JP2002350917A - Image blur correction lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image blur correction lens which can be miniaturized since its structure is simple and its driving source can be arranged at an optional position on the extension of a rocking member to enhance the latitude of the arrangement of parts. SOLUTION: In this image blur correction lens for correcting image blur by displacing at least one part of several lens members in a direction orthogonal to an optical axis, a correction lens frame holding the lens member for correcting image blur is pivotally supported through a correction lens link and engaged slidably on the rocking member pivotally supported by a front lens frame substantially and extended to an image forming side, and the rocking member is rocked by the driving source arranged on the extension of the rocking member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens having an image blur preventing mechanism, and more particularly to an image blur correcting lens for correcting an image blur by eccentrically moving an image blur correcting lens member in a direction perpendicular to an optical axis. It is about.

[0002]

2. Description of the Related Art In an apparatus for stabilizing an image focused on a photosensitive surface through a photographic lens disclosed in Japanese Patent Application Laid-Open No. 63-49729, a guide for determining two degrees of freedom in a plane parallel to an imaging plane. Means for detecting the displacement of the lens over time provided on the device, and controlling the operating means for displacing the guide device according to the displacement detected according to the degree of freedom. Control means is provided to correct image blur by eccentrically moving the correction lens in a direction perpendicular to the optical axis. In the displacement drive of the correction lens, a driving source is arranged around or close to the correction lens, and the lens frame on which the correction lens is mounted is directly driven.

An image blur correction device disclosed in Japanese Patent Application Laid-Open No. 9-80550 includes an image blur correction system, a guide device for a correction optical system, and a driving force generating device for driving the correction optical system. , A portion where a load is generated between the movable portion and the guide device, and a power portion of the driving force generating device are arranged in the same plane. With this configuration, the moment around the image blur correction drive section is reduced, and the image blur correction is performed by driving the image blur correction lens to a desired position.

[0004]

The above prior art has the following problems. Because the drive source is placed around the correction lens,
In addition to the lens diameter, a space for a drive source is required, and it is difficult to reduce the diameter of the lens barrel. In order to maintain the performance of image blur correction, it is necessary to configure a lens other than the correction lens so as not to move due to external vibration. Therefore, the optical system that is moved by a zoom operation or a focus operation also needs to have a mechanism without play, and thus has a drawback that the operation lacks smoothness and power consumption for driving increases.

When performing image blur correction using a compensator system of a zoom lens, it is necessary to increase the amount of image blur correction when the zoom is in a telephoto (high magnification) state, but when the zoom is wide (low magnification), The image blur correction amount is small, and if the resolution of the position control for the image blur correction is low, there is a disadvantage that the image blur may be generated on the contrary. As one of the methods for solving this, a mechanism for adjusting the amount of image blur correction using a cam extending in the optical axis direction has been proposed. That is, the variator optical system of the zoom lens is eccentrically moved as a displacement lens for image blur correction. Is configured to be variable. This configuration has an advantage that the ratio between the drive amount and the eccentric displacement amount, which is convenient for control, can be arbitrarily set. However, there are problems such as a complicated structure and a large friction between the cam and the cam follower. .

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems with the prior art image blur correction mechanism, and
Provided is an image blur correction lens that has a simple structure, and a drive source can be provided at an arbitrary position on the extension of the swinging member, so that the degree of freedom in component arrangement is increased and the lens can be downsized. The purpose is to:

The present invention is also directed to an image blur correction lens in which the optical system for image blur correction can also serve as the optical system for zooming, the number of optical systems requiring movement is reduced, and the occurrence of lens play is reduced. The purpose is to provide. The present invention provides an image in which a fulcrum is assigned to the wide-angle position side where the amount of image blur correction is small and the drive shaft is swung, so that correction control with high resolution can be obtained on the wide-angle side and a sufficient amount of correction can be obtained on the telephoto side. An object of the present invention is to provide a blur correction lens.

