JP2014056145A - Vibration-proof actuator, and lens unit and camera including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration-proof actuator capable of accurately setting a reference position for control or calibrating a position detection sensor.SOLUTION: A vibration-proof actuator (10) includes: a fixation part (12); a movable part (14) to which an image blur prevention lens (16) is attached; a movable part supporting member (18); driving coils (20a, 20b, 20c); driving magnets (22a, 22b, 22c) attached so as to face the respective driving coils; attraction members (26) arranged on sides of the respective driving coils not facing the respective driving magnets; position detection sensors (24a, 24b, 24c); positioning walls (42) arranged inside the windings of the respective driving coils; and positioning projections (40) extending from the sides of the respective driving magnets to the inside of the windings of the respective driving coils and coming into contact with the respective positioning walls to position the movable part.

Description

  The present invention relates to an image stabilization actuator, and more particularly to an image stabilization actuator that moves an image stabilization lens to stabilize an image, and a lens unit and a camera including the image stabilization actuator.

  Japanese Patent Laying-Open No. 2010-185893 (Patent Document 1) describes an optical correction unit. In this optical correction unit, a lens holding frame to which a correction lens is attached is movably supported on a base member by three steel balls. In addition, three permanent magnets are attached to the lens holding frame, and the lens holding frame is driven by passing an electric current through three coils fixed so as to face these permanent magnets. Further, a Hall element is disposed inside the coil winding, and the Hall element detects the magnetism of the permanent magnet, thereby detecting the position of the lens holding frame.

  Each of the three steel balls is disposed inside a movable-side steel ball receiving portion provided in the lens holding frame and a fixed-side steel ball receiving portion provided in the base member. Each of the movable-side steel ball receiving portion and the fixed-side steel ball receiving portion is configured as a cylindrical wall surface. Furthermore, the cylindrical wall surface which comprises a movable-side steel ball receiving part is inserted inside the cylindrical wall surface which comprises a stationary-side steel ball receiving part. For this reason, when the lens holding frame is largely moved with respect to the base member, the outer peripheral surface of the movable-side steel ball receiving portion interferes with the inner peripheral surface of the fixed-side steel ball receiving portion, and the movement of the base member is restricted. . As described above, in the optical correction unit described in Japanese Patent Application Laid-Open No. 2010-185893, the position where the lens holding frame can be mechanically moved is located at the position where the movable-side steel ball receiving portion and the fixed-side steel ball receiving portion interfere. The “mechanism end” which is a portion, and the intermediate position between one “mechanical end” and the other “mechanical end” in a predetermined direction is set as a reference position of the lens holding frame.

  In this way, in a vibration-proof actuator such as an optical correction unit, a movable part such as a lens holding frame is moved to a mechanically movable limit point, and a control “reference position” is set based on that position. Has been done. Alternatively, a sensor that measures the position of the movable portion is calibrated based on the distance between one “mechanical end” and the other “mechanical end”.

JP 2010-185893 A

  However, the optical correction unit (anti-vibration actuator) described in Japanese Patent Application Laid-Open No. 2010-185893 has a problem that the lens holding frame (movable part) cannot be accurately positioned at the “mechanical end”. That is, when driving force is applied to the movable part by the driving means to cause the movable side steel ball receiving part to interfere with the fixed side steel ball receiving part, the movable part is pulled away from the base member (fixed part). The force component also works. As a result, the movable part is displaced so as to float a small distance from the fixed part, and the position accuracy of the movable part detected by the Hall element is lowered.

  Although the displacement of the detection position due to the “lifting” of these movable parts is extremely small, the moving distance of the movable part during the image blur prevention control is generally a minute distance of 1 mm or less, and the influence on the control is ignored. It is not possible. In addition, since the accuracy of the image stabilization control by the image stabilization actuator is improved year by year, the adverse effect of these errors is particularly great.

  Accordingly, an object of the present invention is to provide an anti-vibration actuator capable of accurately setting a control reference position or calibrating a position detection sensor, and a lens unit and a camera including the same.

