JP3206075B2 - Anti-sway device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Currently manufactured cameras are highly electronic and are highly automated in various parts including an automatic exposure mechanism and an auto focus mechanism. But,
One of the insufficiencies of this type of camera as an attempt to automate is a measure against image blur due to hand shake or the like that occurs during hand-held shooting. That is, in the conventional camera of this type, only the following proposals have been made for the image blur problem.

[0003] To briefly explain this, in taking an appropriate photograph, it is necessary to consider the effects of camera shake and the like on the side of the photographer holding the camera. On the basis of the detection result, a warning of the shake state is displayed under the condition where the shake occurs.

[0004] Further, a camera which controls so as not to be able to take a picture under the condition of occurrence of a shake based on the detection result of the shake detection means described above is disclosed, for example, in US Pat.
No. 96 has been proposed.

[0005] Further, there is a camera in which a camera is mounted on a vibration isolating table which can cut off external vibrations, thereby preventing the influence of vibration.

There is also known a camera in which a gyro for generating inertial force is attached to a camera.

[0007]

However, in the conventional measures against image blur as described above, the following problems cannot be avoided.

[0008] That is, merely by displaying the shake state as a warning, it is possible to confirm that the shake has occurred, but it is not possible to avoid the shake directly and take a picture without shake.

Further, if photographing cannot be performed while the camera shakes, the photographing conditions are limited, and a problem arises in that a desired photograph cannot be taken.

Further, when an attempt is made to use an anti-vibration table or a gyro, not only is the entire size increased, but also the price is increased, which is not suitable for a small camera using, for example, 35 mm film.

[0011] For this reason, there is also a method in which a part of the optical system is movably controlled as a shake correcting optical system based on the detection result of the shake detecting means described above to prevent image shake on the film image forming surface as much as possible. Although it has been proposed, the structure of this correction mechanism is complicated, and not only is the whole enlarged, but also there is a problem in movably controlling the correction optical system to a required state. It is desired to take some measures that can eliminate the problem.

In view of such circumstances, the present invention can reliably prevent image blur due to camera shake and the like, and has a simple structure, does not cause an increase in size, and can be easily incorporated into a restricted space. It is inexpensive in terms of cost, and an object of the present invention is to obtain a suitable shake preventing device when applied to, for example, a camera with a 35 mm lens shutter.

[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 orthogonal to the optical axis of a main optical system to prevent shake. A drive mechanism for driving the shake prevention optical system driven by the control means in accordance with the detection result of the shake detection means for detecting the shake, and a lens frame member for holding the shake prevention optical system. A first driving unit for driving the lens frame member in a second direction different from the first direction; a first driving unit for driving the lens frame member in a second direction different from the first direction; Means for driving the lens frame member in a first direction, and a second means independent of the first driving means.
And a second connecting means for driving the lens frame member in the second direction and irrespective of the second driving means. A second connecting member that connects the first and second connecting members so as to be movable in one direction;
The first and second driving means are movably disposed on the outer peripheral portion of the lens frame member holding the shake preventing optical system, and the first and second driving means are provided on the first and second outer peripheral portions of the lens frame member holding the shake preventing optical system. At a position different from the connecting member in the circumferential direction,
The anti-shake optical system is disposed with a positional relationship orthogonal to the optical axis.

Further, according to the present invention, first and second motors are used as the first and second driving means, and the first and second motors are used to control the rotational movement of the respective output shafts. First and second conversion means for converting linear motion in first and second directions are provided, and output shafts of the first and second motors are respectively connected to the first and second motors. Are arranged in parallel to the direction of.

[0015]

According to the present invention, the shake preventing optical system is driven through the lens frame member by the driving force from the first and second driving means which are driven and controlled in a required state by the shake detecting means and the control means. Thus, the shake preventing optical system can be arbitrarily driven in the combined direction to prevent the shake.

Further, according to the present invention, the first and second driving means and the first and second connecting members are moved in a required state around the outer peripheral portion of the lens frame member holding the shake preventing optical system. It is possible to install the unit in a unitized manner, and it is possible to increase the efficiency of the space and to arrange the unit adjacent to other complicated mechanisms.

[0017]

1 to 6 show one embodiment of a shake preventing apparatus according to the present invention. In these figures, first, a photographing lens system with a lens shutter suitable for applying the present invention is provided. The schematic configuration of the camera will be briefly described with reference to FIG.

