JP2012145661A - Image blurring correcting device and optical apparatus - Google Patents

Abstract

An image blur correction apparatus that corrects image blur by moving a shift moving frame 21 that holds a third lens unit L3 is provided to prevent a ball receiving member from being displaced due to an impact. And a shift base 22 fixed to the shift movement frame, each inserted into the ball holder portion 22a and disposed between the shift movement frame and the shift base for shift movement. Three balls 26 that guide the movement of the frame, a ball receiving member 33 that is detachably provided in the ball holder portion through the opening, and a restriction that restricts movement of the ball receiving member in the optical axis direction A portion 22d and an FPC presser fitting 32 that closes the opening.
[Selection] Figure 1

Description

  The present invention relates to an image blur correction apparatus and an optical apparatus (video camera, digital still camera, TV camera, binoculars, etc.).

  2. Description of the Related Art Image blur correction apparatuses that correct image blur by moving a movable frame holding a correction lens in a digital camera in a direction perpendicular to the optical axis are known. In Patent Document 1, a ball is provided between a movable frame having a convex cross section and a fixed frame having a concave shape, and a U-shaped sheet metal (ball receiving member) is disposed between the ball and the concave portion of the fixed frame. Yes. The movement of the movable frame is guided by the rotation of the ball, and the dent on the receiving surface of the fixed frame is prevented by the sheet metal.

JP 2006-350157 A

  However, in the configuration of Patent Document 1, the ball receiving member sometimes floats and gets caught in the hole due to an impact.

  Accordingly, the present invention is to provide an image blur correction device that prevents the ball receiving member from being displaced due to an impact, and an optical apparatus having the image blur correction device.

  An image blur correction apparatus according to the present invention is an image blur correction apparatus that corrects an image blur by moving a movable frame that holds a correction lens in a direction perpendicular to the optical axis of an optical apparatus. A fixed frame that is fixed to the movable frame and has an opening that is connected to at least one of the three holes and opens in a direction different from the optical axis direction. And three balls inserted between the movable frame and the fixed frame and guiding the movement of the movable frame, and detachably attached to the fixed frame through the opening. A ball receiving member that is provided in the hole portion and contacts the ball; a restricting portion that restricts movement of the ball receiving member in the optical axis direction; and the opening portion is closed to close the opening from the hole portion of the ball receiving member. And a retaining member for preventing falling off. To.

  ADVANTAGE OF THE INVENTION According to this invention, the image blurring correction apparatus which prevents that a ball | bowl receiving member slip | deviates by an impact, and an optical apparatus which has it can be provided.

It is sectional drawing of the ball holder part of the image blurring correction apparatus of this embodiment. It is sectional drawing of the lens barrel provided with the image blurring apparatus. FIG. 3 is an exploded perspective view of the lens barrel of FIG. 2. FIG. 3 is an exploded perspective view of the shift unit shown in FIG. 2. It is a perspective view at the time of incorporating a ball receiving member. It is sectional drawing of the ball holder part seen from the direction different from FIG.

  FIG. 1 is a cross-sectional view of the vicinity of a ball receiving portion of the image blur correction device of the present embodiment, FIG. 2 is a cross-sectional view of a lens barrel provided with an image blur device, and FIG. 3 is an exploded perspective view. The photographing optical system is a variable magnification optical system (zoom lens system) configured by four lens units of convex, concave, convex, and convex in order from the object side (left side of each figure) along the optical path.

  L1 is a first lens unit, L2 is a second lens unit that performs a zooming action by moving in the optical axis direction, and L3 is a plane that is substantially orthogonal to the optical axis AXL (see FIG. 2) (hereinafter, optical axis orthogonal). And a third lens unit that performs an image blur correction action. L4 is a fourth lens unit that performs focus adjustment by moving in the optical axis direction.

  The first group lens L1 is held by the fixed front lens barrel 1, the second group lens L2 is held by the second group moving frame 2, the third group lens L3 is held by the shift unit 3, and the fourth group lens L4. Is held by the fourth group moving frame 4. Behind the fourth group moving frame 4 is provided a CCD holder 5 to which an image pickup device such as a CCD is fixed. The front lens barrel 1 is screwed to the front fixed barrel 6, and the CCD holder 5 and the front fixed barrel 6 are screwed to the rear fixed barrel 7.

  The second group moving frame 2 positioned and fixed by the front fixed cylinder 6 and the rear fixed cylinder 7 is supported by the guide bars 8 and 9 so as to be movable in the optical axis direction. 11 is supported so as to be movable in the optical axis direction. The shift unit 3 is positioned with respect to the rear fixed cylinder 7 and is fixed by two screws. The aperture device 12 is disposed in the third group lens L3.

