JP2000330154A - Image blurring correction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the collision of a correction lens against a mechanical end and the consequent generation of uncomfortable shaking sounds and the destruction of a device even if a power source is turned off or an impact is exerted on the device from the outside. SOLUTION: This image blurring correction device has a stationary frame 40, the correction lens which is a part of a main optical system and a moving frame 41 which holes the correction lens and moves the correction lens within a plane approximately orthogonal with the optical axis with respect to the stationary frame. The device suppresses the image blurring by moving the moving frame. The moving frame described above acs when the moving frame arrives at the mechanical end beyond a range where the moving frame moves for the purpose of image deflection correction. The moving frame has an impact absorbing member 43 for relieving the impact at the time of collision against the mechanical end.

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 is likely 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 the shift-type image stabilization method as described above, an electromagnetic actuator is constituted by a coil and a magnet as a driving mechanism for moving the correction lens because the number of parts is small and the response is good. Is held on the fixed side and the other is held on the correction lens side, and the lens frame is directly moved.

[0004]

In the shift type image stabilizer of the prior art, the holding force does not work at all when the power supply to the coil is cut off, so that the movable frame rattles in the apparatus. Unpleasant sounds may be generated and the photographer may be distrusted.

Further, when a strong impact is applied from the outside, there is a danger that the movable frame collides vigorously with a mechanical end, and the apparatus is destroyed. Normally, the holding force of the coil is set to be two to three times the weight of the movable frame part from the impact force in use, so that the correction lens is located at the mechanical edge even if the camera is dropped, even if it is hit. You will hit. Even if an attempt is made to increase the holding power, there is a problem that there is a limit due to limitations on the size of the device and power consumption.

A first object of the present invention is to generate an unpleasant rattling sound when the correction lens collides with a mechanical edge even if the power is turned off or an external impact is applied. It is an object of the present invention to provide an image blur correction device capable of preventing the image blur correction and the destruction of the device.

A second object of the present invention is to provide an image blur correction device capable of effectively absorbing an impact sound and an impact force by the elasticity of a rubber material.

A third object of the present invention is to provide an image blur correction device which has a structure in which a shock absorbing member is held on at least one of a fixed frame and a movable frame, and which can simplify the apparatus. is there.

A fourth object of the present invention is to provide a structure in which the shock absorbing member is formed integrally with at least one of the fixed frame and the movable frame, so that the impact sound and the impact force can be absorbed without increasing the number of parts. It is an object to provide an image blur correction device.

[0010]

In order to achieve the first object, according to the first aspect of the present invention, there is provided a fixed frame, a correction lens which is a part of a main optical system, and a holding mechanism for holding the correction lens. And
A movable frame that moves in a plane substantially orthogonal to the optical axis with respect to the fixed frame, wherein the movable frame is moved to reduce image blur. Image blur correction device having a shock absorbing member that acts when reaching the mechanical end beyond the range of movement for moving, and for mitigating an impact when the movable frame collides with the mechanical end. It is assumed that.

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 shock absorbing member is a rubber ring.

Further, 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 or second aspect, wherein the shock absorbing member is held on at least one of the fixed frame and the movable frame.

Further, in order to achieve the fourth object,
According to a fourth aspect of the present invention, there is provided the image blur correction device according to the first aspect, wherein the shock absorbing member is formed integrally with at least one of the fixed frame and the movable frame.

[0014]

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

In these figures, reference numeral 1 denotes a first group lens L
Reference numeral 1 denotes a fixed lens barrel, and reference numeral 2 denotes a rear lens barrel that holds a low-pass filter 3;
A sensor is attached. Reference numeral 4 denotes a shake correction unit that holds a fixed lens L3A and a correction lens L3B that is driven in a direction perpendicular to the optical axis for shake correction. The shake correction unit 4 is sandwiched between the fixed lens barrel 1 and the rear lens barrel 2 and fixed by screws. ing. Reference numeral 5 denotes a second lens barrel that holds a second lens group L2 that performs zooming.
And two guide bars 6a held in the rear barrel 2,
6b, it is movably held in the optical axis direction. 7
Reference numeral denotes a fourth lens barrel holding a fourth lens group L4 for performing focus adjustment. Like the second lens barrel 5, the fourth lens barrel is held by guide bars 6a and 6b so as to be movable in the optical axis direction. The guide bars 6a and 6b are provided so as to sandwich the optical axis, and the second guide bars 6a and 6b
It guides the group lens barrel 5 and the fourth lens barrel 7 in the optical axis direction and stops rotation around the optical axis. Reference numeral 8 denotes an IG meter that drives the aperture blades 8a and 8b by using an electromagnetic actuator.
It is sandwiched between the fixed lens barrel 1 and the shake correction unit 4.