That is, in the camera generally designated by the reference numeral 1, the taking lens system 2 includes three lenses 4a, 4b, 4c.
Are held by the lens frame 3, and three and four lenses 7a, 7b, 7
c; a second lens group 9 composed of a total of seven lenses by front and rear lens groups 7 and 8 constituted by holding 8a, 8b, 8c and 8d in the lens frames 5 and 6; A third lens group 11 configured by holding a plurality of lenses 11a, 11b, and 11c on a lens frame 10.
The zoom lens is composed of

Here, reference numeral 12 denotes a lens shutter provided between the front and rear lens groups 7, 8 of the above-mentioned second lens group 9, and includes shutter curtains 13, 14 and driving for driving the same. It is composed of a part 15 and the like. The driving section 15 is disposed on the outer peripheral portion of the lens frame 5 of the front lens group 7 in the second lens group 9 and further includes a shutter curtain 1.
Reference numerals 3 and 14 are disposed immediately before the rear lens group 8 functioning as an image blur prevention lens described later.

Further, in the figure, reference numeral 16 denotes the first, second and third lens groups 4, 9 and
Reference numeral 11 denotes an image plane formed by a film on which a subject image is formed, and I denotes an optical axis of the photographing lens system 2 in the figure.

According to the present invention, in the photographing lens system 2 having the three lens groups 4, 9 and 11 as described above, the rear lens group 8 of the second lens group 9 is replaced with an image blur prevention lens. In order to move the image formed on the image plane 16 according to the image blur state by shifting the image in the direction orthogonal to the optical axis I, the image blur prevention mechanism 20 shown in FIGS. The image blur prevention mechanism 20
2, 3 and 6, 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 second lens group 9. It has features.

This will be described in detail with reference to FIGS. 1 to 3. The rear lens group 8 (hereinafter referred to as the anti-shake lens 8) in the second lens group 9 is fixed and held in the lens frame 6. The lens frame 6 has four flange portions 6a provided on the outer peripheral portion of the substrate 21 and a lid 22 provided on the rear end side of the substrate 21 to form an annular space therein. 3 (shown only at two locations) with four front and rear four balls (hard balls) 23 and 24 (two locations are omitted). Accordingly, the substrate 21 is movably supported inside the opening 21a of the substrate 21 with a low load in a direction perpendicular to the optical axis I. In the drawings, reference numerals 25 and 26 denote retainers for holding the balls 23 and 24. Only four locations are shown, and the remaining four locations are omitted.

Reference numerals 30 and 31 denote the image blur prevention lens 8 as x.
DC motors for the x-axis and y-axis (indicated by Mx and My in the figure) serving as driving means for moving in the axial direction and the y-axis direction, 32 and 33 are these motors 30 and 31
Gears 32a, 32b, 32c, 3 for transmitting a driving force from
2d: a gear train for rotation transmission composed of 33a, 33b, 33c, 33d, the rotation of which extends to the bearing portions 21b, 21c provided on the substrate 21 in the x-axis direction and the y-axis direction and is rotatable. First and second shafts 34,
35. The motors 30 and 31 described above are fixed to the substrate 21 side.
Gears 32a, 32b, 32c constituting the gears 2, 33;
a, 33b and 33c are rotatably fixed on the substrate 21 and the final gears 32d and 33d are
It is configured so as to be able to rotate integrally with 4, 35.

The threaded portions 36a and 37a provided on the shafts 34 and 35 are the male threaded portions 3 of the shafts 34 and 35, respectively.
The x-axis side and y-axis side connection members screwed to 4a, 35a have long holes 36b, 36c formed in the x-axis side connection member 36 in parallel with the y-axis direction. Hole 3
Bosses 6b, 6c provided on the flange portion 6a of the lens frame 6 are engaged with 6b, 36c. Also,
Similarly to the above, the connecting member 37 on the y-axis side also has elongated holes 37b and 37c parallel to the x-axis direction, and these elongated holes 37b and 37c are also provided in the flange portion 6a of the lens frame 6.
The bosses 6d and 6e provided in are engaged.

Therefore, the above-described shake preventing lens 8
Is x through the connecting member 36 by the motor 30 on the x-axis side.
Driven in the axial direction, but free in the y-axis direction. Further, the shake preventing lens 8 has a similar mechanism,
The motor 31 is driven in the y-axis direction via the connecting member 37 by the motor 31 on the shaft side, but is free in the x-axis direction. Therefore,
The shake preventing lens 8 can be driven in all directions inside the opening 21a of the substrate 21.

