KR100803602B1 - Image stabilization device and method - Google Patents

Abstract

In the image stabilizer, the driving force for rotational driving is suppressed, and the space occupied by the configuration necessary for the image stabilizer is reduced. The image stabilization device having the rear focus zoom lens 100 constituted by four or more groups of lenses according to the present invention comprises an afocal system, and comprises a convex lens of a freely rotating convex lens with an axis orthogonal to the optical axis. The third group 114 having a concave lens of rotational freedom as a control object is orthogonal to the axis orthogonal to the axis of rotation of the convex lens as the control object, and the rotation is controlled, the driving force is suppressed, and the configuration is simplified, and the cost is reduced. Higher power consumption and lower power consumption can be achieved.

Description

Apparatus for shake correction and method

1 is an explanatory diagram illustrating a lens configuration of a camera shake correction device according to a first embodiment.

2 is a perspective view schematically showing the appearance of the third group.

3 is an explanatory diagram for illustrating the configuration of the third group in more detail.

4 is a functional block diagram for explaining rotation control of a lens in the first embodiment.

Fig. 5 is a perspective view schematically showing the appearance of the third group in the second embodiment.

6 is an explanatory diagram for explaining the amount of movement when the lens is moved perpendicular to the optical axis.

7 is an explanatory diagram for explaining the amount of movement when the lens is rotated around the rotation center.

FIG. 8 is an explanatory diagram for explaining the amount of movement when the lens is rotated around the rotation center disposed on the subject side rather than the lens center.

Fig. 9 is an explanatory diagram for explaining the amount of movement when the lens is rotated around the rotation center disposed on the imager side rather than the lens center.

<Explanation of symbols on main parts of the drawings>

100 rear focus zoom lens

110 First Group

112 Second Group

114 Third Group

116 fourth group

200 convex lens

210 concave lens

130, 132 rotary shaft

230, 430 revolving parts

240, 440 fixing part

250 coil

252 Permanent Magnet for Driving

260 Hall element

262 Permanent Magnet for Angle Detection

310 Image stabilizer

312 rotation angle detector

314 drive signal generator

316 rotary drive

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus, and more particularly, to an image stabilization apparatus and a method for reducing the influence of hand shake received by an imaging apparatus.

In imaging apparatuses, such as a video camera and a digital still camera, the removal of the motion of the image by the camera shake of a user by correction or image processing of the optical axis in the image is examined. The movement of the image due to such shaking is more likely to be affected by the image enlarged by the zoom function.

On the other hand, a technique is known in which a meniscus positive lens and a meniscus negative lens are linearly driven in a plane orthogonal to the optical axis, and image stabilization is performed in the horizontal and vertical directions (for example, Japanese Patent Laid-Open No. 6). 118471).

Moreover, the technique of rotating the driving positional relationship of a flat concave lens and a flat convex lens by the rotation motor (actuator) of an imager side, and changing the angle of a passing light beam is correct | amended to correct the shake of an imaging device is also known. (For example, Japanese Patent Laid-Open No. 9-171204).

Moreover, the technique of changing the angle of a passing light beam by rotatingly rotating the objective lens corresponding to a 1st group among the group of lenses in an optical system on the lens surface and centering on the axis perpendicular | vertical to an optical axis is known (for example, , Japanese Patent Laid-Open No. 6-197258).

However, in the above technique, the light receiving element and the actuator in the rotational drive control have become large-scale, and for example, even if it is an objective lens, a large driving force is required for rotationally driving the controlled object lens. Rotating motors capable of obtaining such a large driving force have a large occupancy volume and have become a disadvantage of miniaturization of cameras.

In addition, in the case of linear driving correction in the plane orthogonal to the optical axis, in order to prevent the lens from falling due to its own weight, a holding power that always maintains the optical axis position is required, and useless power is consumed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of conventional lens correction apparatuses, and an object of the present invention is to suppress driving force for rotational driving, to reduce the occupied space by the configuration necessary for image stabilization, and to reduce the size and cost. It is to provide a new and improved image stabilization device and method which can achieve higher power consumption and lower power consumption.

