JP2000330155A - Image blurring correcting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a dedicated member for preventing a correction lens from rotating around an optical axis and to reduce the deterioration of driving characteristic and a actuation noise caused by sliding by constituting an image blurring correcting device so that the correction lens is held by a supporting member rotatable in a plane nearly orthogonal to the optical axis and movable in a straight advance direction passing through the center of rotation. SOLUTION: A movable frame 41 holds a blurring correction lens. Pins 42 are fixed in three holes 41a provided on the outer periphery of the frame 41. By making the pins 42 smoothly slide in a long groove 40c, the frame 41 freely moves in a direction perpendicular to the optical axis within a specified range with respect to a fixed frame 40. The pins 42 and the long grooves 40c corresponding to the pins 42 are arranged at equal intervals by 120 deg. on the same plane and balance is kept so that moment around the optical axis may not act on the frame 41 by load caused by sliding friction. A flexible printed circuit board 52 is fixed on both a fixed part and a movable part so as to prevent the rotation of the correction lens.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an image blur correction device mounted on a camera or the like and optically correcting the image blur.

[0002]

2. Description of the Related Art Conventionally, a photographing lens system (main optical system) or a part of the optical system is used as a correction lens in order to prevent image shake due to camera shake or the like which tends to occur in hand-held shooting, and this correction lens absorbs the shake. There is known a device that corrects a shift of an image forming position due to a shake by shifting the image in a direction, thereby eliminating the image shake.

In such a shift type image stabilization method, an electromagnetic actuator is constituted by a coil and a magnet as a driving mechanism for moving the correction lens, and one of them is held on the fixed side and the other is held on the correction lens side. The configuration was such that the lens frame was directly moved.

Further, in order to realize accurate shake correction, a guide structure for accurately moving the correction lens in a plane perpendicular to the optical axis is required. Specifically, three pins are arranged at equal intervals on the outer periphery of the movable frame holding the correction lens, a long groove extending in the circumferential direction is formed on the fixed frame, and the pin slides freely in the long groove. By,
It can be moved to any position in the direction perpendicular to the optical axis within a predetermined range.

Further, in order to accurately detect the position and prevent a reduction in driving efficiency, it is necessary to prevent the correction lens from rotating around the optical axis. To do so, first,
By holding the guide member and the movable frame so as to be able to move in parallel in one direction (for example, up and down direction) with the fixed frame, and then holding the guide member and the movable frame so as to be able to move in parallel in the perpendicular direction (for example, left and right direction), the result is obtained. As a result, the correction lens can freely move to an arbitrary position without rotating around the optical axis.

In Japanese Patent Application Laid-Open No. 10-10597, the correction lens is moved straight in one direction, and furthermore, is rotated about a rotation axis parallel to the optical axis so as to be movable in a plane perpendicular to the optical axis. I have.

[0007]

SUMMARY OF THE INVENTION As in the above conventional example,
The shift-type image stabilizing device has a problem that the driving characteristics are deteriorated because there are many sliding portions when driving the correcting lens. In addition, there is a problem that the photographer may feel uncomfortable due to the sliding noise and the operation noise generated by the slight play of the fitting portion.

Further, in Japanese Patent Application Laid-Open No. 10-10597, although the number of parts is reduced, a portion for transmitting a driving force,
In addition, a complicated structure is required for both the rotatable and rotatable holding structures. As a result, the sliding portion cannot be reduced, so that a similar problem has occurred.

(Object of the Invention) A first object of the present invention is to abolish a dedicated member for preventing the correction lens from rotating around the optical axis, to deteriorate driving characteristics due to sliding, and to operate. It is an object of the present invention to provide an image blur correction device capable of reducing sound.

A second object of the present invention is to suppress the rotation of the correction lens by deformation of a thin plate-shaped flexible member, reduce the number of sliding portions, and drive the target lens to a target position with high precision. It is intended to provide a correction device.

A third object of the present invention is to provide an image blur correction apparatus which can utilize the flexibility of a flexible printed circuit board as a support member and can simplify the apparatus without adding special parts. It is assumed that.

A fourth object of the present invention is to provide an image blur correction device which can use a part of a component as a support member and can simplify the device without adding a special component. Things.

[0013]

According to a first aspect of the present invention, there is provided a correction lens for suppressing image blur, which is a part of a main optical system. A driving unit for moving the correction lens in a plane substantially orthogonal to the optical axis, and an image blur correction device having a position detection unit for detecting a movement position of the correction lens, wherein the correction lens is An image blur correction device is provided that is supported by a support member that is capable of rotating in a plane substantially perpendicular to the optical axis and moving in a straight-line direction passing through the center of rotation.