[0008]

SUMMARY OF THE INVENTION The present invention relates to an image blur correction lens for correcting image blur by displacing at least a part of a plurality of lens members in a direction orthogonal to an optical axis.
A correction lens frame holding a lens member for correcting image blur is pivotally supported via a correction lens link, and slides on a swinging member which is substantially pivotally supported by the front lens frame and extends toward the image forming side. An image blur correction lens, wherein the lens is movably engaged, and the oscillating member is oscillated by a drive source disposed on an extension of the oscillating member.

The embodiments of the present invention are as follows.
The correction lens link has a rod shape. It has the advantages that the member is simple and lightweight, and the material can be formed in a small amount. The correction lens link is generally annular with the optical axis as the center. There is an advantage that the strength and rigidity of the member can be increased. The lens member displaced in a direction perpendicular to the optical axis is a variator lens. There is an advantage that image blur correction can be performed optically efficiently. The correction lens frame is engaged with the swing member via a bending portion. There is an advantage that reliable operation can be ensured with a simple configuration. The correction lens frame is engaged with the swing member by line contact. There is an advantage that reliable operation can be ensured with a simple configuration. The bending portion is located at a position farther from the optical axis than the swing axis in the correction lens frame. There is an advantage that the influence of the swing of the swing member on the direction of the optical axis of the correction lens frame can be reduced. The swinging member vibrates to reduce sliding resistance between the correction lens frame and the swinging member. There is an advantage that the operation of the swinging member can be reliably transmitted to the correction lens frame without sliding resistance. A frequency of vibration applied to the swing member is higher than a frequency of vibration of the correction lens frame for correcting image blur. Without affecting the swinging action of the swinging member,
There is an advantage that the operation of the swinging member can be reliably transmitted to the correction lens frame without sliding resistance. The frequency of the vibration applied to the swing member is 30 Hz or more. There is an advantage that the operation of the swinging member can be reliably transmitted to the correction lens frame without sliding resistance without affecting the swinging operation of the swinging member. A driving source of vibration applied to the swing member is different from a driving source of vibration applied to the correction lens frame.
There is an advantage that vibration of an arbitrary frequency can be given to the swing member and the correction lens frame.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image blur correcting zoom lens provided with an image blur correcting device according to the present invention, that is, an optical image stabilizing device will be described below with reference to the drawings. The optical system of the zoom lens 10 includes a lens group of a front lens 15, a variator lens 14, a compensator lens 13, and a rear focus lens 12, as shown in FIGS. The zoom operation is performed by moving the variator lens 14 on the optical axis O, and the focus operation is performed by moving the rear focus lens 12 on the optical axis O. The image blur correction is performed by moving the compensator lens 13 in a direction perpendicular to the optical axis O to move the image position in a direction perpendicular to the optical axis O.

As shown in FIGS. 1 and 2, a mechanism for eccentrically moving the variator lens 14 swings the swing shaft 21 in two directions, up, down, left and right, around a fulcrum A provided integrally with the front lens frame 9. Do it. As shown in FIG. 3A, the fulcrum A of the oscillating shaft 21 is formed by pivoting the end of a ball 21A provided on the oscillating shaft 21 to a fulcrum projecting portion 23 provided on the front lens frame 9 of the front lens 15. Knuckle (joint) structure supported. As a modified example, as shown in FIG. 3B, the end of the swing shaft 21 is gripped by a support portion 25 extending from the front lens frame 9 via the flexible portion 24, and the flexible portion 24 is moved in an elastic range. The rocking shaft 21 is rocked by being bent inside.

FIG. 2 also shows a mechanism for guiding and moving the variator lens 14 in the optical axis direction. The zoom guide shaft 31 is fixed to the optical axis (barrel). The slider link 32 sliding on the zoom guide shaft 31 moves the variator lens 14 in parallel with the variator lens frame 22 in the optical axis direction.