The position of the shake preventing lens 8 is detected by the gears 32a and 33a shown in FIGS.
And discs 40x, 40y provided with a number of holes at equal intervals on the peripheral edge thereof, and photointerrupters 41x, 40x provided on the substrate 21 with the peripheral edges sandwiched therebetween. 41y, the rotation angles of the motors 30 and 31 on the x-axis and y-axis sides are detected. That is, the number of holes on the discs 40x and 40y is detected as pulse signals by the photo interrupters 41x and 41y, and the position is detected by counting the pulse signals.

The center position of the shake preventing lens 8 is determined as follows. 1 and 5
As is clear from FIG. 7, stopper pins 42x and 42y are provided at eccentric positions of the gears 32d and 33d provided integrally on the shafts 34 and 35, and these stopper pins 42x and 42y are provided on both sides of the bearings 21b and 21b on the substrate 21 side. 5 are brought into contact with each other at positions C and D in FIG.
The rotation angle d is restricted within the range of rotation between the positions C and D. Then, the center of the rotation range of the gears 32d and 33d is matched with the center position of the shake preventing lens 8, so that the center position of the shake preventing lens 8 may be determined.

The rear lens group (anti-shake lens) 8 of the second lens group 9 in FIG. 6 described above is shifted in the direction orthogonal to the lens optical axis I by the image blur prevention mechanism section 20 having the above configuration. Thus, the image formed on the image plane 16 is moved in a required state, and as a result, image blur can be prevented.

Further, according to the above-described image blur prevention mechanism 20, the DC motors 30, 31 having a relatively large volume are positioned so that their longitudinal directions are perpendicular to the optical axis I of the photographing lens group 2. 2 and FIG. 3, the DC motors 30 and 31 are connected to the lens shutter 12 and the third lens group 1.
It is not necessary to protrude to the one side, and it is possible to unite and integrate into the outer peripheral side of the lens frame 6 of the shake preventing lens 8 with high density and compactly, which is advantageous in terms of structure, assembly and the like.

Therefore, according to the image blur prevention mechanism 20, the space of the lens shutter 12 and the distance between the second lens group 9 and the third lens group 11 are not damaged. Moreover, since the unit can be easily formed as described above, it is excellent in assembling property. For example, it is very effective to arrange an interchangeable photographing lens adjacent to the aperture mechanism.

FIG. 7 shows a circuit block for controlling the above-mentioned image blur prevention mechanism section 20. In FIG. 7, reference numeral 60x denotes a shake for detecting the vertical angular velocity ωx of the camera by a known angular velocity sensor. The sensor 60y is a known angular velocity sensor, and the camera's horizontal angular velocity ω
These sensors 60x, 6
When the angular velocities ωx and ωy are detected at 0y, the processing circuit 61 converts the angular velocities ωx and ωy into the moving speed of the image on the image plane.

Here, the conversion processing by the processing circuit 61 will be described below with reference to FIG. That is, assuming that the distance from the lens L to the subject is a, the distance from the lens L is b, and the focal length of the lens L is f,

[0033]

(Equation 1)

From the relationship, if the optical axis I is inclined at an angular velocity ω to I ′, the speed v at which the image moves on the image plane at this time is
With the direction of the arrow as positive

[0035]

(Equation 2)

Can be expressed by Therefore, in the vertical direction of the camera,

[0037]

(Equation 3)

In the horizontal direction of the camera,

[0039]

(Equation 4)

## EQU4 ##

Next, the drive circuit 62 includes the DC motor 30,
31 is controlled so as to drive the shake preventing lens 8 so as to cancel the speeds vx and vy of the respective images. The rotation angles and rotation speeds of the DC motors 30 and 31 at this time are determined by the encoder on the x-axis side (by the disk 40x and the photo interrupter 41x) and the encoder on the y-axis side (by the disk 40y and the photo interrupter 41y). ), And is fed back to the drive circuit 62 to perform necessary drive control.

According to the above configuration, the first and second motors 30 and 31 can be movably moved into the annular space formed in the outer peripheral portion of the lens frame 6 of the shake preventing lens 8. First and second connecting members 3 to be arranged
6 and 37, which are arranged at positions shifted in the circumferential direction so that their respective longitudinal directions have a positional relationship orthogonal to the optical axis I. The DC motors 30 and 31 serving as driving means can be disposed without projecting to the outside, and furthermore, the anti-shake mechanism 20 can be configured as a unit, so that space and cost of the mechanism 20 can be reduced. And the like.