  In order to solve the above-described problems, the present invention is an image stabilization actuator that moves an image blur prevention lens and stabilizes an image, and includes a fixed portion, a movable portion to which the image blur prevention lens is attached, A movable part supporting member that supports the movable part movably with respect to the fixed part, at least three drive coils attached to either the fixed part or the movable part, and these drive coils are opposed to each other. Between at least three driving magnets attached to the other of the fixed part and the movable part and each driving coil on the side not facing each driving magnet, and between each driving magnet An attracting member for attracting the fixed part and the movable part by the generated magnetic force, a position detection sensor for measuring the displacement of the movable part, and an inner side of the winding of each driving coil, Almost flat with the optical axis A positioning wall surface extending in a certain direction, and a fixed portion and a movable portion, from the side where each driving magnet is attached, extending toward the inside of the winding of each driving coil, And a positioning projection for positioning the movable part by contact.

  In the present invention configured as described above, the movable portion to which the image blur prevention lens is attached is supported by the movable portion support member so as to be movable with respect to the fixed portion. A driving coil and a driving magnet are attached to the movable part and the fixed part. The attracting member is disposed on the side of each driving coil that does not face each driving magnet, and attracts the fixed portion and the movable portion. The position detection sensor measures the displacement of the movable part. In addition, the positioning wall surfaces provided inside the windings of the respective driving coils contact the positioning projections extending toward the inner side of the windings of the respective driving coils, thereby positioning the movable part.

  According to the present invention configured as described above, the fixed portion and the movable portion are adsorbed by the driving magnet and the adsorbing member disposed on the back side of the driving coil, and inside the winding of the driving coil. The movable portion is positioned by contacting the positioning wall surface provided with the positioning projection. For this reason, according to the present invention, when the positioning wall surface and the positioning projection are brought into contact with each other, it is possible to prevent the movable portion from floating from the fixed portion, and it is possible to position the movable portion with high accuracy.

  In the present invention, preferably, the position detection sensor is a magnetic sensor disposed inside the winding of each driving coil, and these magnetic sensors detect the magnetism of each driving magnet facing each other. Measure the displacement of the movable part.

  According to the present invention thus configured, the positioning wall surface is disposed inside the winding of the driving coil and the position detection sensor is also disposed inside the winding of the driving coil. The part for performing the positioning and the sensor for detecting the position can be arranged close to each other, and the positioned position can be detected with high accuracy.

In the present invention, preferably, each positioning wall surface is provided so as to surround each magnetic sensor inside the winding of each driving coil.
According to the present invention configured as described above, since the positioning wall surface is provided so as to surround the magnetic sensor, it is not necessary to provide a special space for providing the positioning wall surface, and the vibration-proof actuator is reduced in size. can do.

In the present invention, preferably, each of the driving magnets facing each of the driving coils is composed of two magnet pieces, and each positioning projection is formed between each of the two magnet pieces. Extends toward the inside of the winding.
According to the present invention configured as described above, the positioning protrusion extends from between the two magnet pieces constituting the driving magnet, so that the magnetization boundary line of the driving magnet and the position of the positioning protrusion easily match. Can be made.

The present invention is a lens unit including an anti-vibration actuator, and includes a lens barrel, an imaging lens disposed inside the lens barrel, and the anti-vibration actuator of the present invention. Yes.
According to another aspect of the present invention, there is provided a camera including an anti-vibration actuator, comprising a camera body and the lens unit of the present invention.

  According to the vibration-proof actuator of the present invention, and the lens unit and camera including the same, it is possible to accurately perform control reference position setting or position detection sensor calibration.

It is sectional drawing of the camera by embodiment of this invention. It is side surface sectional drawing of the vibration proof actuator with which the camera of embodiment of this invention was equipped. It is the rear view which looked at the movable part of the vibration proof actuator from the fixed part side. It is a front view of the fixed part which removes and shows the movable part of a vibration proof actuator. In a vibration-proof actuator, it is a figure which shows the positional relationship of each driving coil, each positioning wall surface, and each positioning protrusion.

Next, embodiments of the present invention will be described with reference to the accompanying drawings.
First, the configuration of a camera according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a camera according to an embodiment of the present invention.
As shown in FIG. 1, a camera 1 according to an embodiment of the present invention includes a lens unit 2 and a camera body 4. The lens unit 2 includes a lens barrel 6, a plurality of imaging lenses 8 disposed in the lens barrel, an image stabilization actuator 10 that moves the image blur prevention lens 16 within a predetermined plane, and a lens. And a gyro 34 which is a vibration detecting means for detecting the vibration of the lens barrel 6.

