details will also be described later is integrally formed.

  The correction lens frame 5 constitutes a correction moving body in the present invention, and the correction lens RL is fitted in a central circular opening as shown in FIG. A resin-made frame portion 51 formed in a substantially annular shape that is attached and supported, and a substantially annular plate-shaped metal member such as aluminum that is integrally attached to the front surface of the frame portion 51 along the circumference. The support plate portion 52 is formed. As described above, the correction lens RL moves in the X direction and the Y direction to correct image blur of the subject image. An X drive coil 53x is fixed to the right side of the support plate 52 of the correction lens frame 5 along the circumference, and a Y drive coil 53y is fixed to the lower side. Each of the X drive coil 53x and the drive coil 53y has a configuration in which a thin conducting wire is wound so as to have an oval shape having a long axis in the circumferential tangent direction. That is, the X drive coil 53x has a long axis in the Y direction, the Y drive coil 53y has a long axis in the X direction, and each drive coil 53x, 53y penetrates the correction lens frame 5 in the plate thickness direction. And is exposed on both sides in the optical axis direction. A small X position detection magnet 54x is supported on the left side of the frame 51 of the correction lens frame 5, and a small Y position detection magnet 54y is similarly supported on the upper side. Furthermore, a rectangular insertion hole 55 having a small opening size is penetrated in the upper right part and the lower left part of the correction lens frame 5 in the thickness direction. An X guide portion 56 that does not appear in FIGS. 2 to 4 is integrally formed on the back surface of the correction lens frame 5, which will be described later.

  In FIG. 3, the rear yoke 2 is formed of a substantially semi-circular metal plate having a semicircular arc shape extending from the upper right to the lower left when viewed from the front direction, for example, an iron plate, and the right side of the front surface thereof. The rear X magnet 21x is fixed to the area, and the rear Y magnet 21y is fixed to the lower area. Further, post 22 having a required length projecting in the front direction along the optical axis direction is erected on the upper right portion and the lower left portion of the front surface of yoke 2. Although the post 22 will be described later with reference to FIG. 5, a small diameter portion 22 a is provided at each of the longitudinal front and rear ends and the middle, and the rear end portion of the post 22 is caulked and fixed to the rear yoke 2. Yes. The front yoke 3 is also formed in substantially the same shape as the rear yoke 2, and similarly to the rear yoke 2, the front X magnet 31x is fixed to the right area on the front surface, and the front Y magnet 31y is fixed to the lower area. . In addition, support holes 32 are formed in the upper right end portion and the lower left end portion of the front yoke 3 so that the front ends of the posts 22 provided in the rear yoke 2 can be fitted. These front and rear yokes 2, 3 increase the magnetic flux density of the magnets 21x, 21y, 31x, 31y, respectively.

  The base plate 4 is formed in the shape of an annular plate as a fixing member in the present invention, and a similar support hole 41 is opened at the same position as the support hole 32 of the front yoke 3. A front ball retainer 8B, which will be described in detail later, is supported at the lower and lower portions. In addition, Hall element tables 9x and 9y are supported on the upper and left portions of the base plate 4, respectively. These Hall element bases 9x and 9y are attached to the base plate 4 by support arms 91 provided at the respective front ends, and the Hall element bases 9x on the base plate 4 are adjusted by adjusting the mounting positions of the support arms 91. 9y can be finely adjusted. Further, a flexible substrate 7 is attached to the rear surface of the region extending from the upper part to the left part of the base plate 4. The flexible substrate 7 has element substrates 72x and 72y on which the Hall elements 71x and 71y are mounted on the rear surface. When the flexible substrate 7 is attached to the base plate 4, the two Hall elements 71x and 71y are respectively connected to the Hall element bases 9x and 9x. It is supported by the end surface directed to the rear side of 9y.