In order to solve the above problems, according to one aspect of the present invention, a camera shake correction apparatus for camera shake correction of a rear focus zoom lens constituted by a group of four or more lenses, the first group which is an objective lens group, and freedom to move back and forth with respect to an optical axis A second group that adjusts the focal length with a rotational axis, and an axis orthogonal to the optical axis is orthogonal to the convex lens of the rotational freedom material and the optical axis while being orthogonal to the optical axis of the convex lens, and is free to rotate as the rotation axis. A third group having a concave lens of material, a fourth group for correcting image fluctuation accompanying the adjustment of the focal length of the second group, a hand shake detection unit for detecting a hand shake angle, a convex lens of the third group, and A rotation angle detector for detecting rotation angles of each of the concave lenses, and the third group of convex and concave lenses based on the detected shake angle and the rotation angle. And a drive signal generation unit for generating respective drive signals, and a rotation drive unit for rotationally driving each of the third group of convex and concave lenses according to the generated drive signal. do.

By performing the image stabilization by rotational driving instead of linear driving, self-falling of the correcting lens can be prevented, and the holding power for maintaining the optical axis is unnecessary. Therefore, the power for the holding power can be reduced.

In addition, since the convex lens and the concave lens in the third group can be formed compact and lightweight, it becomes possible to rotationally drive the convex lens and the concave lens with the minimum driving force. Therefore, it is possible to form a rotation drive part small and light weight.

The rotation drive unit may be formed of a coil and a magnet disposed in front and facing the plane orthogonal to or parallel to the rotation axis of the convex or concave lens, and either of the coil or magnet may be fixed to the rotation axis.

Since the rotation angle necessary for the image stabilization is small, the rotation driving unit can be formed by a coil and a magnet, and it becomes possible to reduce the occupied space as compared with the rotation motor. Further, by separating the rotation drive unit from the lens rotation center, the rotation angle with respect to the movement amount can be reduced, the rotation resolution can be increased, and high precision rotation control is possible even when compared with the rotation motor.

The rotation angle detector is formed of a Hall element and a magnet disposed in front and facing the plane orthogonal to or parallel to the axis of rotation of the convex or concave lens, and either one of the Hall element or the magnet is fixed to the axis of rotation. You may also

Since the rotation angle detector can be formed by the Hall element and the magnet, it becomes possible to reduce the occupied space. Further, by separating the rotation angle detector from the lens rotation center, the amount of movement with respect to the rotation angle can be increased, the detection resolution can be increased, and high precision rotation control can be achieved. Further, by forming integrally with the rotary drive unit, the occupied space can be made smaller.

The rotation axis of the convex lens or concave lens may be formed spaced apart from the lens center toward the subject.

When the axis of rotation is closer to the subject than the center of the lens, the amount of movement of the image surface is added to the refraction and eccentricity due to the rotation of the lens. Therefore, it becomes possible to suppress the rotational drive for obtaining the same amount of correction amount.

And a fifth group having a convex lens of a free rotational axis as an axis of rotation that is orthogonal to the optical axis, and a concave lens of a rotatable free material as an axis of rotation which is perpendicular to the axis of rotation of the convex lens while being perpendicular to the optical axis. The detection unit and the rotation drive unit may target the fifth group of convex and concave lenses instead of the third group of convex and concave lenses.

In addition, among the camera shake correction apparatus, except for the camera shake detection unit, a lens driving device that simply displaces the angle of the image may be provided.

In order to solve the above problems, according to another aspect of the present invention, as a camera shake correction method for camera shake correction of a rear focus zoom lens composed of four or more lens groups, a camera shake detection step of detecting a camera shake angle and And a third group of convex lenses and concave having a convex lens of free rotation as an axis of rotation and an orthogonal axis of optical convex and an axis of orthogonal to the axis of rotation of the convex lens and having a concave lens of free rotation as an axis of rotation. A rotation angle detection step of detecting rotation angles of each of the lenses, a drive signal generation step of generating drive signals for each of the third group of convex and concave lenses based on the detected shake angle and the rotation angle; And a rotation driving step of rotationally driving each of the third group of convex and concave lenses in accordance with the generated drive signal. The motion compensation method according to claim is provided.