  In the camera 1 according to the embodiment of the present invention, the vibration is detected by the gyro 34, and the image stabilization actuator 10 is operated based on the detected vibration to move the image stabilization lens 16. The image focused on C is stabilized. In the present embodiment, a piezoelectric vibration gyro is used as the gyro 34. In the present embodiment, the image blur prevention lens 16 is constituted by a single lens, but the lens for stabilizing the image may be a plurality of lens groups. In this specification, the image blur prevention lens includes one lens and a lens group for stabilizing an image.

The lens unit 2 is attached to the camera body 4 and configured to form incident light on the image sensor C.
The generally cylindrical lens barrel 6 holds a plurality of imaging lenses 8 therein, and allows focus adjustment by moving some imaging lenses 8.

  Next, the vibration-proof actuator 10 will be described with reference to FIGS. FIG. 2 is a side cross-sectional view of the vibration isolation actuator provided in the camera of the embodiment of the present invention. FIG. 3 is a rear view of the movable portion of the vibration isolation actuator 10 as viewed from the fixed portion side, and FIG. 4 is a front view of the fixed portion with the movable portion of the vibration isolation actuator 10 removed. 2 is a cross-sectional view showing a state in which the vibration-proof actuator 10 is broken along the line II-II in FIG.

  As shown in FIGS. 2 to 4, the anti-vibration actuator 10 is supported by a fixed plate 12 which is a fixed portion fixed in the lens barrel 6, and can be translated and rotated with respect to the fixed plate 12. The movable frame 14 is a movable part, and three ceramic balls 18 are movable part support members that support the movable frame 14. Further, the vibration isolation actuator 10 includes a first drive coil 20a, a second drive coil 20b, a third drive coil 20c attached to the fixed plate 12, and each drive coil 20a, 20b of the moving frame 14. , 20c, the first driving magnet 22a, the second driving magnet 22b, and the third driving magnet 22c, which are attached to the positions corresponding to the respective windings of the driving coils 20a, 20b, and 20c, respectively. It has the 1st magnetic sensor 24a, the 2nd magnetic sensor 24b, and the 3rd magnetic sensor 24c which are the 1st, 2nd, and 3rd position detection sensors arrange | positioned.

  In addition, the vibration isolation actuator 10 includes a suction yoke 26 that is a suction member attached to the back side of the fixed plate 12 so that the moving frame 14 is attracted to the fixed plate 12 by the magnetic force of each driving magnet. The first driving coil 20a, the second driving coil 20b, the third driving coil 20c, and the first driving magnet 22a, the second driving magnet 22b, and the third driving coil, which are respectively attached to the corresponding positions. The drive magnet 22c constitutes first, second, and third drive means for driving the moving frame 14 with respect to the fixed plate 12, respectively.

  Further, as shown in FIG. 1, the vibration isolation actuator 10 detects vibration detected by the gyro 34 and positional information of the moving frame 14 detected by the first, second, and third magnetic sensors 24 a, 24 b, and 24 c. Based on the controller 36, the controller 36 is a control unit that controls the current flowing through the first, second, and third drive coils 20a, 20b, and 20c. The controller 36 includes a microprocessor, a memory, a program for operating these, and the like.

  The anti-vibration actuator 10 translates the moving frame 14 with respect to the fixed plate 12 fixed to the lens barrel 6 in a plane parallel to the imaging element surface C, whereby the lens barrel 6 vibrates. Also, the image blur prevention lens 16 attached to the moving frame 14 is moved so that the image formed on the image sensor surface C is not disturbed.

  As shown in FIGS. 2 and 3, the moving frame 14 has a generally donut plate shape, and an image blur prevention lens 16 is attached to the central opening. A cylindrical peripheral wall portion 14 a is formed around the central opening of the moving frame 14 so as to surround the image blur prevention lens 16.

  Furthermore, first, second, and third driving magnets 22a, 22b, and 22c are disposed on the moving frame 14. As shown in FIG. 3, the centers of these drive magnets are arranged on the circumference of a circle centered on the optical axis A of the image blur prevention lens 16. In the present embodiment, the second drive magnet 22b is disposed vertically below the optical axis, and the first drive magnet 22a, the second drive magnet 22b, and the third drive magnet 22c are equally spaced at a central angle. They are spaced about 120 ° apart.