Further, in order to achieve the second object,
According to a second aspect of the present invention, there is provided the image blur correction device according to the first aspect, wherein the support member is a thin plate-shaped flexible member.

In order to achieve the third object,
According to a third aspect of the present invention, there is provided the image blur correction device according to the first aspect, wherein the supporting member is a flexible printed circuit board for electrically connecting at least one of a control circuit, a driving unit, and a position detecting unit.

In order to achieve the fourth object,
According to a fourth aspect of the present invention, the support member also serves as a guide member for inhibiting movement of the correction lens in the optical axis direction and enabling only movement in a plane perpendicular to the optical axis. 1
The image blur correction device described above.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 is a sectional view showing a zoom lens for a video camera according to a first embodiment of the present invention, and FIG.
FIG. 2 is an exploded perspective view of the zoom lens barrel.

In FIG. 1, reference numeral 1 denotes a fixed lens barrel holding the first group lens L1, 2 denotes a rear lens barrel holding a low-pass filter 3, and further mounted a CCD sensor (not shown) behind. Reference numeral 4 denotes a fixed lens L3A and a correction lens L3 driven in a direction perpendicular to the optical axis for shake correction.
This is a shake correction unit that holds B, is held between the fixed lens barrel 1 and the rear lens barrel 2, and is fixed by screws. 5
Is a second lens barrel holding a second lens group L2 that performs zooming, and is moved in the optical axis direction by two guide bars 6a, 6b held in the front and rear by a fixed lens barrel 1 and a rear lens barrel 2. It is freely held. Reference numeral 7 denotes a fourth lens barrel holding a fourth lens group L4 for performing focus adjustment, and is movably held in the optical axis direction by guide bars 6a and 6b similarly to the second lens barrel 5. Guide bars 6a, 6
b is provided so as to sandwich the optical axis. The two guide bars 6a and 6b serve to guide the second lens barrel 5 and the fourth lens barrel 7 in the optical axis direction and to prevent rotation around the optical axis. Is going.
Reference numeral 8 denotes an IG meter that drives the diaphragm blades 8 a and 8 b by an electromagnetic actuator, and is held between the fixed lens barrel 1 and the shake correction unit 4.

Reference numeral 9 denotes a zoom motor in which a drive section and an output screw section are integrally held on a U-shaped sheet metal, and is fixed to the fixed barrel 1 with screws. On the other hand, a rack 10 is attached to the second lens barrel 5, and the rack 10 is driven in the optical axis direction by engaging with a screw portion of the zoom motor 9. At this time, the rack 10 is urged by the spring 11 in the meshing direction and the optical axis direction so as to remove the mesh play and the thrust play. A focus motor 12 has the same structure as the zoom motor 9 and is fixed to the rear barrel 2 with screws. 4th group lens barrel 7
A rack 13 and a spring 14 are attached to the lens barrel similarly to the second group lens barrel 5, and the rack 13 is configured to be driven in the optical axis direction by meshing with a screw portion of the focus motor 12.

The racks 10 and 13 are mounted by fitting the shaft portions 10a and 13a into holes 5a and 7a formed in the second group barrel 5 and the fourth group barrel 7 so as to extend in the optical axis direction, respectively. The second group lens barrel 5 and the fourth group lens barrel 7 are rotatable around the shaft portions 10a and 13a. Therefore, even if there is a deviation in the parallelism between the guide bars 6a and 6b and the motor output shaft, smooth movement of the second lens barrel 5 and the fourth lens barrel 7 can be ensured. The racks 10 and 13 are urged by springs 11 and 14 in one rotation direction, respectively, and the meshing portions of the racks 10 and 13 are pressed against the motor output screws. Therefore, the meshing portions of the racks 10 and 13 and the male screw of the motor output shaft can be reliably meshed. In this embodiment, the zoom motor 9, the focus motor 12
Uses a stepping motor.

Reference numeral 15 denotes an interrupter fixed with screws to the fixed lens barrel 1 after the terminals are soldered to the substrate 16, and an interrupter and a light receiving part are provided integrally with the second lens barrel. The reference position of the second lens barrel is detected by passing through the light-shielding wall 5b, and the lens is driven to each zoom position by the number of pulses input to the zoom motor. Similarly, the focus adjustment is configured so that the light-shielding wall 7b provided in the fourth lens barrel is detected as a reference position by the interrupter 17 and the substrate 18 attached to the rear lens barrel 2, and is driven stepwise.

Next, the configuration of the shake correction unit 4 will be described.

