JPH0728115A - Camera shake preventive device - Google Patents

Abstract

PURPOSE:To support a shake prevented lens in the low load condition, reduce the moment generated at the time of driving in the lens, and suppress the drive resistance of a moving amount converting means. CONSTITUTION:The positions of a spring 53 and rollers 59, 60 and the positions of another spring 54 and rollers 61, 62 are set in the same plane II which is approx. perpendicular to the optical axis I as the moving direction of movable members 36, 37. The positions of feed screw shafts 34, 35 and rollers 59, 60 and ones 61, 62 are also set in the same plane II approx. perpendicular to the optical axis I as the moving direction of the movable members 36, 37. The spring 53 is located on the extension line in the middle x-axis direction of the rollers 59, 60, while the spring 54 is positioned on the extension in the middle y-axis direction of the other rollers 61, 62.

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. In this shake prevention device, the shake is prevented by moving the shake preventive lens in the direction perpendicular to the optical axis. Therefore, a drive mechanism for driving the shake preventive lens must be provided in the narrow lens barrel.

As such a drive mechanism, for example, a structure is disclosed in which a lens frame of a shake prevention lens is sandwiched by inner flange portions from both front and rear sides in the optical axis direction, and is pushed by a movable member in a direction perpendicular to the optical axis (special feature). Fig. 7 of Kaihei 3-84507).

[0004]

However, in the above-mentioned conventional technique, the lens frame of the shake-preventing lens is sandwiched in front of and behind the optical axis. Therefore, in order to drive the shake-preventing lens at high speed, high precision is required. Processing is required, which leads to an increase in cost and makes it difficult to finely adjust after assembling.

In order to solve this problem, the applicant of the present invention has an anti-shake device having a structure in which the anti-shake lens is guided by one guide surface orthogonal to the optical axis and the anti-shake lens is supported under a low load condition. Has already been proposed (Japanese Patent Application No. 5-95)
No. 204).

That is, this shake preventing device includes a shake preventing optical system, an optical system guiding means, a driving force generating means, a driving force transmitting means, a moving amount converting means, a biasing means and the like. . The shake prevention optical system is an optical system that is movable in a direction substantially orthogonal to the optical axis of the main optical system in order to prevent shake caused by vibration. The optical system guide means is a means for holding the shake prevention optical system so as to be movable along one guide surface. The driving force generation unit is a unit that generates a driving force for driving the shake prevention optical system, and uses, for example, an x-axis motor and a y-axis motor, such as a DC motor, as driving forces, and a reduction mechanism using gears, respectively. And transmit the driving force.

The driving force transmitting means is a means for transmitting the driving force of the driving force generating means to the shake prevention optical system, and for example, a feed screw is used. The movement amount conversion means is a means for converting the driving force of the driving force transmission means into a movement amount for moving the shake prevention optical system, and includes a movable member. At this time, since the shake prevention lens is required to be able to move freely in the xy plane, a roller is rotatably attached to the flange portion of the lens frame and is movable by using the x-axis motor as a driving force. When the member moves in the x-axis direction, the roller can also move in the y-axis direction.
Therefore, this roller serves as a coupling portion between the movement amount conversion means and the shake prevention optical system.

The biasing means is a means for biasing the anti-shake optical system in a direction substantially the same as the moving direction of the anti-shake optical system, and a spring is used here. When the feed screw is used as the movement amount transmitting means, the biasing means removes the rattling of the screwed portion and reliably transmits the movement of the movable member to the lens frame of the shake prevention lens. Is biased in the direction of.

In this shake prevention device, the play of the screw portion of the feed screw is reduced, the spring for surely transmitting the movement of the movable member to the lens frame of the shake preventing lens, and the driving force by the feed screw are used for the shake preventing lens. The positional relationship between the roller and the roller is important. Further, the shake prevention lens has a structure capable of moving within a plane substantially perpendicular to the optical axis, and both the spring and the roller are attached to the lens frame of the shake prevention lens. Therefore, the mounting position of the spring,
Depending on the mounting position of the roller, a moment is generated in the anti-shake lens during driving, which makes the lens unstable. Further, depending on the positions of the feed screw and the roller, a moment is generated in the feed screw, and drive resistance increases.