The components corresponding to the dependent claims in the above-described image stabilizer and the description thereof can also be applied to the image stabilizer method.

The image stabilization caused by the rotational driving can prevent the fall of the self-weight of the correcting lens and at least reduce the electric power by the holding power for maintaining the optical axis. In addition, since the convex lens and the concave lens in the third group can be formed compact and lightweight, it becomes possible to rotationally drive the convex lens and the concave lens with the minimum driving force. Therefore, the size, cost, and power consumption can be reduced.

EMBODIMENT OF THE INVENTION Very preferred embodiment of this invention is described in detail, referring an accompanying drawing below. In addition, in this specification and drawing, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol about the component which has substantially the same functional structure.

As a method of suppressing camera shake such as an image pickup device, a variable angle prism disposed in front of the photographing optical system is used to correct hand shake, and an inner lens for correcting hand shake by linearly eccentric lens inside the photographing optical system. The lens shift method is common.

In the former method, since the variable vertex prism is formed on the front surface of the optical system, the optical effective luminous flux is increased, and therefore, a drive actuator having a large torque is required, and the image stabilization device is formed large in overall, and the manufacturing cost is also high. .

In addition, the latter method has an advantage that the effective light flux can be reduced as compared with the former method, but since the lens must be linearly eccentric along the guide member, the direction in which the lens always stops falling down to maintain the optical axis. There is a need to supply the driving power, wasted wasted power consumption.

In the camera shake correction apparatus described below, the driving force for the camera shake correction driving is suppressed, the space occupied by the component is reduced, and the size, size, cost, and power consumption are reduced. As such image stabilization apparatuses, analog cameras, digital still cameras, video cameras, camcorders, and the like are assumed, but they can be applied to various electronic devices using optical lenses.

(First Embodiment: Image Stabilization Device)

1 is an explanatory diagram illustrating a lens configuration of a camera shake correction device according to a first embodiment. Here, the four groups of rear focus zoom lenses 100 are used to describe the functions of each lens. However, such functions as changing to a different lens configuration, changing the order of the cords, and adding another group such as the fifth group are described. Modifications also belong to the technical scope of this embodiment.

As shown in Fig. 1, in the rear focusing system in which the rear lens focuses by moving the lens behind the first group on the subject side, focusing is possible only by moving a relatively small lens group, thereby suppressing the driving force and quickly. It becomes possible to focus. Hereinafter, each lens group in this embodiment is demonstrated in detail.

The first group 110 is a fixed objective lens having positive refractive power. By this first group 100, the main focal length (the distance from the lens to the image surface) can be determined.

The second group 112 is a movable free zoom lens before and after having a negative refractive power. For example, the second group 112 can shift from the wide angle to the telephoto by moving the rear lens toward the image plane (photographer side). Cover the focal length before and after the focal length specified in 100).

The third group 114 constitutes a fixed afocal system, and the axis perpendicular to the optical axis 120 is orthogonal to the convex lens 200 of the rotational freedom material and the optical axis 120 as the rotation axis 130. An axis of orthogonal to the axis of rotation 130 of the convex lens 200 is included as the axis of rotation 132 to include the concave lens 210 of the rotational freedom. Here, the term “fixed” is used to differentiate the lens moving in the optical axis 120 direction of the second group 112, and refers to a state in which movement or rotation in a direction other than the optical axis is permitted. "No focal length" is represented by an optical system in which a pair of shops and shops are in infinity, that is, a telescope.

The fourth group 116 is a lens that corrects image fluctuations accompanying the variation of the second group 112.

The CCD unit 118 includes a glass block such as a charge coupled device (CCD), a face plate accompanying it, a low pass filter (LPF), and the like. Such LPF may be formed as a fifth group.

In this embodiment, the camera shake is corrected by the convex lens and the concave lens of the third group 114 which are rotationally orthogonal to each other. Hereinafter, the third group 114 will be described in detail.