  Each of the first, second, and third drive magnets 22a, 22b, and 22c is configured by arranging two generally square magnet pieces adjacent to each other. That is, the first drive magnet 22a is composed of two magnet pieces 22a1, 22a2, the second drive magnet 22b is composed of magnet pieces 22b1, 22b2, and the third drive magnet 22c is composed of magnet pieces 22c1, 22c2. Has been. Further, the adjacent sides of the substantially square magnet pieces are arranged so as to be directed in the radial direction of a circle centered on the optical axis A of the image blur prevention lens 16. Furthermore, each magnet piece is provided with a magnetization boundary line in the thickness direction as shown by a one-dot chain line in FIG. For this reason, each magnet piece is magnetized so that the back side of the S pole facing the drive coil is the N pole and the back side of the N pole facing the drive coil is the S pole.

  In the present embodiment, as shown in FIG. 3, the magnet piece 22a1 is arranged so that the north pole faces the magnet piece 22a2, and the south pole faces the first driving coil 20a. Similarly, the magnet piece 22b1 is arranged with the N pole, the magnet piece 22b2 with the S pole, the magnet piece 22c1 with the N pole, and the magnet piece 22c2 with the S pole facing the drive coil. As described above, since one set of magnet pieces constituting the first driving magnet is directed to the opposite polarity, a magnetizing boundary is also formed between the adjacent magnet pieces 22a1 and 22a2 as a magnetic pole boundary line. A line is constructed. Similarly, a magnetization boundary line is also formed between each pair of magnet pieces constituting the second and third driving magnets.

  As shown in FIGS. 2 and 4, the fixed plate 12 is a generally donut-shaped disk and is located at a position on the circumference facing the first, second, and third drive magnets 22a, 22b, and 22c. First, second, and third drive coils 20a, 20b, and 20c are arranged, respectively. The first, second, and third drive coils 20a, 20b, and 20c are wound in a generally rectangular shape with rounded corners, and one of the center lines is centered on the optical axis A. It is arranged toward the radial direction of the circle.

  The first, second, and third drive magnets 22a, 22b, and 22c apply magnetism to the rectangular first, second, and third drive coils 20a, 20b, and 20c. Thus, when a current flows through each driving coil, a driving force in the circumferential direction (a tangential direction of a circle with the optical axis A as the center) is generated between the opposing driving magnets.

  As shown in FIGS. 2 and 4, the three ceramic balls 18 are sandwiched between the fixed frame 12 and the moving frame 14, and each have a central angle of 120 ° on the circumference of a circle centered on the optical axis A. They are arranged at intervals. The fixed frame 12 is formed with a recess 30 at a position corresponding to each ceramic ball 18. Further, the moving frame 14 is formed with a recess 31 at a position corresponding to each ceramic ball 18. Each ceramic ball 18 is disposed in these recesses 30 and 31 and is prevented from falling off. Further, as will be described later, since the moving frame 14 is attracted to the fixed plate 12 by the driving magnet, each ceramic ball 18 is sandwiched between the fixed plate 12 and the moving frame 14. As a result, the moving frame 14 is supported on a plane parallel to the fixed plate 12, and each ceramic ball 18 is rolled while being held, so that translational movement and rotational movement of the moving frame 14 with respect to the fixed plate 12 are allowed. Is done. In the present embodiment, a non-magnetic ceramic ball is used. However, a steel sphere, a resin sphere, or another form of member may be used as the movable portion support member.

  As shown in FIG. 2, the suction yoke 26 has a substantially rectangular plate shape, and is attached to the back side of each driving coil of the fixed plate 12. That is, the attracting yoke 26 is attached to the side of each driving coil that does not face each driving magnet. The moving frame 14 is attracted to the fixed plate 12 by the magnetic force exerted on each attracting yoke 26 by each driving magnet. In the present embodiment, three suction yokes 26 are attached to the back side of each drive coil. A single donut plate-like yoke is provided by integrating these three suction yokes. You can also.

  As shown in FIGS. 2 and 4, a first magnetic sensor 24a, a second magnetic sensor 24b, and a third magnetic sensor 24c are arranged inside each driving coil, respectively. It is configured to measure directional displacement. Based on the signals detected by the first, second, and third magnetic sensors 24a, 24b, and 24c, the position where the moving frame 14 is translated and rotated with respect to the fixed frame 12 can be specified. In the present embodiment, a Hall element is used as the magnetic sensor.