An object of the present invention is to support an anti-shake lens in a low load state, reduce the moment generated in the anti-shake lens during driving, and suppress the drive resistance of the movement amount converting means. Is to provide.

[0011]

In order to solve the above-mentioned problems, the first solution means of the shake preventive apparatus according to the present invention is to prevent the shake caused by vibration from occurring in the optical axis of the main optical system. An anti-shake optical system that is movable in a direction substantially orthogonal thereto, an optical system guide unit that holds the anti-shake optical system movably along one guide surface, and an anti-shake optical system for driving the anti-shake optical system. Driving force generating means for generating driving force, driving force transmitting means for transmitting the driving force of the driving force generating means to the shake prevention optical system, and driving force of the driving force transmitting means for moving the shake preventing optical system A shake preventing device having a moving amount converting means for converting the moving amount for moving the shake preventing optical system and a biasing means for biasing the shake preventing optical system in a direction substantially the same as the moving direction of the shake preventing optical system, The conversion unit of the movement amount conversion means is Characterized in that it placed on the surface and substantially coplanar to the action of the biasing force of the biasing means.

The second solving means is a shake prevention optical system which is movable in a direction substantially orthogonal to the optical axis of the main optical system in order to prevent shake caused by vibration, and the shake prevention. Optical system guide means for holding the optical system movably along one guide surface, driving force generating means for generating a driving force for driving the shake prevention optical system, and driving force of the driving force generating means. Driving force transmission means for transmitting the driving force of the driving force transmission means to a movement amount for moving the shake prevention optical system, and the shake prevention optical system. A shake prevention device having a biasing means for biasing the shake prevention optical system in a direction substantially the same as the movement direction of the shake prevention optical system, wherein the connecting portion between the movement amount conversion means and the shake prevention optical system is the biasing means. The same plane as the surface on which the urging force of Characterized in that it placed on.

Further, according to a third solving means, in the shake preventing apparatus according to the second solving means, the coupling portion between the movement amount converting means and the shake preventing optical system is arranged such that the center line at the neutral position is the biasing means. It is characterized in that it is substantially coincident with the urging direction.

[0014]

According to the present invention, the conversion portion of the movement amount conversion means and the coupling portion of the movement amount conversion means and the shake prevention optical system are arranged on substantially the same plane as the surface on which the biasing force of the biasing means acts. Therefore, it is possible to reduce the moment generated in the shake preventing lens at the time of driving and reduce the drive resistance of the movement amount conversion means. Further, since the connecting portion of the movement amount conversion means and the shake prevention optical system is arranged so that the center line at the neutral position substantially coincides with the biasing direction of the biasing means, it is possible to reduce the moment generated in the shake prevention optical system during driving. You can

[0015]

Embodiments will be described in more detail below with reference to the drawings and the like. 1 to 5 are views showing an embodiment of an anti-shake device according to the present invention. In these drawings, 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 described.
A brief description will be given 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 and 4a.
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.

Here, the lens shutter 12 is provided so as to be interposed between the front and rear lens groups 7 and 8 of the second lens group 9 described above, and the shutter curtains 13 and 14 and a drive section for driving them. 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 forming surface 16 is composed of the first, second and third lens groups 4 constituting the above-mentioned taking lens system 2.
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 in the direction orthogonal to the optical axis I as an image blur prevention lens, the image blur prevention mechanism section 20 as shown in FIGS. 1 to 4 is used. , The image formed on the image plane 16 is moved according to the image shake state. As shown in FIGS. 2, 3, 4, and 5, the image blur prevention mechanism section 20 is provided in the outer peripheral space of the rear lens group 8 of the second lens group 9.