2 is a perspective view schematically showing the appearance of the third group. The third group includes the convex lens 200 and the concave lens 210, and is freely disposed with the rotation axis 130 and the rotation axis 132 as the central axis, respectively.

As shown in Fig. 2, the camera shake correction is performed by the rotational rotation of the lens instead of the linear driving of the lens, so that the fall of the weight of the correcting lens can be prevented and the holding power for maintaining the optical axis is unnecessary. Therefore, the power for the holding power can be reduced.

In addition, the rotating shaft 130 of the convex lens 200 and the rotating shaft 132 of the concave lens 210 are fixed to respective rotating shafts, and a rotating part 230 of rotational freedom is provided, and the rotating portion 230 is surrounded therein. The fixing part 240 facing the front with a space on the face of the is disposed.

The rotating part 230 and the fixing part 240 may be a rotation driving part that cooperates with each other and generates a driving force for rotating driving. In addition, similarly, the rotation unit 230 and the fixing unit 240 may be a rotation angle detector that detects the rotation angle of rotation of the rotation shaft in cooperation with each other.

3 is an explanatory diagram for illustrating the configuration of the third group in more detail. Here, only the concave lens 210 of the third group 114 will be described for ease of understanding.

The rotating part 230 is fixed to the rotating shaft 132 of the concave lens 210 installed at a right angle with the optical axis. On the other hand, the fixing unit 240 is fixed to the image stabilization main body side with a space between the rotating unit 230.

A coil 250 and a hall element 260 are installed in the rotating part 230, and a driving permanent magnet 252 and an angle detection permanent magnet 262 are installed in fixing parts 240 facing each other. . Since the drive permanent magnet 252 and the angle detection permanent magnet 262 share the polarity, they can be formed integrally, and further miniaturization of the fixed portion can be achieved. Therefore, also in FIG. 3, the driving permanent magnet 252 and the angle detection permanent magnet 262 are integrally shown as a shared magnet in which the N pole and the S pole are arranged in parallel. In addition, although the permanent magnet is held as the magnet, the present invention is not limited to this case, and it is also possible to form an image stabilizer using an electromagnet.

The coil 250 and the driving permanent magnet 252 cooperate with each other to form a rotation driving unit, and by flowing a current through the coil 250 generates an electromagnetic force, it is possible to obtain a rotation driving force according to the amount of current. In this way, it becomes possible to drive in the rotation direction as indicated by the arrow. Such a driving method may use the principle of VCM (Voice Coil Motor) used for positioning the head of the HDD.

In addition, the Hall element 260 and the angle detection permanent magnet 262 form a rotation angle detector, and the current angle can be known by the current generated by the Hall element 260. Here, the hall element 260 is a magnetic sensor using the Hall effect, and can directly convert magnetism into electricity.

The concave lens 210 is driven to rotate about the rotation shaft 132 by a rotation driving unit composed of the coil 250 and the driving permanent magnet 252, and the rotation driving amount thereof is the hole element 260. It is calculated by the feedback of the rotational angle detector composed of the angle detection permanent magnet 262. In this embodiment, since the desired angle or angular velocity is maintained, closed loop control for feeding back the rotational angle is performed.

Since the concave lens 210 belongs to the third group 114, it is formed compact and lightweight. For example, if the objective lens of the first group 100 occupies the weight of 60% to 70% of all rear focus zoom lenses, the third group 114 and the fifth group described later are about 1 to 20% weight. Since the concave lens 210 can be rotationally driven with the minimum driving force. Therefore, it is possible to form the rotary drive part in a small size and light weight.

By reducing such a driving force, the expensive sintered neodium magnet used for a drive can be miniaturized, for example. In this manner, even if the magnet is miniaturized and the required torque is reduced to half or less, sufficient image stabilization performance can be ensured in the above configuration. Therefore, in the present embodiment, it is possible to reduce the size, reduce the cost, and reduce the power consumption by using the third group as the control target.

4 is a functional block diagram for explaining rotation control of a lens in the first embodiment. Here, only the system of the concave lens 210 is described for ease of understanding, but it is naturally applicable to the convex lens 200.

