JP2003140218A - Image blur correction lens system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image blur correction lens system having a simple structure, constituted so that the degree of freedom in terms of the arrangement of parts may be high and realizing a miniaturization of lens. SOLUTION: This image blur correction lens system provided with a guide member arranged nearly in parallel with an optical axis, a link member pivotally supported by the guide member and sliding on the guide member, a lens supporting member pivotally supported by the link member and supporting a correction lens and a driving member which is arranged nearly in parallel with the optical axis and pivotally supports the lens supporting member and on which the lens supporting member slides, is characterized in that the correction lens is made eccentric to the optical axis by rocking the driving member.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In a device for stabilizing an image focused on a photosensitive surface through a photographic lens disclosed in Japanese Patent Laid-Open No. 63-49729, a guide for determining two degrees of freedom in a plane parallel to an image plane. Means for controlling displacement of the lens according to the passage of time provided on the device, and means for controlling actuating means for displacing the guide device according to the displacement detected according to the degree of freedom A control means is provided to eccentrically move the correction lens in the direction perpendicular to the optical axis to correct the image blur. In the displacement driving of the correction lens, a driving source is arranged around or in the vicinity of 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 the correction optical system, and a driving force generating device for driving the correction optical system. The center of gravity, the portion where the load is generated between the movable portion and the guide device, and the power portion of the driving force generation device are arranged in the same plane. With this configuration, the moment around the image blur correction drive unit is reduced, and the image blur correction lens is driven to a desired position to perform image blur correction.

Japanese Unexamined Patent Publication No. 8-194242 discloses a moving mechanism for moving the fixed support end side of the parallel movement mechanism of the correction lens in a direction orthogonal to the movement direction of the correction lens frame by the parallel movement mechanism. A configuration is disclosed in which the optical axis of the correction lens is aligned with the photographing optical axis. JP-A-9-2440
Japanese Patent Laid-Open No. 88 discloses a configuration in which a correction lens is supported by a first driving unit so as to be movable in a second direction and is supported by a second driving unit so as to be movable in a first direction. According to this structure, when the correction lens is moved in the first direction by the first drive unit, the correction lens is guided by the second drive unit and moves in parallel in the first direction. When the correction lens is moved in the second direction by the second drive unit, the correction lens is
It moves in the second direction guided by the first driving unit.

Japanese Unexamined Patent Publication No. 6-35022 relates to an image blur correction device for a camera, and a first device parallel to the optical axis on a fixed member.
The first rotation member having the rotation center axis of
A second rotation member having a second rotation center axis parallel to the optical axis and supporting a correction lens is provided on the first rotation member,
Disclosed is a configuration in which the rotation driving sources of the first and second rotating members are installed on the fixed member and on the first rotating member. Japanese Unexamined Patent Publication No. 7-5514 relates to an image stabilizing lens,
The correction lens is provided so as to be respectively movable in a plurality of directions different from each other in a plane orthogonal to the optical axis, and at least one driving direction is provided about a shaft parallel to the optical axis. The configuration is disclosed.

[0006]

In the antivibration lens currently commercialized, and in the antivibration lens disclosed in the above-mentioned Japanese Patent Laid-Open No. 63-49729 and Japanese Unexamined Patent Publication No. 9-80550, the driving thrust is a correction lens. By causing the movable portion including the frame and the like to act directly on the center of gravity of the movable portion, a moment that causes rotation or tilt does not act, and stable operation can be performed. However, in order to achieve such a configuration, it is necessary to dispose a drive source around the correction lens, and it is possible to configure a compact anti-vibration lens by reducing the outer diameter of the lens barrel. Have difficulty.

In the mechanism proposed in Japanese Unexamined Patent Publication No. 8-194242, since the drive source is concentrated in one direction, the drive source is housed in the empty space of the camera, so that the space efficiency can be improved and the size can be reduced. However, if the center of thrust and the center of gravity of the moving part deviate, rotational torque will be applied to the link mechanism,
The accuracy and followability of the operation are lost, and the altitude cannot be corrected. In the method described in Japanese Patent Laid-Open No. 9-244088, the center of gravity of the movable part and the direction of thrust are improved. However, the combination of the pin and the long hole makes it difficult to maintain the accuracy of the image blur correction and smooth the operation, and the drive source is arranged around the correction lens, which does not lead to downsizing.

