JP4080230B2 - Image blur prevention device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical image stabilizer, and more particularly to a structure of an image shake preventer installed in a lens barrel in order to correct image vibration.
[0002]
[Prior art]
The mechanism that moves some of the correction lenses that make up the photographic lens in the direction perpendicular to the optical axis predicts image blur, for example, by detecting the camera shake acceleration that causes image blur in the camera. Based on the above, a vibration isolator that suppresses image blur by moving the lens in a direction perpendicular to the optical axis has been proposed and commercialized.
[0003]
Various methods have been proposed for these anti-vibration devices. However, as described above, depending on the photographing posture of the photographer, it is not a mechanism that can move the correction lens in a direction perpendicular to the optical axis in any direction. For example, as shown in Japanese Patent Laid-Open No. 10-26783, guide shafts 12a are provided radially from three locations on the side surface of the correction lens frame in order to correct image blur, and provided on the side surface of the vibration isolator main body. A system is proposed in which each of the three guide grooves 13a is inserted and the amount of movement and direction perpendicular to the optical axis is determined by the combined force of the moving coils 16y and 16p for movement in the X and Y directions. Although it has been proposed to reduce the contact resistance during movement by installing a roller on the guide shaft 12a, the guide shaft 12a including the roller in the guide groove 13a is improved in order to improve accuracy. If the error is suppressed as little as possible, the moving load increases, and depending on the direction, when a combined force perpendicular to the rotation direction of the roller acts, the roller surface and the guide groove surface show a large frictional resistance, and the moving load is There is a problem that the movement speed is delayed depending on the optical axis movement direction of the correction lens, and the accurate function of the image blur prevention device cannot be exhibited.
[0004]
[Problems to be solved by the invention]
In view of the above problems, there is a demand for a mechanism that can move the correction lens more lightly and with high accuracy in any direction. The cause of the variation in the movement of the correction lens is that the frictional resistance factor is greatly related to the holding structure of the correction lens. Therefore, it is necessary to reduce the frictional resistance.
[0005]
[Means for Solving the Problems]
In the conventional mechanism, the surface holding structure in the guide groove is modified so that the correction lens can be moved in a plane perpendicular to the optical axis, and the correction lens is supported by a single hinge shaft installed parallel to the optical axis. The lens can be tilted in all directions, allowing the correction lens to move.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the best embodiment of the present invention will be described with reference to the drawings.
[0007]
1 shows an embodiment of a correction lens moving mechanism in a vibration isolator to which the present invention is applied, FIG. 2 is a sectional view of the structure of an omnidirectional hinge, and FIG. 3 shows a state in which the hinge shaft is tilted in all directions. . FIG. 4 shows how the hinge shaft tilts and the correction lens moves. FIG. 5 is an exploded perspective view of a practical product.
[0008]
The moving mechanism of the correction lens 2 in the image blur prevention device shown in FIG. 1 is movable inside the holding frame 3 on the fixed side of the lens barrel so as to be substantially perpendicular to the optical axis 1 and in all directions. A partially ring-shaped movable frame 6 is installed between the correction lens 2 and the holding frame 3, and the movable frame 6 has two support portions 7 that support the Y guide shaft 8. In between, two support arms 5 fixed on one side of the support frame 4 of the correction lens 2 are installed so as to penetrate the Y guide shaft 8. This means that the correction lens 2 can slide in the Y direction with respect to the movable frame 6 and can rotate about the Y guide shaft 8.
[0009]
There are two similar support portions 9 at a position just 90 ° away from the two support portions 7 installed on the movable frame 6, and the shaft is arranged on a part of the arc on the inner periphery of the holding frame 3 on the fixed side. The movable frame 6 is slidable in a direction different from the Y guide shaft 8 by 90 ° with respect to the fixed-side holding frame 3 and rotates around the X guide shaft 10. It has a possible structure.
