JP2017184600A - Stage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of a thrust in a direction that is not in parallel with a specific plane in a stage device comprising a trust generation device for moving a movable member at least within the plane.SOLUTION: The present invention relates to a stage device comprising: a movable member that is movable in a direction in parallel with a specific plane; a base member which holds the movable member in a relatively freely movable manner; and thrust generation means provided in one and the other of the movable member and the base member and including a magnet and a coil for generating a trust that moves the movable member in the direction in parallel with the specific plane. A magnetic flux density of the magnet at a side facing the coil is being changed in a direction of the thrust.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a stage apparatus, and more particularly to a stage apparatus capable of driving a movable member within a specific plane.

  In order to perform camera shake correction of a single-lens reflex camera, a camera shake correction apparatus that moves an image sensor in a direction orthogonal to the optical axis by a voice coil motor (thrust generating means) using a saddle-shaped drive coil is already known ( Patent Documents 1, 2, 3, 4).

JP 2006-94185 A JP 2007-72089 A Japanese Patent No. 5308457 JP 2013-050499 A

  A conventional camera shake correction device is driven by mounting an image sensor on a movable unit that moves in a plane (XY plane) orthogonal to the optical axis. However, when the movable unit is driven in the X and Y directions in the XY plane, driving noise is generated, the movable unit is tilted from the XY plane, or the movable unit is moved in the orthogonal direction to cause surface tilt and focusing error. was there.

  As a result of diligent research, the present inventor has found that, in the conventional camera shake correction device, when the movable unit is driven in the X direction or the Y direction, not only the thrust for moving the movable unit in the X direction or the Y direction but also out of plane. It was found that a component force in the direction (Z direction) was generated, and that the component force varied depending on the position of the movable unit. Then, it has been found that these component forces and fluctuations in component force cause abnormal noise during operation of the camera shake correction device, the above-described surface tilt, focusing error, and the like.

  The present invention has been made on the basis of the above research results by the present inventor, and suppresses the generation of thrust in a direction non-parallel to the plane in a stage apparatus having a thrust generation apparatus that moves the movable member at least in the plane. The purpose is to do.

  The stage apparatus of the present invention is provided on a movable member that is movable in a direction parallel to a specific plane, a base member that holds the movable member so as to be relatively movable, and one or the other of the movable member and the base member. A thrust generating means having a magnet and a coil for generating a thrust for moving the movable member in a direction parallel to the specific plane, wherein the magnet has a magnetic flux density on the side facing the coil in the thrust direction; It is characterized by changing along.

  In the stage apparatus of the present invention, the movable member and the base member are each single, the magnet is disposed on one of the movable member and the base member, and the coil is disposed on the other of the movable member and the base member. It may be arranged opposite to the magnet.

  In the stage apparatus of the present invention, the base member is composed of a pair opposed to the movable member from a direction orthogonal to the specific plane, and the magnet is opposed to the movable member of the pair of base members. The coil may be provided between the pair of magnets facing the movable member.

  The magnet may have a cross-sectional concave shape in which the thickness in the direction orthogonal to the specific plane is thick at both ends and thin at the center in the thrust direction.

  When the magnet is disposed on one of the movable member and the base member, the depth of the concave portion having a concave cross section is preferably 3/5 to 4/5 of the thickness of the magnet.

  When the magnet is disposed on one of the movable member and the base member, the magnetic flux density ratio or the magnetized magnetic force ratio of the central portion is 0.15 to 0.3 with respect to both end portions of the magnet in the thrust direction. It is preferable.

  The magnet has a cross-sectional concave shape in which the thickness in a direction orthogonal to the specific plane is thick at both ends and thin at the center in the thrust direction, and the magnet is paired at a position opposite to the movable member and the base member. When provided, it is preferable that the depth of the concave portion having a concave cross section is ¼ to ½ of the thickness of the magnet.

  When a pair of the magnets are provided at the opposing positions of the movable member and the base member, the magnetic flux density ratio or the magnetized magnetic force ratio of the central portion with respect to both end portions in the thrust direction of the magnet is 0.2 to 0.5. It is preferable that

  The magnetism in the thrust direction of the magnet is distributed in a valley shape where both end portions are higher than the central portion, a substantially trapezoidal shape where both end portions are higher than the central portion, or a substantially rectangular shape where both end portions are higher than the central portion. It is practical to do.

  The magnet may have a nonmagnetic material at a central portion in the thrust direction, and a pair of magnets on both sides of the nonmagnetic material.

  The imaging device of the present invention includes any one of the above stage devices, and an imaging element is mounted on a movable member of the stage device.

  The optical apparatus according to the present invention includes any one of the above stage devices, and one of the optical elements constituting the optical system is mounted on a movable member of the stage device.

  Another aspect of the stage apparatus of the present invention includes a movable member that can move in a direction parallel to a specific plane, and a base member that holds the movable member in a relatively movable manner. A stage device of an image projection apparatus on which any one of an image forming element that forms an image and a projection optical system that projects an image formed by the image forming unit is mounted, and includes one of the movable member and the base member Provided on the other side is a thrust generating means having a magnet for generating a thrust for moving the movable member in a direction parallel to the specific plane and a coil, and the magnet has a magnetic flux density on the side facing the coil. Changes along the thrust direction.

  In the stage device of the present invention, when the movable member is driven in a specific plane, an out-of-plane force is hardly generated regardless of the position of the movable member.

It is a block diagram which shows the main structural members of the digital camera carrying the imaging device provided with the stage apparatus of this invention. 2A is a rear view showing an embodiment of an imaging apparatus having a stage device having six degrees of freedom according to the present invention, in which the left half is a diagram excluding the rear fixed yoke and the movable stage, and FIG. 2B is a diagram of FIG. 2A. It is sectional drawing which follows the IIB-IIB cutting line. It is sectional drawing which expands and shows one X direction thrust generator of FIG. 2B. It is sectional drawing which follows the IV-IV cutting line of FIG. 2A. It is a figure which shows the magnetic flux density distribution of the X direction of the magnet for X directions of the X direction thrust generator with a graph. 6A is a graph showing the relationship between the position of the movable stage and the thrust of the X-direction thrust generator in the embodiment, and FIG. 6B is a graph showing the relationship between the position of the movable stage and the thrust in the comparative example. FIG. 7A, FIG. 7B, and FIG. 7C are graphs showing examples of different magnetization intensity distributions of magnets of the stage device. FIG. 8A is a rear view showing a second embodiment of an imaging apparatus having a stage device having six degrees of freedom according to the present invention, in which the left half is a diagram excluding the rear fixed yoke and the movable stage, and FIG. It is sectional drawing which follows the VIIIB-VIIIB line | wire of FIG. 8A. It is sectional drawing which expands and shows one X direction thrust generator of FIG. 8B. It is sectional drawing which follows the XX line of FIG. 8A. 11A is a cross-sectional view similar to FIGS. 3 and 9 showing an X-direction thrust generator to which another embodiment of the magnet is applied, and FIG. 11B is a perspective view of the magnet. 12A and 12B are perspective views of an embodiment in which the stage apparatus of the present invention is applied to a correction optical system, as seen from different directions. It is sectional drawing corresponding to FIG. 8B which shows other embodiment which applied the stage apparatus of this invention to the shake correction apparatus of the imaging lens. It is sectional drawing corresponding to FIG. 8B which shows embodiment which applied the stage apparatus of this invention to the image projector.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. FIG. 1 is a conceptual diagram showing, in block form, main constituent members and main circuit elements of a digital camera equipped with an imaging apparatus equipped with a stage device of the present invention. In the drawing, in the present embodiment, one direction parallel to the optical axis O of the photographing optical system is defined as the first direction (Z direction, Z axis direction), and one direction orthogonal to the first direction is defined as the second direction. One direction orthogonal to both the direction (X direction and X axis direction), the first direction, and the second direction is defined as a third direction (Y direction, Y axis direction). For example, assuming that the X axis, the Y axis, and the Z axis are coordinate axes of a three-dimensional orthogonal coordinate system, when the optical axis O is the Z axis, the two axes orthogonal to the Z axis and orthogonal to each other are the X axis. And the Y axis. When the camera is in the normal position (lateral position), the first direction (Z direction, Z axis, optical axis O) and the second direction (X direction, X axis) are horizontal, and the third direction (Y (Direction, Y axis) is vertical, and the subject direction is front and front. In addition, in this specification, tilting or turning around the first direction means tilting or turning about a virtual axis parallel to the first direction. Similarly, tilting or turning around the second direction means tilting or turning around a virtual axis parallel to the second direction, and tilting or turning around the third direction is the third This means tilting or turning about a virtual axis parallel to the direction of.

