Hereafter, an embodiment of the present invention is described in more detail with reference to the drawings. The following embodiment is described by taking a camera system as optical equipment comprising a vibration reduction apparatus, as an example.
The interchangeable lens 2 has a cylindrical shape as a whole, and the end at the image side in an optical axis direction is secured to the camera body 3 detachably through a mounting portion 2a. The interchangeable lens 2 is provided with a vibration reduction apparatus 10 and a plurality of lens unit arranged on an optical axis Z (lens unit other than a blur correcting lens 20 are not shown in the figure).
In
The vibration reduction apparatus 10 corrects image blur in the photographing portion by moving the blur correcting lens 20, which is part of the photographing optical system, in a direction that counteracts image blur caused by a photographer's hand shakiness, etc., to the photographing portion (imaging element or film, not shown) in a plane perpendicular to the optical axis Z, placed in the focal plane of the photographing optical system.
As shown in
As shown in
The top plane 30b is a part formed in a flange shape by projecting from an end of one side of the optical axis direction of the sidewall 30a to the inside diameter side of the sidewall 30a. In order to facilitate the understanding of the constitution of the movable lens frame 40 described later, the top plane 30b is omitted in
Referring to
Moreover, the casing lid 33 of the vibration reduction apparatus has a notch portion 33a formed by notching a part of the peripheral portion thereof to be straight. As a result, the vibration reduction apparatus case 30 is provided with an opening 36 at the other end side thereof in the optical axis direction.
In
The movable lens frame 40 is supported to be movable in a plane perpendicular to the optical axis Z relative to the vibration reduction apparatus case 30, by a steel ball 41 placed between the movable lens frame 40 and the top plane 30b.
For example, three steel balls 41 are arranged around the optical axis at substantially equal intervals (refer to
The movable lens frame 40 is biased in the direction that approaches the top plane 30b of the vibration reduction apparatus case 30 by springs 42a and 42b. The springs 42a and 42b are extension coil springs having one end connected to the top plane 30b of the vibration reduction apparatus case 30 and the other end connected to the movable lens frame 40.
As shown in
The first slit 40a and the second slit 40b are formed to extend through the movable lens frame 40 in the thickness direction, and are rectangular holes that extend in the directions perpendicularly intersecting each other (X axis direction and Y axis direction described later, respectively).
A first slit 40a is formed near a Hall element 61x and a second slit 40b is formed near a Hall element 61y, respectively.
VCMs 50x and 50y are electromagnetic actuators which drive the blue correcting lens 20 in the directions orthogonal to two axles (hereafter referred to as X axis and Y axis) in a plane orthogonal to the optical axis Z. The VCM 50x is a motor for driving the blue correcting lens 20 along the direction of the X axis and the VCM 50y is a motor for driving the blue correcting lens 20 along the direction of the Y axis.
Hereafter, VCMs 50x and 50y, position detecting portions 60x and 60y described later, and respective elements included therein, are described by appending the sign x to the element for the direction of the X axis, and the sign y to the element for the direction of the Y axis, respectively.
The VCM 50x is arranged in such a manner that the electromagnetic force effects to the center of the blur correcting lens along the axis parallel to the X axis. The VCM 50y is arranged in such a manner that the electromagnetic force effects to the center of the blur correcting lens along the axis parallel to Y axis. In the VCMs 50x and 50y, and the position detecting portion 60x and 60y, the constitution of the elements for the X axis direction and the constitution of elements for the Y axis direction are substantially identical. Therefore, as the constitution of the VCM 50y and the position detecting portion 60y, in
The VCM 50x has a coil 51x and a magnet 52x as shown in
The coil 51x is an armature winding fixed to the movable lens frame 40.
The magnet 52x is a permanent magnet fixed to the top plane 30b of the vibration reduction apparatus case 30 in the opposed state to the coil 51x.
The VCM 50y (refer to
In
The position detecting portion 60x is arranged at the side opposite to the VCM 50x of the blur correcting lens 20, and the position detecting portion 60y is arranged at the side opposite to VCM 50y of the blur correcting lens 20.
