JPH0736075A - Camera shake preventing device - Google Patents

Abstract

PURPOSE:To make a camera shake preventing device simple in structure and low in cost by using the parts of the driving mechanism part of a camera shake preventing lens in common. CONSTITUTION:One set of motors 30 and 31 being a driving force generation means and one set of gear trains 32 and 33, shafts 34 and 35, movable members 36 and 37, springs 51 and 52, springs 53 and 54, guide members, rollers 59, 60, 61 and 62 and roller shafts 63, 64, 65 and 66 being a driving force transmission means are respectively provided for x axis and y axis, that means, totally two sets are provided. The respective parts of two sets of driving force generation means and two sets of driving force transmission means are constituted of the common parts and arranged almost symmetrically to a straight line L dividing an angle formed by two axes into almost halves.

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 for preventing image shake caused by camera shake in a camera or the like.

[0002]

2. Description of the Related Art Conventionally, as a shake preventing device of this type, a part of a photographing lens (hereinafter referred to as a shake preventing lens) is used as an optical axis in order to prevent shake caused by vibration of a camera at the time of photographing. It is known that it moves in the direction perpendicular to. Such a shake preventing device is known as a driving force generating means and a drive transmitting means for moving the shake preventing lens, for example, a structure disclosed in FIG. 7 of JP-A-3-110530. .

[0003]

In the above-described conventional shake preventing device, two driving force transmitting means are provided to drive the shake preventing lens independently in the x-axis direction and the y-axis direction. However, since the structure has a line-symmetrical arrangement (right-hand and left-hand relationship), there is a problem in that parts cannot be shared, leading to cost increase. Further, since the driving force transmitting means drives the shake prevention lens on both sides around the optical axis, the driving force generating means such as a motor must be able to rotate forward and backward. Since the means are not completely the same (the structure is opposite to the rotation direction), it is difficult to control.

On the other hand, if each component is simply shared,
Another problem arises in that the respective parts cannot be arranged efficiently and the device becomes rather large.

An object of the present invention is to provide an anti-shake device having a drive mechanism section for an anti-shake lens capable of highly accurately preventing shake by a simple and inexpensive structure.

[0006]

A first solution of the shake prevention apparatus according to the present invention is substantially orthogonal to the plane perpendicular to the optical axis of the main optical system in order to prevent shake caused by vibration. A shake prevention optical system driven in two axial directions, a driving force generation unit that generates a driving force that drives the shake prevention optical system, and a driving force from the driving force generation unit are transmitted to the shake prevention optical system. In a shake prevention device having a driving force transmitting means, the driving force generating means and the driving force transmitting means are provided in two sets, one set for each of the two shafts.
The two sets of the driving force generating means and the driving force transmitting means are composed of common parts, and are arranged substantially symmetrically with respect to a straight line that bisects the angle formed by the two axes. It is characterized by

A second solution means is a shake prevention optical system driven in two axial directions substantially orthogonal to each other in a plane perpendicular to the optical axis of the main optical system in order to prevent shake caused by vibration. In a shake preventing device having a driving force generating means for generating a driving force for driving the shake preventing optical system, and a driving force transmitting means for transmitting the driving force from the driving force generating means to the shake preventing optical system, The driving force transmission means includes a gear train, and the gear train is characterized in that the shafts of the gears meshing with each other are arranged on a straight line.

A third solving means is a shake prevention optical system driven in two axial directions substantially orthogonal to each other in a plane perpendicular to the optical axis of the main optical system in order to prevent shake caused by vibration. In a shake preventing device having a driving force generating means for generating a driving force for driving the shake preventing optical system, and a driving force transmitting means for transmitting the driving force from the driving force generating means to the shake preventing optical system, The driving force transmitting means includes a gear train, and a mounting hole for each gear is formed on one straight line on the substrate on which the gear train is mounted, or two mounting holes are formed at positions symmetrical to the straight line. It is characterized by

[0009]

According to the first solution, the shake prevention optical system 2
Since the driving force generating means and the driving force transmitting means of the set are shared by the respective parts and are arranged substantially symmetrically, the types of the parts can be reduced. Further, since the two sets of driving force transmitting means have the same components and the same arrangement, the load characteristics applied to the driving force generating means become the same when the shake prevention optical system is driven.

According to the second solving means, since the gear trains are arranged on a straight line, the driving force generating means can be rotated forward and backward,
The gear train efficiency is the same and the structure is completely symmetrical.