Next, a mechanical positioning mechanism of the moving frame 14 will be described with reference to FIGS.
First, as shown in FIGS. 2 and 3, the moving frame 14 is provided with first, second, and third positioning protrusions 40a, 40b, and 40c. Each positioning protrusion is a protrusion having a circular cross section extending toward the fixing plate 12 from between two magnet pieces constituting the first, second, and third driving magnets 22a, 22b, and 22c.

  On the other hand, the fixed plate 12 is provided with first, second, and third positioning wall surfaces 42a, 42b, and 42c inside each driving coil. These positioning wall surfaces are wall surfaces extending in a direction parallel to the optical axis A of the image blur prevention lens 16 and are formed so as to surround a substantially hexagonal region.

  A first positioning projection 40a extending from between two magnet pieces constituting the first driving magnet 22a is an inner region surrounded by a first positioning wall surface 42a provided on the inner side of the first driving coil 20a. It extends to. Similarly, the second positioning projection 40b extending from the second driving magnet 22b extends into the second positioning wall surface 42b inside the second driving coil 20b and extends from the third driving magnet 22c. The protrusion 40c extends into the third positioning wall 42c inside the third drive coil 20c. Since each positioning protrusion extends to the inside of each positioning wall surface, when the moving frame 14 is moved to a predetermined position, the positioning protrusion comes into contact with the positioning wall surface, and the moving frame 14 is mechanically positioned. Is done.

Next, with reference to FIG. 5, the structure of the positioning protrusion and the positioning wall surface of the positioning mechanism will be described in detail.
FIG. 5 is a diagram illustrating a positional relationship among the driving coils, the positioning wall surfaces, and the positioning protrusions in the vibration-proof actuator 10.

  First, as described above, the first, second, and third drive coils 20a, 20b, and 20c are arranged on the circumference with the optical axis A as the center, separated by a central angle of 120 °. In FIG. 5, each driving coil is arranged on a radial axis D1, D2, D3 extending radially from the optical axis A at an interval of 120 °. Each positioning wall surface provided inside each driving coil is also provided on each of the radial axes D1, D2, and D3. Each hexagonal region surrounded by the positioning wall surfaces has a diagonal line. It is formed so as to coincide with the radiation axes D1, D2, and D3. That is, the hexagonal region surrounded by the first positioning wall surface 42a is formed so that the longest diagonal line coincides with the radial axis D1. Similarly, the longest diagonal line of the hexagonal region surrounded by the second positioning wall surface 42b matches the radial axis D2, and the longest diagonal line of the hexagonal region surrounded by the third positioning wall surface 42c and the radial axis D3 Match.

  Further, the sides extending from the apex through which the longest diagonal line of the hexagonal region enclosed by each positioning wall surface passes are directed in a direction orthogonal to other radial axes that do not pass through the hexagonal region. That is, the radial axis D1 passes through the hexagonal region surrounded by the first positioning wall surface 42a, and the sides 44a and 44c extending from the apex of the hexagonal region through which the radial axis D1 passes are directed in a direction orthogonal to the radial axis D2. Also, the sides 44b and 44d are oriented in a direction perpendicular to the radial axis D3. Similarly, sides 46a and 46c extending from the apex of the hexagonal region of the second positioning wall surface 42b through which the radial axis D2 passes are directed in a direction perpendicular to the radial axis D3, and the sides 46b and 46d are set to the radial axis D1. The direction is orthogonal to Furthermore, sides 48a and 48c extending from the apex of the hexagonal region of the third positioning wall 42c through which the radial axis D3 passes are directed in a direction perpendicular to the radial axis D1, and the sides 48b and 48d are connected to the radial axis D2. It is oriented in the orthogonal direction.

  Since each positioning wall surface is configured in this way, when the moving frame 14 is moved in the direction of any radial axis, the two positioning projections and the positioning wall surface that are not on the radial axis line are in contact with each other. The remaining one set of positioning protrusions and the positioning wall surface are not in contact with each other. Specifically, when the moving frame 14 is moved in the direction of the radial axis D1, the second positioning projection 40b and the side 46b or 46d of the second positioning wall surface 42b come into contact with each other, and the third positioning projection 40c The side 48a or 48c of the third positioning wall 42c abuts. On the other hand, since the first positioning projection 40a is moved in the longest diagonal direction (the direction of the radial axis D1), it does not contact the first positioning wall surface 42a. Similarly, when the moving frame 14 is moved in the direction of the radial axis D2, the first positioning projection 40a abuts the side 44a or 44c of the first positioning wall surface 42a, and the third positioning projection 40c 3 The side 48b or 48d of the positioning wall surface 42c comes into contact. When the moving frame 14 is moved in the direction of the radial axis D3, the first positioning projection 40a and the side 44b or 44d of the first positioning wall surface 42a come into contact with each other, and the second positioning projection 40b and the second positioning projection 40b The side 46a or 46c of the positioning wall 42b comes into contact.