Reference numeral 9 denotes a zoom motor in which a drive unit and an output screw unit 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. The second lens barrel 7 also has a second
A rack 13 and a spring 14 are attached similarly to the 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 attached to the second group lens barrel 5 and the fourth group lens barrel 7 by fitting the shaft parts 10a and 13a into holes 5a and 7a formed to extend in the optical axis direction. The second group lens barrel 5 and the fourth group lens barrel 7 are rotatable around the shaft portions 10a and 13a. For this reason, even if the parallelism between the guide bars 6a and 6b and the motor output shaft is shifted, 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.
The meshing portions 0 and 13 are in pressure contact with the motor output screw. 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 and the focus motor 12 use stepping motors.

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

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

FIG. 3 is an exploded perspective view of the shake correction unit 4. In FIG. 3, reference numeral 40 denotes a fixed frame, and a positioning boss 40a (see FIG. 2) for fixing the fixed barrel 1 and the rear barrel 2 are connected to each other. The two positioning bosses 40b are respectively held by the fixed lens barrel 1 and the rear lens barrel 2. A fixed lens L3A (see FIG. 1) is held on the inner periphery of the fixed frame 40, 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 is attached for the purpose of eliminating the impact sound and protecting the apparatus when the movable frame described later comes into contact first when the power of the shake correction is turned off or when a strong external shock is applied. Have been.

An L3B 41 (FIG. 1) is a shake correction lens.
(See FIG. 2), and 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. When the pins 42 and the long grooves 40c slide smoothly, 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 at equal intervals of 120 ° in the same plane, and maintain a balance so that a moment around the optical axis does not act on the movable frame 41 due to a load due to sliding friction.

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 the horizontal direction (hereinafter, referred to as X direction) and the 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 fixed 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 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 shows 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 camera shake amount 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 amount of movement (target position) of the correction lens L3B for canceling even 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.

In this embodiment, the flexible printed circuit board 52 is fixed to both the fixed part and the movable part.
Thus, the correction lens is prevented 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. The correction lens rotates slightly,
In most cases, the normal shake correction is held almost at the center, so that the error amount is within a negligible range.

In addition, during the shake correction, in order to use the entire movable range of the correction lens, control is performed so that the correction lens always starts from the state where the correction lens is located at the center of the optical axis when the shake correction is started. During the correction, the correction lens is controlled so as to be centered slowly so as not to make the photographer aware so that the correction lens does not approach the vicinity of the mechanical end too much. In addition, it is controlled so that the electric stopper works so as not to hit the mechanical end. However, if the power is turned off, the correction lens loses its holding power, causing rattling in the device. You will collide.

In the first embodiment, the stopper operates electrically in the ordinary shake correction, and the movable frame 41 is fixed to the fixed frame 4.
Range not to hit 0 (range to move for shake correction)
It is driven by. When the power is turned off, the inner wall 41e of the movable frame 41 moves beyond the range and the rubber ring 4
Contact 3 As shown in FIG. 7, which is a plan view of the movable frame 41 as viewed from the back, the inner wall 41e is arranged in an annular shape so that the stopper operates with the same shift amount even when the movable frame 41 rotates around the optical axis. It is composed. Therefore, the movable frame 4
No unpleasant sound is generated even if 1 is shaken by vibration or the like. Further, when a strong impact is applied from the outside, the rubber ring 43 is deformed, and the inner wall 41e comes into contact with the cylindrical portion 40j of the fixed frame 40. This protects the rubber ring 43 itself, which is a shock absorbing member, and prevents the device from being broken due to the movable portion hitting other than the stopper.

(Second Embodiment) FIGS. 8 and 9 show the configuration of a shake correction unit according to a second embodiment of the present invention. FIG. 8 shows the movable frame 41 viewed from the back. FIG. 9 is a plan view, and FIG. 9 is a cross-sectional view taken along a line BB in FIG. Note that the basic configuration of the configuration of this embodiment is the same as that of the above-described first embodiment. Therefore, the same components are denoted by the same reference numerals as those of the first embodiment and will not be described.

The operating frame 41 is integrally formed with protrusions 241a at five equally spaced locations on the inner periphery (alternatively, it may be provided on the fixed frame 40 side). The movable frame 41 is fixed during the shake correction.
However, when the power is turned off or when an impact is applied, the projection 241a comes into contact with the cylindrical portion 240a of the fixed frame 40. And projection 2
The shock is absorbed by the deformation of 41a, and when the shock is stronger, the inner wall 241b of the movable frame 41 comes into contact with the cylindrical portion 240a.