According to the third means for solving the problems, since the preliminary holes are provided in the base plate of the gear train and the common base plate is used, the gear trains can be arranged in a staggered manner.

[0012]

Embodiments will be described in more detail below with reference to the drawings and the like. 1 to 6 are views showing a first embodiment of a shake prevention device according to the present invention. In these figures, first, a schematic configuration of a camera having a photographing lens system with a lens shutter, to which the present invention is applied, will be briefly described with reference to FIG.

That is, in the camera 1, the taking lens system 2 is configured as a zoom lens composed of the first lens group 4, the second lens group 9 and the third lens group 11. The first lens group 4 includes three lenses 4a, 4
b and 4c are held by the lens frame 3. The second lens group 9 includes three and four lenses 7.
a, 7b, 7c; 8a, 8b, 8c, 8d are constituted by a total of seven lenses by front and rear lens groups 7, 8 held by the lens frames 5, 6. Third lens group 11
Means that the three lenses 11a, 11b and 11c are the lens frame 1
It is configured to be held at 0.

The lens shutter 12 is provided between the front lens group 7 and the rear lens group 8 of the second lens group 9 described above, and the 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 15 is arranged in the second lens group 9 on the outer peripheral portion of the lens frame 5 of the front lens group 7 and the like.
The lenses 3 and 14 are arranged immediately in front of the rear lens group 8 which functions as an image blur prevention lens described later.

Further, the image plane 16 has the first, second and third lens groups 4, 4 which constitute the photographing lens system 2 described above.
9 and 11 is a surface on which a film on which a subject image is formed is arranged. In the figure, I is the optical axis of the taking lens system 2.

In this embodiment, in the taking lens system 2 having the three lens groups 4, 9 and 11 as described above,
By shifting the rear lens group 8 of the second lens group 9 as an image blur preventing lens in directions orthogonal to each other in a plane perpendicular to the optical axis I, image blur prevention as shown in FIGS. The mechanism unit 20 is used to move the image formed on the image plane 16 in accordance with the image shake state. This image blur prevention mechanism 2
0 is the second as shown in FIGS. 2, 3, 4, and 6.
The lens group 9 is provided in the outer space of the rear lens group 8.

Next, the image blur prevention mechanism section 20 will be described in detail with reference to FIGS. The rear lens group 8 of the second lens group 9 (hereinafter referred to as the shake prevention lens 8) is fixed and held in the lens frame 6. As shown in FIG.
Around the opening 21a of the substrate 21, a receiving member 69 for receiving the balls 70 and 71 is fixed by a structure in which a retainer member 68 for determining the position of the balls 70 and 71 is sandwiched.

The retainer member 68 includes balls 70 and 71.
There is a through hole that is freely rotatable inside. The lens frame 6 includes arms 6f and 6g provided on a part of the lens frame 6.
Springs 51 and 52 are laid between the substrate and the substrate 21,
The receiving member 67, which is fixed to the flange portion 6a and is made of a high hardness material such as hardened steel, is always in contact with the balls 70 and 71. As a result, the shake prevention lens 8
Can move with a low load in a plane perpendicular to the optical axis I, and since it is biased by the springs 51 and 52, it does not fall down and deteriorate the optical performance. Although only the balls 70 and 71 are shown in two places in FIG. 4, they are arranged in four places around the opening 21a of the substrate 21, including the balls 72 and 73 shown in FIG. .

DC motors 30 and 31 for x-axis and y-axis
Is a drive means for moving the image stabilizing lens 8 in the x-axis direction or the y-axis direction (indicated by Mx and My in FIG. 1). The gear trains 32 and 33 are used for these motors 3.
Gears 32a, 32b, which transmit the driving force from 0, 31
32c, 32d; 33a, 33b, 33c, 33d is a gear train for rotation transmission, and its rotation is transmitted to the first or second shaft 34, 35. First and second shaft 3
4, 35 are bearing members 21b, 2 provided on the substrate 21.
It is rotatably supported by 1c or 21d and 21e so as to extend in the x-axis direction or the y-axis direction. Further, the bearing members 21b and 21d are common parts, and as shown in FIG. 1 (a), they extend and also serve as the substrates of the shafts of the gear trains 32 and 33.