In particular, such an advantage is obtained by using the motors 30 and 3
The first and second output shafts are arranged in the x-axis direction and the y-axis direction, respectively, and their rotational force is converted into first and second conversion means via gear trains 32 and 33 as first and second conversion means. Axis 3 of
4, 35, and the first and second connecting members 36, 37, each of which is converted into a linear motion in the x-axis direction and the y-axis direction, so that it can be further exerted. is there.

Further, in the above configuration, the shake preventing mechanism 20 is formed by using a case member composed of the substrate 21 and the lid 22 in an annular space formed on the outer peripheral side of the lens frame 6 of the shake preventing lens 8. And is small in size, so that other complicated mechanical parts such as the lens shutter 12 as illustrated in FIG. It can exert an effect when used.

It should be noted that the present invention is not limited to the structure of the embodiment described above, and the image blur preventing mechanism 2 constituting the blur preventing device is used.
Needless to say, the shape, structure, etc. of each part including 0 can be appropriately modified and changed.

For example, in the above-described embodiment, the lens frame member 6 for holding the shake preventing optical system (shake preventing lens 8)
And balls 23, 2 as sliding means so as to be slidable with a low load only in a direction perpendicular to the optical axis I.
Although it is supported on the fixed portion side (substrate 21) via 4, it goes without saying that the present invention is not limited to this. That is, as is clear from FIGS. 9 to 11, the lens holding member 6 is slidably supported on the substrate 21 side via the sliding member 50 made of a material having low friction characteristics such as Teflon or fluororesin. At the same time, the flanges 6a on the lens frame member 6 side are always urged and held by the springs 51 and 52 so that the flange portion 6a on the lens frame member 6 side is always slidable. The sliding member 50 is fixed to the substrate 21 side, and the springs 51 and 52 are connected to the lens frame member 6.
Is stretched between the arm portions 6f and 6g provided on a part of the substrate 21 and the substrate 21.

The sliding member 50 made of such a low-friction material can of course obtain the required sliding support state of the lens frame member 6, and can obtain the same operation and effect as those of the above-described embodiment. It is something that can be done.

In the above-described embodiment, the case where the present invention is applied to the camera having the lens shutter 12 has been described. However, the present invention is not limited to this. Optical axis I
Needless to say, the present invention can be applied to a shake preventing lens that shifts in a direction perpendicular to the camera, and is not limited to the structure on the camera side.

Further, the anti-shake device according to the present invention is not limited to the above-described camera, but can be effectively applied to various optical devices and devices.

[0050]

As described above, according to the shake preventing apparatus of the present invention, the drive mechanism driven by the shake detecting means and the control means so that the shake preventing optical system can be moved in the direction orthogonal to the optical axis. Comprises a first driving means for driving a lens frame member holding the shake preventing optical system in a first direction, and a second driving means for driving in a second direction different from the first direction. And the first drive means is provided with the lens frame member in the first drive means.
The first connecting member which is driven in the direction of and is movably connected in the second direction independently of the first driving means, is driven by the second driving means, and the lens frame member is driven in the second direction. A second connecting member is provided for movably connecting in the first direction irrespective of the second driving means, and the first and second driving means are movable around an outer peripheral portion of a lens frame member of the shake preventing optical system. At a position shifted in the circumferential direction from the free first and second connecting members,
Since it is arranged with a positional relationship orthogonal to the optical axis, even if a DC motor is used as a driving means, these components do not protrude to the outside even if a DC motor is used, despite a simple mechanism structure. Has various excellent effects such as space saving and cost saving.

In particular, these effects are obtained by using a motor as a driving means and having first and second conversion means for converting the rotational movement of each output shaft into a linear movement in first and second directions. With the configuration described above, the output shafts of the first and second motors are arranged so as to be parallel to the first and second directions, respectively, so that the motor can be further exerted.

Further, according to the present invention, since the shake preventing mechanism can be made compact and unitary, there is an advantage that another complicated mechanism such as a lens shutter or an aperture mechanism can be arranged adjacently.

According to the present invention, the lens frame member holding the anti-shake optical system is made of a sliding means made of a low-friction material so as to be slidable with a low load in a direction perpendicular to the optical axis. , The shake preventing optical system can be moved with a low load in a direction orthogonal to the optical axis, and thereby, can be moved in the first and second directions (that is, There is an advantage that it can be moved in a required state in a direction synthesized by the driving means for driving in the x-axis direction and the y-axis direction).

[Brief description of the 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 part of a shake preventing mechanism that is a main part of a lens barrel of the camera.

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

FIG. 3 is a sectional view taken along line III-III of FIG. 1;

FIG. 4 is an enlarged view of a main part for describing a position detecting unit of a shake preventing lens.