  The digital camera 10 includes a camera body 11 and a photographing lens 100 as a photographing optical system. The camera body 11 includes a body CPU 20 that controls, calculates, and drives and controls functions of the entire camera, and an imaging block 30 that includes an imaging element 31 that captures a subject image projected by the imaging lens 100. The body CPU 20 controls the photographing operation of the image sensor 31, processes the captured image signal by the image processing unit 32, displays the captured subject image on the image display unit (monitor) 33, and captures image data of the captured subject image Is written into the memory card 34.

  The digital camera 10 includes a contrast detection unit 35 that detects the contrast of a subject from an image signal processed by the image processing unit 32, a camera operation unit 21 that has a switch that allows a photographer to operate the camera functions, and the like. The focus adjustment optical system (not shown) is driven in the direction of the optical axis to adjust the focus, and an AF unit (focus adjustment means) 22, an aperture, a shutter, and the like are driven to open and close to adjust the amount of light incident on the image sensor 31. An exposure control unit 23 that drives the imaging element 31 to control imaging and a lens communication unit 24 that inputs lens information such as the focal length f of the photographic lens 100 through lens communication with the photographic lens 100 are provided.

  The digital camera 10 has a roll (Z-direction tilt (rotation)) detection unit GSα, a pitch (X-direction tilt (rotation)) detection unit GSβ as detection means for detecting camera shake (hand shake, vibration). A yaw (tilt (rotation) rotation) detection unit GSγ, an X direction acceleration detection unit GSX, a Y direction acceleration detection unit GSY, and a Z direction acceleration detection unit GSZ are provided, and these are connected to a shake detection circuit 44.

  The imaging block 30 includes an imaging element 31 and a stage device (moving mechanism) 60 that supports the imaging element 31. The stage device 60 includes a movable stage 61 on which the image pickup device 31 is mounted, a front fixed yoke 62 and a rear fixed yoke 63 positioned in front of and behind the movable stage 61, and the energized stage 61 is fixed to the front and rear fixed yokes 62 when energized. , 63 can be floated (floated against gravity and kept stationary (floating stationary state)). The imaging element 31 constitutes a thin driven member (a part of the movable member) having a flat front surface. The stage device 60 moves the movable stage 61 in the floating state in the Z direction (first direction), the X direction (second direction) orthogonal to the Z direction, and the Y direction orthogonal to both the Z direction and the X direction. (Third direction) Translation, tilting (rotation) around the X direction (second direction), tilting (rotation) around the Y direction (third direction), and tilting around the Z direction (first direction) (Rotation) (6 degrees of freedom movement, 6 axis movement) is possible. Further, the movable stage 61 of the stage device 60 is capable of moving by combining a plurality of these six degrees of freedom of translation and tilting, translation during tilting, translation after tilting, and tilting after translation (see FIGS. 2 to 5). ). “Translation” is to move straight without changing the orientation and tilt of the image plane (imaging plane of the imaging device 31) with respect to the camera body, and “tilt” refers to the orientation of the image plane with respect to the camera body or This is a movement that changes the tilt, and includes rotating the image plane around the Z direction (the optical axis O or a virtual axis parallel to the optical axis O). “Floating” means that the movable stage 61 is held in a non-contact manner between the front fixed yoke 62 and the rear fixed yoke 63, and the movable stage 61 is positioned at the center where the center of the imaging surface of the image sensor 31 intersects the optical axis O (imaging This is a concept including the case where the front fixed yoke 62 and the rear fixed yoke 63 are held in a non-contact manner at the initial position.

  For example, the body CPU 20 inputs focal length f information from the photographing lens 100 via the lens communication unit 24, and detects a pitch (tilt (rotation) around the X direction) detection unit GSβ, yaw (tilt (rotation) around the Y direction). Direction of the digital camera 10 based on detection signals of the part GSγ, the roll (tilt (rotation) rotation in the Z direction) detection part GSα, the X direction acceleration detection part GSX, the Y direction acceleration detection part GSY, and the Z direction acceleration detection part GSZ The shake speed and the like are calculated, and the direction in which the image sensor 31 is driven, the drive speed, the drive amount, and the like are calculated so that the subject image projected on the image sensor 31 does not move relative to the image sensor 31. Based on this, the stage device 60 (movable stage 61) is driven in six axial directions (translation (shift), tilting, translation during tilting, and translation (shifting) after tilting). The order of these operations does not matter.

  The stage device 60 translates (shifts), tilts, translates during tilting, and translates (shifts) after tilting the movable stage 61 on which the image sensor 31 is fixed with respect to the front fixed yoke 62 and the rear fixed yoke 63. ) Functions as a support member that can be freely held. The movable stage 61 is a rectangular plate (frame) -like member that is larger than the image pickup device 31 when viewed from the front (viewed from the Z direction). The front fixed yoke 62 and the rear fixed yoke 63 are formed of a rectangular plate (frame) member having the same shape whose plan view and outer shape are slightly larger than the movable stage 61, and each has a central portion in front view (viewed from the Z direction). ), Rectangular openings 62a and 63a larger than the outer shape of the image sensor 31 are formed. The front fixed yoke 62 and the rear fixed yoke 63 are coupled by a plurality of connecting struts (not shown) at positions where they do not interfere even when the movable stage 61 moves (translates, tilts, rotates) within a predetermined range, and is parallel and at a predetermined interval. Is retained.

  The rear surface of the front fixed yoke 62 (the surface opposite to the subject side) is located on at least one of the left and right sides (X direction) of the opening 62a with the Y axis as the center line and the Z axis. In this manner, an X-direction magnet (second direction magnet) MX composed of a pair of left and right permanent magnets having the same specifications is fixed. Each of the left and right X-direction magnets MX has a plate shape that is long in the Y direction and thin in the Z direction, and is disposed in parallel with the Y axis and spaced apart in the X direction. As for the pair of left and right X-direction magnets MX, one (left side) magnet in FIG. 2B has the front surface (surface on the front fixed yoke 62 side) as the S pole, the rear surface is the N pole, and the other (right side) magnet is the front surface. Is the N pole and the rear surface is the S pole. Then, when the front fixed yoke 62 and the rear fixed yoke 63 pass the magnetic flux of the X direction magnet MX, the thrust in the X direction (second direction) is provided between the opposing portions of the X direction magnet MX and the rear fixed yoke 63. Part of the magnetic circuit that generates

  On the rear surface of the front fixed yoke 62, a pair having the same specification as the Y-direction magnet MYA made of a pair of permanent magnets having the same specification, with the Y axis as the center line and being spaced apart from the Z axis below the opening 62a. The Y-direction magnet MYB is fixed. Each of these Y-direction magnets MYA and MYB2 is composed of a pair of plate-like magnets that are long in the X direction and thin in the Z direction, and each pair of magnets is arranged parallel to the X axis and spaced apart in the Y direction. Yes. Both the pair of Y-direction magnets MYA and the pair of Y-direction magnets MYB have an S-pole on one side (front side) on the front and back and an N-pole on the other side (rear side), as shown in FIG. In the magnet on the side, one of the front and rear surfaces is an N pole, and the other surface (rear surface) is an S pole. Then, the front fixed yoke 62 and the rear fixed yoke 63 pass the magnetic fluxes of the Y direction magnets MYA and MYB, so that the Y direction magnets MYA and MYB and the rear fixed yoke 63 are respectively in the Y direction (third Part of the magnetic circuit that generates the thrust in the direction).