In the above-mentioned Japanese Patent Laid-Open No. 6-35022, the correction lens is supported by a link with two rotating shafts as in the present invention, but one of the driving sources is arranged on the link. Not suitable for downsizing the entire lens. In Japanese Patent Laid-Open No. 7-5514, the arrangement of the drive source is not mentioned, but in the embodiment, the drive source is provided on the link, that is, the support arm, and similarly, the configuration is not suitable for downsizing. There is.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems associated with the conventional image blur correction mechanism,
It is an object of the present invention to provide an image blur compensating lens system that has a simple structure, has a high degree of freedom in the arrangement of components, and can downsize the lens.

[0010]

SUMMARY OF THE INVENTION The present invention is directed to a guide member arranged substantially parallel to the optical axis, a link member pivotally supported by the guide member and sliding on the guide member, and an axis of the link member. A lens support member that is supported and supports the correction lens, and a drive member that is disposed substantially parallel to the optical axis and that axially supports the lens support member and on which the lens support member slides are provided. It is an image blur correction lens system characterized in that the correction lens is decentered with respect to the optical axis by moving.

The embodiment of the present invention is as follows.
The link member and the lens support member are coupled by a shaft member. With this configuration, it is possible to perform highly accurate image blur correction with a simple configuration. The link member and the lens support member are integrally formed by being joined together by a hinge. With this configuration, there is an advantage that the manufacturing cost and the number of assembling steps of the link member and the lens supporting member can be reduced.

The driving direction for the image blur correction by the driving member substantially coincides with the detection direction of the displacement detection system of the correction lens. With such a configuration, there is an advantage that the control system of the drive member can be simply designed. The correction lens is a variator lens. With this configuration, there is an advantage that the number of lenses in the optical system can be reduced.
The correction lens is a fixed lens. Such a configuration has an advantage of facilitating the design of the optical system.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an image blur compensating zoom lens including an image blur compensating device, that is, an optical image stabilizing device according to the present invention will be described below with reference to the drawings.

(1) Optical System The optical system of the first image blur correction zoom lens 10 is shown in FIG.
And as shown in FIG. 2, the front lens 1 is placed on the optical axis O.
5, the variator lens 14, the third lens group fixing system 13, the rear focus lens 12, and the image pickup element 11. FIG. 1 shows a state in which the zoom lens 10 can be expanded to form an image. FIG. 2 shows the retracted state of the zoom lens 10.

The zoom operation is performed by moving the variator lens 14 parallel to the optical axis, and the focus adjustment is performed by moving the rear focus lens 12 parallel to the optical axis O. The image blur correction is performed by moving the third group fixed system 13 in a direction perpendicular to the optical axis O, that is, by eccentrically moving the image position, thereby moving the image position in a direction orthogonal to the optical axis O. It can be seen from FIG. 2 that in order to store the zoom lens 10 compactly, the third lens group fixed system 13 which is an image blur correction lens also needs to move in the direction of the optical axis O.

As shown in FIG. 3, the optical system of the second image blur compensating zoom lens 100 has substantially the same optical configuration as that of the first embodiment, and is the same as the optical system of the first zoom lens 10. The same optical configurations are assigned the same reference numerals and explanations thereof are omitted. The zoom lens 100 moves the variator lens 14 in the direction of the optical axis O for zooming, and also moves the variator lens 14 in a direction perpendicular to the optical axis O, that is, eccentrically moves, so that image blurring occurs. The correction is made.

(2) First Embodiment (Correction Lens Decentering Movement Mechanism) FIG. 4 is a front view (a) and a side view (b) of a decentering movement mechanism 200 for the correction lens CL of the first embodiment. The eccentric movement mechanism 200 moves the correction lens CL in the direction of the optical axis O to perform a focusing operation,
Further, it is a mechanism for eccentrically moving in the direction perpendicular to the optical axis O to perform image blur correction. The zoom shaft 220 on which the correction lens CL slides is installed substantially parallel to the optical axis O, and the positional relationship between the optical axis O and the zoom shaft 220 is configured to be maintained constant.

