JPH0720522A - Shake preventing device - Google Patents

Abstract

PURPOSE:To accurately restrict the movable range of a shake preventing lens by a simple mechanism and to obtain high reliability as for the preventing device of image blurring caused by camera-shake. CONSTITUTION:The shake preventing lens 8 moved in a direction almost orthogonally crossed to the optical axis I of a main optical system and a mechanism part transmitting driving force from motors 30 and 31 to the lens 8 are provided. The driving force transmitting mechanism part is constituted of decelerating gear trains 32 and 33 decelerating rotation from the motors and moving quantity generation mechanism parts 34 and 36; 35 and 37 moving a shake preventing optical system in a prescribed direction by the decelerated rotational driving force. Besides, a restriction means restricting the movable range of the shake preventing optical system within a prescribed range is constituted of a second decelerating gear train coupled to the decelerating gear trains separately from the generation mechanism parts, 34, 36, 35 and 37. The second decelerating gear train includes a gear member 80 whose rotation within the range of one rotation is mechanically or electrically restricted and the actuation range thereof is mechanically and electrically restricted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shake prevention device suitable for use in a camera or the like to prevent image shake due to camera shake.

[0002]

2. Description of the Related Art Recent cameras are highly automated due to remarkable digitization in various parts such as an automatic exposure mechanism and an autofocus mechanism. However, in this type of camera, there is a countermeasure against image shake due to camera shake that is likely to occur during handheld shooting, etc., which is insufficient as an attempt for automation.

For this reason, in this type of camera, in order to prevent image shake caused by camera shake, particularly camera shake or tilt, the shake condition of the camera is detected by shake detecting means, and the detection result is detected. A shake prevention device having a structure in which the photographing lens system (main optical system) or a part of the optical system is used as a shake prevention optical system (shake prevention lens), and is shifted in a direction orthogonal to the optical axis. However, it is conventionally known.

That is, in a camera having such a shake prevention function, a shake prevention optical system (hereinafter referred to as a shake prevention lens) which constitutes at least a part of a photographing lens system is movably supported, and this shake prevention lens is used. By moving in a direction that absorbs shake in a plane orthogonal to the optical axis of the main optical system, the deviation of the image forming position due to shake is corrected,
It was to eliminate the image blur.

In such an anti-shake apparatus, as a drive mechanism for shifting the anti-shake lens, a mechanism portion such as disclosed in Japanese Patent Laid-Open No. 3-110530 is proposed.

In this conventional example, the lens frame of the shake preventing lens is held so as to be movable in the direction orthogonal to the optical axis, and the lens frame is provided with driving means (motor, gear train, lever or screw shaft, ball and V-shape). (Via a groove or the like) to act as a connecting means (via a rod member or a drive shaft) that transmits a driving force from a pressing force and a pulling force,
It has a structure in which the shake prevention lens is directly driven and moved.

Further, in this conventional example, a detection switch is provided in a part of the driving means to detect the amount of movement of the lens frame, that is, the shake-preventing lens, and limit the movement above a predetermined level. .

[0008]

By the way, in the conventional anti-shake device as described above, in order to drive and control the anti-shake lens according to the shake condition, it is necessary to drive the anti-shake lens at high speed and with high accuracy. In addition to being desired, it is necessary to appropriately and surely detect the position of the anti-shake lens and additionally provide a limiting means for restricting the shift range of the anti-shake lens within a predetermined range.

That is, if such an anti-shake lens is moved more than necessary, the lens frame, driving means, etc. may collide with or interfere with other mechanical parts. In consideration of the above, it is necessary to limit the shift range of the shake prevention lens within a predetermined range.

Therefore, in the above-described conventional shake preventing apparatus, the detecting means for detecting the position of the shake preventing lens and the limiting means for restricting the shift range of the shake preventing lens are individually and independently provided, and By appropriately using these means, the shift amount of the shake prevention lens is limited within a predetermined range.

However, in such a conventional example, the detecting means and the limiting means are independently used,
It cannot be said that the structure is complicated and the movable range of the anti-shake lens with high reliability cannot be limited, and it is necessary to take some measures to eliminate these problems with a simple structure. There is.

The present invention has been made in view of the above circumstances, and a shake prevention device capable of limiting the shift range of the shake prevention lens with high precision and reliability with a simple and inexpensive structure. The purpose is to get.