The drive control circuit of the hand shake compensator 300 includes a hand shake detector 310, a rotation angle detector 312, a drive signal generator 314, and a rotation driver 316.

The camera shake detector 310 detects an angle or linear movement amount of the camera shake correction apparatus 300 that is moved due to the shake of the user. The shake detection unit 310 may be formed of an angle sensor, an angular velocity sensor, an angular acceleration sensor, a position sensor, a speed sensor, an acceleration sensor, or the like. Therefore, the detection subject can be one or two or more operations selected from the angle, angular velocity, angular acceleration, position, velocity, and acceleration of the image stabilizer itself.

The rotation angle detector 312 is formed of a Hall element 260 and an angle detection permanent magnet 262 which are disposed to face in front of a surface orthogonal to the rotation axis 132 of the concave lens 210. Either one of the 260 or the angle detecting permanent magnet 262 is fixed to the rotating shaft 132.

In this embodiment, the hall element 260 is fixed to the rotation shaft 132 to detect the rotation angle of the concave lens 210 of the third group 114. It is preferable that the fixed object of the rotating shaft 132 be the hall element 260 from the relationship of the load. Such rotation angle detector 312 may be capable of detecting an angular velocity or an angular acceleration in addition to the angle.

In addition, by separating the rotation angle detector 312 from the lens rotation center, the amount of movement with respect to the rotation angle can be increased, the detection resolution can be increased, and high precision rotation control is possible. The rotation angle detection range can be ± 0.5 °, for example.

The driving signal generator 314 drives the concave lens 210 of the third group 114 based on the shaking angle detected by the shake detecting unit 310 and the rotating angle detected by the rotating angle detecting unit 312. Generate a signal. Specifically, first, the sign of the camera shake angle θ detected by the camera shake detection unit 310 is reversed (−θ), so that the target value of the concave lens 210 is set. The rotation angle of the rotation angle detection part 312 which is a feedback signal is subtracted from this target value (-theta), and the rotation drive part 316 is rotated by the deviation.

Here, although angle control using feedback is performed, it is not limited to this case, It is possible to apply all the angular velocity control, the angular acceleration control, the position control, the speed control, and the acceleration control.

In addition, the drive signal generator 314 may be included in a semiconductor integrated circuit such as a central processing unit (CPU) or a digital signal processing unit (DSP), and such a central processing unit manages the whole image stabilizer 300. And control.

The rotation driving unit 316 is formed of a coil 250 and a driving permanent magnet 252 which are disposed to face in front of a surface orthogonal to the rotation axis 132 of the concave lens 210, and the coil 250 or One of the driving permanent magnets 252 is fixed to the rotating shaft 132.

In the present embodiment, the coil 250 is fixed to the rotation shaft 132, and according to the drive signal of the concave lens 210 of the third group 114 generated by the drive signal generator 314, the concave lens Drive 210 in rotation. Like the rotation angle detector 312, it is additionally advantageous to install the coil 250 in the rotation unit 230.

The rotation driving unit 316 can be controlled with higher precision than the rotation motor because the rotation angle required for image stabilization is small (for example, ± 0.5 °). In this control, as the rotation axis 132 of the concave lens 210 and the coil 250 have a distance, the rotation angle with respect to the movement amount can be reduced, and the accuracy can be increased. In addition, the occupied space can be made smaller than that of the rotating motor. In addition, since the rotation angle detector 312 is formed integrally, the occupied space can be made smaller.

The concave lens 210 is rotated about the rotation shaft 132 to obtain a driving force by the rotation drive unit 316.

In the above-described image stabilization apparatus 300, the rotation angle detector 312 and the rotation drive unit 316 are provided in the third group 114. When there is a fixed fifth group, rotation is performed in the fifth group. The angle detector 312 and the rotation driver 316 may be provided.

Accordingly, the fifth group, like the third group 114, is free to rotate as an axis of orthogonal rotation to the optical axis as a rotation axis, and an axis orthogonal to the axis of rotation of the convex lens as the rotation axis while being orthogonal to the optical axis. It has a concave lens of material.