The eccentric movement mechanism 200 supports the correction lens CL by the lens support frame 221, and the lens support frame 22
1 is axially supported by a shaft member 230 provided on a slide frame 222 that slides on the zoom shaft 220. As shown in FIG. 5, the lens support frame 221 has a shaft member hole 242 through which the shaft member 230 passes and a correction drive shaft 2 for image blur correction drive in the peripheral portion of the frame member 240 holding the correction lens CL.
A correction drive shaft hole 246 into which 44 is inserted is provided.

The slide frame 222, as shown in FIG.
The node member has a zoom shaft hole 250 through which the zoom shaft 220 passes and a shaft member hole 252 for fixing the shaft member 230. The slide frame 222 is formed in a ring shape with a cutout in consideration of preventing the light flux from being kicked and avoiding interference with the correction drive shaft 244. It is formed so that the rigidity of can be obtained. As another shape, an arc-shaped bar in which the zoom shaft hole 250 and the shaft member hole 252 are connected in an arc shape may be used in consideration of not blocking the light flux.

(Operation of Correction Lens Decentering Movement Mechanism) The eccentricity moving mechanism 200, as shown in FIG.
Is a base line 260 connecting the zoom shaft 220 and the shaft member 230.
The correction lens CL can be moved in a direction substantially orthogonal to the base line 260 by moving the correction lens CL in a direction A substantially orthogonal to. Similarly, as shown in FIG. 8, by moving the correction drive shaft 244 in the direction B parallel to the base line 260 connecting the zoom shaft 220 and the shaft member 230, the correction lens CL is substantially parallel to the base line 260. Can be moved to. By moving the drive shaft 244 in a combination of the directions A and B, the correction lens CL can be moved in any direction, that is, decentered.

(Analysis of Correction Lens Decentering Movement Mechanism) FIG.
Is an elliptical movement locus 1 m around the center of the correction drive shaft 244,
When driven so as to be 2 m to 11 m, 12 m, the center of the shaft member 230 is a linear movement locus 1n, 2n to 11
n, 12n, which indicates that the movement locus of the optical center 00 of the correction lens CL is circular 1l, 2l to 11l, 12l. A reference angle (described later) formed by the center of the zoom shaft 220, the optical center 00 of the correction lens CL, and the center of the shaft member 230 is about 120 °.

When the movement locus of the optical center 00 of the correction lens CL is circular, the ratio of the minor axis to the major axis of the ellipse formed by the movement locus of the correction drive shaft 244 is the reference line 260 and the optical axis O of the correction lens CL. And the ratio of the distance between the reference line 260 and the center axis of the correction drive shaft 244 are approximately equal. If the ratio of the minor axis and the major axis of the ellipse formed by the movement trajectory of the correction drive shaft 244 is large, the major axis is large and the correction amount for correction is large, which causes an error. Therefore, it is preferable that the ratio of the minor axis and the major axis of this ellipse is close to 1.

With a constant distance from the optical center 00 of the correction lens CL to the center of the zoom shaft 220, the center of the shaft member 230, and the correction drive shaft 244, the minor axis of the ellipse formed by the movement locus of the correction drive shaft 244, In order to bring the ratio of the major axis ratio closer to 1, the center of the zoom shaft 220, the correction lens C
It is preferable that the reference angle S formed by the optical center 00 of L and the center of the shaft member 230 is small. On the other hand, if the reference angle S becomes too small, the center of the zoom shaft 220 and the shaft member 2
Since the center of 30 approaches, the center movement of the correction drive shaft 244 and the center movement of the shaft member 230 become the same, and the movement amount of the slide frame 222 increases, which is not preferable. Considering this, the reference angle S is preferably about 60 °.