  The rear yoke 2, the correction lens frame 5, the front yoke 3, and the base plate 4 are assembled on the front surface of the fixed frame 1 in a state where they are stacked in this order in the optical axis direction. FIG. 5 is an enlarged cross-sectional view along the longitudinal direction of the post 22 in an assembled state. The rear yoke 2 is disposed along the front surface of the fixed frame 1, and the rear end 22 b of the post 22 protruding from the rear surface side of the rear yoke 2 is inserted into a hole provided in the fixed frame 1, thereby fixing the fixed frame. 1 is connected and positioned. Next, the correction lens frame 5 is disposed from the front side, and the insertion hole 55 of the correction lens frame 5 is inserted into the post 22. The correction lens frame 5 is positioned with respect to the rear yoke 2 and the fixed frame 1 by inserting the post 22 into the insertion hole 55. However, since the opening size of the insertion hole 55 is larger than the diameter size of the small diameter portion 22a of the post 22, the correction lens frame 5 is relatively small with respect to the rear yoke 2 and the fixed frame 1 at a minute distance in the X direction and the Y direction. Movement is possible. Further, the front yoke 3 is disposed on the front side of the correction lens frame 5. When the support hole 32 provided in the front yoke 3 is fitted into the front end 22 c of the post 22, the front yoke 3 is positioned with respect to the rear yoke 2 and the fixed frame 1 and is integrated with the rear yoke 2. It will be. Similarly, when the base plate 4 is disposed on the front surface side of the front yoke 3, the base plate 4 is positioned with respect to the front yoke 3 by fitting the support hole 41 of the base plate 4 to the front end 22 c of the post 22. At the same time, it is integrated with the front yoke 3. Further, two electrodes 73 extending on both sides of the flexible substrate 7 attached to the base plate 4 shown in FIG. 3 are respectively connected to the X and Y drive coils 53x and 53y mounted on the correction lens frame 5. Connected to the electrode and electrically connected.

  When the rear yoke 2, the correction lens frame 5, the front yoke 3 and the base plate 4 are assembled in this way, the correction lens frame 5 is provided on the rear ball retainer 8 </ b> A provided on the fixed frame 1 and the base plate 4. The front ball retainer 8B is sandwiched in the optical axis direction at three locations around the circumference, and the correction lens frame 5 is positioned in the optical axis direction. As shown in a sectional view along the longitudinal direction of the ball retainers 8A and 8B in FIG. 6, here, the support plate portion 52 of the correction lens frame 5 is sandwiched between the ball retainers 8A and 8B in the optical axis direction. Thereafter, each of the previous ball retainers 8A and 8B has substantially the same configuration, and a cylindrical retainer 81, and a set screw 82 that is inserted into the retainer 81 and screwed into the inner surface of the retainer 81 with a screw 84. The ball 83 is in contact with and supported by the front end surface of the set screw 82. The ball 83 is configured so as not to drop out of the retainer 81 although it does not appear in the drawing. The retainer 81 of the rear ball retainer 8A is caulked and fixed in a hole opened in the fixed frame 1 and is integrally supported by the fixed frame 1. The retainer 81 of the front ball retainer 8B is caulked in the hole opened in the base plate 4. It is fixed and supported integrally with the base plate 4.

  With this configuration, the correction lens frame 5 is supported while being sandwiched in the optical axis direction by the balls 83 of the rear ball retainer 8A and the front ball retainer 8B. With this support, the optical axis of the correction lens frame 5 is supported. Directional positioning is performed. Here, in the rear ball retainer 8A, a thin plate-like spacer (shim) 85 is inserted between the proximal end portion of the retainer 81 and the proximal end portion of the set screw 82, and the distal end position of the ball 83 is finely adjusted. . Further, in the front ball retainer 8B, a compression coil spring 86 is inserted between the proximal end portion of the retainer 81 and the proximal end portion of the set screw 82, and urges the set screw 82 in the proximal direction (left direction in the figure). Thus, backlash in the set screw 82 is absorbed, and the position of the ball 83 in the optical axis direction is held. As a result, the correction lens frame 5 is supported in a state where a small gap in the optical axis direction is formed between the balls 83 of the both ball retainers 8A and 8B. While maintaining a vertically oriented posture, it is possible to smoothly move between the balls 83 in a direction substantially perpendicular to the optical axis direction.