[0010]
Next, the support frame 4 that supports the correction lens 2 has a flange 11 as shown in the figure, and a Y drive coil 12 and an X drive coil 14 that are oriented 90 degrees different from each other about the correction lens 2. Two magnets 13 fixed and fixed to a yoke 16 installed on the holding frame 3 of the main body are opposed to the Y drive coil 12, and the other two magnets 15 are opposed to the X drive coil 14, and each coil is sandwiched between them. If the yoke 17 is installed, a magnetic path is formed, and if the X drive coil 14 is energized, it can move in the X direction, and if the Y drive coil is energized, it can move in the Y direction, and the X drive coil 14 and the Y drive coil 12 have a current direction. And the amount of current can be moved in all directions.
[0011]
The correction lens 2 is supported by the X guide shaft 10 through the movable frame 6 with respect to the holding frame 3 of the main body, and a Y drive coil 12 fixed to the flange 11 of the correction lens 2 as shown in FIG. An A hinge bearing 18 is fixed at the crossing position of the X drive coil 14 and is supported by a hinge shaft 20 received by the A hinge bearing 18 and a B hinge bearing 19 fixed to the holding frame 3 of the main body.
[0012]
Next, the hinge structure, which is a feature of the present invention, will be described in detail. The moving-side A hinge bearing 18 and the fixed-side B hinge bearing 19 of the correction lens 2 have the same structure and are representatively shown in FIG. Both ends 20a and 20b of the shaft 20 are spherical, and the A hinge bearing 18 and the B hinge bearing are composed of two parts. The A hinge bearing 18 comprises a hinge shaft 20 side plate 18a and an outer plate 18b, and the B hinge bearing 19 comprises a hinge shaft 20 side plate 19a and an outer plate 19b, and the plates 18a and 18b of the A hinge bearing 18 include In order to hold the spherical end 20a of the hinge shaft 20 in the center, straight or partially spherical chamfered taper holes 18c and 18d are formed on the opposite side of the hole, and the plates 19a and 19b of the B hinge bearing 19 are hinged in the center. Tapered holes 19c and 19d are formed on the opposite side of the hole to hold the other spherical end 20b of the shaft 20, and the A hinge bearing 18 is replaced with the plates 18a and 18b by the spherical end 20a of the hinge shaft 20 and the B hinge bearing. Reference numeral 19 denotes plates 19a and 19b in which a spherical end 20b of the hinge shaft 20 is sandwiched between the chamfered sides of both parts as shown in the figure and fixed in a sandwich shape.
[0013]
FIG. 3 shows a hinge operation that can be tilted in all directions. The spherical surface of the end 20a of the hinge shaft 20 has tapered holes 18c and 18d of the plates 18a and 18b of the A hinge bearing 18 and the ends 20b of the hinge shaft 20. The spherical surface has a configuration in which the tapered holes 19c and 19d of the plates 19a and 19b of the B hinge bearing 19 are in contact with each other, the hinge function is provided at both ends of the hinge shaft 20, and the terminals 20a and 20b are connected to the A hinge bearing 18 and the B hinge bearing. It is not supplemented by. In this manner, in the tilting operation of the hinge shaft 20, the contact resistance of the spherical terminal is extremely suppressed, and the hinge operation becomes extremely smooth.
[0014]
Next, the actual operation will be described. When the image shake prevention mode is set, the vibration direction and the magnitude are calculated based on the signal obtained from the vibration detection by the vibration detection means not shown in the lens barrel. A drive current is output to the X drive coil 14 and the Y drive coil 12. When a current in a certain direction flows in the X drive coil 14, a thrust in the first direction is generated in the X drive coil 14 by the action of the magnetic lines of force between the magnet 15 and the yoke 17. If there is a reverse current, thrust is generated in the plus direction if there is a reverse current, and the supporting portion 9 of the movable frame 6 is moved from the support arm 5 of the support frame 4 through the Y guide shaft 8 together with the correction lens 2 to the X direction. It slides along the guide shaft 10.