  The fourth group lens L4 is driven in the optical axis direction by a voice coil motor 13, and the voice coil motor 13 includes a magnet 13a, yokes 13b and 13c, and a coil 13d. In the voice coil motor 13, the yoke 13b is press-fitted and fixed to the rear fixed cylinder 7, and the magnet 13a and the yoke 13c are fixed to the yoke 13b by magnetic force. By passing a current through the coil 13d, a Lorentz force is generated in the coil 13d, and the coil 13d can be driven in the optical axis direction. The coil 13d is fixed to the fourth group moving frame 4, and the fourth group moving frame 4 is driven in the optical axis direction by driving the coil 13c.

  The zoom motor 14 is fixed to the rear fixed cylinder 7 with three screws, and the second lens unit L2 is driven in the optical axis direction by the zoom motor 14 to perform a zooming operation. The zoom motor 14 has a lead screw 14a coaxial with the rotating rotor. The lead screw 14a meshes with a rack 2a provided on the second group moving frame 2, and the second group lens L2 is rotated by the rotation of the rotor. Driven in the optical axis direction.

  The photo interrupter 15 optically detects the movement of the oblique light portion 2c formed in the second group moving frame 2 in the optical axis direction, and a zoom for detecting that the second group lens L2 is located at the reference position. Used as a reset switch.

  The optical sensor 16 fixed to the rear fixed cylinder 7 is composed of a light emitting part and a light receiving part, irradiates light emitted from the light emitting part to a scale 17 bonded and fixed to the fourth group moving frame 4, and receives reflected light as a light receiving part. , The absolute position of the fourth lens unit L4 is detected.

  The image blur correction apparatus moves a shift moving frame (movable frame) 21 that holds a third lens unit L3 that is a correction lens in a direction perpendicular to the optical axis AXL of an optical apparatus (a digital camera in this embodiment). Correct image blur.

  FIG. 4 is an exploded perspective view of the shift unit 3. In addition, although the actuator and position sensor for the pitch direction and the actuator and position sensor for the yaw direction are arranged so as to form an angle of 90 degrees with each other, since the configuration itself is the same, only the pitch direction is described below. explain. Note that the suffixes p and y of the reference numerals of the members indicate the pitch direction and the yaw direction.

  In the shift unit 3, a shift moving frame 21 that is a movable frame, a shift base 22 that is a fixed frame fixed to the movable frame, a metal plate 23, and a magnet base 24 are arranged.

  The shift moving frame 21 holds the third lens unit L3 and is displaced in a direction perpendicular to the optical axis in order to further correct shake. The magnet base 24 is integrally coupled and fixed by screws in a state where the metal plate 23 is sandwiched between the shift moving frame 21. As the material of the metal plate 23, stainless steel or the like is suitable.

  A magnet 25p serving both for driving and for position detection is press-fitted and held in the magnet base 24. By inserting the magnet 25p into the magnet base 24 and incorporating it, the relative positional relationship between the magnet base 24 and the magnet 25p does not shift after incorporation. For this reason, the position of the magnet 25p, which also serves as a position detection function, is fixed at a fixed position with respect to the shift movement frame 21, and the position of the third group lens L3 can be accurately detected by the magnet 25p.

  Between the shift base 22 and the shift moving frame 21 (magnet base 24), three balls 26 for guiding the movement of the shift base 22 are arranged around the optical axis in the plane orthogonal to the optical axis.

  The shift base 22 is formed with ball holder portions 22a and 22b as three holes into which the balls 26 are inserted. Each of the ball holder portions 22a and 22b opens in the optical axis direction. A plate-shaped ball receiving member 33 is disposed on the ball holder portion 22a. In the present embodiment, the ball receiving member 33 is disposed only on the ball holder portion 22a, but may be disposed on the ball holder portion 22b. The ball receiving member 33 is detachably provided on the ball holder portion 22a through the opening 22c and contacts the ball 26.

  Next, the actuator that drives the magnet base 24 and the shift unit 3 will be described. The magnet 25p is two-pole magnetized in the radial direction from the optical axis A, the front yoke 28p is attracted and fixed to the magnet 25p, and closes the magnetic flux on the front side in the optical axis direction of the magnet 25p.

  An electromagnetic coil 29p is bonded and fixed to the shift base 22, and the rear yoke 27p is for closing the magnetic flux on the rear side in the optical axis direction of the magnet 25p. The rear yoke 27p is disposed on the opposite side of the magnet 25p with the electromagnetic coil 29p interposed therebetween and is held by the shift base 22. A magnetic circuit is formed by the magnet 25p, the front yoke 28p, the rear yoke 27p, and the electromagnetic coil 29p. Yes.

  This magnetic circuit is a so-called moving magnet type actuator. When a current is passed through the electromagnetic coil 29p, a Lorentz force is generated in the direction substantially perpendicular to the magnetizing boundary of the magnet 25p due to the repulsion between the magnetic lines of force generated in the magnet 25p and the electromagnetic coil 29p. Move in the direction.

  Since the actuator having such a configuration is arranged in the vertical direction and the horizontal direction with respect to the third lens unit L3, the third lens unit L3 can be driven in two optical axis orthogonal directions that are substantially orthogonal to each other. it can. The third lens unit L3 can be freely moved within a predetermined range in the plane orthogonal to the optical axis by combining the driving in the vertical direction and the horizontal direction, that is, the pitch direction and the yaw direction.