  Further, by assembling in this way, the rear X magnet 21x and the front X magnet 31x are disposed to face each other in the optical axis direction, and an X drive coil 53x is disposed between the magnets 21x and 31x, thereby the X magnetism. An actuator XM is configured. Similarly, the Y magnetic actuator YM is composed of the rear Y magnet 21y, the front Y magnet 31y, and the Y drive coil 53y. 7A and 7B are a perspective view in which a part of the front X magnet 31x of the X magnetic actuator XM is broken, and an enlarged cross-sectional view taken along the line bb in FIG. 7A. Thereafter, the front X magnets 21x and 31x are constituted by end face dipole magnets in which the S pole and the N pole are magnetized adjacent to each other without providing a neutral area (a non-magnetized area). The S poles and N poles of the magnets 21x and 31x are opposed to each other. Therefore, a magnetic circuit is formed between the magnets 21x and 31x along the facing direction. By passing a current through the X drive coil 53x disposed in the magnetic circuit, the X drive coil 53x has an X A driving force F in the direction is generated, and the correction lens frame 5 is moved in the X direction. Although not shown, the same applies to the Y magnetic actuator YM, and the correction lens frame 5 can be moved in the Y direction by energization control to the Y drive coil 53y.

  The correction lens frame 5 is restricted from moving in the X and Y directions by a Y guide portion 11 provided on the fixed frame 1 and an X guide portion 56 provided on the correction lens frame 5. As shown in an exploded perspective view in FIG. 8, a thin rod-shaped guide 12 is disposed between the front surface of the fixed frame 1 and the rear surface of the correction lens frame 5. The guide 12 is formed in an inverted L shape having an X side portion 12x extending in the left-right direction and a Y side portion 12y extending downward from the left end of the X side portion 12x. On the other hand, the Y guide portion 11 provided on the left side of the front surface of the fixed frame 1 is configured to sandwich the Y side portion 12y of the guide 12 in a loose state from the left and right at two locations arranged in the vertical direction. Yes. Further, the X guide portion 56 provided on the upper side of the rear surface of the correction lens frame 5 is configured to hold the X side portion 12x of the guide 12 in a loose state from above and below at two locations arranged in the left-right direction. ing.

  With this configuration, when the correction lens frame 5 is moved in the X direction by the X magnetic actuator XM, the X guide portion 56 of the correction lens frame 5 remains in the state where the X side portion 12x of the guide 12 is sandwiched. It is moved in the X direction along the part 12x. Further, when the correction lens frame 5 is moved in the Y direction by the Y magnetic actuator YM, the X guide portion 56 moves the guide 12 integrally while sandwiching the X side portion 12x of the guide 12, and the guide 12 The Y side portion 12y is moved in the Y direction while being sandwiched between the Y guide portions 11 of the fixed frame 1. As a result, the movement of the correction lens frame 5 by the X magnetic actuator XM can be restricted in the X direction, and the movement of the correction lens frame 5 by the Y magnetic actuator YM can be restricted in the Y direction, and correction can be performed by the magnetic actuators XM and YM. The lens frame 5 can be accurately and smoothly moved in the X direction and the Y direction, and camera shake correction can be performed quickly.

  On the other hand, in order to detect the movement position of the correction lens frame 5 in the X direction and the Y direction, the X position sensor XS and the Y position sensor YS are provided. That is, the X position detection magnet 54x is supported on the left side of the correction lens frame 5, and the Y position detection magnet 54y is supported on the upper side. On the base plate 4, two Hall elements 71 x and 71 y are mounted on the Hall element bases 9 x and 9 y by the flexible substrate 7 so as to oppose the X and Y position detection magnets 54 x and 54 y. The X position detection magnet 54x and the Hall element 71x constitute the X position sensor XS, and the Y position detection magnet 54y and the Hall element 71y constitute the Y position sensor YS.

  FIG. 9 is a partially exploded perspective view of the Y position sensor YS. The Y position detection magnet 54y is spaced apart in the Y direction via a spacer 54i made of a non-magnetic material, and the S pole and N pole pole faces that are long in the X direction with respect to the Hall element 71y are on the same plane. It is composed of a pair of magnets 54s and 54n directed. The pair of magnets 54s and 54n and the spacer 54i are inserted and supported in a rectangular frame 57 provided in the frame portion 51 of the correction lens frame 5. The front surfaces of the pair of magnets 54s and 54n, that is, the S pole surface of the magnet 54s and the N pole surface of the magnet 54n, which are surfaces facing the Hall element 71y, have substantially the same shape as the magnetic pole surfaces, respectively. That is, yokes 58s and 58n made of thin iron plates having the same length in the X direction are arranged. The yokes 58s and 58n are attracted and held on the magnetic pole surfaces by the magnetic force of the magnets 54s and 54n. The spacer 54i is formed of a resin in a substantially rectangular parallelepiped shape, and a pair of rails 541 arranged in parallel on the upper and lower surfaces are integrally formed in the front-rear direction.