The mechanism for preventing the variator lens frame 22 from sliding on the swing shaft 21 and preventing the variator lens frame 22 from tilting due to the effect of the tilt of the swing shaft 21 is shown in FIG.
As shown in (a), a sliding hole 26 in which the swinging shaft 21 slides is provided in the outer peripheral portion of the variator lens frame 22, and the swinging shaft 2
The swing of 1 allows the variator lens 14 to be eccentrically moved. In order to minimize the mechanical resistance caused by the positional relationship between the swing shaft 21 and the variator lens frame 22 other than orthogonal, the configuration of the sliding hole 26 is such that the inside swings as shown in FIG. The shaft 21 is formed so as to make a line contact on the vicinity of one circumference. As another embodiment of the sliding hole 26, FIG.
As shown in (b), the inner part 22A is in line contact with the swing shaft 21 and the other part is in pressure contact with the elastically deformable holding projection 27. According to this configuration, there is an advantage that rattling does not occur between the sliding hole 26 and the swing shaft 21.

A modification of the mechanism in which the variator lens frame 22 slides on the swing shaft 21 is shown in FIG.
1 and the variator lens frame 22 supporting the variator lens 14 are connected only on the side away from the optical axis O, and when the bearing 28 in contact with the swing shaft 21 is inclined with respect to the lens optical axis O. The generated deflection is generated at a position outside the swing shaft 21. That is, the bent portions C and C ′ in FIG. 5A have a relatively thin structure as shown in FIG. 5B which is a side view. With this structure,
Even if the swing shaft 21 is inclined with respect to the optical axis O, FIG.
As shown in (a) and (b), the flexures C and C ′
The movement of the connecting portion in the optical axis direction due to the inclination of the swing shaft 21 and the movement of the mounting position, that is, the knot position, to the variator lens frame 22 are offset, and the variator lens 14 is moved on the optical axis O.
It is constituted so that the force which inclines is suppressed. FIG.
FIG. 5C is a cross-sectional view along a line DD in FIG.

In the above configuration, if the bending position is closer to the optical axis O than the swing shaft 21, for example, when the swing shaft 21 swings toward the optical axis O, the bending position is closer to the fulcrum A. Moving. Since the bending force applied to the variator lens frame 22 is also applied in the direction of the fulcrum A, the movement cannot be absorbed unless the variator lens frame 22 slides in the direction opposite to the fulcrum. Swing shaft 21
Conversely swings in the anti-optical axis direction, the bending position moves away from the fulcrum until the swing amount exceeds the bending position. Since the bending applied to the variator lens frame 22 is also in the direction opposite to the fulcrum, the movement cannot be absorbed unless the variator lens frame 22 slides in the direction of the fulcrum A.

On the other hand, in the configuration of the present invention described above, when the swing shaft 21 swings toward the optical axis O, the bending position moves in the direction opposite to the fulcrum. On the other hand, the variator lens frame 22
Is applied in the direction of the fulcrum A, so that the force applied by the swinging acts only as a force to bend the flexures C and C ′ of the variator lens frame 22, and the variator lens 14
Is maintained vertically. When the swing shaft 21 swings in the direction opposite to the optical axis, the bending position moves toward the fulcrum A. Since the bending force applied to the variator lens frame 22 is in the direction opposite to the fulcrum, the force applied by the swing of the swing shaft 21 acts only as a force for bending the bent portion of the variator lens frame 22, and the variator lens 14 is maintained vertical. .

Next, the configuration of the slider link 32 and the variator lens frame 22 will be described. Slider link 3
2 moves at a fixed angle with respect to the zoom guide shaft 31 parallel to the optical axis O of the lens barrel as shown in FIG.
The optical axes of the variator lens frame 22 and the variator lens 14 also move while maintaining a constant angle with respect to the optical axis O of the lens barrel. Basically, it is desirable that the optical axis of the variator lens 14, the lens barrel, and the optical axis O are always parallel. The slider link 32 and the variator lens frame 22 have the shapes shown in FIGS. 8A and 8B, both of which are rotatably connected about the axis F in FIG. 7, and are shown in FIG. 9B. So that they can rotate with each other. The rotation surfaces of the slider link 32 and the variator lens frame 22 are planes perpendicular to the optical axis O of the lens barrel. In order to maintain the rotation surface of the variator lens 144 parallel to the optical axis O, a guide groove (not shown) is provided in a part of the slider link 32, and a convex portion (not shown) provided on the variator lens frame 22. To prevent falling.