FIG. 3 is an exploded perspective view of the shake correcting unit 4. In FIG. 3, reference numeral 40 denotes a fixed frame, and a positioning boss 40a (see FIG. 2) for fixing to the fixed barrel 1, and a rear barrel. 2 and two positioning bosses 40 b, each being held between the fixed lens barrel 1 and the rear lens barrel 2. Fixed frame 4
A fixed lens L3A (see FIG. 1) is held on the inner periphery of the lens 0, and a rubber ring 43 is held on a cylindrical portion 40d on the outer periphery of the fixed lens L3A. The rubber ring 43
When the power of the shake correction is turned off or when a strong shock is applied from the outside, the movable frame, which will be described later, comes into contact first, thereby eliminating the impact noise and protecting the apparatus.

Reference numeral 41 denotes a movable frame holding an L3B which is a shake correction lens. Pins 42 are fixed to three holes 41 a provided on the outer periphery of the movable frame 41. The pin 42 is fitted in the long groove 40c of the fixed frame 40. These pins 4
2 and the long groove 40c slide smoothly, so that the movable frame 41 is movable in a predetermined range with respect to the fixed frame 40 in a direction perpendicular to the optical axis. Here, the pins 42 and the corresponding long grooves 40c are arranged in the same plane at equal intervals of 120 °, and the movable frame 4 is loaded by a load due to sliding friction.
The balance is maintained so that the moment around the optical axis does not act on 1.

Next, a method of driving the movable frame 41 will be described.

Reference numerals 45a and 45b denote coils, which are fixed to the movable frame 41 for driving in a horizontal direction (hereinafter referred to as X direction) and a vertical direction (hereinafter referred to as Y direction), respectively. Reference numerals 46a and 46b denote magnets, each of which is magnetized in two poles in the X and Y directions. Magnets 46a, 46b
Are fixed to the lower yokes 47a and 47b made of a material such as iron and inserted into the holes 40h and 40i from the back side of the fixing frame 40. Then, the lower yokes 47a, 47
b. The upper yoke 48 made of the same material is attached to the supporting columns 40f and 40g of the fixed frame 40 together with a sensor holder 49 described later from the front.
Are fixed by screws 53 to form a magnetic circuit for driving in the X and Y directions.

50a and 50b are light emitting elements such as IRED,
Reference numerals 51a and 51b denote light receiving elements such as PSDs, which are inserted into the sensor holder 49 from the outer peripheral side and fixed by bonding. Then, elongated hole-shaped slits 41c and 41d provided integrally with the movable frame 41 are inserted between the respective light emitting elements and light receiving elements, and out of the infrared light emitted from the light emitting elements 51a and 51b. Only the light passing through the slits 41c and 41d is received by the light receiving elements 51a and 51b, and the positions of the movable frame 41 in the X and Y directions are detected. These light projecting elements 50a, 50b and light receiving elements 51a, 51b are provided on a flexible printed circuit board 52 (shown separately in the figure).
And to a control circuit (not shown) provided on the camera body side.

FIG. 4 shows that the above-mentioned shake correction unit 4 is a CCD.
It is the front view seen from the side (the sensor part and the upper yoke 48 were removed). FIG. 5 is a cross-sectional view of the shake correction unit 4 of FIG. 4 cut at a position indicated by AA.

The flexible printed circuit board 52 is partially extended, and the tip 52a is fixed to the flat surface of the movable frame 41 with a double-sided tape or the like. The tip 52a is provided with four lands 52b for energizing the coils 45a and 45b, and the terminals of the coils 45a and 45b are connected by soldering. As shown in FIG. 5, the flexible printed board 52 has a bent portion 52c bent in a U-shape.
After that, it is fixed to the sensor holder 49 as a fixing part with a double-sided tape or the like. Then, the sensor unit (light emitting element 50)
a, 50b and the light receiving elements 51a, 51b) are connected together with a control circuit provided on the camera body side (not shown).

Next, a control system of the shake correction unit 4 will be described.

FIG. 6 is a diagram showing a control system of the shake correction unit 4. Reference numeral 70 denotes a microcomputer that controls the entire system. Reference numeral 71 denotes a shake sensor constituted by a vibrating gyroscope or the like, which detects camera shake as an angular velocity or an angle.

The microcomputer 70 calculates the amount of camera shake based on the detection signal from the shake sensor, and corrects the correction lens L so as to cancel the image shake caused by the camera shake.
The target position of 3B is calculated. Then, according to the calculation result of the movement amount, the coils 45a, 4
5b is driven to drive the correction lens L3B. that time,
The position of the correction lens L3B is determined by a correction lens position sensor (5
0, 51), and is fed back to the microcomputer 70 to drive accurately to the calculated target position.