[0013]

In order to meet such a demand, a shake preventing apparatus according to the present invention comprises a shake preventing optical system which is movable in a direction substantially orthogonal to an optical axis of a main optical system, and this shake preventing device. Driving force generating means for generating a driving force for driving the prevention optical system, driving force transmitting means for transmitting the driving force of the driving force generating means to the shake preventing optical system, and a movable range of the shake preventing optical system are predetermined. With limiting means for limiting within the range,
The driving force transmission / transmission means is composed of a reduction gear train that reduces the rotation from the rotational drive source, and a movement amount generation mechanism unit that moves the shake prevention optical system in a predetermined direction by the rotational driving force that is reduced by the reduction gear train. In addition, the limiting means is configured by a limiting mechanism portion coupled to the reduction gear train, separately from the movement amount generating mechanism portion.

Further, according to the present invention, the second reduction gear train is used as the limiting means, and the operation range of the second reduction gear train is mechanically restricted within the range of one rotation. It is configured so as to be mechanically limited by using a gear member.

Further, according to the present invention, the operation of the gear member included in the second reduction gear train, which is the limiting means, and whose rotation is mechanically limited within the range of one rotation is operated. In the force acting on the bearing portion at the limit position in the first direction and the force acting on the bearing portion at the limit position in the second direction, the first
Direction and the second direction, the force acting on the bearing portion at the limit position in one direction is weaker than the force acting on the bearing portion at the limit position in the other direction. It is composed.

Further, according to the present invention, the second reduction gear train used as the limiting means uses a gear member whose rotation range is electrically limited within one rotation range. It is configured to be electrically limited.

[0017]

According to the present invention, the driving force transmitting means is composed of the reduction gear train and the movement amount generating mechanism portion, and the limiting means is connected to the reduction gear train separately from the movement amount generating mechanism portion. By doing so, it becomes possible to limit the movable range of the shake prevention optical system to within a predetermined range.

Further, according to the present invention, the operating range of the second reduction gear train as the limiting means is reduced by using a gear member or the like whose rotation is mechanically limited within one rotation. It is possible to limit the movable range of the anti-shake optical system to within a predetermined range by restricting the movement.

Further, according to the present invention, the force acting on the bearing portion of the gear member forming the second reduction gear train at the limit position in the first direction and the bearing portion at the limit position in the second direction. With respect to the force acting on the gear member, the operation of the gear member can be mechanically limited so as to weaken the force acting on the bearing portion at the limiting position in one of the first direction and the second direction. Becomes

Further, according to the present invention, the operating range of the second reduction gear train is electrically limited by using a gear member or the like for electrically limiting the rotation within one rotation. This makes it possible to limit the movable range of the shake prevention optical system to within a predetermined range.

[0021]

1 to 7 show an embodiment of a shake preventing device according to the present invention. In these drawings, first, a photographing lens system with a lens shutter to which the present invention is applied is provided. The schematic configuration of the camera will be briefly described with reference to FIG. 7.

That is, the taking lens system 2 which is the main optical system in the camera denoted by reference numeral 1 as a whole has a first lens group 4 and a second lens group 9 consisting of front and rear lens groups 7 and 8.
And a third lens group 11, and is configured as a zoom lens.

Here, the first lens group 4 is constructed by holding three lenses 4a, 4b and 4c on the lens frame 3. The second lens group 9 is composed of a total of seven lenses by holding three lenses, four lenses 7a, 7b, 7c; 8a, 8b, 8c, 8d in the lens frames 5, 6. . The third lens group 11 is configured by holding three lenses 11a, 11b, 11c on the lens frame 10.

Reference numeral 12 in the figure denotes a lens shutter, which is provided between the front and rear lens groups 7 and 8 of the second lens group 9 described above, and is provided with shutter curtains 13 and 14 and a drive unit for driving the shutter curtains 13 and 14. It is composed of 15 parts. The drive unit 1
5 is arranged in the second lens group 9 on the outer periphery of the lens frame 5 of the front lens group 7, and the shutter curtains 13 and 14 are provided.
Is disposed immediately before the rear lens group 8 that functions as an image blur prevention lens described later.

Further, reference numeral 16 in the drawing denotes the first, second and third lens groups 4, 9, which constitute the above-mentioned taking lens system 2.
An image forming surface of a film on which a subject image is formed by 11 and I in the drawing is an optical axis of the taking lens system 2.