The slider link 32 has a ring shape as shown in FIG. 8B in consideration of its strength and rigidity, but may have a rod shape. That is, the rod-shaped slider link has an end 31A through which the zoom guide shaft 31 passes at one end.
And a hole FA having an axis F at multiple ends. The drive source for the zoom movement of the variator lens 14 is manual, linear motor drive, screw shaft drive, or the like. The slider link 32 is, as shown in FIG.
The zoom guide shaft 31 is rotatable about an axis G.
When the swing shaft 21 passing through the sliding hole 26 of the variator lens frame 22 swings, the optical axis of the variator lens 14 can be moved to any position within the regulation range according to the movement of the swing shaft 21.

When the slider link 32 rotates,
Consideration should be given to problems caused by changing the angular position between the zoom drive mechanism and the slider link 32. However, also in the conventional zoom drive mechanism, the member for receiving the drive screw and the slider link 32 are rotatably connected, and if the movement amount is the same as that of the present configuration, a large error causing a problem in the conventional mechanism is not great. Does not occur.

Next, a device for driving the swing shaft 21 will be described. As shown in FIGS. 10A and 10B, the swing plate 41 vertically coupled to the swing shaft 21 has
Two sets of magnets 42, 43 are provided, and two sets of coils 44, 45 provided at opposing positions constitute a linear motor. As shown in FIG. 10B, the linear motor including the magnet 43 and the coil 45 drives the rocking plate 41 in the vertical direction on the paper. In addition, a linear motor including the magnet 42 and the coil 44 drives the swinging plate 41 in the left-right direction on the paper.

The first reflection type photo interrupter 46 is
As shown in FIGS. 10A and 10B, the position of the rocking plate 41 in the left-right direction on the paper is detected in combination with the position measurement pattern 48. The second reflective photo-interrupter 47 is shown in FIG.
As shown in FIG. 0 (a), the position of the rocking plate 41 in the vertical direction of the drawing is detected by a position measurement pattern (not shown) provided at a position facing the position. The coils 44 and 45 and the reflection type photo interrupters 46 and 47 are placed at positions fixed with respect to the optical axis (barrel) of the barrel.

As a mechanism for suppressing the rotation of the rocking plate 41, a link mechanism disclosed in Japanese Patent Application Laid-Open No. 9-244088 may be used. As a simple method of suppressing the rotation of the swinging plate 41, the swinging plate 41 may be suspended by two springs 51 and 52 as shown in FIG. When the spring is provided on an extension of a line passing through the center of gravity H, a rotational moment generated by driving or disturbance can be effectively suppressed. There may be three or more springs. When there are three springs, it is desirable that the lines in the pulling direction of each spring pass through the center of gravity.

The swing shaft 21 and the variator lens frame 22 are
Since it is necessary to smoothly move the variator lens 14 in the direction perpendicular to the optical axis, the variator lenses 14 need to be coupled so as to prevent play. For this reason, when trying to move the variator lens 14 in the optical axis direction for zoom operation,
The movement is hindered by the sliding friction between the swing shaft 21 and the variator lens frame 22, or the optical axis O of the variator lens 14
May tilt. In order to prevent this, when the variator lens 14, the variator lens frame 22, and the slide link 32 are to be moved by the zoom drive, the swing shaft 21 is driven to vibrate at a frequency higher than that required for image blur correction. The movement of the swing shaft 21 and the variator lens frame 22 is smoothed to prevent the zoom operation from being hindered. This frequency is approximately 30
Hz or more, but the swing shaft 21 and the variator lens frame 2
It is preferable to set the frequency to easily resonate 2 or to multiply the frequency.

The vibration drive of the swing shaft 21 may be superimposed on the drive signal of the image blur correction driving device. Alternatively, a vibration source may be provided separately from the image blur correction driving device to apply vibration. Good. At this time, the vibration direction of the shaft may be the axial direction of the swing shaft 21. For example, as shown in FIG. 12, a swing shaft may be attached to a lens barrel via a bimorph piezoelectric element 25 so that vibration can be generated in the axial direction of the swing shaft 21.