In the zoom lens, since the movement amount (target position) of the correction lens L3B for canceling the same shake amount changes depending on the focal length, the number of drive pulses of the second lens unit L2 is measured. The focal length is detected by the zoom position sensor 72, and the driving amount of the correction lens is changed accordingly.

When the correction lens is actually driven, the driving amount in the X direction and the driving amount in the Y direction are combined to enable driving in any direction on the plane. The holding force is applied only in the X and Y directions, and no holding force is applied in the direction in which the correction lens rotates around the optical axis. However, even if the position sensor signal does not change, if the correction lens rotates, a deviation occurs between the output signal and the actual position, so that a means for preventing rotation is required.

In this embodiment, as shown in FIG. 5, the flexible printed circuit board 52 is fixed to both the fixed portion and the movable portion, thereby preventing the correction lens from rotating. That is, when the flexible printed board 52 is elastically deformed, the flexible printed board 52 is driven to swing about the bent portion 52c as a center of rotation. Although the correction lens slightly rotates, it is often held almost at the center in normal shake correction, so that the error amount is within a negligible range.

As described above, in order to prevent the correction lens from rotating around the optical axis, the elastic deformation of the flexible printed circuit board 52 for energizing the coil is used without adding a new component. In addition, the rotation is appropriately prevented, and it is possible to drive in all directions in the plane. Therefore, since there is no sliding by the rotation preventing member, it is possible to prevent the driving characteristics of the correction lens from being deteriorated due to friction. Further, it is possible to prevent generation of unpleasant operation noise and sliding noise due to rattling of the rotation preventing member.

(Second Embodiment) FIG. 7 is a diagram showing a configuration of a shake correction unit according to a second embodiment of the present invention. Note that the configuration of this embodiment is the same as that of the first embodiment in the basic configuration, and therefore, the same components are denoted by the same reference numerals as in the first embodiment, and description thereof will be omitted.

The fixed frame 40 is provided with long grooves 40c which are long in the circumferential direction at three places on the outer periphery (shown in a sectional view in the figure), and the pins 42 implanted in the movable frame 41 are engaged. . One portion of the long groove 40c has a narrow portion 240a, and an interval is set so that the pin 42 is fitted with a small gap. Further, the narrow portion 240a has an arcuate shape on the outer side to reduce the area in contact with the pin 42.

With the above configuration, the movable frame 41 is formed in the narrow portion 24.
It becomes movable so as to swing about 0a. And
Since the narrow portion 240a can move in the axial direction of the pin 42, the correction lens can freely move in a plane perpendicular to the optical axis as a result.

In this embodiment, the position serving as the center of rotation is set near the intersection of the longitudinal center axes of the two slits 41c and 41d for position detection when viewed from the optical axis direction. As a result, the position detection error can be reduced. In addition, since the center of rotation is provided on the axis of symmetry (the line indicated by Z in the figure) when the sensor for detecting the position in the X and Y directions and the drive coil are arranged, the drive characteristics in both the X and Y directions Are equal, and the shake correction control can be easily performed.

As described above, in the second embodiment, only a part of the component is deformed without adding a new component for preventing rotation of the correction lens.
Similar effects can be obtained with a simple configuration.

(Third Embodiment) FIG. 8 shows the configuration of a shake correction unit according to a third embodiment of the present invention. The configuration of this embodiment is also the same as that of the first embodiment in the basic configuration. Therefore, the same components are denoted by the same reference numerals as those in the first embodiment, and description thereof will be omitted.

The long groove 40c of the fixed frame 40 is the same as that of the first embodiment, but the movable frame 41 has a movable hook 341a.
Are provided, and a fixed hook 34 provided on the fixed frame 40 is provided.
A coil spring 301 is mounted between the coil spring 301 and the coil spring 301.

Thus, the movable frame 41 is connected to the coil spring 30
It is configured to rotate around the fixed hook 340a by one pulling force. Therefore, the rotation of the correction lens can be suppressed only by attaching one coil spring, so that there is no sliding portion and good vibration correction can be realized.

(Fourth Embodiment) FIGS. 9 and 10 show the configuration of a shake correction unit according to a fourth embodiment of the present invention. FIG. 10 shows the shake correction unit of FIG. It is the side view (partial sectional drawing) seen from the position shown by. In addition,
The configuration of this embodiment is also the same as that of the first embodiment in the basic configuration. Therefore, the same components are denoted by the same reference numerals as those in the first embodiment, and description thereof will be omitted.