  Furthermore, since the sides 46b and 46d of the hexagonal region of the second positioning wall surface 42b and the sides 48a and 48c of the third positioning wall surface 42c are oriented in a direction perpendicular to the radial axis D1, the moving frame 14 is The distance that can be moved in the direction of the radial axis D1 is always constant. That is, since each side contacting the positioning projection is directed in a direction perpendicular to the radial axis D1, the first positioning projection 40a is moved in the radial axis D1 direction while being on the radial axis D1. Even in the case where the first positioning projection 40a is moved in a state slightly shifted from the radial axis D1, the movable distance in the radial axis D1 direction is the same. Similarly, the distance that the moving frame 14 can move in the direction of the radial axis D2 and the distance that can move in the direction of the radial axis D3 are always constant. In this embodiment, each positioning wall surface is continuously formed so as to surround the entire hexagonal region, but the positioning wall surface is not continuously formed over the entire circumference. For example, a part of the positioning wall surface may be cut out in a slit shape.

  Next, the operation of the camera 1 according to the embodiment of the present invention will be described with reference to FIG. First, when the photographer turns on an activation switch (not shown) for the image blur prevention function of the camera 1, image blur prevention control by the image stabilizer actuator 10 provided in the lens unit 2 is started.

  In the image blur prevention control, the gyro 34 attached to the lens unit 2 detects vibration in a predetermined frequency band every moment and outputs it to an arithmetic circuit (not shown) built in the controller 36. The gyro 34 outputs an angular velocity signal to the arithmetic circuit, and the arithmetic circuit integrates the input angular velocity signal with time to calculate a deflection angle, and adds a predetermined correction signal to this to generate a lens position command signal. To do. By moving the image blur prevention lens 16 momentarily to the position commanded by the lens position command signal output in time series by the arithmetic circuit, the image focused on the image sensor C of the camera body 4 is stabilized. Is done.

  The controller 36 causes a current corresponding to the difference between the detection signal of each magnetic sensor and the lens position command signal in each direction to flow through each driving coil. When a current flows through each driving coil, a magnetic field proportional to the current is generated. Due to this magnetic field, the first, second, and third driving magnets 22a, 22b, and 22c arranged corresponding to the first, second, and third driving coils 20a, 20b, and 20c receive the driving force and move. The frame 14 is moved. When the moving frame 14 is moved by the driving force and each driving coil reaches the position specified by the lens position command signal, the driving force becomes zero. Further, when the moving frame 14 moves out of the position specified by the lens position command signal due to a disturbance or a change in the lens position command signal, a current is again supplied to each driving coil, and the moving frame 14 Returns to the position specified by the signal.

  By repeating the above operation every moment, the image blur prevention lens 16 attached to the moving frame 14 is moved so as to follow the lens position command signal. Thereby, the image focused on the image sensor surface C of the camera body 4 is stabilized.

Next, with reference to FIG. 5, the calibration procedure of the magnetic sensor for position measurement will be described.
Calibration of the first, second, and third magnetic sensors 24a, 24b, and 24c is performed in the manufacturing process of the camera 1 or the lens unit 2 that includes the vibration-proof actuator 10. Each magnetic sensor is configured to detect the magnetism of each driving magnet and output a predetermined electrical signal. However, variation in the output signal of the magnetic sensor with respect to the moving distance of the moving frame 14 varies due to individual differences of the magnetic sensors, individual differences of the driving magnets, errors in the mounting positions of the magnetic sensors and the driving magnets, and the like. . For this reason, in the vibration proof actuator 10 of this embodiment, the magnetic sensor is calibrated in a state where the vibration proof actuator 10 is assembled.