In
The Hall element 61x is a magnetic sensor fixed to the movable lens frame 40 via an FPC 70 described later.
The magnet 62x is a permanent magnet fixed to the top plane 30b of the vibration reduction apparatus case 30 in a state opposed to the coil 61x.
The position detecting portion 60y (refer to
In the position detecting portions 60x and 60y, the Hall elements 61x and 61y detect and output the change in the magnetic field of the magnets 62x and 62y corresponds to the movement in the vibration reduction apparatus case 30 of the movable lens frame 40, and a CPU (not shown) provided in the interchangeable lens 2 calculates the distance moved of the movable lens frame 40 on the basis of the output.
In
In
As shown in
As shown in
In
As shown in
A first folding back portion 70xa is a folded portion formed by bending the X side FPC 70x, and the FPC 70x has a substantially U-shaped form viewed from the X direction. Non-fixing portions 753 and 754 provided on both sides of the substantially U-shaped portion of the FPC 70x are not secured to the casing lid 33 and the movable lens frame 40, respectively, so that the X side FPC 70x deforms so as to follow for the movement of the movable lens frame 40, in the case where the movable lens 40 moves in the Y direction shown in the figure. Therefore, even if the movable lens frame 40 moves in the Y direction shown in the figure, the frame 40 does not receive any substantial resistive force from the X side FPC 70x.
Furthermore, a first folding back portion 70xa formed by bending the X side FPC 70x is provided between the casing lid 33 and the movable lens frame 40 so that the movable lens frame 40 only receives the elastic force in a direction away from the casing lid 33 (+Z direction), from the X side FPC 70x, so that the frame 40 does not receive the resistive force in the moving direction of the movable lens frame 40 (X and Y directions).
In
Therefore, the X side FPC 70x is provided with the notch portion 71x for preventing the mount portion 70xc from being peeled off from the movable lens frame 40 by the elastic force generated from the second folding back portion 70xb.
The notch portion 71x is described in detail referring to
The notch portion 71x encloses a Hall element 61x on a mount portion 70xc of the X side FPC 70x, and is formed by cutting away a part except for the conductive pattern.
More specifically, the notch 71x is provided with a first notch 71xa, a second notch 71xb, and a third notch 71xc. The first notch 71xa is arranged between the Hall element 61x and the second folding back portion 70xb (refer to
The second notch 71xb and the third notch 71xc are respectively formed continuously at both ends of the first notch 71xa. The second notch 71xb and the third-notch 71xc are provided so as to sandwich the Hall element 61x therebetween, and extend in the longitudinal direction of the FPC 70x on the X side (Y axis direction). As a result, the notch 71x is formed in a substantially U-shaped configuration as a whole.
In the above explained camera system 1, when the release switch 4 provided to the camera main body 3 is operated, the blur detecting sensor 5 provided to the interchangeable lens 2 detects and outputs the angular velocities around the X axis and Y axis. The blur around the X axis is called pitching (Pitch) and the blur around Y axis is called yawing (Yaw) respectively, and the blur correcting action is performed, for example, by correcting image blurs cased by the blurring in the two directions.
The vibration reduction apparatus 10 performs the correction control for a well-known image blur in such a manner that the CPU (not shown) calculates a driving direction and driving amount of a blur correcting lens 20 on the basis of the output of a blur detecting sensor 5, and the VCMs 50x and 50y are controlled according to the calculated result, thereby driving the blur correcting lens 20.
According to the vibration reduction apparatus 10 of the present embodiment, the following effects can be obtained.
(1) In the vibration reduction apparatus of the present embodiment, as shown in
Thus, the restoring force of the FPC 70 acts in a direction orthogonal to the direction of the relative movement to the vibration reduction apparatus case 30 of the movable lens frame 40, therefore the VCM 50 does not become a resistor in a case of driving the movable lens frame 40 in the plane perpendicular to the optical axis of the casing lid 33 of the vibration reduction apparatus. As a result, the blur correction precision of the vibration reduction apparatus 10 can be improved.