According to the present embodiment, the taking lens system 2 having the three lens groups 4, 9 and 11 as described above.
In FIG. 3, the rear lens group 8 of the second lens group 9 is shifted in the direction orthogonal to the optical axis I as an image blur preventing lens, so that the image blur preventing mechanism shown in FIGS. 1 and 3 to 5 is obtained. The unit 20 is used to move the image formed on the image forming surface 16 in accordance with the image shake state.

Such an image blur prevention mechanism section 20 is provided with a second image stabilization mechanism as shown in FIGS. 1, 3 to 5 and FIG.
The substrate 21 on the lens shutter 12 side is provided as a base member in the space on the outer peripheral side of the rear lens group 8 in the lens group 9.

In the image blur preventing mechanism 20 as described above, the rear lens group 8 (hereinafter referred to as the shake preventing lens 8) in the second lens group 9 is as shown in FIGS. 1 and 3 to 5. , Is fixedly held in the lens frame 6. Further, a flange portion 6a is provided in a portion of the outer peripheral portion of the lens frame 6 that faces the opening portion 21a of the substrate 21.

As is apparent from FIGS. 1 and 5, balls 70, 71, 72, which are positioned and held by the through holes of the retainer member 68, are formed in the opposing portions of the flange portion 6a and the substrate opening portion 21a. A receiving member 67 made of a high hardness material such as hardened steel for receiving 73,
69 is attached. The balls 70, 71, 72,
73 is held in a state of being sandwiched by these receiving members 67, 69, whereby the lens frame 6 is opened through the flange portion 6a, the receiving member 67, and the balls 70 to 73 in the opening 21a of the substrate 21. It is ready to move.

That is, the retainer member 68 is formed with through holes in which the balls 70, 71, 72, 73 are rotatably held therein, which are evenly arranged in the circumferential direction. Further, the lens frame 6 has arms 6f and 6g provided on a part of its outer peripheral portion.
The springs 51 and 52 are bridged between the base plate 21 and the base plate 21, so that the receiving members 67 and 69 are connected to the balls 70 to 70.
It is always in contact with 73.

With such a structure, the shake prevention lens 8
Is movably supported in a plane orthogonal to the optical axis I with a low load, and is constantly urged by the springs 51 and 52, so that there is no problem that the optical performance deteriorates due to tilting. . In addition, in FIG.
Although 0 and 71 are shown only at two places, they may be arranged at four places around the opening 21a of the substrate 21 and between the flange 6a and the balls 72 and 73 as shown in FIG. .

In FIG. 1, reference numerals 30 and 31 denote x-axis and y-axis DC motors (Mx, in the figure) serving as driving means for moving the image stabilizing lens 8 in the x-axis direction and the y-axis direction.
My is attached), and is attached and fixed to the substrate 21 side. Further, 32 and 33 are those motors 30 and 31.
Gears 32a, 32b, 32c, 3 for transmitting driving force from
2d; 33a, 33b, 33c, 33d for transmission of rotation of the gear train, the rotation of which is the first and second shafts 34, 3
5 is transmitted. These first and second shafts 34, 35 are
Bearings 21b, 21c or 21 provided on the substrate 21
The d and 21e are rotatably supported by extending in the x-axis direction or the y-axis direction.

Incidentally, the gears 32b constituting the gear trains 32, 33 for transmitting the rotations from the motors 30, 31 described above,
32c; 33b and 33c are rotatably fixed on the substrate 21, respectively, and the gears 32d and 33d are provided on the shaft 3 respectively.
It is configured to be rotatable integrally with 4, 35.

Reference numerals 36 and 37 denote movable members on the x-axis side and the y-axis side, respectively.
a is screwed to the male threads 34a, 35a of the shafts 34, 35, and the movable member 3 is moved by the feed screw mechanism.
A movement amount generating mechanism portion for moving the lens frame 6 in the x-axis and y-axis directions via 6, 37 is configured.

Further, the guide member 5 is provided on each of the movable members 36 and 37 adjacent to the female screw portions 36a and 37a.
5,56 are fixed. These guide members 55,
As shown in FIG. 3, reference numeral 56 denotes the bearing portion 2 of the substrate 21.
It is guided by guide shafts 57 and 58 which are fixed to 1b and 21d or 21c and 21e in parallel with the shafts 34 and 35. The movable members 36 and 37 are connected to the motors 30 and 3 respectively.
1 can move in the x-axis direction and the y-axis direction, respectively.