10 to 14, the reference angle S is about 6
The structure of the correction lens eccentric movement mechanism when 0 ° is shown. 10 to 14 correspond to FIGS. 4 to 8 showing the correction lens decentering movement mechanism, and therefore, the same reference numerals as those in FIGS. 4 to 8 are given and the description thereof is omitted. FIG. 11 shows the movement locus of the center of the shaft member 230, the movement locus of the optical center 00 of the correction lens CL, and the movement locus of the center of the correction drive shaft 244 when the reference angle S is about 60 °. The ratio of the minor axis and the major axis of the ellipse formed by the movement trajectory of the correction drive shaft 244 having the configuration of the reference angle of about 60 degrees shown in FIG. It can be seen that the ratio is closer to 1 than the ratio.

In FIG. 16, when the reference angle S is about 60 ° and the movement locus of the optical center 00 of the correction lens CL is circular, the displacements A1 to A1 of the center position of the correction drive shaft 244 are shown.
2 and the change of the movement track. Even if the position of the correction drive shaft 244 deviates from the center right above by about 30 ° from the center, that is, A3
The shape of the ellipse formed by the movement locus of the correction drive shaft 244 during the period 5 is almost unchanged, and the same correction drive shaft 24
The same image shift correction can be performed by the control of 4. Being able to select the position of the correction drive shaft 244 in this way increases the degree of freedom in the layout of the correction drive shaft inside the camera, and is effective for downsizing and simplification of the camera.

(3) Second Embodiment (Correction Lens Decentering Movement Mechanism) FIGS. 17 to 19 show the shaft member 2 of the correction lens decentering movement mechanism 200 of the first embodiment.
Reference numeral 30 denotes the correction lens decentering movement mechanism of the second embodiment configured by the hinge 302, and the lens support frame 221 and the slide frame 222 are integrally molded. Further, when the lens support frame 322 and the slide frame 323 are formed as an integral part, there is no rattling unlike the mechanism of the shaft and the bearing, so that the correction lens CL can be smoothly moved by the input from the correction drive shaft 244. It can be carried out. The slide frame 322 has a guide groove 350 on the optical axis O, and the guide groove 350 is provided on the lens support frame 221 and has a guide protrusion 35.
2 is configured to fit.

(Correction Driving Mechanism) The correction driving mechanism 400 for driving the correction driving shaft 244 to correct the image blur is
As shown in FIGS. 20 and 21, a fixed arm 410 fixed to the main body 402, a sub arm 412 pivotally supported by the fixed arm 410, and a main arm 414 pivotally supported at one end by the sub arm 412 are provided. The other end of the main arm 414 is
The correction drive shaft 244 is pivotally supported. The main arm 414 has a vertical actuator 44 for driving the correction drive shaft 244 in the vertical and horizontal directions via the main arm 414.
0 and lateral actuators 444 are provided.

The vertical actuator 440 and the horizontal actuator 444 have substantially the same structure, and the magnet 450 fixed to the main arm 414 and the magnet 450 whose power supply is controlled by a control system (not shown). Of the control coil 452 for adsorbing and not adsorbing. The control coil 452 is substantially fixed to the body 402. Vertical actuator 440 and horizontal actuator 44
4 further includes a position detection pattern 460 having different reflectances on both sides of the predetermined reference position and a position detection sensor 462 for detecting the position of the predetermined reference position based on the difference in the reflectances of the position detection pattern 460. Position detection sensor 4
Reference numeral 62 detects vertical and horizontal displacements of the main arm 414 with respect to the main body 402.

When the thrust directions of the two actuators 440 and 444 for eccentrically driving the correction lens CL and the detection direction of the position detection system are made to coincide with the major axis and minor axis directions of the locus ellipse, respectively, the control system of the actuators 440 and 444 is controlled. Can be simplified. The correction drive system described above is a link mechanism, but a slide mechanism or the like can be used instead.

(Correction Driving Mechanism) As shown in FIG. 22, the correction driving system 500 for driving the correction driving shaft 244 to correct the image blur is located at a position where the extension line of the main arm 514 does not intersect the optical axis O. Will be placed. Other configurations are the same as those of the correction drive mechanism of the first embodiment, and the same reference numerals as those in the description of the first embodiment are given in FIG.