  The magnets 54s and 54n, the spacer 54i, and the yokes 58s and 58n are disposed in the rectangular frame 57 by being inserted forward from the rear opening of the rectangular frame 57. FIG. 10 is a longitudinal cross-sectional view showing a state in which the magnet 54s and the yoke 58s are disposed on the upper side and the magnet 54n and the yoke 58n are disposed on the lower side with the spacer 54i interposed therebetween. The magnet 54s is sandwiched between the upper rail 541 of the spacer 54i and the upper bottom surface of the rectangular frame 57, and the magnet 54n is sandwiched between the lower rail 541 of the spacer 54i and the lower bottom surface of the rectangular frame 57. The yokes 58s and 58n are attracted and held by the magnetic force of the magnets 54s and 54n, respectively. A step portion 542 is formed at the front end portion of the rail 541 of the spacer 54i. This is because the magnets 54s and 54n attracting the yokes 58s and 58n are inserted into the rectangular frame 57. This is to allow 58n to move inward. Without this stepped portion 542, the yokes 58s, 58n may interfere with the inner surface of the rectangular frame 57 during insertion, and may fall off the magnets 54s, 54n, making it difficult to efficiently assemble. Further, by providing the rail 541, a space can be secured inside the yokes 58s and 58n when inserted into the rectangular frame 57. Therefore, the front surface of the rectangular frame 57 is opened using this space as shown by a chain line in FIG. Through the jig J, the yoke 58s can be attracted to the correct position, that is, the S pole surface of the magnet 54s in the correct positional relationship. For example, if the stepped portion 542 is formed in a tapered shape, both the yokes 58s and 58n are pressed outward by the taper action when the spacer 54i is inserted between the magnets 54s and 54n, and automatically set to a predetermined position. It is also possible to set.

  As shown in FIG. 9, the Hall element 71y is mounted and supported on the Hall element base 9y of the base plate 4 so as to face the Y position detection magnet 54y. The circular element substrate 72y of the flexible substrate 7 is supported on the front end surface of the Hall element base 9y, and the Hall element 71y is mounted on the surface of the element substrate 72y. The element substrate 72y is positioned by fitting a pair of positioning holes 72a to protrusions 92 provided on the Hall element base 9y. As shown in FIG. 11 which is an overall cross-sectional view of the Y position sensor YS, the Hall element 71y has a central position of the Y position detection magnet 54y, more precisely, a pair of magnets 54s and 54n in the X and Y directions. Opposing to each other at an intermediate position.

  In the Y position sensor YS, when the correction lens frame 5 moves in the Y direction, the magnetic field formed by the Y position detection magnet 54x is also moved integrally, and the magnetic flux density with respect to the Hall element 71y changes. FIG. 12 is a schematic diagram showing a change in magnetic flux density with respect to the Hall element 71y. The Y position sensor YS can detect the movement position of the Y position detection magnet 54y, that is, the position of the correction lens frame 5 in the Y direction by detecting the change in the output current of the Hall element 71y accompanying the change in the magnetic flux density. it can. The Y direction is a direction along the direction in which the magnets 54s and 54y face each other, and when detecting the position in the Y direction, the pair of magnets 54s and 54n are spaced apart from each other in the Y direction via the spacer 54i, and both the magnets 54s. , 54n, a linear region can be secured in the magnetic flux density characteristic over a region corresponding to the length of the neutral region, as shown in the upper part of FIG. Highly accurate position detection is possible.

  In this Y position sensor YS, yokes 58s and 58n of the same size are arranged on the S pole surface and N pole surface of the paired magnets 54s and 54n, respectively, and are attracted and held by the magnetic force of each magnet. Therefore, the magnetic flux density formed by the magnets 54s and 54n is extended along the extending direction of the magnets 54s and 54n, that is, the X direction, as shown by the magnetic flux density T1 in the lower part of FIG. And approximately uniform characteristics. Thereby, when the Y position sensor YS detects the position in the Y direction, when the correction lens frame 5 is moved in the X direction by the camera shake correction operation, that is, the Hall element 71y moves in the X direction with respect to the position detection magnet 54y. Even in the case of relative movement, fluctuations in detection characteristics are suppressed. Thereby, the position in the Y direction can be detected with high accuracy. Incidentally, when each of the magnets 54s and 54n is not provided with a yoke, as shown by a magnetic flux density T2 in the lower part of FIG. 12, similarly to the case described in Patent Document 2, the magnetic flux density in the intermediate region in the X direction. Significantly increases, and as a result, the position detection accuracy in the Y direction decreases. In addition, although illustration and detailed description are abbreviate | omitted, X position sensor XS is also the same structure, and a highly accurate position detection is possible by the same effect | action.