The flange portion 6a of the lens frame 6 has a
As is clear from FIGS. 1 and 4, the rollers 59, 60, 6
1, 62 are rotatably attached by roller shafts 63, 64, 65, 66. Further, the spring hook portion 6b on the opposite side of the rollers 59 and 60 of the lens frame 6, the roller 61,
Between the spring hook portion 6c on the opposite side of 62 and the substrate 21,
As shown in FIGS. 1 and 4, each of the springs 53 and 54 has an x-axis direction in which the movable members 36 and 37 move,
It is bridged in the same direction as the y-axis direction. The rollers 59, 60 and 61, 62 have springs 53, 54 attached to abutting portions 36b, 36c or 37b, 37c having a substantially L-shaped cross section at both ends of the movable members 36, 37, respectively. Abut by power.

Therefore, the shake prevention lens 8 described above is used.
Shifts following the moving direction of the movable member 36 (x-axis direction) by the motor 30 on the x-axis side, but is free in the y-axis direction. Further, this shake prevention lens 8 is
The movable direction of the movable member 37 (y
It shifts following the (axial direction), but is free in the x-axis direction. From this, the shake prevention lens 8 is
It is possible to shift in all directions inside one opening 21a.

Further, the lens frames 6 are formed by the springs 53 and 54.
The lens frame 6 and the movable members 36, 37 are always in contact with each other by urging the movable members 36, 37 in substantially the same directions as the x-axis direction and the y-axis direction, which are the movable directions.
As a result, the movements of the movable members 36 and 37 can be reliably transmitted to the lens frame 6.

Further, due to the urging force of the springs 53 and 54,
The rattling of the shafts 34 and 35 in the thrust direction is caused by the rattling of the male threads 34a and 35a of the shafts 34 and 35 and the female threads 36a and 37a of the movable members 36 and 37, respectively. You can always take in the direction. Therefore, the driving force of each of the motors 30 and 31 can be accurately and reliably transmitted to the shake prevention lens 8.

The small gears 32d and 33d include:
As is clear from FIGS. 1 and 2 (a) and (b),
The limiting gears 80x and 80y are in mesh with each other. The limiting gears 80x and 80y are rotatably supported by the gear bearing portions 21f and 21h of the substrate 21.

These limiting gears 80x and 80y are parts characterizing the present invention as limiting means, and their functions will be described below with reference to FIGS. 2 (a) and 2 (b). 2A corresponds to the arrow IIa in FIG. 1 and shows the relationship between the x-axis gear 32d and the limiting gear 80x. Further, (b) of the figure corresponds to IIb in FIG. 1 and shows the relationship between the y-axis gear 33d and the limiting gear 80y.

Grooves 80xa and 80ya each having a substantially C-shape are formed on the rear surface side (the movable members 36 and 37 side in FIG. 1) of the limiting gears 80x and 80y. Then, the gears 32d, 33d inside the grooves 80xa, 80ya.
Projections 21g and 21i projecting from the gear bearings 21f and 21h face the portion substantially opposite to the above. Therefore,
These limiting gears 80x and 80y do not rotate 180 degrees in both directions, so that the limiting gears 80x and 80y are not rotated.
The rib portions 80xb and 80yb of the above contact the convex portions 21g and 21i to mechanically limit the rotation.

Here, as shown in FIGS. 2 (a) and 2 (b), the shake prevention lens 8 is provided with the convex portions 21g and 21i positioned at the centers of the grooves 80xa and 80ya of the limiting gears 80x and 80y. The center position (the position where the optical axis of the shake prevention lens 8 and the optical axis I coincide with each other) is set, and the shift amount of the shake prevention lens 8 and the rotation angle of the limiting gears 80x and 80y are configured to match, thereby preventing the shake The shift amount of the lens 8 can be limited within a predetermined range. At this time, when the rotation is limited by the limiting means described above, the motors 30 and 31 are stopped and the state is maintained for a certain time,
It is preferable to perform control such that the power is turned off. Further, in such a configuration, since the rotation of the limiting gears 80x and 80y is mechanically limited, it is effective when a runaway problem or the like occurs in the electric control system.