[0015]
Next, when a current is output to the Y drive coil 12, a thrust in the second direction perpendicular to the first direction is generated in the Y drive coil 12 by the action of the magnetic lines of force between the magnet 13 and the yoke 17. However, if this is outside the optical axis 1, a thrust is generated in the plus direction, and if it is a reverse current, a thrust is generated in the minus direction on the inside, and the support arm 5 of the support frame 4 is attached to the movable frame 6 along with the correction lens 2. It slides according to the Y guide shaft 8 pivoted on the support portion 7.
[0016]
Since the other direction is obtained by the combined vector of the first and second directions, the X driving coil 14 and the Y direction are detected by the moving direction and moving amount detecting means (not shown). This is obtained by controlling the current output to the drive coil 12.
[0017]
For the sake of simplicity, FIG. 4 shows the operation in the first direction caused by the current passed through the X drive coil 14, but FIG. 4 (I) shows the optical axis of the correction lens 2 in the normal state outside the operation. Is aligned with the optical axis 1 of the lens barrel. The correction lens 2 and the support frame 4 are supported by the hinge shaft 20 received by the A hinge bearing 18 and the B hinge bearing 19 with respect to the holding frame 3 on the fixed side, and the other through the support portion 9 of the movable frame 6 from the Y guide shaft 8. The X frame is supported by an X guide shaft pivoted on the holding frame 3.
[0018]
Now, when a current flows through the X drive coil 14 and a thrust is applied in a direction toward the optical axis 1, that is, a downward direction as shown in FIG. 4 (II), it moves from a point n on the hinge shaft 20 toward p. Therefore, the hinge shaft 20 is tilted so that the spherical end 20b of the A hinge bearing 18 rotates counterclockwise with the spherical end 20b as a fulcrum, and the support arm 5 and the Y guide shaft 8 move downward in the direction of the arrow. However, the correction lens 2 and the support frame 4 move around the Y guide shaft 8 while rotating to the right by a small angle.
[0019]
Further, when an upward thrust as shown in FIG. 4 (III) is exerted by the current flowing through the X drive coil 14, the point n on the hinge shaft 20 moves toward q, so the hinge shaft 20 has a spherical end 20b. The spherical end 20a of the A hinge bearing 18 is tilted so as to rotate clockwise in the arc shape with the fulcrum as a fulcrum, and the support arm 5 and the Y guide shaft 8 are corrected around the Y guide shaft 8 while moving upward in the direction of the arrow. The lens 2 and the support frame 4 move while rotating to the right by a small angle.
[0020]
As described above, FIG. 4 considered the operation in the first direction acting on the X drive coil 12, but the same applies to the operation in the second direction acting on the Y drive coil 12. The correction lens 2 and the support frame 4 move while rotating to the right by a small angle, and the correction lens 2 and the support frame 4 are rotated by a small angle to the right even when the first and second directions are combined. Although there is a phenomenon, in the maximum movements X1 and X2, the slight inclination in the right direction of the optical axis of the correction lens 2 is caused by the shift amount of the correction lens 2, the length of the hinge shaft 20, and the fixed position of the B hinge bearing 19 Although it is determined by the distance up to 8, it can be neglected in terms of image blur prevention performance because it can be suppressed to a very small amount with respect to the shift amount necessary for substantial correction.
[0021]
In the above description, the structure of the hinge shaft 20, the A hinge bearing 18, and the B hinge bearing 19 can be considered in various ways, and the spherical ends 20a and 20b may be combined with each other in terms of the manufacturing method of the hinge shaft 20. 2 is integrated with the spherical shafts 20a and 20b, the shaft-side plates 18a and 19a of the A hinge bearing 18 and the B hinge bearing 19 are inserted into the hinge shaft 20. Needless to say, must be divided in two with respect to the center.