  In this embodiment, the lock ring 6 is disposed and supported on the rear surface side of the fixed frame 1 as described above. As shown in the rear view of FIG. 13, the lock ring 6 is formed in an annular plate shape, and is disposed around an annular rib 57 formed on the rear surface of the correction lens frame 5 and around the optical axis. It is supported so that it can be rotated within a small angle range. A gear 61 is formed on a part of the circumference of the lock ring 6, and meshes with the pinion 10 a of the motor 10 supported by the fixed frame 1 and is rotated by the motor 10. Yes. On the inner peripheral surface of the lock ring 6, a cam recess 62 having a plurality of circumferential recesses formed in the outer diameter direction is formed. This cam recess 62 is formed on the peripheral surface of the annular rib 57 of the correction lens frame 5. The plurality of protrusions 58 protruding in the radial direction are opposed to each other in the radial direction. Further, a photo interrupter 13 for detecting the rotational position of the lock ring 6 is disposed on a part of the circumference of the fixed frame 1.

  When the lock ring 6 is rotated to the reference position by the motor 10, as shown in FIG. 13A, the cam recess 62 is in a position facing the protrusion 58 of the annular rib 57, and the protrusion 58 is the lock ring. 6 is not brought into contact with the inner peripheral edge. Therefore, the correction lens frame 5 has the projection 58 that can move within the region of the cam recess 62, and can move in the X direction and Y direction within the region. On the other hand, as shown in FIG. 13B, when the lock ring 6 is rotated to the lock position by the motor 10, the cam recess 62 is disengaged from the position facing the protrusion 58, and the inner peripheral edge of the lock ring 6 is the protrusion 58. It comes into contact. As a result, the correction lens frame 5 is in a locked state in which the movement in the X direction and the Y direction is restricted and the optical axis position is restricted. The lock position and the reference position of the lock ring 6 are detected by the photo interrupter 13, and the motor 10 is feedback-controlled by this detection output.

  As described above, in the correction optical apparatus ROD of this embodiment, that is, the camera shake correction apparatus, when camera shake occurs during shooting with the camera CAM, the vibration detection means XG and YG detect camera shake vibration. Although not described, the lens CPU mounted on the camera lens CL performs a required calculation based on the hand vibration, and the calculated drive current is sent to the X drive coil 53x and the Y drive coil 53y via the flexible substrate 7. Supply. As a result, the X and Y magnetic actuators XM and YM are driven, and the correction lens frame 5 is moved in the X and Y directions to cancel out the camera shake vibration and execute the camera shake correction. At this time, the amount of movement of the correction lens frame 5 in the X and Y directions is detected by the X and Y position sensors XS and YS, and the magnetic actuators XM and YM are feedback-controlled so that the correction lens frame 5 has a target position. Control to correct the camera shake by moving accurately.

  At this time, in this correction optical device ROD, the rear yoke 2 and the front yoke 3 supporting the magnets 21x and 21y and 31x and 31y, respectively, and the base plate 4 supporting the Hall elements 71x and 71y are coupled by the post 22. Further, since the position of the correction lens frame 5 that supports the drive coils 53x and 53y and the position detection magnets 54x and 54y is regulated using the post 22, the drive accuracy of the magnetic actuators XM and YM is increased. be able to. That is, in the magnetic actuators XM and YM, the rear and front magnets 21x and 31x, 21y and 31y can be easily positioned and assembled with high accuracy, and the magnetic poles of both magnets are opposed to each other with high accuracy. Thus, the magnetic flux density of the magnetic circuit constituted by both magnets can be set to a high density. Therefore, even when the magnets 21x, 31x, 21y, and 31y are magnets that do not have a neutral region as described above, a magnetic actuator that exhibits a high driving force can be realized, and a magnet that does not have a neutral region can be realized. By adopting it, the dimensions of the magnetic actuators XM, YM in the X and Y directions can be reduced, the diameter of the correction lens frame 5 can be reduced, and the camera shake correction device ROD can be downsized. Further, by controlling the positions of the drive coils 54x and 54y with respect to the magnets 21x, 31x, 21y and 31y, a larger driving force can be obtained when the drive coils are driven in the magnetic actuators XM and YM. An independent configuration for positioning and position regulation is not necessary, which is advantageous for downsizing the camera shake correction device.