A method of detecting the position and speed of the preventive lens 8 will be described below. That is, the circular discs 40x and 40y with holes, which are provided integrally with the gears 32a and 33a shown in FIGS. 1 and 6 and have a large number of holes in the peripheral edge portion at equal intervals, and the peripheral edge portion. And the photo interrupter 41 provided on the substrate 21 side.
x, 41y, the disc 40x. The number of holes on the 40y side is detected as a pulse signal and counted.

Such position detection is carried out by (a) in FIG.
In (b), for example, when the gears 32d and 33d are rotated in the arrow "-" direction, the shake prevention lens 8 shifts to the lower left direction in FIG. 1 and reaches the limit position. The position is detected by counting pulses with the photo interrupters 41x and 41y with this position as the origin. The speed is determined by detecting the speed of the pulse.

Therefore, an encoder including the discs with holes 40x and 40y and the photo interrupters 41x and 41y is provided on the output shafts of the motors 30 and 31, and the limiting gears 80x and 80y are provided through the reduction gear train. Because
The operation limit position and the operation angle of the limit gears 80x and 80y can be detected with high resolution.

Further, by setting the operating rotation angles of the limiting gears 80x and 80y to be smaller than 360 degrees, the shift range of the shake preventing lens 8 can be limited to a predetermined range by one limiting gear. Further, since the shake prevention lens 8 is driven via the feed screw mechanism which is the movement amount generating mechanism in addition to the limiting gears 80x and 80y, the shake prevention lens 8 is directly applied with a high load and highly accurately. The shake prevention lens 8 can be limited to a predetermined range.

In such a structure, in the driving force transmission mechanism portion from the motors 30, 31 to the lens frame 6, the shafts 34, 35 of the reduction gear systems 32, 33 and their bearings, and the shafts of the limiting gears 80x, 80y. The force acting on the bearings and bearings can be minimized to prevent unnecessary rattling and wear problems over time. Further, when the limiting gears 80x and 80y are provided in this way and the rotation is limited within one rotation, the gear ratios in the reduction gear trains 32 and 33 and the feed screw mechanism (movement amount generating mechanism portion). There is an advantage that the degree of freedom of the lead angle can be increased.

In this embodiment, the motors 30, 31 are
Although the driving force of the driving mechanism is transmitted to the movable members 36 and 37 via the screw mechanism, it is a mechanism for converting not only the screw mechanism but also the rotary motion into the linear motion. It goes without saying that the existing mechanism can also be applied.

In the above-described embodiment, the limiting gears 80x and 80y as the limiting means are engaged with the final gears 32d and 33d of the reduction gear trains 32 and 33 in the driving force transmission mechanism. Of course, it may be connected to any position of the gear train. In this case, coupling to a gear near the end of the gear train is advantageous from the viewpoint of reduction gear ratio and the like.

According to the image blur preventing mechanism 20 having the above-described structure, the rear lens group (anti-vibration lens) 8 of the second lens group 9 shown in FIG. 7 is arranged in the direction orthogonal to the lens optical axis I. By shifting, the image formed on the image forming surface 16 can be moved in a desired state, and as a result, image blur can be prevented.

Further, according to the image blur prevention mechanism section 20 described above, the DC motors 30 and 31 having a relatively large volume have a positional relationship in which the longitudinal direction thereof is orthogonal to the optical axis I of the photographing lens group 2. As can be seen from FIGS. 3 and 4, the DC motors 30 and 31 are connected to the lens shutter 12 and the third lens group 1 as shown in FIG.
It is not necessary to project it to the first side, and it is possible to assemble the shake prevention lens 8 onto the outer peripheral side of the lens frame 6 in a high density and compact form, which is advantageous in terms of structure and assembly.

Therefore, according to such an image blur prevention mechanism section 20, the space of the lens shutter 12 and the space between the second lens group 9 and the third lens group 11 are not damaged. In addition, since it can be easily unitized as described above, it is excellent in assembling, and is very effective even if it is arranged adjacent to the diaphragm mechanism in, for example, an interchangeable taking lens.