Reference numeral 452 denotes a flexible printed circuit board, and a central portion 452c is fixed to a flat portion of the movable frame 41 with a double-sided tape or the like. 441a and 441b are positioning bosses provided on the movable frame 41, and 452d and 452e are fitting holes corresponding thereto. The central portion 452a has four lands 452f, and terminals of the coils 45a and 45b are soldered. Reference numeral 441c denotes a guide wall provided on the movable frame 41 so that the coil terminal does not hit the fixed portion during the shake correction.

The flexible printed circuit board 452 is the same as that shown in FIG.
As shown in FIG.
52g has been extended. The arm 452h bent about 90 degrees again has two bosses 4 provided on the sensor holder 49.
The IRED 5 guided to maintain the bent shape by 49a and 449b and then fixed to the sensor holder 49
0a, 51b and the PSDs 51a, 51b. The X- and Y-direction coils and the IRED and PSD wirings are combined into one, and the connection portions 452a,
452b is connected to a shake correction circuit of the camera body.

The flexible printed circuit board 452 has a symmetrical shape, and the arms 452g and 452h are deformed, so that the movable frame 41 can move in parallel in a plane without rotating around the optical axis. It is thought that rotation will occur to some extent due to variations in weight balance, arm shape, friction of the sliding part, etc. However, the amount of rotation can be reduced by devising the shape of the flexible printed circuit board.

(Modification) In each of the above embodiments, a moving coil type actuator is used as the driving means of the correction lens. However, a motor, an electrostrictive element, or another electromagnetic actuator may be used.

Although an example using a light emitting / receiving element is shown for the position detecting means, a similar effect can be obtained with a sensor utilizing magnetism.

[0052]

As described above, according to the first aspect of the present invention, the exclusive member for preventing the correction lens from rotating around the optical axis is eliminated, and the driving characteristic by sliding is eliminated. It is possible to provide an image blur correction device which can reduce the deterioration of the image and the operation noise.

According to the second aspect of the present invention, the rotation of the correction lens is appropriately suppressed by the deformation of the thin plate-like flexible member, the sliding portion is reduced, and the lens is driven to the target position with high accuracy. It is possible to provide an image blur correction device capable of performing the above.

According to the third aspect of the present invention, the flexibility of the flexible printed circuit board is utilized for the supporting member,
An object of the present invention is to provide an image blur correction device that can simplify the device without adding special parts.

According to the fourth aspect of the present invention, there is provided an image blur correction apparatus which can use a part of the component parts as a support member and can simplify the apparatus without adding special parts. It can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a zoom lens for a video camera according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the zoom lens barrel of FIG.

FIG. 3 is an exploded perspective view of a shake correction unit mounted on the zoom lens of FIG.

FIG. 4 is a plan view illustrating a shake correction unit of FIG. 3;

FIG. 5 is a sectional view of the shake correction unit of FIG. 4;

FIG. 6 is a system diagram showing shake correction control.

FIG. 7 is a plan view illustrating a shake correction unit according to a second embodiment of the present invention.

FIG. 8 is a plan view illustrating a shake correction unit according to a third embodiment of the present invention.

FIG. 9 is a plan view illustrating a shake correction unit according to a fourth embodiment of the present invention.

FIG. 10 is a sectional view of the shake correction unit of FIG. 9;

[Explanation of symbols]

 4 Vibration Correction Unit 40 Fixed Frame 41 Movable Frame 42 Pin 45a, 45b Coil 50a, 50b IRED 51a, 51b PSD 52, 452 Flexible Printed Circuit Board 301 Coil Spring

Claims (4)

[Claims] 1. A correction lens which is a part of a main optical system and suppresses image blur, driving means for moving the correction lens in a plane substantially orthogonal to an optical axis, and the correction lens An image blur correction device having a position detecting means for detecting a movement position of the optical lens, wherein the correction lens is rotated in a plane substantially orthogonal to the optical axis and moved in a straight-line direction passing through a rotation center. An image blur correction device, wherein the image blur correction device is held by a support member that enables the image blur correction. 2. The image blur correction device according to claim 1, wherein the support member is a thin plate-shaped flexible member. 3. The image blur correction device according to claim 1, wherein the support member is a flexible printed circuit board for electrically connecting at least one of a control circuit, the driving unit, and the position detection unit. 4. The support member also serves as a guide member for inhibiting movement of the correction lens in an optical axis direction and enabling only movement in a plane perpendicular to the optical axis. The image blur correction device according to claim 1.