Thus, the collision noise caused by the rattling of the movable frame 41 can be reduced, and the device can be protected. As shown in FIG. 8, five protrusions 241a are arranged at regular intervals so as to be able to absorb an impact even when shifted in any direction. Also, they are arranged in a circle around the optical axis,
The movable frame 41 is configured not to be affected by rotation about the optical axis.

(Third Embodiment) FIGS. 10 and 11 show the configuration of a shake correction unit according to a third embodiment of the present invention. FIG. 10 shows the movable frame 41 viewed from the back. FIG. 11 is a plan view, and FIG. 11 is a cross-sectional view taken along a line CC in FIG. In this embodiment, the basic configuration is the same as that of the first embodiment.
Common components are denoted by the same reference numerals as in the first embodiment, and description thereof is omitted.

On the fixed frame 40, three projections 340a are integrally formed. The movable frame 41 is provided with a stepped hole 341a at a position corresponding to the projection 340a.
The drive is controlled so as not to come into contact with the fixed frame 40 during the shake correction, but when the power is turned off or when an impact is applied, the projection 340a comes into contact with the small diameter portion 341b of the hole 341a. The impact is absorbed by the deformation of the projection 340a.
41c comes into contact with the cylindrical portion 340b of the fixed frame 40.

Thus, the collision noise caused by the rattling of the movable frame 41 can be reduced, and the device can be protected. As shown in FIG. 10, three projections 340a are arranged at equal intervals, and even if the projections 340a are shifted in any direction, the impacts are equally absorbed at three locations, and the movable frame 41 does not receive the force that rotates the optical frame 41 around the optical axis. It is configured as follows.

According to each of the above embodiments, when the movable frame collides with the fixed frame, the impact force is absorbed by the impact absorbing members (rubber ring 43, projections 241a, 340a). You can prevent making sounds,
At the same time, it is possible to prevent the device from being destroyed. Further, since the shock absorbing effect is generated when the correction lens moves out of the shake correction range, the shake correction range is not narrowed.

(Modification) In the first embodiment, rubber is used as the shock absorbing member.
Other materials, such as a soft resin material, may be used. Further, the shock absorbing member may be held on either the movable frame side or the fixed frame side, or may be held on both sides.

Further, although a moving coil type actuator is employed as a driving means of the correction lens, a motor, an electrostrictive element, or another electromagnetic actuator may be used. Also, in the present embodiment, the position detecting means uses the light emitting / receiving element, but the same effect can be obtained by a sensor using magnetism.

[0043]

As described above, according to the first aspect of the present invention, even if the power is turned off or an external impact is applied, the correction lens collides with the mechanical edge and is uncomfortable. It is an object of the present invention to provide an image blur correction device capable of preventing generation of rattling sound and destruction of the device.

According to the second aspect of the present invention, it is possible to provide an image blur correction device capable of effectively absorbing an impact sound and an impact force by the elasticity of a rubber material.

According to the third aspect of the present invention, it is possible to provide an image blur correction device which has a structure in which the shock absorbing member is held on at least one of the fixed frame and the movable frame, thereby simplifying the device. Things.

According to the fourth aspect of the present invention, the shock absorbing member is formed integrally with at least one of the fixed frame and the movable frame to absorb the impact sound and the impact force without increasing the number of parts. It is possible to provide an image blur correction device capable of performing the above.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a zoom lens for a video camera according to each 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 diagram illustrating a control system of the shake correction apparatus according to each embodiment of the present invention.

FIG. 7 is a plan view of the movable frame of FIG. 4 as viewed from the back.

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

FIG. 9 is a sectional view showing the shake correction unit of FIG. 8;

FIG. 10 is a plan view illustrating a shake correction unit according to a third embodiment of the present invention.

11 is a cross-sectional view of the shake correction unit of FIG.

[Explanation of symbols]

 4 Shake Correction Unit 40 Fixed Frame 41 Movable Frame 42 Pin 43 Rubber Ring (Shock Absorbing Member) 241a Projection (Shock Absorbing Member) 341a Projection (Shock Absorbing Member)

Claims (4)

[Claims] A fixed frame, a correction lens that is a part of a main optical system, and a movable frame that holds the correction lens and moves in a plane substantially orthogonal to an optical axis with respect to the fixed frame. Then, in an image blur correction apparatus that suppresses image blur by moving the movable frame, the movable frame moves beyond the range in which the movable frame moves for image blur correction, acts when reaching a mechanical edge, An image blur correction device, comprising: a shock absorbing member for reducing a shock when the movable frame collides with the mechanical end. 2. The image blur correction device according to claim 1, wherein said shock absorbing member is a rubber ring. 3. The image blur correction device according to claim 1, wherein the shock absorbing member is held by at least one of the fixed frame and the movable frame. 4. The image blur correction device according to claim 1, wherein the shock absorbing member is formed integrally with at least one of the fixed frame and the movable frame.