  The position of the third lens unit L3 is detected by a hall element (detection means) 30p. The hall element 30p converts the magnetic flux density into an electric signal, and the electric signal is transmitted by an FPC (flexible printed circuit board) 31. The Hall element 30p is soldered to the FPC 31, and the FPC 31 is positioned and fixed with respect to the shift base 22. By fixing the FPC presser fitting 32 to the shift base 22 with screws, the FPC 31 is fixed, the FPC 31 is prevented from floating, and the position of the Hall element 30p is prevented from shifting.

  When the third lens unit L3 is driven in the vertical direction or the horizontal direction, a change in magnetic flux density is detected by the Hall element 30p, and an electrical signal indicating the change in magnetic flux density is output from the Hall element 30p. Based on the electrical signal from the hall element 30p, the position of the third lens unit L3 can be detected. The magnet 25p is a drive magnet and is also used as a position detection magnet.

  Next, a method for assembling the ball holder portion and the ball receiving member in the present embodiment will be described with reference to FIGS. 1 is a cross-sectional view of the ball holder portion 22a, FIG. 5 is a perspective view when the ball receiving member 33 is assembled, and FIG. 6 is a cross-sectional view of the ball holder portion 22a viewed from a direction different from FIG. .

  An opening 22c is provided on the outer side surface of the ball holder 22a. The opening 22c is connected to at least one of the three holes and opens in a direction different from the optical axis direction. Just do it. The ball receiving member 33 is disposed on the ball holder portion 22 through the opening 22c. Thereafter, the FPC 31 and the FPC presser fitting 32 are fixed to the shift base 22. As shown in FIG. 6, the FPC pressing metal fitting 32 closes the opening 22 c and prevents the ball receiving member 33 from falling off the shift base 22.

  1 and 6 are sectional views of the ball holder portion 22a. The shift base 22 and the magnet base 24 are urged by an attractive force acting between the magnet 25p and the rear yoke 27p made of a magnetic member.

  Due to the urging force, the ball 26, the metal plate 23, and the ball receiving member 33 come into contact in a pressed state. Further, due to the urging force, the ball receiving member 33 is pressed against the bottom surface of the ball holder and is fixed, so that it does not need to be bonded and the contact surface with the ball 26 does not tilt.

  Reference numeral 22d denotes a restricting portion that restricts the movement of the ball receiving member 33 in the optical axis direction by narrowing the hole diameter perpendicular to the optical axis direction of the ball holder portion 22a. The restricting portion has a slight clearance of about 0.3 mm from the surface of the ball receiving member so as not to interfere when the ball receiving member 33 is inserted. When receiving an impact, the ball receiving member 33 is lifted only by the clearance and is restricted by the restricting portion 22d, so that it does not get caught in the hole. In the present embodiment, the ball receiving member 33 has a plate shape, so that the cost can be reduced.

  The shape of the ball receiving member 33 is not limited, and may be U-shaped as in the past. Further, the restricting portion 22d does not have to be a protrusion fixed or formed on the fixed portion so as to narrow the hole diameter in the optical axis direction of the ball holder portion 22a that is a hole. For example, a convex portion is provided on the bottom surface of the ball receiving member 33, a concave portion is provided on the receiving surface of the hole portion, and the convex portion and the concave portion are engaged like a rail.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  The optical apparatus can be applied to an application for observing or capturing an image.

L3 Third lens unit (correction lens)
21 Shift movement frame (movable frame)
22 Shift base (fixed frame)
22a Ball holder (hole)
22c Opening 22d Restriction part 26 Ball 32 FPC presser fitting (Retaining member)
33 Ball receiving member

Claims (4)

An image blur correction device that corrects image blur by moving a movable frame that holds a correction lens in a direction perpendicular to the optical axis of an optical instrument,
Three holes opened in the optical axis direction and an opening connected to at least one of the three holes and opened in a direction different from the optical axis direction; A fixed frame fixed by
Three balls inserted into the hole and disposed between the movable frame and the fixed frame to guide the movement of the movable frame;
A ball receiving member which is provided in the hole of the fixed frame so as to be detachable through the opening and is in contact with the ball;
A restricting portion for restricting movement of the ball receiving member in the optical axis direction;
A retaining member that closes the opening and prevents the ball receiving member from falling off the hole;
An image blur correction apparatus comprising:   The image blur correction apparatus according to claim 1, wherein the opening is on a side surface of the fixed frame perpendicular to the optical axis direction. The image blur correction device includes:
Detecting means for detecting the position of the correction lens;
A flexible printed circuit board for transmitting an electrical signal detected by the detection means;
Further comprising
The image blur correction device according to claim 1, wherein the retaining member is a metal fitting that fixes a flexible printed circuit board to the fixed frame.   An optical apparatus comprising the image blur correction device according to claim 1.