The above-mentioned motors 30 and 31 are fixed to the substrate 21 side, and gears 32a, 32b and 32c constituting the gear trains 32 and 33; 33a and 33b,
33c is rotatably supported by shafts planted on the bearing members 21b and 21d of the substrate 21, and gears 32d and
33d is configured to be rotatable integrally with the shafts 34 and 35, respectively. Here, the gears 32a and 33a, the gear 32
b and 33b, gears 32c and 33c, gears 32d and 33d
Are common parts.

The movable members 36 and 37 on the x-axis side and the y-axis side are
Internal thread 3 that is a common part and is provided for each
6a and 37a are male threads 34a and 35a of the shafts 34 and 35.
It is screwed to. Guide members 55 and 56 are fixed to the movable members 36 and 37 adjacent to the female screw portions 36a and 37a. The guide members 55 and 56 are also common parts, and as shown in FIG.
It is guided by guide shafts 57 and 58 fixed to the shafts b and 21d or 21c and 21e in parallel with the shafts 34 and 35.
Therefore, the movable members 36 and 37 are moved in the x-axis direction and the y-axis direction by the motors 30 and 31, respectively.

To the flange portion 6d of the lens frame 6, rollers 59, 60, 61 and 62, which are common parts, are rotatably attached by roller shafts 63, 64, 65 and 66 which are common parts. 6, between the spring hooking portion 6b on the opposite side of the rollers 59 and 60, the spring hooking portion 6c on the opposite side of the rollers 61 and 62, and the substrate 21, the respective springs 53 and 54, which are also common parts, respectively. The movable members 36 and 37 are bridged in a direction substantially the same as the x-axis direction and the y-axis direction of the movable direction (see FIGS. 3 and 1). The rollers 59, 60 and 61, 62 have abutting portions 36b, 3 having substantially L-shaped cross-sections at both ends of the movable members 36, 37, respectively.
6c or 37b, 37c is contacted by the biasing force of the springs 53, 54.

Therefore, the anti-shake lens 8 described above is
The shaft-side motor 30 shifts the movable member 36 following the movable direction (x-axis direction) of the movable member 36, but is free in the y-axis direction. Further, similarly, the shake prevention lens 8 shifts following the movable direction (y-axis direction) of the movable member 37 by the y-axis side motor 31, but is free in the x-axis direction. From this, the shake prevention lens 8 is provided in the opening 2 of the substrate 21.
It is possible to shift in all directions inside 1a.

Further, the lens frame 6 is provided by the springs 53 and 54.
The lens frame 6 and the movable members 36 and 37 are always in contact with each other by urging the movable member 36 and 37 in substantially the same directions as the x-axis direction and the y-axis direction which are the movable directions of the movable member 3 and 37.
The movements of 6, 37 can be reliably transmitted to the lens frame 6.

Further, due to the urging force of the springs 53 and 54,
The thrust rattling of the shafts 34 and 35 and the rattling of the screw threads of the male screw portions 34a and 35a of the shafts 34 and 35 and the female screw portions 36a and 37a of the movable members 36 and 37 can always be taken in the respective biasing directions. . Therefore, each motor 3
The driving force of 0, 31 can be accurately and reliably transmitted to the shake prevention lens 8.

Limiting gears 80x and 80y mesh with the small gears of the gears 32d and 33d, respectively, and the limiting gears 80x and 80y are the bearing members 21b and 2 of the base plate 21.
It is rotatably attached to 1d. Next, the function of the limiting gears 80x and 80y will be described. FIG. 7A shows
1 is a view taken along the line VII (a) of FIG. 1, showing the gear 32d and the limiting gear 80x in the x-axis direction, and FIG. 7B is a view taken along the line VII of FIG.
FIG. 13B is a diagram showing a gear 33d and a limiting gear 80 in the y-axis direction.
It shows y.

The limiting gears 80x, 80y are provided with substantially C-shaped grooves 80xa, 80ya on the rear surface side as viewed in the drawing, and the both ends of the grooves 80xa, 80ya in the rotational direction are ribs 80xb, 80yb. Has become. Protrusions 21g and 21h are formed on the bearing members 21b and 21d so as to enter the grooves 80xa and 80ya. Therefore, the limiting gears 80x and 80y are respectively 18
Ribs 80xb, 80y in a range that does not rotate 0 degree
b contacts the convex portions 21g and 21h, and mechanically limits the rotation.