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. In FIG. 4, a receiving member 69 for receiving the balls 70 and 71 is fixed around the opening 21a of the substrate 21 by a structure in which a retainer member 68 for determining the positions of the balls 70 and 71 is sandwiched therebetween. .

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 hung between the substrate and the substrate 21,
A receiving member 67 fixed to the flange portion 6a and 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-proof lens 8 has the optical axis I
Since it can move with a low load on a plane perpendicular to and is biased by the springs 51 and 52, it does not fall and the optical performance is not deteriorated. Although only two balls 70 and 71 are shown in FIG. 4, the balls 7 and 71 shown in FIG. 1 are provided around the opening 21 a of the substrate 21.
There are 4 locations including 2, 73.

In FIGS. 1, 2 and 3, for the x-axis,
The DC motors 30 and 31 for the y-axis are the image blur prevention lens 8
Is a drive means for moving the X axis direction or the Y axis direction (indicated by Mx and My in FIG. 1). Gear train 3
Reference numerals 2 and 33 denote gears 32a, 32b, 32c, 32d; 33 that transmit the driving forces from these motors 30 and 31, respectively.
a gear train for transmitting rotation composed of a, 33b, 33c, 33d, the rotation of which is performed by the first or second shafts 34, 35.
Be transmitted to. The first and second shafts 34 and 35 are used for the substrate 21.
Bearings 21b, 21c or 21d, 21 provided on the
The e is rotatably supported by extending in the x-axis direction or the y-axis direction.

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, respectively.
33c is rotatably fixed on the substrate 21, and
The gears 32d and 33d are configured to be rotatable integrally with the shafts 34 and 35, respectively.

The movable members 36 and 37 on the x-axis side and the y-axis side are
Female thread portions 36a and 37a provided respectively are screwed onto the male thread portions 34a and 35a of the shafts 34 and 35.
The movable members 36 and 37 include female screw portions 36a and 37a.
Guide members 55 and 56 are fixed adjacent to. The guide members 55 and 56 are, as shown in FIG.
The shaft 3 to the bearing parts 21b, 21d or 21c, 21e of the
It is guided by guide shafts 57 and 58 which are fixed in parallel with 4 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.

On the flange portion 6a of the lens frame 6, rollers 59, 60, 61 and 62 are provided with roller shafts 63, 64 and 65, respectively.
The roller 5 is rotatably mounted by a roller 66.
Spring hooking part 6 on the extension line of the intermediate x-axis driving direction of 9, 60
b, the springs 53 and 54 are respectively stretched between the spring hooking portion 6c on the extension line of the intermediate y-axis driving direction of the rollers 61 and 62 and the substrate 21 (see FIGS. 3 and 1). Also,
The spring 53 includes the rollers 59 and 60 and the spring 54 includes the roller 6
1 and 62 are installed so as to be located in the same plane II substantially orthogonal to the optical axis.

Each of the rollers 59, 60 and 61, 62 has an abutting portion 36b, 36c or 37 having a substantially L-shaped cross section at both ends of the movable members 36, 37, respectively.
The springs 53 and 54 are in contact with b and 37c.

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 frames 6 are formed 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 direction 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 and 37 can be reliably transmitted to the lens frame 6.

Furthermore, 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 and 31 can be accurately and reliably transmitted to the shake prevention lens 8.

By providing the positions of the spring 53 and the rollers 59 and 60, and the positions of the spring 54 and the rollers 61 and 62 on the same plane II substantially perpendicular to the optical axis I which is the moving direction of the movable members 36 and 37, A driving force transmitted to the rollers 59, 60 and 61, 62 and a biasing force of the springs 53, 54 do not generate a pitching moment about the lens frame 6. Therefore, the lens frame 6 is not tilted by the driving force of the motors 30 and 31, and the shake stabilizing lens 8 can be moved accurately and reliably.