  Further, on the rear surface of the front fixed yoke 62, three Z-direction magnets MZA, MZB and MZC made of permanent magnets of the same specification are provided at three locations different from the X-direction magnet MX and the Y-direction magnets MYA and MYB. Is fixed (FIG. 2). The Z-direction magnets MZA, MZB, and MZC have a rectangular plate shape when viewed from the front, and the front surface (the contact surface of the front fixed yoke 62) has an S pole and the rear surface (the surface facing the movable yoke 61) has an N pole (FIG. 4). . The three Z-direction magnets MZ have the same mode (specifications), and are arranged at substantially equal intervals on the same circumference around the Z axis in the Z axis orthogonal plane. The front fixed yoke 62 and the rear fixed yoke 63 pass the magnetic fluxes of the Z direction magnets MZA, MZB, and MZC, so that the Z direction magnets MZA, MZB, MZC and the rear fixed yoke 63 are opposed to each other in the Z direction. It constitutes a part of a magnetic circuit (thrust generation means, thrust control means) that generates thrust in the (first direction).

  The movable stage 61 located between the front fixed yoke 62 and the rear fixed yoke 63 is a nonmagnetic member integrally formed by press molding from a nonmagnetic material. A rectangular image pickup device mounting hole 61a is formed in the center of the movable stage 61, and the image pickup device 31 is fitted and fixed in the image pickup device mounting hole 61a. The image sensor 31 protrudes forward in the optical axis O direction of the movable stage 61 from the image sensor mounting hole 61a.

  The image sensor 31 is arranged so that the long side is parallel to the X direction and the short side is parallel to the Y direction when the movable stage 61 is located at the initial position (initial position where the magnetic levitation is performed). And When the movable stage 61 is in the initial position, the center of the imaging surface 31a of the imaging device 31 is located on the optical axis O of the photographing lens 100, and the optical axis O and the Z axis coincide. The Z direction (first direction), the X direction (second direction), and the Y direction (third direction) are relative to the camera body 11 and the photographing lens 100 where the Z direction coincides with or is parallel to the optical axis O. However, the direction may be constant with respect to the image sensor 31.

  A pair of X driving coils (X driving unit) CX is fixed to the movable stage 61 at positions outside the left and right sides (short sides) of the image sensor 31, and one side below the image sensor 31 ( A pair of Y driving coil (YA driving unit) CYA and Y driving coil (YB driving unit) CYB are fixed at a lower part of the long side and separated from each other on the left and right. The pair of X driving coils CX are long and long in the Y direction, and are arranged at symmetrical positions (equal distance) across the Y axis so that the longitudinal direction is parallel to the Y direction and overlapping the X axis. The pair of Y drive coils CYA and CYB are horizontally long and long in the X direction, and are arranged at symmetrical positions (equal distance from the Y axis) across the Y axis so that the longitudinal direction is parallel to the X direction. ing. This arrangement is easy to manufacture, adjust and control.

  Further, a circular Z driving coil (ZA driving unit) CZA is fixed to the movable stage 61 between the pair of Y driving coils CYA and CYB (intermediate position). A pair of circular Z drive coils (ZB drive unit) CZB and Z drive coil (ZC drive unit) CZC are fixed to be positioned above. The Z drive coil CZA is arranged on the Y axis, and the Z drive coils CZB and CZC are arranged at symmetrical positions (equal distance from the Y axis) with respect to the Y axis. The center of gravity (total center of gravity) of the Z driving coils CZA, CZB, and CZC substantially coincides with the center of gravity of the movable stage 61. Any two of the Z drive coils CZA, CZB, and CZC, in the illustrated embodiment, a line connecting the Z drive coils CZB and CZC, and a perpendicular line drawn from the other one to the above line are parallel to the Y axis (Or coincides with the Y axis). The arrangement of the Z drive coils CZA, CZB, and CZC is arbitrary, but the line connecting any two is parallel to the X axis or Y axis, and the other one is lowered to the line connecting the two. It is preferable to arrange the vertical line so that it is parallel to the Y axis or the X axis. This arrangement is easy to manufacture, adjust and control.

  The pair of X driving coils CX, the pair of Y driving coils CYA and CYB, and the three Z driving coils CZA, CZB, and CZC are wound in a spiral shape on the XY plane. A planar (thin) coil parallel to the optical axis orthogonal plane (XY plane), which is laminated a plurality of times in the plate thickness direction (Z direction).

  The pair of X driving coils CX are arranged in such a manner that the longitudinal portions are parallel to the Y axis and face the corresponding X direction magnets MX, and the longitudinal portions of the pair of Y driving coils CYA and CYB are parallel to the X axis. And each corresponding is arrange | positioned in the aspect which opposes a pair of Y direction magnets MYA and MYB.

  The X driving coil CX, the Y driving coil CYA and the Y driving coil CYB, the Z driving coil CZA, the Z driving coil CZB and the Z driving coil CZC are connected to the actuator driving circuit 42 and are connected to the actuator driving circuit. The energization is controlled via 42.

The X driving coil CX and the pair of X direction magnets MX constitute thrust generating means (thrust control means) for generating thrust in the X direction (second direction). The movable stage 61 can be translated in the X direction by thrust in the X direction generated by controlling the current flowing through the X driving coil CX. Regardless of the posture of the camera body 11, the X driving coil CX and the X direction magnet MX can move the movable stage 61 to the center position (initial position), for example, in vertical position shooting where the grip of the camera body 11 is held up or down. Acts (functions) as a floating means for holding.
One Y drive coil CYA and a pair of Y direction magnets MYA, and the other Y drive coil CYB and a pair of Y direction magnets MYB generate a pair of thrusts that generate thrust in the Y direction (third direction). The generating means (thrust control means) is configured. The movable stage 61 is translated in the Y direction and tilted about the Z direction (Z axis) by the interaction of a pair of Y direction thrusts separated in the X direction generated by the current control flowing through the Y driving coils CYA and CYB ( Rotation). The Y driving coil CYA and the pair of Y direction magnets MYA and the Y driving coil CYB and the pair of Y direction magnets MYB are movable stages in, for example, lateral position (normal position) shooting regardless of the posture of the camera body 11. Acts (functions) as a floating means for holding 61 at the center position (initial position).
The three Z driving coils CZA, CZB, CZC and the three Z direction magnets MZA, MZB, MZC include three thrust generating means (thrust control means) that generate thrust in the Z direction (first direction). ). Three Z driving coils CZA, CZB, CZC and three Z direction magnets MZA, MZB, MZC, which are separated from each other in the XY plane, are controlled by current control through the three Z driving coils CZA, CZB, CZC. Due to the interaction of the three generated thrusts in the Z direction, the movable stage 61 is levitated so as not to contact the front and rear fixed yokes 62 and 63 (Z direction magnets MZA, MZB, and MZC), and is translated in the Z direction. And tilt around the X direction (X axis) and tilt around the Y direction (Y axis). The Z driving coils CZA, CZB, CZC and the respective pairs of Z direction magnets MZA, MZB, MZC have the movable stage 61 in the initial position in the optical axis direction and the initial posture (the imaging surface of the imaging device 31 is orthogonal to the optical axis) Acts (functions) as a levitation means for holding in the initial state.