Here, as shown in FIGS. 7 (a) and 7 (b), when the convex portions 21g and 21h are located at the centers of the grooves 80xa and 80ya, the anti-vibration lens 8 moves to the center position (vibration). The position where the optical axis of the prevention optical system coincides with the optical axis I of the main optical system), and the shift amount of the shake preventing lens 8 and the rotation angle of the limiting gears 80x and 80y are adjusted to match the shake preventing lens 8 The shift amount of can be limited.

The shake prevention lens 8 detects its position and speed by a rotary encoder RE as shown in FIG. This rotary encoder RE is shown in FIG.
Also, the circular plates with holes 40x and 40y, which are provided integrally with the gears 32a and 33a shown in FIG. 5 and have a large number of holes in the peripheral portion at equal intervals, and the substrate 21 with the peripheral portion sandwiched therebetween. Photo interrupter 41 provided on the side
x, 41y. That is, the photo interrupters 41x and 41y allow the disks 40x and 40y to
The position and the velocity are detected by detecting the number of holes on the y side as a pulse signal and counting this.

To detect the position, for example, when the gears 32d and 33d are rotated in the arrow (-) direction in FIG. 7, the shake prevention lens 8 shifts to the lower left direction in FIG. 1 and reaches the limit position. This is performed by counting pulses with the photo interrupters 41x and 41y with the position as the origin, and the speed is detected by detecting the speed of the pulse.

That is, since the rotary encoder RE is provided on the output shafts of the motors 30 and 31 and is provided on the limiting gears 80x and 80y via the reduction gear train, the limiting gears 80x and 80y are
The operation limit position and the operation angle of 80y can be detected with high resolution. Further, the limiting gears 80x and 80y can limit the shift range of the shake preventing lens 8 to a predetermined range by one limiting gear by setting the operating rotation angle to an angle smaller than 360 degrees. Further, since the shake prevention lens 8 is driven via the feed screw mechanism in addition to the limiting gears 80x and 80y, the shake prevention lens 8 can be accurately moved without directly applying a load to the shake prevention lens 8.
The shift range of can be limited to a predetermined range.

The shake prevention device of this embodiment is shown in FIG.
As is clear from FIG.
At the neutral point in the axial direction, from the y-direction drive motor 31 of the shake preventing lens 8 to the gear train 33 and the bearing member 21.
d, screw parts 35a, 37a, lens frame 6 and its supporting part,
A y-direction drive system including an urging spring 54, the x-direction drive motor 30 of the shake preventing lens 8 to the gear train 32, the bearing member 21b, the screw portions 34a and 36a, the lens frame 6 and its supporting portion, and the urging spring. An x-direction drive system composed of 53 and the like intersects the optical axis I, and has an inclination of 45 degrees with respect to the x-axis and the y-axis that drive the shake prevention lens 8 orthogonal to each other in a plane perpendicular to the optical axis I. They are arranged substantially symmetrically with respect to the straight line L. The limiting gears 80x and 80y are also arranged substantially symmetrically with respect to the straight line L.

Further, the gear trains 33 and 32 are shown in FIG.
As shown in FIG. 3, they are linearly arranged (the gear train 32 is not shown, but has the same structure as the gear train 33). Since the limiting gears 80x and 80y are also arranged on a straight line, they are common parts with the bearing members 21b and 21d, and the types of parts are reduced.

FIG. 8 shows a second embodiment of the shake prevention device according to the present invention.
FIG. 3 is a plan view showing a gear train of the embodiment of FIG. As shown in FIG. 1A, the gear train 32 of the first embodiment has three gears 3
3a, 33b, 33c, 33d, 80 are arranged on a straight line. However, there are cases where it is unreasonable to arrange them on a straight line for the convenience of design. Therefore, in the second embodiment, the gears 33'a, 33'd are arranged on the straight line M, but the other gears 33'b, 33'c, 80'y are
The straight lines M are arranged in a zigzag pattern.

In such a case, the gear trains in the x and y directions are not perfectly symmetrical. Therefore, with respect to the mounting holes of the gears 33'b, 33'c, 80'y which are not arranged on the straight line M, the preliminary holes 133b, at positions symmetrical to the straight line M,
133c and 180 are provided. That is, this spare hole 1
33b, 133c, 180, and the gear 3 in the x direction
If 2'b, 32'c, 80'x are attached, similar gear trains can be assembled in both the x and y directions, and the board 21'd and the board 21'b can be made common,
The types of parts can be reduced.