In addition, a camera shake correction method for camera shake correction of a rear focus zoom lens 100 constituted by four or more lens groups is also provided.

In the camera shake correction method, first, the camera shake detector 310 detects a camera shake angle, and the rotation angle detector 312 uses the convex lens 200 and the concave lens of the third group 114 of the rear focus lens 100. 210. Each rotation angle is detected. The driving signal generator 314 generates driving signals of each of the convex lens 200 and the concave lens 210 based on the detected shaking and rotating angles. In response to the generated drive signal, the rotation driver 316 rotates each of the convex lens 200 and the concave lens 210.

In addition, each step in the image stabilization method does not necessarily need to be processed in time series in the above-described order, but also includes processing executed in parallel or separately (for example, parallel processing or processing by an object). You may also

(2nd Embodiment: Modified Example of Image Stabilizer 300)

Next, the camera shake correction apparatus 400 in which the positional relationship between the rotation angle detector 312 and the rotation driver 316 is different will be described.

Fig. 5 is a perspective view schematically showing the external appearance of the third group in the second embodiment. The third group 114 is composed of a convex lens 200 and a concave lens 210, and each of the rotating shafts 130 is shown. And a rotation axis 132, which is freely rotated as a central axis.

In addition, the rotating shaft 130 of the convex lens 200 and the rotating shaft 132 of the concave lens 210 are fixed to respective rotating shafts, and a rotating part 430 of rotational freedom is provided, and around the rotating portion 430. The fixing part 440 facing the front with a space on the face of () is arranged.

The rotating part 430 and the fixing part 440 may be rotational driving parts that cooperate with each other to generate driving force for rotating driving. In addition, similarly, the rotation unit 430 and the fixing unit 440 may be a rotation angle detection unit that detects the rotation angle of rotation of the rotation shaft in cooperation with each other.

Since the convex lens 200, the concave lens 210, the rotating shaft 130, and the rotating shaft 132 described above are substantially the same as the components in the first embodiment, their overlapping description is omitted, and the configuration is different here. The rotating unit 430 and the fixing unit 440 will be mainly described.

The rotation part 430 is disposed on a surface parallel to the rotation axis of the convex lens or the concave lens, and is fixed to the rotation axis.

The fixing part 440 is disposed to face the rotating part 430 in front, and is fixed to the main body side of the image stabilizer 400.

Therefore, the coil of the rotary drive unit provided in the rotating unit 430 and the permanent magnet for driving the rotary drive unit provided in the fixed unit 440 are parallel to the rotating shaft while facing the surface. The Hall element of the detection unit and the permanent magnet for angle detection of the rotation angle detection unit provided in the fixing unit 440 are also parallel to the rotation axis while facing the surface. The driving permanent magnet and the angle detecting permanent magnet can be integrally formed by arranging the N pole and the S pole in parallel.

This configuration makes it possible to obtain the same rotational operation as the rotational drive unit described in the first embodiment.

(Third Embodiment: Center of Rotation of Lens)

Although the rotation axis of the convex lens 200 or the concave lens 210 described in the first or second embodiment passes through the lens center, the rotation axis may be further spaced apart from the subject side. Hereinafter, the advantages of providing the rotating shaft on the subject side will be described.

6 is an explanatory diagram for explaining the amount of movement when the lens is moved perpendicular to the optical axis 500. In this case, since the lens is moved in the vertical image direction with respect to the optical axis 500, the eccentric portion 510 appearing on the image surface 502 becomes the total correction amount 540 as it is.

In the method of linearly moving such a lens vertically with respect to the optical axis, when the driving actuator is energized, the moving lens falls along a guide for parallel eccentric displacement by its own weight. In addition, in order to maintain the optical axis, it is necessary to always supply the driving force in the direction of stopping the self-fall of the lens, and wasteful power consumption is wasted.

7 is an explanatory diagram for explaining the amount of movement when the lens is rotated about the rotation center 520. Here, since the lens is inclined in the direction of the arrow by θ, the optical axis 500 refracts the rotation center 520 by 2θ as the point of refraction, and the refraction fraction 530 appearing on the image surface 502 remains the total correction amount as it is. (540).