[0031]

According to the image blur compensating lens of the present invention, it is possible to provide an image blur compensating lens system which has a simple structure, has a high degree of freedom in arranging components, and can make the lens compact. Have an effect.

[Brief description of drawings]

FIG. 1 is an optical diagram of a first image blur correction lens system of the present invention in an image forming state.

FIG. 2 is an optical diagram of a housed state of a first image blur correction lens system of the present invention.

FIG. 3 is an optical diagram of an image formation state of a second image blur correction lens system of the present invention.

FIG. 4 is a front explanatory view and a side view of an eccentric movement mechanism of a first embodiment of an image blur correction lens system of the present invention.

FIG. 5 is a front explanatory view of a lens support frame of the image blur correction lens system according to the first embodiment of the present invention.

FIG. 6 is a front explanatory view of a slide frame of the image blur correction lens system according to the first embodiment of the present invention.

FIG. 7 is a front view of the correction lens decentering movement mechanism of the image blur correction lens system according to the first embodiment of the present invention.

FIG. 8 is an explanatory front view of the correction lens decentering movement mechanism of the image blur correction lens system according to the first embodiment of the present invention.

FIG. 9 is an operation explanatory diagram of a correction system of the image blur correction lens system according to the first embodiment of the present invention.

FIG. 10 is a front explanatory view of the decentering movement mechanism of the image blur compensating lens system according to the first embodiment of the present invention.

FIG. 11 is a front explanatory diagram of a lens support frame of the image blur correction lens system according to the first embodiment of the present invention.

FIG. 12 is a front explanatory view of a slide frame of the image blur correction lens system according to the first embodiment of the present invention.

FIG. 13 is a front explanatory view of the correction lens decentering movement mechanism of the image blur correction lens system according to the first embodiment of the present invention.

FIG. 14 is a front view for explaining the correction lens decentering movement mechanism of the image blur correction lens system according to the first embodiment of the present invention.

FIG. 15 is an explanatory diagram of a drive system of the image blur correction lens system according to the first embodiment of the present invention.

FIG. 16 is an explanatory diagram of a drive system of the image blur correction lens system according to the first embodiment of the present invention.

FIG. 17 is a front explanatory view of the correction lens decentering movement mechanism according to the second embodiment of the present invention.

FIG. 18 is an explanatory diagram of a correction lens decentering movement mechanism according to the second embodiment of the present invention.

19 is a cross-sectional view taken along the line XV shown in FIG.

FIG. 20 is a front explanatory view of the correction drive mechanism according to the second embodiment of the present invention.

FIG. 21 is a rear view of the correction drive mechanism according to the second embodiment of the present invention.

FIG. 22 is a front explanatory view of the correction drive mechanism according to the second embodiment of the present invention.

[Explanation of symbols]

CL correction lens 10 zoom lens 13 Third group fixed system 14 Variator lens 100 zoom lens 200 Eccentric movement mechanism 220 zoom axis 221 lens support frame 222 slide frame 230 shaft member 240 frame member 244 Correction drive axis 260 basic line 414 Main arm

Claims (6)

[Claims] 1. A guide member disposed substantially parallel to an optical axis, a link member axially supported by the guide member and sliding on the guide member, and a lens axially supported by the link member and supporting a correction lens. It has a support member and a drive member which is arranged substantially parallel to the optical axis, supports the lens support member, and slides the lens support member. An image blur compensating lens system that is decentered with respect to the axis. 2. The image blur compensating lens system according to claim 1, wherein the link member and the lens support member are coupled by a shaft member. 3. The image blur compensating lens system according to claim 1, wherein the link member and the lens support member are integrally molded by being joined together by a hinge. 4. The image blur correction lens system according to claim 1, wherein a drive direction for image blur correction by the drive member substantially coincides with a detection direction of a displacement detection system of the correction lens. 5. The image blur correction lens system according to claim 1, wherein the correction lens is a variator lens. 6. The image blur compensating lens system according to claim 1, wherein the compensating lens is a fixed system lens.