The present invention is not limited to the embodiments described above, and various modifications and changes are possible, which are also included in the present invention. For example, the shake prevention device of each embodiment has been described using the camera with a lens shutter, but the same can be applied to a single lens reflex camera.

[0037]

As described above in detail, according to the first aspect, the two sets of the driving force generating means and the driving force transmitting means of the shake prevention optical system are made common to each other and are arranged substantially symmetrically. Therefore, there is an effect that the number of types of parts can be reduced and the cost can be reduced. Further, since the two sets of driving force transmitting means have the same components and the same arrangement, when the shake prevention optical system is driven, the load characteristics and the like applied to the driving force generating means become the same, which facilitates control.

According to the second aspect, since the gear train is arranged in a straight line, the efficiency of the gear train becomes the same with the forward rotation and the reverse rotation of the driving force generating means, the control is easy, and the structure is complete. There is an effect that it becomes symmetrical and can be simplified.

According to the third aspect of the present invention, the preliminary holes are provided in the base plate of the gear train so that the base plate is commonly used. Therefore, the gear trains can be arranged in a staggered manner, and the degree of freedom in design is widened. .

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a shake preventing device according to the present invention, FIG. 1 (a) is a plan view of a gear train, FIG.
(B) is a sectional view of a main part.

FIG. 2 is a sectional view taken along line II-II in FIG.

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

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

FIG. 5 is an enlarged view of an essential part for explaining the position detecting means of the shake prevention lens.

FIG. 6 is a schematic configuration diagram showing a camera with a lens shutter suitable for using an embodiment of the shake preventing apparatus according to the present invention.

FIG. 7 is an enlarged view of an essential part for explaining a limiting means for limiting the movable range of the shake prevention lens according to the first example.

FIG. 8 is a plan view showing a gear train of a second embodiment of the anti-vibration device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 camera 2 photographing lens 4 first lens group 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 section 16 image forming surface 20 image blur prevention mechanism section 30, 31 Motor (common part) 32, 33 Gear train (common part) 34, 35 Shaft (common part) 36, 37 Movable member (common part) 50 Sliding member 51, 52 Spring (common part) 53, 54 Spring (Common parts) 55,56 Guide member (common parts) 59,60,61,62 Rollers (common parts) 63,64,65,66 Roller shafts (common parts) 67,69 Receiving members 68 Retainer members 70,71 Balls (Common parts) 80x, 80y Limiting gear (Common parts) I Optical axis of shooting lens system

Claims (3)

[Claims] 1. In order to prevent a shake caused by a vibration, the light beams are substantially orthogonal to each other in a plane perpendicular to the optical axis of the main optical system.
A shake preventing optical system driven in the axial direction, a driving force generating means for generating a driving force for driving the shake preventing optical system, and a drive for transmitting the driving force from the driving force generating means to the shake preventing optical system. In the shake prevention device having force transmitting means, the driving force generating means and the driving force transmitting means each have one set for each of the two axes, and there are a total of two sets. The shake preventing device is characterized in that the force transmitting means is configured such that each of the components is a common component, and is arranged substantially symmetrically with respect to a straight line that divides the angle formed by the two axes into two substantially equal parts. 2. A shake prevention optical system driven in two axial directions substantially orthogonal to each other in a plane perpendicular to the optical axis of the main optical system to prevent shake caused by vibration, and the shake prevention optical system. In the shake preventing device, there is provided drive force generating means for generating a drive force for driving the drive force, and drive force transmitting means for transmitting the drive force from the drive force generating means to the shake preventing optical system, wherein the drive force transmitting means Includes a gear train, wherein the gear train has shafts of gears meshing with each other arranged in a straight line. 3. A shake prevention optical system driven in two axial directions substantially orthogonal to each other in a plane perpendicular to the optical axis of the main optical system in order to prevent shake caused by vibration, and the shake prevention optical system. In the shake preventing device, there is provided drive force generating means for generating a drive force for driving the drive force, and drive force transmitting means for transmitting the drive force from the drive force generating means to the shake preventing optical system, wherein the drive force transmitting means Includes a gear train, and a mounting hole for each gear is provided on the substrate on which the gear train is mounted.
An anti-vibration device, which is formed on one straight line or two at a position symmetrical to the straight line.