FIG. 5 is an enlarged view of a main part for describing a method of locating the center of the shake preventing lens.

FIG. 6 is a schematic configuration diagram for explaining a schematic configuration of a camera with a lens shutter suitable for applying the shake prevention device according to the present invention.

FIG. 7 is a circuit block diagram for explaining control means for controlling the shake prevention device according to the present invention.

FIG. 8 is a schematic explanatory diagram of a shake preventing optical system for describing control by a control unit of the shake preventing device in FIG. 7;

FIG. 9 is a cross-sectional view of a main part of a shake preventing mechanism in a lens barrel portion of a camera showing another embodiment of the shake preventing device according to the present invention.

FIG. 10 is a sectional view taken along line XX of FIG. 9;

FIG. 11 is a sectional view taken along line XI-XI in FIG. 9;

[Explanation of symbols]

 Reference Signs List 1 camera 2 photographing lens system 4 first lens group 6 lens frame (lens frame member) 6a flange portion 6b boss 6c boss 6d boss 6e boss 7 front lens group 8 rear lens group (anti-shake lens) 9 second lens group Reference Signs List 11 Third lens group 12 Lens shutter 15 Lens shutter driving unit 16 Image forming surface by film 20 Image blur prevention mechanism unit 21 Substrate 21a Opening 21b Bearing unit 21c Bearing unit 22 Lid 23 Ball (hard ball) 24 Ball (hard ball) 30 DC motor for x-axis (driving means) 31 DC motor for y-axis (driving means) 32 Gear train for driving force transmission 32d Final gear 33 Gear train for driving force transmission 33d Final gear 34 First shaft (one of conversion means) 34a male thread 35 second shaft (constituting a part of the conversion means) 35a male thread 36 on the x-axis side Coupling member 36a Female thread portion 36b Long hole 36c Long hole 37 y-axis side connecting member 37a Female thread portion 37b Long hole 37c Long hole 40x Disk with hole 40y Disk with hole 41x Photointerrupter 41y Photointerrupter 42x Stopper pin 42y Stopper Pin 50 Sliding member (sliding means made of low friction material) 51 Spring 52 Spring 60x Shaking sensor on x-axis side 60y Shaking sensor on y-axis 61 Processing circuit 62 Drive circuit I Optical axis of imaging lens system

Claims (4)

(57) [Claims] 1. A shake detecting means for detecting a shake, a shake preventing optical system movable in a direction orthogonal to an optical axis of a main optical system so as to prevent the shake, and driving the shake preventing optical system. A vibration preventing device comprising: a driving mechanism; and control means for controlling the driving mechanism so as to prevent vibration based on a detection result of the vibration detecting means, wherein a lens frame member holding the vibration preventing optical system includes an optical element. On the axis
It will be able to slide with low load in the direction perpendicular to it
Sliding means made of a low friction material and the lens frame member
Urging means for urging the sliding means always in contact with the sliding means;
A shake preventing device, which is supported on a fixed portion side via a support . 2. The shake preventing device according to claim 1, wherein the driving mechanism holds the shake preventing optical system.
First driving means for driving the frame member in a first direction;
A second drive for driving in a second direction different from the first direction
Means, and the first driving means moves the lens frame member in a first direction.
And a first drive unit in the second direction.
First connection to be connected movably independent of the moving part
And a second driving unit for moving the lens frame member to a second position.
A second driving unit for driving in the first direction, and a second driving unit for driving in the first direction.
The second unit is connected movably regardless of the driving unit of the second unit.
A connecting member, and the first and second connecting portions are connected to the shake preventing optical system.
Movably arranged on the outer periphery of the lens frame member
And the first and second driving means are provided with the shake preventing optical system.
The first and second portions of the outer peripheral portion of the lens frame member
The anti-shake optical element is located at a position different from the connecting portion in the circumferential direction.
An anti-shake device, wherein the anti-shake device is disposed in a positional relationship orthogonal to the optical axis of the system. 3. The shake preventing device according to claim 2 , wherein the first and second driving means are first and second motors.
Over data have been used, the first and second motors, the respective output shaft
Convert rotary motion into linear motion in first and second directions
And first and second conversion means, and output shafts of the first and second motors are respectively
Are arranged parallel to the first and second directions.
And vibration preventing device, characterized in that it is. 4. The anti-shake device according to claim 2, wherein
Here, the first and second motors hold a shake preventing optical system.
A shake preventing device, which is arranged adjacent to an outer peripheral portion of a lens frame member .