Further, the feed screw shaft 3 which is a moving amount converting means.
4, 35 and the positions of the rollers 59, 60 and 61, 62 are provided in the same plane II substantially perpendicular to the optical axis I which is the moving direction of the movable members 36, 37, so that the feed screw shafts 34, 35 can be driven. It is possible to suppress the moment generated in the and to reduce the driving resistance.

Further, by providing the spring 53 on the extension line in the middle x-axis direction of the rollers 59 and 60 and the spring 54 on the extension line in the middle y-axis direction of the rollers 61 and 62, the movable member 3
The driving force center for moving the lens frame 6 transmitted from the rollers 6, 37 to the rollers 59, 60 and 61, 62 is the spring 53,
54 accords with the center of the biasing force that biases the lens frame 6 in the x-axis direction and the y-axis direction. Therefore, no moment is generated in the substantially orthogonal plane on the optical axis I centered on the lens frame 6 during driving. As a result, the lens frame 6 can be moved accurately and reliably during driving.

[0034]

As described in detail above, according to the present invention, the conversion portion of the movement amount conversion means and the coupling portion of the movement amount conversion means and the shake prevention optical system act on the biasing force of the biasing means. Since it is arranged on the substantially same plane as the surface, there is an effect that the shake-preventing lens can be stably moved by a simple and inexpensive structure without adding a special mechanism.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing a first embodiment of a shake prevention device according to the present invention.

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 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.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 camera 2 photographing lens 4 first lens group 7 front lens group 8 rear lens group 9 second lens group (anti-shake lens) 11 third lens group 12 lens shutter 15 shutter drive section 16 image forming surface 20 image shake prevention mechanism section 30, 31 Motor 32, 33 Gear train 34, 35 Shaft 36, 37 Movable member 51, 52, 53, 54 Spring 55, 56 Guide member 59, 60, 61, 62 Roller 63, 64, 65, 66 Roller shaft 67, 69 receiving member 68 retainer member 70, 71 ball I optical axis of photographing lens system

Claims (3)

[Claims] 1. A shake prevention optical system which is movable in a direction substantially orthogonal to an optical axis of a main optical system in order to prevent shake caused by vibration, and a single guide surface for the shake prevention optical system. An optical system guide means for holding the same so as to be movable along, a driving force generating means for generating a driving force for driving the shake preventing optical system, and a driving force of the driving force generating means for the shake preventing optical system. Driving force transmitting means for transmitting, a movement amount converting means for converting the driving force of the driving force transmitting means into a movement amount for moving the shake preventing optical system, and a direction substantially the same as the moving direction of the shake preventing optical system. A shake prevention device having a biasing means for biasing the shake prevention optical system, wherein the conversion portion of the movement amount conversion means is substantially coplanar with the surface on which the biasing force of the biasing means acts. Shake prevention device characterized by being arranged . 2. A shake prevention optical system that is movable in a direction substantially orthogonal to the optical axis of the main optical system in order to prevent shake caused by vibration, and a single guide surface for the shake prevention optical system. An optical system guide means for holding the same so as to be movable along, a driving force generating means for generating a driving force for driving the shake preventing optical system, and a driving force of the driving force generating means for the shake preventing optical system. Driving force transmitting means for transmitting, a movement amount converting means for converting the driving force of the driving force transmitting means into a movement amount for moving the shake preventing optical system, and a direction substantially the same as the moving direction of the shake preventing optical system. A shake preventing device having a biasing means for biasing the shake preventing optical system, wherein the movement amount converting means and the shake preventing optical system are coupled to each other,
A shake preventing device, which is arranged on substantially the same plane as a surface on which the biasing force of the biasing means acts. 3. The shake preventive apparatus according to claim 2, wherein the movement amount conversion means and the shake preventive optical system are coupled together.
A shake prevention device characterized in that a center line at a neutral position is made to substantially coincide with a biasing direction of the biasing means.