The X-direction magnet MX and the Y-direction magnets MYA and MYB that generate thrust to move the movable stage 61 in the X-axis and Y-direction within the plane orthogonal to the optical axis are opposed to the X drive coil CX and the Y drive coil CYA. The magnetic flux density (magnetic force) on the CYB side is not the same along the thrust direction in the X direction and the Y direction, but is changing.
FIG. 3 shows a pair of X direction magnets MX arranged on the left side of the stage device 60, and the magnetic flux density (magnetic force) generated by the pair of X direction magnets MX is indicated by arrows. Each X-direction magnet MX has a concave portion 81 in the central portion in the X direction, which is the thrust direction generated, on the surface facing the X driving coil CX, and wall portions 82 on both sides (both ends) of the concave portion 81. It has a concave cross section. The depth of the recess 81 is about 3/5 to 4/5 of the thickness of the X-direction magnet MX (the height of the wall portion 82).
The X direction (thrust force direction) width of the recess 81 of the X direction magnet MX is wider than the X direction width of one Y direction (longitudinal direction, direction orthogonal to the thrust direction) coil wire portion of the X drive coil CX.

The pair of X-direction magnets MX has a concave portion 81 and a wall portion 82, so that the distribution of the magnetic flux density in the thrust direction (X direction) is the lowest in the central portion (recessed portion 81) and both side portions (wall portion 82). Exhibit the highest, substantially concave shape distribution. FIG. 5 is a graph showing a change in magnetic flux density in the thrust direction (magnetic flux density distribution) depending on the shape of the recess 81 of the X-direction magnet MX. In the graph, the horizontal axis represents the magnet width and the vertical axis represents the magnetic flux density. The magnetic flux density distribution is lowest at the center of the recess 81 and highest at both ends in the X direction of the recess 81 (X-direction magnet MX). The same graph shows a comparative example in the case where there is no recess. The magnetic flux density of the comparative example is highest at the center of the magnet, and gently decreases toward both ends. As for the magnetic flux density of this embodiment, the magnetic flux density ratio of the center part is 0.15-0.3 (15-30%) with respect to both ends.
The pair of right-side X-direction magnets MX has the same shape as the left-side X-direction magnet MX and the magnetic poles are reversed, but the magnetic flux density distribution is the same.

  Although not shown, the pair of Y-direction magnets MYA and the pair of Y-direction magnets MYB have a concave portion at the center in the Y direction where the surfaces facing the Y driving coil CYA and the Y driving coil CYB are the thrust directions. And has a concave cross section with protrusions on both sides (both ends) in the Y direction of the recess. The depth of the concave portions of the Y-direction magnets MYA and MYB is about 3/5 to 4/5 of the magnet thickness. The Y-direction (thrust direction) width of the concave portions of the Y-direction magnets MYA and MYB is larger than the Y-direction width of one Y direction (longitudinal direction, direction orthogonal to the thrust direction) of the Y drive coils CYA and CYB. wide. Thus, the Y-direction magnets MYA and MYB have a substantially V-shape in which the distribution of the magnetic flux density in the thrust direction (Y direction) is lowest at the center and highest at both ends. The pair of Y-direction magnets MYA have reversed magnetic poles, and the pair of Y-direction magnets MYB have reversed magnetic poles, but the magnetic flux density distribution in these thrust directions (Y direction) is the same.

  FIG. 6A is a graph showing the relationship between the position of the movable stage 61 in the X direction, the thrust in the X direction, and the thrust in the Z direction in the stage device 60. FIG. 6B is a graph showing the X-direction position, the X-direction thrust, and the Z-direction thrust of the movable stage 61 in a comparative example (conventional example) in which the magnetic flux density in the thrust direction of the X-direction magnet is constant. is there. In these graphs, the horizontal axis represents the position in the X direction, and the vertical axis represents the thrust.

  As is clear from the above graph, the stage device 60 of the present embodiment has a small variation in the X-direction thrust even when the movable stage 61 moves from the center position in the X direction, regardless of the X-direction position, and the Z-direction thrust. Is small, and fluctuations in the Z direction thrust are small. On the other hand, in the comparative example (conventional example), when the movable stage 61 moves from the center position, the X-direction thrust decreases, and the Z-direction thrust increases greatly at the same time.

  The movable stage 61 includes an X-direction hall element (X position detector) HX located in the air core region of the X driving coil CX, and a Y direction coil located in the air core regions of the Y driving coils CYA and CYB, respectively. Hall element (YA position detector) HYA, Y-direction hall element (YB position detector) HYB, and Z-direction hall elements (ZA position) respectively located in the air core regions of the Z drive coils CZA, CZB, and CZC A detection unit) HZA, a Z-direction Hall element (ZB position detection unit) HZB, and a Z-direction Hall element (ZC position detection unit) HZC are fixed. The X-direction hall elements HX, the Y-direction hall elements HYA and HYB, and the Z-direction hall elements HZA, HZB, and HZC are connected to the position detection circuit 43, respectively.

The X-direction hall element HX constitutes position detection means for detecting the magnetic force of the corresponding X-direction magnet MX (magnetic flux of the X-direction magnetic circuit). The position detection circuit 43 detects the X-direction position of the movable stage 61 by a predetermined calculation using the detection signal of the X-direction hall element HX. The translation position in the X direction can be detected by the detection signal from the X direction hall element HX.
The Y-direction hall element HYA detects the magnetic force (magnetic flux of the Y-direction magnetic circuit) of the corresponding Y-direction magnet MYA, and the Y-direction hall element HYB detects the magnetic force (Y-direction magnetism) of the corresponding Y-direction magnet MYB. The position detecting means for detecting the magnetic flux of the circuit is constructed. Then, the position detection circuit 43 detects the translation position in the Y direction and the tilt position around the Z direction by a predetermined calculation using the detection signals of both the Y-direction hall elements HYA and HYB. The Y direction position and the tilt position around the Z direction can be detected by the detection signals of the Y direction hall elements HYA and HYB.
Each Z-direction hall element HZA, HZB, HZC constitutes a position detecting means for detecting the magnetic force (magnetic flux of the Z-direction magnetic circuit) of the corresponding Z-direction magnets MZA, MZB, MZC. The position detection circuit 43 calculates the Z-direction translation position, the X-direction tilt position, and the Y-direction tilt position by a predetermined calculation using the detection signals of the Z-direction hall elements HZA, HZB, and HZC. Is detected. The Z direction position, the tilt position about the X direction, and the tilt position about the Y direction can be detected by the detection signals of the respective hall elements HZA, HZB, and HZC for Z direction.

  The position detection circuit 43 detects the X direction hall element HX, the Y direction hall elements HYA, HYB, and the Z direction hall elements HZA, HZB, and HZC. (First direction), X direction (second direction) and Y direction (third direction) translation positions, Z direction (first direction), X direction (second direction) and Y direction (first direction) The calculation means is configured to calculate the tilt position around (direction 3).

  The X driving coil CX, the Y driving coils CYA, CYB, and the Z driving coils CZA, CZB, CZC, the X direction hall element HX, the Y direction hall elements HYA, HYB, and the Z direction hall element. HZA, HZB, and HZC are mounted on a flexible printed circuit board (not shown), and include an actuator drive circuit 42, a position detection circuit 43, and the like built in the camera body 11 through a flexible printed circuit board extending from the movable stage 61. It is electrically connected to each circuit (see FIG. 1).

The pair of X driving coils CX, the pair of Y driving coils CYA, CYB, and the three Z driving coils CZA, CZB, CZC are energized and controlled by the actuator driving circuit 42. The actuator drive circuit 42 is controlled by the body CPU 20 via the image stabilization control circuit 41.
The position detection circuit 43 detects the X direction position and the Y direction position of the movable stage 61 based on the detection signals detected by the X direction hall element HX, the Y direction hall elements HYA, HYB, and the Z direction hall elements HZA, HZB, HZC. , Z position, tilt position around X direction (tilt (rotation) angle, pitch angle around X direction), tilt position around Y direction (tilt (rotation) angle, yaw angle around Y direction), and Z direction Rotating position (tilting (rotation) angle around the Z direction, roll angle) is detected.