  At the same time, the post 22 and the insertion hole 55 of the correction lens frame 5 constitute a position restricting structure according to the present invention. In the position sensors XS and YS, the position detection magnets 54x and 54y are connected to the Hall elements 71x and 71y. Therefore, the Hall element 71y can be set at the center position in the X direction and the Y direction of the position detection magnet 54y as exemplified by the position sensor YS in FIG. Therefore, the position detection of the correction lens frame 5 in the X direction and the Y direction can be detected in a region having excellent linearity, and the position detection by the position sensors XS and YS can be performed with high accuracy. That is, as described with reference to FIG. 12, the pair of magnets 54s and 54n constituting the position detection magnets 54x and 54y are spaced apart from each other in the X direction or the Y direction via the spacer 54i, and the two magnets 54s. , 54n, a linear region can be secured in the magnetic flux density characteristic over a region corresponding to the length of the neutral region, and accurate and highly accurate position detection becomes possible. In addition, in each of the position sensors XS and YS, the yokes 58s and 58n having the same size are provided on the magnetic pole surfaces of the paired magnets 54s and 54n, respectively, so that the magnets 54s. , 54n can have uniform characteristics along the extending direction of the magnets 54s, 54n. Thereby, when the position sensor XS, YS detects the position of the correction lens frame 5 in the X direction or the Y direction, the correction lens frame 5 is moved in the Y direction or the X direction orthogonal thereto by the camera shake correction operation. However, fluctuations in detection characteristics are suppressed, and highly accurate detection is possible.

  Further, by providing a rail 541 on a spacer 54i interposed between a pair of magnets 54s and 54n constituting a position sensor as in this embodiment, as shown in FIG. 10, the magnets 54s and 54n are provided. In addition, a gap can be secured between the yokes 58s and 58n and the spacer 54i, the magnets 54s and 54n and the yokes 58s and 58n can be accurately supported at predetermined positions, and highly accurate detection can be performed. It becomes possible.

  Here, in the embodiment, the yokes 58s and 58n are attracted to the magnets 54s and 54n by magnetic force, respectively. However, in some cases, they may be bonded using an adhesive. Alternatively, the magnets 54s and 54n and the spacer 54i may be subassembled and integrated in advance, and the integrated product may be inserted and supported in the rectangular frame 57. In the embodiment, the position detection magnets 54x and 54y are supported by the correction lens frame 5. However, the position detection magnets 54x and 54y are supported by the base plate 4 which is a fixed member, and the Hall elements 71x and 71y are corrected by moving bodies. It may be configured to be supported by a certain correction lens frame 5. Furthermore, in the embodiment, the magnets 54s and 54n have a configuration in which the S pole face and the N pole face of the magnet having the S pole and the N pole are arranged in the same direction, respectively, but a recently proposed monopole magnet, That is, it is possible to use a magnet having only the S pole or the N pole. Or it is good also as a structure using the S pole surface and N pole surface of a U-shaped magnet.

  Therefore, the camera shake correction device ROD provided with the position detection device of the present invention is disposed on the camera lens CL or the camera body CB of the camera CAM as shown in FIG. It is possible to eliminate image blur. Also, a correction lens that is moved in the X and Y directions orthogonal to each other by forming a neutral region with spacers on the magnet constituting the position sensor and disposing a yoke of the same size on the magnetic pole face of the paired magnet It is possible to detect a frame position with high accuracy, and to realize a small camera CAM with high shooting performance incorporating a small camera shake correction device with high camera shake correction performance.

  When the correction optical device according to the present invention is configured as a device for performing image blur correction of a camera as in the embodiment, the correction optical device according to the present invention is built in the camera body, and an image sensor is used instead of the correction lens. You may comprise so that movement control may be carried out to XY direction. In this case, the correction lens frame of the embodiment may be configured as a correction moving body, and the image sensor may be held by the correction moving body.