(2) For example, in a case of driving the movable lens frame 40 in the direction of X the axis by the VCM 50x, a force acts on the Y side FPC 70y in a direction orthogonal to the longitudinal direction of the FPC 70y. The Y side FPC 70y is made to twist by the force, however, for example, the restorative force against the twist of the FPC is small to the extent that can be substantially disregarded, compared with the restorative force in a case of restoring the bent FPC to its original shape. Therefore, the restorative force does not become a resistor in a case of driving the movable lens frame 40 in the vibration reduction apparatus case 30.
(3) The direction of the restoring force of the X side FPC 70x and the Y side FPC 70y is the same as the direction of the biasing of the movable lens frame 40 by the spring 42 (42a, 42b) so that the biasing of the movable lens frame 40 by the spring 42 is not hindered by this restoring force. Thus, in the vibration reduction apparatus 10, the restoring force of the X side FPC 70x and the Y side FPC 70y act in the direction that the movable lens frame 40 approaches the top plane 30b, so that the spring 42 can be constituted by using a spring with little elastic force. In some instances, the spring 42 can be omitted.
(4)
A vibration reduction apparatus 110 of the comparison embodiment is different from the vibration reduction apparatus 10 of the embodiment of the present invention in the point that the mount portion 170xc is not provided with the notch portion 71x (refer to
In the vibration reduction apparatus 10 of the embodiment shown in
Here, the restoring force that the FPCs 70x and 170x trying to restore to an original shape acts in the direction that the mount portions 70xc and 170xc of the FPC 70x and FPC 170x, respectively, are detached from the plane of the movable lens frame 40. This force acting to detach the mount portions 70xc and 170xc from the movable lens frame 40, becomes large as the second folding back portions 70xb and 170xb get closer.
In vibration reduction apparatus 110 of the comparison embodiment shown in
In a case of the FPC 170x is detached from the movable lens frame 40, the position of the Hall element 61x relative to the movable lens frame 40 changes, and there is a possibility that the calculation of the moving distance of the movable lens frame 40 relative to the vibration reduction apparatus case 30 can not be performed accurately.
On the contrary, in the vibration reduction apparatus 10 of the embodiment shown in
Furthermore, as shown in
Moreover, in
As a result, the position relative to the movable lens frame 40 of the Hall element 61x becomes stable, and the moving distance of the movable lens frame 40 relative to the vibration reduction apparatus case 30 can surely be calculated. The above effect can be said for the Hall element 61y shown in
The present invention is not limited to the above explained embodiment, various changes and modifications are made possible, and these are also being within the technical scopes of the present invention.
(1) In the vibration reduction apparatus of the present embodiment, the FPC 70x is fixed to the movable lens frame 40 at two places of the fixing portion 751 and the fixing portion 752, as shown in
(2) As shown in
(3) The optical equipment of the embodiment is a camera system, but the optical equipments are not limited thereto, and may be binoculars, a telescope, a microscope, etc. Moreover, the vibration reduction apparatus according to the present invention may have been prepared for in electronic equipment including optical equipments such as portable telephones including a picture imaging function.
(4) The vibration reduction apparatus of the present embodiment moves the blur correcting lens on a plane perpendicular to the optical axis, but the present invention is not limited thereto, and the vibration reduction apparatus may be so constituted to move, for example, the imaging element such as a CCD or the like in the plane perpendicular to the optical axis, thereby correcting the image blur.
(5) The notch portion of the embodiment is formed so that the second notch and the third notch are orthogonal to the first notch, but it is not limited to thereto, as long as the notch is formed at the outer side of the Hall element and, for example, the boundary of these notches may be made in a curved shape. Moreover, these notches may not be a straight shape.
(6) In the vibration reduction apparatus of the embodiment, the Hall element is mounted on the mount portion, but the electronic part of the Hall element or the like, which control the relative movement of such a first member and second member may be mounted to, for example, other parts of the wiring board. In this case, the packaging area of electronic parts increases.
Number | Date | Country | Kind |
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2006-262411 | Sep 2006 | JP | national |
2006-262433 | Sep 2006 | JP | national |