In the above-mentioned structure, the first and second motors 30 and 31 are movably arranged in the annular space formed in the outer peripheral portion of the lens frame 6 of the shake prevention lens 8. The first and second movable members 36,
Since they are arranged at positions deviated in the circumferential direction from 37 in such a manner that their respective longitudinal directions have a positional relationship orthogonal to the optical axis I, despite the simple mechanical structure,
The DC motors 30 and 31 serving as drive means can be arranged without projecting to the outside, and the shake prevention mechanism portion 20 can be configured as a unit to reduce the space and cost of the mechanism portion 20. There are advantages.

Such an advantage is that the output shafts of the motors 30 and 31 are arranged so as to be oriented in the x-axis direction and the y-axis direction, respectively, and the rotational force thereof is first and First and second shafts 34, 35 serving as second converting means
Further, the first and second movable members 36 and 37 are configured to be converted into linear motions in the x-axis direction and the y-axis direction, respectively, so that they can be further exerted.

Further, in the above structure, the shake prevention mechanism section 20 uses the case member composed of the substrate 21 and the lid body 22 in the annular space formed on the outer peripheral side of the lens frame 6 of the shake prevention lens 8. It is configured as a unit and is small in size, so that other complicated mechanical parts such as the lens shutter 12 illustrated in FIG. 7 can be arranged adjacent to each other. It can be used to exert an effect.

FIGS. 8A and 8B show a second embodiment of the shake preventing apparatus according to the present invention. In this embodiment, a gear bearing for limiting the rotation of the limiting gears 80x, 80y. This is a case where the positions of the convex portions 21g and 21i of the portions 21f and 21h are changed. In these figures, the gears 32d,
When 33d is rotated in the directions of the "+" and "-" arrows, respectively, the axes of the limiting gears 80x and 80y are at the limiting position in the gear 32.
d, 33d driving force p +, p- and bearings 21f, 21
The resultant force P of the reaction force N + and N- of the convex portions 21g and 21i of h
Receive + and P-.

Therefore, as shown in FIGS. 8A and 8B, by changing the positions of the convex portions 21g and 21i that limit the rotation of the limiting gears 80x and 80y, the limiting gears at the limiting position can be changed. 80x and 80y axes are P
When the gears 32d and 33d are rotated in the arrow "-" direction, the force applied to the shafts of the limiting gears 80x and 80y can be reduced at the limiting position.

When detecting the position of the anti-shake lens 8, the limiting position obtained by rotating the gears 32d and 33d in the direction of the arrow "-" is used as the origin of the position detection, so that the limiting gear 80x at the limiting position, The force acting on the shaft of 80y can be reduced, and the shaft can be prevented from being damaged. That is,
If the limiting position on the side where the acting force on the gear shaft or bearing is small is used as the origin, the other side is hardly used. Therefore, the force exerted on the shaft and the bearing is minimized, which is excellent in reliability and durability in operation.

FIGS. 9A and 9B show modified examples of FIGS. 2 and 8 described above. In these drawings, in this embodiment, the rotation of the limiting gears 80x and 80y described above is shown. The limiting positions of the convex portions 21g and 21i are set so that the driving force p− of the gear 32d and the reaction force N− of the convex portions 21g and 21i are in opposite directions (positions of 180 degrees). By doing so, the force acting on the shaft and the bearing can be minimized at the limit position rotated in the "-" direction, and the force acting on each shaft can be reduced to the minimum and The influence can be minimized, and it corresponds to the optimum position as the limiting means.

10 (a) and 10 (b) are shown in FIG.
A modified example different from FIG. 8 and FIG. 9 is shown.
The case where the rotation of 80y is limited by an electric signal is illustrated. That is, the bosses 80xc and 80yc are provided at eccentric positions of the limiting gears 80x and 80y, and the bosses 80xc and 80yc are provided.
Switches 81x and 81y whose contact pieces are located within the rotation range of xc and 80yc are fixedly provided on the substrate 21.

According to such a configuration, the limiting gear 80
By rotating x and 80y in each direction,
The bosses 80xc and 80yc press the contact pieces of the switches 81x and 81y to turn them on, thereby stopping the rotation of the motors 30 and 31, thereby making this position the limiting position.
Then, by detecting the operation limiting positions of the limiting gears 80x, 80y by the switches 81x, 81y in this way,
The reliability can be further improved.

The present invention is not limited to the structure of the above-described embodiment, and the image blur prevention mechanism section 2 which constitutes the image blur prevention device.
It goes without saying that the shape, structure, etc. of each part including 0 can be appropriately modified and changed.