  In the photographing apparatus of the present invention, it is needless to say that the correction optical device provided with the position detection device, that is, the camera shake correction device of the camera shown in the embodiment can be incorporated in the camera lens (lens barrel) of the camera. It may be installed inside the camera body. Further, the photographing apparatus of the present invention is not limited to a camera that captures still images, and may be a photographing apparatus that captures moving images.

  The present invention is effective when employed in a position detection apparatus including a magnet and a magnetic detection element and a photographing apparatus including a correction optical apparatus including the position detection apparatus.

1 fixed frame 2 rear yoke 3 front yoke 4 base plate (fixing member)
5 Correction lens frame (correction moving body)
6 Lock ring 7 Flexible substrate 8A, 8B Ball retainer 9x, 9y Hall element base 10 Motor 12 Guide 21x, 21y Rear magnet 22 Post 31x, 31y Front magnet 53x, 53y Drive coil 54x, 54y Position detection magnet 54s, 54n First and Second magnet 54i Spacer 55 Insertion hole 71x, 71y Hall element (magnetic detection element)
541 Rail 542 Stepped CAM Camera (Photographing Device)
CL camera lens CB camera body ROD correction optical device (camera shake correction device)
XM, YM Magnetic actuator XS, YS Position sensor XG, YG Vibration detection means IS Image sensor

Claims (11)

  A correction moving body that supports a correction lens or an image pickup device that performs image correction and is moved in a plane direction; and a fixing member that is disposed along a moving surface of the correction moving body, the correction moving body and the fixing member The position detection magnet is supported on one side, and the magnetic detection element arranged opposite to the magnetic pole surface of the position detection magnet is supported on the other side. The position detection magnet and the magnetic detection element are used to detect the position of the correction moving body. The position detection magnet has a neutral region that is not magnetized between the magnetic pole surfaces arranged in pairs, and these magnetic pole surfaces are substantially the same as the magnetic pole surfaces. A position detecting device having a size yoke.   The correction movable body is movable in the X direction and the Y direction along the plane direction, and the position detection device is configured by an X position detection device and a Y position detection device that detect respective positions in the X direction and the Y direction. The position detection device according to claim 1, wherein   The X position detection device has a pair of magnets arranged in the X direction with a neutral region in between, and the Y position detection device has a pair of magnets arranged in the Y direction with the neutral region in between. The position detection device according to claim 2.   The position detection magnet is composed of a magnet in which the S-pole surface of the first magnet and the N-pole surface of the second magnet that are paired are arranged on the same plane, and is interposed between the first and second magnets. The position detection device according to claim 1, wherein the neutral region is configured by a mounted spacer.   5. The position detection device according to claim 1, wherein the position detection magnet is internally supported in a frame provided on the correction moving body or the fixed member.   6. The correction optical apparatus according to claim 5, wherein the first and second magnets are supported by the spacer while being sandwiched between the spacer and the inner surface of the frame.   The spacer is formed with a rail for forming a gap between each of the pair of magnets, and a jig for moving the yoke can be inserted into the gap. The position detection device according to claim 6.   The position detection device according to claim 7, wherein the rail is provided with a step portion for allowing the yoke to move to the rail side.   A position restricting structure for restricting relative movement of the correction moving body is configured by a post provided on the fixing member and an insertion hole provided in the correction moving body and into which the post is inserted. The position detection device according to claim 1.   A correction moving body that supports a correction lens or an image pickup device that performs image correction and is moved in a plane direction; and a fixing member that is disposed to face a moving surface of the correction moving body, and one of the correction moving body and the fixing member The position detection magnet is supported on the other side, and the magnetic detection element disposed opposite to the magnetic pole surface of the position detection magnet is supported on the other side. The position detection magnet and the magnetic detection element are configured to detect the position of the correction moving body. A position detection device, wherein the position detection magnet is composed of two or more magnets, a single pole is magnetized in a longitudinal direction of the magnet, and the position detection magnets are arranged in pairs. A neutral region made of a non-magnetic material that is not magnetized between the surfaces is configured, and the position detection magnet is provided on the surface facing the magnetic detection element. Position detecting apparatus characterized by comparable size of the yoke are disposed in the longitudinal direction. A position detection device according to any one of claims 1 to 10 is provided in a camera lens or a camera body, and a subject image is corrected based on the position of a correction moving body detected by the position detection device, and shooting is performed. An imaging device characterized by the above.

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