  The above digital camera 10 can perform the following operations when performing a photographing operation. First, under the control of the body CPU 20, by energizing the pair of X driving coils CX, the pair of Y driving coils CYA and CYB, and the three Z driving coils CZA, CZB, and CZC, the movable stage 61 is moved forward. The fixed yoke 62 and the rear fixed yoke 63 are held (floated) in an initial position that is not in contact with other members.

  Furthermore, the digital camera 10 (body CPU 20) can perform the following drive control based on each position calculated by the body CPU 20 (position detection circuit 43) while the movable stage 61 is lifted.

The movable stage 61 is translated in the Z direction by the interaction of three equivalent thrusts in the Z direction generated by equally energizing the Z driving coils CZA, CZB, CZC, and the Z driving coils CZA, CZB, CZC are The movable stage 61 can be tilted around the X direction and tilted around the Y direction by the interaction of three different thrusts in the Z direction generated by individually controlling energization.
The movable stage 61 can be translated in the X direction by the X direction thrust generated by energizing each X driving coil CX.
The movable stage 61 is translated in the Y direction by the interaction of two equivalent thrusts in the Y direction generated by controlling the energization of the Y drive coils CYA and CYB equally, and the Y drive coils CYA and CYB are individually energized. The movable stage 61 can be tilted around the Z direction by the interaction of the two different thrusts in the Y direction generated by the control.
Z drive coils CZA, CZB, CZC, X drive coil CX, Y drive coils CYA, CYB, a plurality of Z direction thrusts, a plurality of X direction thrusts, By the interaction of thrust in the Y direction, the movable stage 61 can be translated, tilted, tilted during translation, tilted during translation, tilted after translation, and translated after translation in all directions with six degrees of freedom (six axes).

  The body CPU 20 performs the above-described drive control of the movable stage 61 in synchronization with the shake (vibration) of the camera body 11 and the photographing lens 100 detected by the shake detection circuit 44, thereby performing a shake correction operation.

  In the stage device 60 of this embodiment described above, the thrust generated when the X driving coil CX and the Y driving coils CYA and CYB are energized is large regardless of the position of the movable stage 61 in the XY plane. Are the X-direction component and the Y-direction component, and there are few fluctuations. Therefore, the XY plane and the non-parallel component (the direction component away from the XY plane, the inclined direction component, and the Z direction component) are very small. It translates while maintaining a parallel state with respect to the plane, and tilts (rotates) in the XY plane (around the Z direction). That is, since the movable stage 61 does not swing or tilt in the direction of tilting from the XY plane and does not move in the Z direction, no abnormal noise occurs, the image plane does not tilt, and no focusing error occurs. .

  In the first embodiment, the magnetic flux density on the side of the X direction magnet MX, the Y direction magnets MYA, MYB facing the X drive coil CX, and the Y drive coils CYA, CYB is made different along the thrust direction. Furthermore, the thickness of the X-direction magnet MX (the height of the wall portion 82) is 2/5 to 4.5 / in the center of the surface facing the X driving coil CX and the Y driving coils CYA and CYB. A recess 81 having a depth of about 5 was formed. The depth and width of the recess 81 are set by the material of the magnet, the overall size, the drive coil constituting the thrust generating means, the relationship with the yoke, the amount of movement of the movable stage 61, and the like.

The depth of the recess 81 is preferably 3/5 to 4/5 of the magnet thickness (height of the wall portion 82), but may be in the range of 2/5 to 4.5 / 5. If it is shallower than the minimum value, the overall magnetic flux density becomes high, but the Z direction component also becomes large, and the thrust fluctuation in the X direction and Y direction becomes large. If it is deeper than the maximum value, the overall magnetic flux density becomes too low, and the Z direction. The ratio of the components increases, and the thrust fluctuation in the direction and the Y direction becomes relatively large. That is, regardless of whether the depth of the recess 81 is shallower than the lower limit or deeper than the upper limit, thrust variation in the X direction and Y direction increases in the moving range of the movable stage 61, and the Z direction component of thrust increases.
If the X direction width of the concave portion 81 of the X direction magnet MX is narrower than the X direction width of the Y direction (longitudinal direction) coil wire portion of the X driving coil CX, the above effect cannot be obtained sufficiently.

  The above restrictions and effects are the same for the Y-direction magnets MYA and MYB.

  In 1st Embodiment, the recessed part 81 was formed in the center part of the thrust direction of the magnet MX for X directions, the magnets YYA for Y directions, and MYB. In another embodiment, the X-direction magnet MX, the Y-direction magnets MYA and MYB facing the X driving coil CX and the Y driving coils CYA and CYB have a planar shape, and the distribution of the magnetized magnetic strength is thrust. Can vary in direction.

7A to 7C are graphs showing examples of the distribution shape (distribution characteristics) of the magnetization strength (magnetization force) of the X-direction magnet MX. In the figure, the horizontal axis represents the X-direction position of the X-direction magnet MX, and the vertical axis represents the magnetization intensity ratio. The magnetization intensity ratio is an intensity ratio where the magnetization intensity at both ends in the X direction of the X-direction magnet MX is 1. 0 on the horizontal axis indicates the center position of the X direction magnet MX in the X direction.
In the embodiment shown in FIG. 7A, the magnetization intensity ratio is distributed in a valley shape that is highest at both ends in the X direction of the X-direction magnet MX and gradually decreases toward the center.
The embodiment shown in FIG. 7B has an inverted trapezoidal shape in which the magnetization intensity ratio is highest at both ends in the X direction of the X-direction magnet MX, decreases toward the center, and has a certain range at the center. Distributed in a trapezoidal groove shape).
In the embodiment shown in FIG. 7C, the magnetization intensity ratio is highest at both ends in the X direction of the X-direction magnet MX, and decreases rapidly after maintaining a substantially constant value from both ends toward the center. It is distributed in a rectangular shape.
The magnetizing strength and magnetizing force are the magnetic force when magnetizing the magnet, and the magnetic flux density is the retained magnetizing density (residual magnetic flux density) after magnetized by the magnetizing force.

In each of the embodiments described above, the ratio of the magnetization (magnetization strength) at both ends in the thrust direction of the magnet MX for X direction to the magnetization (magnetization strength) at the center is the ratio of the magnetization at the center with respect to both ends. May be 0.15 to 0.3 (15 to 30%).
The magnetic flux density is such that the magnetic flux density ratio at the center portion is about 0.15 to 0.3 (15 to 30%) with respect to both end portions in the thrust direction of the X-direction magnet MX.
This magnetizing force (magnetizing strength) ratio and magnetic flux density ratio are set by the material of the magnet, the overall size, the relationship with the drive coil and the yoke constituting the thrust generating means, the amount of movement of the movable stage 61, and the like. The The same applies to the Y-direction magnets MYA and MYB.
If the magnetizing force (magnetizing strength) ratio and the magnetic flux density ratio are smaller than the lower limit, the Z-direction component force becomes larger, and if larger than the upper limit, the Z-direction component force becomes larger. That is, regardless of whether it is larger or smaller than the numerical range, fluctuations in the X-direction thrust and Y-direction thrust increase in the moving range of the movable stage 61, and the Z-direction component of the thrust increases.

  Due to the magnetization intensity distribution as in the above examples, in these examples as well, the thrust having the characteristics shown in FIG. 6A can be generated as in the embodiment of FIGS. That is, the thrust in the X direction and the Y direction has a small variation regardless of the position of the movable stage 61 in the XY plane, and the component force in the Z direction is very small. Therefore, the movable stage 61 does not swing or move in the Z direction, and generation of abnormal noise and focusing error are suppressed.