For example, in the above-mentioned embodiment, the reduction gear train (32, 32) which is the driving force transmission means from the driving force generation means (motors 30, 31) for the shake prevention optical system (the shake prevention lens 8; the lens frame member 6). 33), a screw mechanism (34a, 35a; 36a, 37) as a movement amount generating mechanism section.
As a limiting means provided separately from a), the second
Although the case where the gear members 80x and 80y that form the reduction gear train is used is shown, the present invention is not limited to this.
That is, the limiting means is not limited to the above-mentioned gear member, but may be a gear mechanism or a mechanical structure using a cam, a rack, or the like.

Further, in the above-described embodiment, the limiting gear 8
Grooves are provided on 0x and 80y, and a protrusion is provided on the bearing side.
These relationships can be changed appropriately, and various modifications of the shape and the like are conceivable.

Further, in the above-described embodiment, the case where the present invention is applied to the camera having the lens shutter 12 has been described, but the present invention is not limited to this, and image blur due to camera shake or the like is prevented in a conventionally known camera. In order to do
Needless to say, it can be applied to an anti-shake lens that shifts in a direction orthogonal to from, and is not limited to the structure on the camera side.

Furthermore, the shake prevention device according to the present invention is not limited to the above-mentioned camera, but can be applied to various optical instruments, devices, etc. to exert its effect.

[0068]

As described above, according to the shake preventing apparatus of the present invention, the driving force of the driving force generating means is applied to the shake preventing optical system which is movable in the direction substantially orthogonal to the optical axis of the main optical system. The driving force transmitting means for transmitting is composed of a reduction gear train for reducing the rotation from the rotary drive source, and a movement amount generating mechanism portion for moving the shake prevention optical system in a predetermined direction by the rotation driving force reduced by the reduction gear train. At the same time, since the limiting means for limiting the movable range of the shake prevention optical system within the predetermined range is configured by the limiting mechanism portion coupled to the reduction gear train, separately from the movement amount generating mechanism portion, the configuration is simple. Nevertheless,
The movable range of the shake prevention optical system can be restricted with high accuracy. Further, if such limiting means is additionally provided, there is an advantage that the degree of freedom of the lead angle in the gear ratio of the reduction gear train from the rotary drive source and the movement amount generating mechanism portion by the feed screw mechanism can be exhibited.

Further, according to the present invention, the limiting means is the second reduction gear train, and the operation range of the second reduction gear train is mechanically or electrically limited, and the second reduction gear train is further provided. By including a gear member that mechanically or electrically limits the rotation within a range of 1 rotation, it is possible to limit the movable range of the shake prevention optical system with an extremely simple mechanism and ensure high reliability. It has various excellent effects such as being able to.

Further, according to the present invention, the operation of the gear member included in the second reduction gear train, which is the limiting means, and whose rotation is mechanically limited within the range of one rotation is operated by this gear member. In the force acting on the bearing portion at the limit position in the first direction and the force acting on the bearing portion at the limit position in the second direction, the first
Direction and the second direction, the force acting on the bearing portion at the limit position in one direction is weaker than the force acting on the bearing portion at the limit position in the other direction. By configuring, it is possible to prevent an overload on the shaft and the bearing portion for moving the movable member, limit the movable range of the movable member in a required state, and have excellent durability and the like. There are also advantages.

[Brief description of drawings]

FIG. 1 shows an embodiment of a shake prevention device according to the present invention,
FIG. 3 is a cross-sectional view of a main portion of a shake prevention mechanism portion that is a main portion in a lens barrel portion of a camera.

FIG. 2 is a view for explaining an example of a limiting means for limiting the movable range of the shake prevention lens, and FIGS.
FIG. 7 is an enlarged view of a main part of a portion indicated by arrows IIa and IIb in FIG.

3 is a sectional view taken along line III-III in FIG.

4 is a sectional view taken along line IV-IV in FIG.

5 is a sectional view taken along line VV of FIG.

FIG. 6 is an enlarged view of a main part for explaining the position detecting means of the shake prevention lens.

FIG. 7 is a schematic configuration diagram for explaining a schematic configuration of a camera with a lens shutter, to which the shake prevention device according to the present invention is applied.