[0025]

According to the image blur correction lens of the present invention, the structure is simple, the drive source can be provided at any position on the extension of the swing shaft, and the degree of freedom in arranging parts is increased. This has the effect that the camera can be downsized.

According to the present invention, since the optical system for image blur correction can also be used as the optical system for zooming, the number of optical systems that need to be moved is reduced, and the cause of lens play is reduced. Having.

The present invention further provides a correction control with a high resolution on the wide side and a sufficient correction amount on the tele side by arranging a fulcrum on the wide position side where the image blur correction amount is small and swinging the drive shaft. Has the effect that can.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of an image blur correction lens according to an embodiment of the present invention.

FIG. 2 is an explanatory sectional view of an image blur correction lens according to an embodiment of the present invention.

FIG. 3 is an explanatory cross-sectional view of a pivot support portion of a swing shaft according to an embodiment of the present invention.

FIG. 4 is an explanatory sectional view of an engaging portion between the variator lens frame and the swing shaft according to the embodiment of the present invention.

FIG. 5 is an explanatory sectional view of an engaging portion between the variator lens frame and the swing shaft according to the embodiment of the present invention.

FIG. 6 is an explanatory sectional view of an engaging portion between the variator lens frame and the swing shaft according to the embodiment of the present invention.

FIG. 7 is an explanatory diagram showing engagement between a variator lens frame and a slider link according to an embodiment of the present invention.

FIG. 8 is a plan view of a variator lens frame according to an embodiment of the present invention.

FIG. 9 is an explanatory diagram showing engagement between a variator lens frame and a slider link according to an embodiment of the present invention.

FIG. 10 is an explanatory diagram of a drive system of an image blur correction lens according to an embodiment of the present invention.

FIG. 11 is an explanatory diagram of a drive system of an image blur correction lens according to an embodiment of the present invention.

FIG. 12 is an explanatory diagram of a drive system of an image blur correction lens according to an embodiment of the present invention.

[Explanation of symbols]

 O Optical axis 10 Zoom lens 11 Image sensor 15 Front lens 21 Swing axis 22 Variator lens frame 23 Support point protruding part 24 Flexible part 26 Sliding hole 28 Bearing 31 Zoom guide shaft 32 Slider link

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H633 BB08 BB10 BB16 GG02 GG06 GG09 GG17 HH03 HH05 HH09 JA02 5H680 AA19 BB02 BB13 BC01 DD01 DD15 DD24 DD46 DD53 DD67 DD83 EE20 FF32

Claims (11)

[Claims] 1. An image blur correction lens for correcting image blur by displacing at least a part of a plurality of lens members in a direction orthogonal to an optical axis, wherein a correction for holding a lens member for the image blur correction is provided. The lens frame is pivotally supported via a correction lens link, and is slidably engaged on a swinging member which is substantially supported by the front lens frame and extends toward the image forming side. An image blur correction lens, wherein the swing member is swung by a drive source disposed above. 2. The image blur correction lens according to claim 1, wherein the correction lens link has a rod shape. 3. The image blur correction lens according to claim 1, wherein the correction lens link is formed in a ring shape about the optical axis. 4. The image blur correction lens according to claim 1, wherein the lens member displaced in a direction perpendicular to the optical axis is a variator lens. 5. The apparatus according to claim 1, wherein the correction lens frame is engaged with the swing member via a bending portion.
2. The image blur correction lens according to 1. 6. The image blur correction lens according to claim 1, wherein the correction lens frame is engaged with the swing member by an image in line contact. 7. The image blur correction lens according to claim 6, wherein the bending portion is located at a position farther from the optical axis in the correction lens frame than the swing axis. 8. The image blur correction lens according to claim 1, wherein the oscillating member vibrates to reduce a sliding resistance between the correction lens frame and the oscillating member. 9. The image blur correction lens according to claim 9, wherein a frequency of vibration applied to the swing member is higher than a frequency of vibration of the correction lens frame for correcting image blur. 10. The image blur correction lens according to claim 9, wherein the frequency of the vibration applied to the swing member is 30 Hz or more. 11. The image blur correction lens according to claim 1, wherein a driving source of vibration applied to the swing member is different from a driving source of vibration applied to the correction lens frame.