[Second Embodiment]
In the first embodiment, the X-direction magnet MX and the Y-direction magnets MYA and MYB constituting the thrust generating means are provided only on the front fixed yoke 62. The X-direction magnet MX and the Y-direction magnets MYA and MYB may be provided on the rear fixed yoke 63. The X-direction magnet CX and the Y-drive coils CYA and CYB may be provided on the movable stage 61. It may be provided on one or both of the fixed yokes 63. 8 to 10 show a second embodiment in which the X-direction magnet MX and the Y-direction magnets MYA and MYB constituting the thrust generating means are provided on both the front fixed yoke 62 and the rear fixed yoke 63. FIG. . The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  X-direction magnet MX1, Y-direction magnet MX1, fixed in front fixed yoke 62, X-direction magnet MX1, Y-direction magnet MYA1, MYB1, and Z-direction magnet MZA1, MZB1, MZC1 in the form opposite to each other MYA 1, MYB 1 and Z direction magnets MZA 1, MZB 1, MZC 1 are fixed to the rear fixed yoke 63. The movable stage 61 is provided with an X driving coil CX positioned between the opposing X direction magnets MX1 and MX1, and is positioned between the opposing Y direction magnets MYA1 and MYB1 with the Y driving coil CYA. Is provided between the opposing Y-direction magnets MYB1 and MYB1, and a Y-drive coil CYB is provided between the Z-direction magnets MZA1 and MZA1, between MZB1 and MZB1, and between MZAC1 and MZA1. Z driving coils CZA, CZB and CZC are provided.

  The X-direction magnet MX1 and the Y-direction magnets MYA1 and MYB1 of the rear fixed yoke 63 are opposed to the magnetic poles different from the X-direction magnet MX1 and the Y-direction magnets MYA1 and MYB1 of the opposed front fixed yoke 62. (Fig. 9). On the other hand, the Z-direction magnets MZA1, MZB1, and MZC1 of the rear fixed yoke 63 are arranged so that the same magnetic poles as the Z-direction magnets MZA1, MZB1, and MZC1 of the opposed front fixed yoke 62 face each other (FIG. 10). ).

  The X-direction magnet MX1 is formed in a concave shape in cross section like the X-direction magnet MX shown in FIGS. That is, the X-direction magnet MX1 has a concave portion 81 ′ at the center in the X direction, which is the thrust direction, on the surface facing the X driving coil CX, and on both sides (both ends) of the concave portion 81 ′ in the X direction. It is formed in a concave cross section having a wall portion 82 '. Similarly, the cross-sectional shapes of the Y-direction magnets MYA1 and MYB1 have a concave shape at the central portion in the Y direction, which is the thrust direction, and have protruding portions on both sides of the concave portion. However, the thickness of the entire X-direction magnet MX1 is thinner than the X-direction magnet MX shown in FIGS. The Y-direction magnets MYA1 and MYB1 have the same shape as the X-direction magnet MX1, and are thinner than the Y-direction magnets MYA and MYB of the first embodiment. The width in the X direction (thrust direction) of the recess 81 ′ of the X direction magnet MX1 is the width in the X direction of one Y direction (longitudinal direction, direction perpendicular to the thrust direction) of the opposing X drive coil CX. Wider.

The magnetic flux density distribution and the magnetized magnetic force distribution of the X-direction magnet MX1 are substantially the same as or approximate to the shape of the magnetic flux density distribution and the magnetized magnetic force distribution of the X-directional magnet MX1. However, according to experiments by the present inventors, the depth of the recess 81 ′ is preferably ¼ to ½ of the thickness of the X-direction magnet MX1 (height of the wall portion 82 ′). The ratio of the magnetizing force of the central portion with respect to both end portions of the X-direction magnet MX1 is preferably 0.2 to 0.5 (20 to 50%).
The above-described configurations are the same for the Y-direction magnets MYA1 and MYB1.

If the depth of the recess 81 ′ is shallower than the lower limit, the Z direction component increases, and if it is deep, the Z direction component increases.
When the ratio of magnetization (magnetization strength) is smaller than the lower limit, the Z-direction component increases, and when larger than the upper limit, the Z-direction component increases.
If the X-direction width of the concave portion 81 ′ of the X-direction magnet MX1 is narrower than the X-direction width of the Y-direction (longitudinal direction) coil wire portion of the X driving coil CX, the above effect cannot be obtained sufficiently.

  The above limitations and effects are the same for the Y-direction magnets MYA1 and MYB1.

  According to the second embodiment, the magnetic flux density of the X-direction magnet MX1, the Y-direction magnets MYA1, MYB1 of the front fixed yoke 62, and the X-direction magnet MX1, Y-direction magnets MYA1, MYB1 of the rear fixed yoke 63. Since the center portion is low and the both end portions in the X direction and Y direction are high, even if the movable stage 61 moves in the X direction and Y direction, the variation in thrust in the X direction and Y direction is small. In addition, in the second embodiment, the different magnetic poles face each other across the longitudinal direction portions of the X driving coil CX and the Y driving coils CYA and CYB of the movable stage 61, so that the magnetic lines of force are in the direction of the optical axis O (Z axis). The X-direction magnet MX1 and the X-drive coil CX, the Y-direction magnets MYA1 and MYB1, and the Y-drive coil CYA can be generated regardless of the X-direction position and the Y-direction position of the movable stage 61. Because the fluctuation of thrust generated during CYB is small, it is possible to drive accurately in the X direction and Y direction, and the Z direction component force of these thrusts is very small, so the position in the Z direction is accurately maintained. It is possible to drive accurately when driving in the Z direction.

  In the second embodiment, since the X-direction magnets MX1 and MX1, the Y-direction magnets MYA1 and MYA1, and the Y-direction magnets MYB1 and MYB1 are arranged to face each other, the X-direction magnets MX1 and MX1, and the Y-direction magnet MYA1 Even if the thickness of the magnets MYB1 and MYB1 for the Y direction is made thinner than the magnets MX for the X direction MX and the magnets for the Y direction MYA and MYB of the first embodiment, a high magnetic density can be obtained.

  In the above embodiment, a pair of X driving coils CX having the same specifications are provided on both the left and right sides of the imaging device 31 of the movable stage 61, and a pair of X direction magnets MX having the same specifications, or a pair of X direction coils. Although the magnet MX1 is provided on both the left and right sides of the image sensor 31, the X driving coil CX and the X direction magnets MX and MX1 may be provided only on one of the left and right sides. The X-direction hall element HX may be provided on only one of the left and right sides.

  In the above embodiment, the driving coil is provided on the movable stage (movable member), and the permanent magnet is provided on the fixed yoke (fixed base member). In the stage apparatus of the present invention, the driving coil can be provided on the fixed yoke (fixed base member), and the permanent magnet can be provided on the fixed yoke (fixed base member). When the permanent magnet is provided on the fixed yoke, the permanent magnet can be provided on the front and rear yokes with the coil of the movable stage interposed therebetween. When the coil is provided on the fixed yoke, the coil can be provided on the front and rear yokes with the magnet of the movable stage interposed therebetween.

In the above embodiment, the movable member (movable stage 61) can be driven in the six-axis directions. However, the present invention can also be applied to a drive device in which the movable member moves only in the XY plane, or a drive device that moves straight in only the X direction or the Y direction.
In this embodiment, the concave portion of the magnet has a groove shape penetrating in the longitudinal direction. However, the concave portion is not limited to the groove shape, and may have a box shape whose outer periphery is surrounded by a wall (four sides higher than the central portion). . If it is a box shape, the strength of the magnet is improved.

  In the present embodiment, each magnet (X-direction magnet, Y-direction magnet) is shown as an integrated body made of a single material. However, in the present invention, each magnet may be formed of a plurality of materials or a plurality of members instead of a single material. 11A and 11B show another embodiment in which the structure of the X-direction magnet is different. FIG. 11A shows a cross-sectional view similar to FIGS. 3 and 9, and FIG. 11B shows the X-direction magnet alone. A perspective view is shown. The same members and the members having the same functions are denoted by the same reference numerals and description thereof is omitted.