  Calibration of the magnetic sensor is performed based on an output signal of the magnetic sensor when the moving frame 14 is moved in a predetermined direction by a known predetermined distance. In the vibration-proof actuator 10 of this embodiment, the position of the positioning protrusion is in contact with one of the positioning wall surfaces, and based on the moving distance until the contact with the opposing positioning wall surface, Calibration is in progress.

  First, the controller 36 applies current to each driving coil to drive the moving frame 14 in the direction of the radial axis D1, and the second positioning projection 40b and the side 46b of the second positioning wall surface 42b come into contact with each other, and the third The positioning projection 40c and the side 48a of the third positioning wall surface 42c are in contact with each other. The values of the output signals of the second magnetic sensor 24b and the third magnetic sensor 24c in this state are stored in a memory (not shown) of the controller 36. Further, when the moving frame 14 is driven in the direction of the radial axis D1, the current flowing through the first driving coil 20a is such that the magnetization boundary line of the first driving magnet 22a is positioned on the first magnetic sensor 24a. Be controlled.

  Next, the controller 36 drives the moving frame 14 in the opposite direction along the radial axis D1. As a result, each positioning projection is brought into contact with the wall surface facing the positioning wall surface that has been in contact. That is, the second positioning protrusion 40b and the side 46d of the second positioning wall surface 42b come into contact with each other, and the third positioning protrusion 40c and the side 48c of the third positioning wall surface 42c come into contact with each other. In this state, the values of the output signals of the second magnetic sensor 24b and the third magnetic sensor 24c are stored again in the memory (not shown) of the controller 36.

  Here, since the distance from one side of each positioning wall surface to the opposite side and the diameter of each positioning projection are known, the distance that the moving frame 14 can move in the direction of the radial axis D1 is also known. . Based on this distance and the value of the output signal of each magnetic sensor stored in the memory (not shown) of the controller 36, the gain error, offset error, etc. of the magnetic sensor can be calibrated.

  Similarly, the controller 36 drives the moving frame 14 in the directions of the radial axes D2 and D3, and each magnetic sensor is calibrated based on the value of the output signal of each magnetic sensor detected at that time. The moving frame 14 is moved in the direction of each radial axis, and based on the output signal of each magnetic sensor in the state where each positioning projection and each positioning wall surface are in contact, the reference position for image blur prevention control is set. It can also be calculated.

  The moving frame 14 is attracted to the fixed plate 12 by a magnetic force between each driving magnet and each attracting yoke 26 arranged corresponding to the driving magnet. For this reason, even when the positioning protrusion is pressed against the positioning wall surface, the moving frame 14 can be prevented from being lifted off the fixed plate 12. That is, the positioning protrusion and the positioning wall surface that are in contact with each other are arranged between the driving magnet generating the attracting force and the attracting yoke so as to be surrounded by them. For this reason, the force component in the direction of pulling the moving frame 14 away from the fixed plate 12 generated by pressing the positioning protrusions against the positioning wall surface is effectively offset by the attracting force and prevents the moving frame 14 from being lifted. be able to.

  According to the vibration-proof actuator 10 of the embodiment of the present invention, the fixed plate 12 and the moving frame 14 are attracted by the drive magnets 22a, 22b, 22c and the suction yokes 26 disposed on the back side of each drive. Then, the movable frame 14 is positioned by bringing the positioning wall surfaces 42a, 42b, 42c provided inside the winding of the driving coil into contact with the positioning protrusions 40a, 40b, 40c. For this reason, according to this embodiment, when the positioning wall surface and the positioning projection come into contact with each other, it is possible to prevent the moving frame 14 from being lifted from the fixed plate 12 and to position the moving frame 14 with high accuracy. be able to.

  Further, according to the vibration-proof actuator 10 of the present embodiment, the positioning wall surfaces 42a, 42b, and 42c are disposed inside the windings of the driving coils 20a, 20b, and 20c, respectively, and the magnetic sensors 24a, 24b, and 24c. Are also arranged inside the windings of each driving coil (FIG. 4), so that the positioning part and the sensor for detecting the position can be arranged close to each other, and the position can be detected with high accuracy. .

  Furthermore, according to the vibration-proof actuator 10 of the present embodiment, the positioning wall surfaces 42a, 42b, 42c are provided so as to surround the magnetic sensors 24a, 24b, 24c (FIG. 4), so the positioning wall surfaces 42a, 42b , 42c is not required to be provided, and the vibration-proof actuator can be reduced in size.