[0022]
As described above, according to the present invention, in the movement of the optical axis of the correction lens 2 to prevent image blurring, the X-guide shaft 10 and the Y-guide shaft 8 slide and the hinge shaft 20 tilts as well as the A-hinge bearing 18 and the B-hinge. Since the spherical ends 20a and 20b of the hinge shaft 20 are rolled inside the A hinge bearing 18 and the B hinge bearing 19 so that the bearing 19 is kept substantially parallel, extremely reliable and light operation is guaranteed. Become.
[0023]
In the above description, with respect to the tilting operation of the hinge shaft 20 shown in FIG. Alternatively, it has been described that the support arm 5 slides with a slight rotation of the Y guide shaft 8. However, since this rotation slide can be simplified to only one of X and Y, an example of an exploded view of a practical product is shown. This will be described briefly. A guide receiver 32 is installed in the holding frame 30 at a position opposite to the yoke 16 with the optical axis 1 as the center. As shown in the drawing, an X driving pair magnet 15 and a Y driving pair magnet 13 are fixed to the yoke 16 as shown in the figure, and another yoke 17 maintaining a certain distance is provided to these magnets. It is fixed and forms a magnetic circuit. At one end of one guide receiver 32, a support portion 33 and a rack (straight gear) 34 are provided.
[0024]
A support frame 31 of an image blur correction lens is installed so as to be inserted into a gap formed by the magnets 13 and 15 and the yoke 17 in the yoke 16, and the X drive coil 14 arranged at a right angle on the support frame 31. The Y drive coil 12 is provided, and a hinge bearing tray 36 is provided at the center thereof. Guide bearings 35 are installed at opposing positions with the optical axis 1 in between, and guide holes 35a and 35b in which the guide shaft 37 can slide are formed at both ends.
[0025]
The support frame 31 is supported by the hinge shaft 20 so that the support frame 31 can move in all directions approximately perpendicular to the optical axis 1, but this structure is the same as that described in the mechanism of FIG. Both terminals 20a and 20b are spherical and are received by an A hinge bearing 18 and a B hinge bearing 19. The structure of the hinge shaft 20, the A hinge bearing 18, and the B hinge bearing 19 is as shown in FIG. 2, and the A hinge bearing 18 has a plate 18a having a tapered hole 18c and a tapered hole 18d (hidden invisible). The B hinge bearing 19 is constituted by a plate 19b having a tapered hole 19c (hidden and invisible) and a plate 19b having a tapered hole 19d. It is configured and received with the other spherical terminal 20b sandwiched therebetween.
[0026]
The hinge shaft 20 passes through the holding frame 30 and the support frame 31, the A hinge bearing 18 is fixed to the hinge bearing tray 36 of the support frame 31, and the other B hinge bearing 19 is a component pressing plate from the back side of the holding frame 30. 39 is fixed to the holding frame 30 together. Thus, one side of the support frame 31 is supported by the holding frame 30 by the hinge shaft 20.
[0027]
The guide bearing 35 at a position facing the hinge bearing tray 36 of the support frame 31 is received between both support portions 33 of the guide receiver 32 on the holding frame 30, and is guided from the elongated hole 33 a of the support portion 33 by the guide shaft 37. The guide pin 35 passes through the guide holes 35 a and 35 b and passes through the other elongated hole 33 b of the support portion 33. The right pinion 38 a and the left pinion 38 ba of the pinion 38 are fixed to both ends of the guide shaft 37. The pinion 38 is engaged with the rack 34 of the guide receiver 32, the right pinion 38a is engaged with the right rack 34a, and the left pinion 38b is engaged with the left rack 34b. When the pinion 38 rolls on the top, it can move vertically without being twisted.
[0028]
The X drive coil 14 and the Y drive coil 12 on the support frame 31 supported by the hinge shaft 20 and the guide receiver 32 are magnetized by the magnet pairs 13 and 15 of the yoke 16 fixed to the holding frame 30 and the upper yoke 17. Since it is configured to be at an intermediate position in the gap of the road, when current is passed through the X drive coil 14 and the Y drive coil 12, a driving force is generated by electromagnetic action. It can be moved. 5 is moved by the driving force when the guide shaft 37 penetrating the guide bearing 35 of the support frame 31 rolls on the rack 34 by the rotation of the pinion 38, and the guide bearing 35 moves up and down. When sliding up and down, the support frame 31 moves in all directions without rotation components by combining the rotation of the pinion 38 and the sliding motion of the guide bearing 35 on the guide shaft 37. You can move to.