  Each X-direction magnet MXA is provided with a non-magnetic material between two magnets MXa and MXa. The magnets MXa and MXa of each X-direction magnet MXA have the same poles on the side facing the coil CX, and the left and right X-direction magnets MXA are set on different poles on the side facing the coil CX. By providing a non-magnetic material between the magnets MXa and MXa, the magnetic flux density characteristics and magnetic flux density distribution shown in FIGS. 5 and 7 can be obtained.

  As means for integrating the magnet MXa and the nonmagnetic material, known means such as adhesion can be used.

In this embodiment, the magnetic flux density characteristics can be set by the dimensions of two single magnets MXa and one non-magnetic material, and the magnetizing force of the magnet MXa, so that it is easy to obtain a desired magnetic flux density characteristic. .
In the present embodiment, since one set can be manufactured with two single magnets MXa and one nonmagnetic material, stable manufacturing is easy and the manufacturing cost is low.

  The above is an embodiment applied to the X-direction magnet MXA, but it can also be applied to a Y-direction magnet.

  The above embodiment is an example applied to a stage apparatus that drives the movable stage 61 on which the image sensor 31 is mounted. The stage apparatus of the present invention can also be applied to a correction optical system that drives one of the optical elements of the photographing optical system. 12A and 12B are exploded perspective views of a correction optical system to which the stage apparatus of the present invention is applied. In FIG. 12, the left side is called the subject side and the front side, and the right side is called the image side and the rear side.

  The correction optical system includes a movable lens frame 101 to which a lens group as the correction optical system is fixed, and a fixed lens frame 103 that holds the movable lens frame 101 and linearly guides it in the X and Y directions orthogonal to the optical axis O. It has. The movable lens frame 101 corresponds to a movable member (movable stage), and the fixed lens frame 103 corresponds to a base member (fixed yoke). A fixed lens frame 103 is fixed to a fixed lens barrel of the photographing optical system.

  The movable lens frame 101 includes a cylindrical lens holding portion 111 centered on the optical axis O as viewed from the front, and an outer flange portion 113 that surrounds the outer periphery of the lens holding portion 111 and extends in a direction perpendicular to the optical axis O. The outer flange portion 113 has an X driving coil CXL and a Y driving coil CYL arranged in an L shape. The movable lens frame 101 has a pair of X-direction guide portions 115 provided on the back surface of the outer flange portion 113 so as to project apart from each other in the X direction.

  The fixed lens frame 103 has a cylindrical portion 120 and an inner flange portion 123 having an optical path opening 121 centered on the optical axis O at the rear portion of the cylindrical portion 120. A pair of X-direction magnets MXL and a pair of Y-direction magnets MYL facing the X driving coil CXL and the Y driving coil CYL are mounted on the front surface of the inner flange portion 123 via a yoke 124. On the front surface of the inner flange portion 123 of the fixed lens frame 103, there is a pair of Y-direction guide portions 125 projecting apart in the Y direction. Although not shown in detail, the pair of X-direction magnets MXL and the pair of Y-direction magnets MYL have the same structure as the X-direction magnet MXA shown in FIG. Has been.

  The movable lens frame 101 and the fixed lens frame 103 are connected via an L-shaped L-shaped guide shaft 131 and are guided so as to be relatively movable in the X direction and the Y direction. More specifically, the X-direction shaft 131X of the L-shaped guide shaft 131 is guided by the pair of X-direction bearing grooves 115 of the movable lens frame 101 so as to be slidable in the X-direction, and further the Y-direction shaft 131Y of the L-shaped guide shaft 131. Is slidably guided in the Y direction by the pair of Y direction guide portions 125 of the fixed lens frame 103. The movable lens frame 101 moves in the X direction, with the X direction guide portion 115 guided by the X direction axis 131X of the L shape guide shaft 131, and the L direction guide shaft 131 integrally with the L shape guide shaft 131 in the Y direction. The Y-direction shaft 131Y of 131 moves while being guided by the Y-direction guide portion 125 of the fixed lens frame 103.

  The movable lens frame 101 is restricted from tilting and rotating about the X direction axis 131X and the Y direction axis 131Y, and is a guide member (not shown) such as a ball and a ball retainer that can move in the X direction and the Y direction. It is guided by. The fixed lens frame 103 is provided with X direction and Y direction position detecting means (not shown) for detecting the X direction position and the Y direction position of the movable lens frame 101.

  When the movable lens frame 101 and the fixed lens frame 103 are connected via the L-shaped guide shaft 131, the X driving coil CXL and the X direction magnet MXL, the Y driving coil CYL and the Y direction magnet MYL are lighted. Opposite at predetermined intervals in the axial direction.

  Thrust for moving the movable lens frame 101 in the X and Y directions between the X direction magnet MXL and the Y direction magnet MYL by controlling the energization of the X drive coil CXL and the Y drive coil CYL. Occurs.

  In the pair of X-direction magnets MXL and the pair of Y-direction magnets MYL, the magnetic flux density on the side facing the X driving coil CXL and the Y driving coil CYL changes along the thrust direction. The X-direction magnet MXL has the lowest magnetic flux density at the center in the X direction and the highest magnetic flux density at both ends in the X direction. The Y-direction magnet MYL has the lowest magnetic flux density at the center in the Y direction and the highest magnetic flux density at both ends in the Y direction. Due to this magnetic flux density distribution, when the movable lens frame 101 is driven, almost no thrust component non-parallel to the XY plane is generated, and no matter which position in the X direction or the Y direction is moved, the constant X direction and Y direction thrust can be generated. Therefore, in this embodiment, there is no chatter or abnormal noise in the movable lens frame 101, and the tilt with respect to the optical axis O hardly occurs, and the movable lens frame 101 can be moved with high accuracy.

  In the illustrated embodiment, the surfaces of the X-direction magnet MXL and the Y-direction magnet MYL facing the X driving coil CXL and the Y driving coil CYL are shown in a planar shape. However, the X-direction magnet MXL and the Y-direction magnet MYL may have a concave cross section having a concave portion at the center as shown in FIGS. In short, the magnetic flux density or magnetic force on the side facing the X driving coil CXL and the Y driving coil CYL changes in the thrust direction, and preferably has a weak distribution at the center and strong distribution at both ends. The magnetic flux density distribution and the magnetic force distribution are not limited to the embodiments shown in FIGS. 5 and 7A to 7C.

  In this embodiment, the X direction magnet MXL and the Y direction magnet MYL are shown only on one side of the X drive coil CXL and Y drive coil CYL. However, the X drive coil CXL and Y drive coil CYL are optical axes. You may provide on both sides on both sides from the direction. Further, a magnet may be provided on the movable lens frame 101 and a coil may be provided on the fixed lens frame 103.

  In the embodiment applied to the above photographic lens, the movable member is driven in the X direction and the Y direction in the plane orthogonal to the optical axis. The present invention can also be applied to a lens barrel that can also be driven in the Z direction. For example, in the photographic lens, one or a plurality of optical elements constituting the photographic optical system can be used as the correction optical element (driven member). In one embodiment, a lens between the first lens group 91 and the second lens group 93 is used as a driven member (correcting optical element) 92 (FIG. 13). In the case of this embodiment, the correction optical element 92 is mounted in the opening 61 c formed at the approximate center of the movable stage 61. According to this embodiment, the movable stage (correcting optical element 92) 61 is translated in the optical axis O direction (first direction), the second or third direction, or tilted around the second or third direction. By doing so, special shooting such as camera shake correction operation and tilt shooting is possible. Furthermore, in this embodiment, focusing fine adjustment is possible by moving the movable stage (correcting optical element 92) 61 in the optical axis O direction (first direction).

  The stage apparatus of the present invention includes a so-called mirrorless digital camera, a single-lens digital camera, a compact digital camera, a digital video camera, a drive recorder, an action camera, a digital camera mounted on a portable terminal, etc., and an interchangeable lens barrel. It can be applied to various photographing devices and optical devices in general, such as a camera-integrated lens.