FIG. 8 is a view for explaining a modified example of the restricting means for restricting the movable range of the shake preventing lens, and FIGS. 8A and 8B are enlarged views of a main part corresponding to FIGS. 2A and 2B. It is a figure.

FIG. 9 is a view for explaining another modified example of the limiting means for limiting the movable range of the shake preventing lens, and FIGS.
FIG. 9 is an enlarged view of an essential part corresponding to FIGS. 2 and 8A and 8B.

FIG. 10 is for explaining still another modified example of the limiting means for limiting the movable range of the shake prevention lens,
(A), (b) is a principal part enlarged view corresponding to (a), (b) of FIG. 2, FIG. 8, FIG.

[Explanation of symbols]

1 camera 2 photographing lens 4 first lens group 6 lens frame (lens frame member) 6a flange part 7 front lens group 8 rear lens group (anti-shake lens) 9 second lens group 11 third lens group 12 lens shutter 15 shutter drive Part 16 Image forming surface 20 Image blur prevention mechanism part 21 Substrate 21a Opening part 30 x-axis DC motor (driving means) 31 y-axis DC motor (driving means) 32 Driving force transmission gear train (reduction gear train) 32d gear 33 driving force transmission gear train (reduction gear train) 33d gear 34 first shaft (constituting a part of movement amount generation mechanism part) 34a male screw part 35 second shaft (part of movement amount generation mechanism part) 35a Male screw part 36 x Movable member on x-axis side 36a Female screw part 37 y Movable member on y-axis side 37a Female screw part 40x Disc with hole 40y Disc with hole 41x Photo 41y Photo interrupter 51 Spring 52 Spring 53 Spring 54 Spring 55 Guide member 56 Guide member 59 Roller 60 Roller 61 Roller 62 Roller 63 Roller shaft 64 Roller shaft 65 Roller shaft 66 Roller shaft 67 Retaining member 68 Retainer member 69 Retaining member 70 Ball 71 Ball 80 Limiting gear (gear member that constitutes the second reduction gear train serving as limiting means) I Optical axis of photographing lens system

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasushi Sakagami Marunouchi 3-chome 3-3, Chiyoda-ku, Tokyo Nikon Corporation (72) Inventor Etsuo Tanaka Marunouchi 3-chome 2-3, Chiyoda-ku, Tokyo Company Nikon

Claims (6)

[Claims] 1. A shake prevention optical system for preventing image shake by being moved in a direction substantially orthogonal to an optical axis of a main optical system, and a drive for generating a driving force for driving the shake prevention optical system. A force generation unit, a driving force transmission unit that transmits the driving force of the driving force generation unit to the shake prevention optical system, and a limit unit that limits the movable range of the shake prevention optical system within a predetermined range, The driving force transmission transmission means is a reduction gear train that reduces the rotation from the rotary drive source, and a movement amount generation mechanism for moving the shake prevention optical system in a predetermined direction by the rotation driving force that is reduced by the reduction gear train. And a limiting means separate from the movement amount generating mechanism section.
A shake preventing device comprising a limiting mechanism portion coupled to the reduction gear train. 2. The shake prevention device according to claim 1, wherein the limiting means is constituted by a second reduction gear train, and the second reduction gear train is constituted so that the operation range is mechanically limited. A shake prevention device characterized by being. 3. The shake preventive device according to claim 2, wherein the second reduction gear train that constitutes the limiting means includes a gear member that mechanically limits rotation within a range of one rotation. Anti-shake device characterized by. 4. The anti-vibration device according to claim 3, wherein the gear member included in the second reduction gear train that is the limiting means and mechanically limited in rotation within a range of one rotation is the gear member. One of the first direction and the second direction of the force acting on the bearing portion at the limit position in the first direction and the force acting on the bearing portion at the limit position in the second direction of the member. Is configured so that its operation is mechanically limited so that the force acting on the bearing portion at the limit position of is weaker than the force acting on the bearing portion at the limit position in the other direction. Anti-shake device. 5. The shake prevention device according to claim 1, wherein the limiting means is constituted by a second reduction gear train, and the second reduction gear train is constituted so as to electrically limit the operating range. A shake prevention device characterized by being. 6. The shake prevention device according to claim 5, wherein the second reduction gear train that constitutes the limiting means includes a gear member that is electrically limited in rotation within a range of one rotation. Anti-shake device characterized by.