  Further, according to the vibration-proof actuator 10 of the present embodiment, the positioning protrusions 40a, 40b, and 40c extend from between the two magnet pieces constituting the driving magnets 22a, 22b, and 22c (FIG. 3). The magnetization boundary line B of the driving magnet and the position of the positioning projection can be easily matched.

  As mentioned above, although preferable embodiment of this invention was described, a various change can be added to embodiment mentioned above. In particular, in the above-described embodiment, the present invention is applied to a digital camera. However, the present invention can be applied to any camera for capturing still images or moving images, such as a film camera and a video camera. The present invention can also be applied to a lens unit used with the camera body of these cameras.

  In the above-described embodiment, each driving coil is attached to the fixed plate 12 and each driving magnet is attached to the moving frame 14. However, each driving coil is attached to the moving frame 14 and each driving magnet is attached. Can also be attached to the fixed plate 12.

  Further, in the above-described embodiment, each of the driving coils 20a, 20b, and 20c and each of the driving magnets 22a, 22b, and 22c is disposed so as to surround the image blur prevention lens 16, and each of the driving magnets has an image blur. Although the magnetization boundary line B is provided so as to be directed substantially in the radial direction of the circle centered on the optical axis A of the prevention lens 16 (FIG. 3), the present invention is applied to other vibration-proof actuators. can do.

DESCRIPTION OF SYMBOLS 1 Camera of embodiment of this invention 2 Lens unit 4 Camera main body 6 Lens barrel 8 Imaging lens 10 Anti-vibration actuator 12 Fixed plate (fixed part)
14 Moving frame (movable part)
14a Surrounding wall portion 16 Image blur prevention lens 18 Ceramic ball (movable portion supporting member)
20a First drive coil 20b Second drive coil 20c Third drive coil 22a First drive magnet 22b Second drive magnet 22c Third drive magnet 24a First magnetic sensor (first position detection sensor)
24b Second magnetic sensor (second position detection sensor)
24c 3rd magnetic sensor (3rd position detection sensor)
26 Suction yoke (suction member)
30 Concave part 31 Concave part 34 Gyro 36 Controller (control part)
40a First positioning protrusion 40b Second positioning protrusion 40c Third positioning protrusion 42a First positioning wall surface 42b Second positioning wall surface 42c Third positioning wall surface

Claims (6)

An anti-vibration actuator that moves the image blur prevention lens to stabilize the image,
A fixed part;
A movable part to which the lens for preventing image blur is attached;
A movable part support member for supporting the movable part movably with respect to the fixed part;
At least three driving coils attached to one of the fixed part and the movable part;
At least three driving magnets attached to the other of the fixed portion and the movable portion so as to face these driving coils;
An attracting member that is disposed on a side of each of the driving coils that is not opposed to the driving magnet and that attracts the fixed portion and the movable portion by a magnetic force generated between the driving coils. ,
A position detection sensor for measuring the displacement of the movable part;
A positioning wall surface provided inside each of the windings of each of the driving coils, and extending in a direction substantially parallel to the optical axis of the image blur prevention lens;
Of the fixed part and the movable part, from the side where each of the driving magnets is attached, it extends toward the inside of the winding of each of the driving coils, and comes into contact with each of the positioning wall surfaces, A positioning projection for positioning the movable part;
An anti-vibration actuator comprising:   The position detection sensors are magnetic sensors arranged inside the windings of the drive coils, and the magnetic sensors detect the magnetism of the drive magnets facing each other, thereby moving the movable part. The anti-vibration actuator according to claim 1, wherein the displacement is measured.   The anti-vibration actuator according to claim 2, wherein each positioning wall surface is provided inside the winding of each driving coil so as to surround each magnetic sensor.   Each of the driving magnets facing each of the driving coils is composed of two magnet pieces, and each of the positioning protrusions is a winding of the driving coil between the two magnet pieces. The anti-vibration actuator according to any one of claims 1 to 3, wherein the anti-vibration actuator extends toward the inside. A lens unit equipped with an anti-vibration actuator,
A lens barrel;
An imaging lens disposed inside the lens barrel;
An anti-vibration actuator according to any one of claims 1 to 4,
A lens unit comprising: A camera with an anti-vibration actuator,
The camera body,
A lens unit according to claim 5;
A camera characterized by comprising:

Images