  The present invention can also be applied to projectors, laser scanners, and the like that project video, data, and the like. When applied to a projector, projection light is incident on one side (rear side) of the movable stage 61 in the thickness direction (first direction, Z direction) substantially at the center of the movable stage 61 of the stage device. An image forming element (liquid crystal panel) that emits toward the projection optical system on the side (front), or a projection light beam that is incident on the approximate center of the movable stage 61 from a direction different from the first direction (Z direction), A DMD (digital mirror device, digital micromirror device) panel that reflects in a first direction (projection optical system direction) can be mounted. The movable stage 61 may be equipped with a projection optical system instead of the image forming element.

FIG. 14 shows an outline of an embodiment of an image projection apparatus (projector) provided with a stage apparatus 60 having a movable stage 61. This embodiment includes a light source 71, an illumination optical system 72 that uniformizes light emitted from the light source 71, an image forming element 73 that receives illumination light emitted from the illumination optical system 72 and forms an image, and the image A movable stage 61 having a forming element 73 fixed in the opening 61c and a projection optical system 74 for projecting an image formed by the image forming element 73 are provided. Specifically, the image forming element 73 is a liquid crystal panel or a DMD panel. The image forming element 73 is provided in the projector casing or the projection optical system 74 via the movable stage 61, and the image forming element 73 is in a state where the movable stage 61 is not driven (held at the initial position). The plane on which the image is formed is arranged in the projector so as to be perpendicular to the optical axis O of the projection optical system 74 or the optical axis of any lens in the projection optical system 74. . The movable stage 61 is translated in the optical axis O direction (first direction), the second or third direction, or tilted around the first, second, or third direction, and the like, thereby causing the image forming element 73 to move. The projection direction and the projection position are adjusted by changing the direction of the projection light beam that passes through the (liquid crystal panel) and travels toward the projection optical system 74, or the direction of the projection light beam that reflects from the DMD panel and travels toward the projection optical system 74. The tilt of the image can be adjusted, or the focus can be adjusted by adjusting the distance between the liquid crystal panel or DMD panel and the projection optical system.
Note that the projector may further include a focus detection unit that detects a shift amount of the focus and, for example, a trapezoid detection unit that detects distortion of the projection image. These detection means are used at the time of focusing and trapezoidal distortion correction. In particular, trapezoidal distortion correction can be automatically corrected by detecting the amount of trapezoidal distortion by providing a trapezoidal detection means and tilting the image plane by the image plane tilting means based on the amount of focus deviation. .

  Furthermore, the projector can be applied to digital signage. Specifically, the present invention can be applied to shake correction when mounted on a moving object such as in a train or car, or shake correction when mounted on a movable robot. Furthermore, camera shake can be corrected efficiently by mounting on a small handheld projector. Note that a projector can be mounted on the photographing apparatus. When a small projector is mounted on the main body of the photographic device or its display unit, the photographic image is corrected by translation and tilting of a movable stage that holds one of the optical elements of the image sensor and photographic optical system during shooting. During the projection, shake correction may be performed so that the projected image does not shake due to translation, tilting, or the like of the movable stage holding the image forming element. When mounted on a projector, it is possible to achieve higher resolution by shifting the image forming element by half a pixel or one pixel to increase the number of pixels to be displayed. However, instead of shifting the pixel or by shifting the pixel, In addition to the tilting, high resolution can be achieved.

10 Digital camera 11 Camera body 20 Body CPU (position detection means, thrust control means)
21 Camera operation unit 22 AF unit 23 Exposure control unit 24 Lens communication unit 30 Imaging unit 31 Imaging element (movable member, imaging unit)
32 Image processing unit 33 Image display unit (monitor)
34 Memory card 35 Contrast detector 41 Anti-vibration control circuit 42 Actuator drive circuit 43 Position detection circuit (position detection means, calculation means)
44 shake detection circuit 60 stage device 61 movable stage (movable member)
61a Image sensor mounting hole 62 Front fixed yoke (base member)
62a Opening 63 Rear fixed yoke (base member)
63a Opening 81, 81 'Recess 82, 82' Wall 100 Photographing lens CX, CXA, CXB, CXL X driving coil (coil, thrust generating means)
CX, CYA, CYB, CYLY Y drive coil (coil, thrust generating means)
CZA, CZB, CZC Z drive coil (coil, thrust generating means)
Hall element for HX X direction (position detection means)
HYA, HYB Y-direction Hall element (position detection means)
HZA, HZB, HZC Z-direction Hall element (position detection means)
MX, MX1, MXL, MXA X direction magnet (magnet, thrust generating means)
MYA, MYB, MYA1, MYB1, MYL Y direction magnet (magnet, thrust generating means)
MZA, MZB, MZC, MZA1, MZB1, MZC1 Z direction magnet (magnet, thrust generating means)

Claims (13)

A movable member movable in a direction parallel to a specific plane;
A base member that holds the movable member so as to be relatively movable; and a magnet that is provided on one and the other of the movable member and the base member and generates a thrust force that moves the movable member in a direction parallel to the specific plane. A thrust generating means having a coil,
The stage apparatus according to claim 1, wherein the magnet has a magnetic flux density on a side facing the coil that is changed along the thrust direction.   2. The stage device according to claim 1, wherein the movable member and the base member are each single, the magnet is disposed on one of the movable member and the base member, and the coil is the other of the movable member and the base member. A stage device disposed opposite to the magnet.   2. The stage device according to claim 1, wherein the base member includes a pair opposed to the movable member from a direction orthogonal to the specific plane, and the magnet sandwiches the movable member of the pair of base members. The stage device is provided at a position opposed to each other, and the coil is disposed between the pair of opposed magnets of the movable member.   3. The stage apparatus according to claim 2, wherein the magnet has a concave cross-sectional shape with a thickness in a direction orthogonal to the specific plane, with both end portions being thick and a central portion being thin in the thrust direction.   5. The stage device according to claim 4, wherein the depth of the concave portion having a concave cross section is 3/5 to 4/5 of the thickness of the magnet.   6. The stage device according to claim 2, 4 or 5, wherein a magnetic flux density ratio or a magnetized magnetic force ratio of a central portion with respect to both end portions of the magnet in the thrust direction is 0.15 to 0.3.   4. The stage device according to claim 3, wherein the magnet has a thickness in a direction orthogonal to the specific plane, the both ends of the thrust direction being thick and the central portion being thin in a cross-sectional concave shape. A stage apparatus in which the depth of the recess is 1/4 to 1/2 of the thickness of the magnet.   The stage device according to claim 3 or 7, wherein a magnetic flux density ratio or a magnetized magnetic force ratio of a central portion with respect to both end portions of the magnet in the thrust direction is 0.2 to 0.5.   9. The stage device according to claim 1, wherein the magnetism in the thrust direction of the magnet is a valley in which the vicinity of both end portions is higher than the central portion and the vicinity of both end portions is higher than the central portion. A stage apparatus in which the shape or both end portions are distributed in a substantially rectangular shape higher than the central portion.   4. The stage device according to claim 1, wherein the magnet has a nonmagnetic material at a central portion in the thrust direction, and a pair of magnets on both sides of the nonmagnetic material. Stage device.   An imaging apparatus comprising the stage apparatus according to claim 1, wherein an imaging element is mounted on a movable member of the stage apparatus.   An optical apparatus comprising the stage device according to any one of claims 1 to 10, wherein one of optical elements constituting the optical system is mounted on a movable member of the stage device. Optical equipment. An image forming element that has a movable member movable in a direction parallel to a specific plane and a base member that holds the movable member in a relatively movable manner, and forms an image on the movable member, and the image forming means A stage device of an image projection apparatus equipped with any one of the projection optical systems that project the image formed by
Provided with thrust generating means provided on one and the other of the movable member and the base member and having a magnet and a coil for generating a thrust for moving the movable member in a direction parallel to the specific plane;
The stage apparatus according to claim 1, wherein the magnet has a magnetic flux density on a side facing the coil that is changed along the thrust direction.

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