[0029]
In the example of FIG. 5 as well as the mechanism of FIG. 1, the single-support hinge shaft 20 tilts with respect to the omnidirectional movement of the support frame 31, and as shown in FIG. A slight rotation occurs with the guide shaft 37 as an axis, but it is negligible in terms of performance, and a mechanism with a high degree of superiority from the viewpoint of operational efficiency such as simplicity of the configuration of the image shake prevention device and reduction of moving friction. realizable.
[0030]
【The invention's effect】
The surface holding structure in the guide groove is modified so that the correction lens can be moved in a plane perpendicular to the optical axis, and the correction lens is supported by a single hinge shaft installed parallel to the optical axis, and the axis is tilted in all directions. Due to the possible structure, an image blur prevention device that can move the correction lens more easily and with high accuracy in any direction was obtained. The correction lens movement variation is caused by the correction lens holding structure, but the structure that reduces the frictional resistance enables the movement of the correction lens with less frictional resistance, delaying the moving speed, and image blur prevention device. Can demonstrate the exact function of
[Brief description of the drawings]
FIG. 1 is a perspective view of a correction lens moving mechanism in a vibration isolator to which the present invention is applied.
FIG. 2 is a structural cross-sectional view of an omnidirectional hinge.
FIG. 3 is an explanatory view showing a state in which a hinge shaft is tilted in all directions.
FIG. 4 is an explanatory diagram showing a state of the tilting operation of the hinge shaft and the movement of the correction lens.
FIG. 5 is an exploded perspective view of a practical product.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Optical axis 2 Correction lens 3 Holding frame 4 Support frame 5 Support arm 6 Movable frame 7 Support part 8 Y guide shaft 9 Support part 10 X guide shaft 11 Head 12 Y drive coil 13 Magnet 14 X drive coil 15 Magnet 16 Yoke 17 Yoke 18 A Hinge bearing 19 B Hinge bearing 20 Hinge shaft 30 Holding frame 31 Support frame 32 Guide receiver 33 Support part 34 Rack 35 Guide bearing 36 Hinge bearing tray 37 Guide shaft 38 Pinion 39 Parts pressing plate

Claims (3)

A correction lens installed in the lens barrel and decentering the optical axis; vibration detection means for detecting vibration applied to the lens barrel; and driving the correction lens based on a signal obtained from the vibration detection, In the image shake prevention apparatus including the control means for preventing shake, the first movement mechanism and the first direction in which the correction lens is dedicated to the eccentric movement in the first direction with respect to the optical axis and installed on the main body fixing side. And a second movement mechanism installed on the first movement mechanism side, the second movement mechanism side including the correction lens and the first lens. A correction mechanism including a support frame having a drive element movable in a second direction, the correction mechanism having a single shaft capable of tilting the support frame in all directions with respect to the fixed side, and the first Supported by a second moving mechanism connected to one moving mechanism. Image blur prevention apparatus, characterized in that. The first moving mechanism and a second moving mechanism for correcting mechanism both have a slidable shaft relative to the first and second directions, said one axis shaft is pivotally supporting the support frame of the correction lens 2. The image blur prevention apparatus according to claim 1, wherein the first and second movement mechanisms are combined with a rotation axis of minute rotation that occurs during the omnidirectional tilting operation. The receiving both ends of a single omnidirectional tilt axis pivotally supporting the support frame of the correction mechanism has been processed into a spherical or tapered surface shaped to receive a ball or spherical, in all who direction tilting operation of the shaft, the 2. The image blur prevention device according to claim 1, wherein both end receivers of the shaft are configured to be kept approximately parallel to each other.

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