In any case of FIGS. 6 and 7, either the eccentric part 510 or the refraction part 530 becomes the total correction amount 540 as it is in one correction operation. In this embodiment shown below, the total correction amount 540 can be made large by providing a rotation axis further spaced to the subject side.

8 is an explanatory diagram for explaining the amount of movement when the lens is rotated around the rotation center 520 disposed on the subject side rather than the lens center. Here, since the lens itself moves vertically upward by tilting the lens by θ in the direction of the arrow, the optical axis 500 not only refracts the rotation center 520 by 2θ as the point of refraction, but also the vertical image. It also moves in the direction. Therefore, the sum of the refraction fraction 530 and the eccentric fraction 510 appearing on the upper surface 502 becomes the total correction amount 540.

In this way, when the rotation axis is located on the subject side rather than the center of the lens, the amount of movement (total correction amount 540) of the image surface is an amount to which the refraction portion 530 and the eccentric portion 510 moving in the same direction are added. Therefore, it becomes possible to suppress the rotation amount (theta) for performing the same amount of correction small.

As described above, the desired total correction amount 540 does not maintain a proportional relationship with the command angle commanded to the rotary drive unit. Therefore, the rotation angle of the rotation drive unit may be derived as a table or a nonlinear function from the angle detected by the camera shake detection unit.

Under such a configuration that the rotation amount θ is kept small, the rotation driving unit can be further reduced in size and light in weight, and the cost can be reduced.

In FIG. 8, although the rotation center 520 was made into the subject side, the correction amount in the case of making it into the imager side is demonstrated below.

9 is an explanatory diagram for explaining the amount of movement when the lens is rotated around the rotation center 520 disposed on the imager side rather than the lens center. Here, since the lens itself moves vertically downward by tilting the lens by θ in the direction of the arrow, the optical axis 500 not only refracts the rotation center 520 by 2θ as the point of refraction, but also vertically downward. It also moves in the direction. Therefore, the total correction amount 540 appearing on the upper surface 502 is equal to the difference between the refraction portion 530 and the eccentric portion 510.

When the rotation axis is located on the imager side rather than the center of the lens as described above, the amount of movement of the image surface becomes the difference between the refraction portion 530 and the eccentric portion 510 due to the rotation of the lens. The ratio of the total correction amount 540 to the deterioration is deteriorated. Therefore, as shown in FIG. 9, when the rotation center 520 is provided in the imager side, it is understood that correction efficiency will worsen.

As described above, when the rotation center of the lens is installed at a position spaced apart from the center of the lens (for example, 5 mm or less) to rotate the lens, the lens group is displaced by the inclination of the upper surface by the rotation driving. Apart from (refractive powder), parallel eccentric component displacement (eccentric component) of the upper surface accompanying rotation is also generated.

The same result can be obtained in any of the convex lens 200 and the concave lens 210, and since the refraction portion 530 and the eccentric portion 510 generated by the rotation are added and moved as the correction amounts in the same direction, The amount of displacement on the image surface can be maximized while suppressing the rotation amount θ of each lens group. Therefore, sufficient camera shake correction can be performed while reducing unnecessary rotation.

Under such a configuration, it is possible to solve a small amount of driving of the rotational drive unit without causing extreme deterioration of the imaging performance, and to assume a small torque. Further, the actuator can be miniaturized, further reducing power consumption and cost reduction of the image stabilizer.

As mentioned above, although the preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this example. It is apparent to those skilled in the art that various modifications or modifications can be made within the scope described in the claims, and that they naturally belong to the technical scope of the present invention.

For example, in the above-described embodiment, as a combination of the rotation angle detection unit and the rotation drive unit, a configuration in which both are formed on a surface orthogonal to the rotation axis of the lens or a configuration in which both are formed on a parallel surface has been described. It is not limited to the case, You may form in the surface parallel to orthogonal surface, respectively, or in the surface orthogonal to the parallel surface, respectively. In the configuration in which the mutually orthogonal structures are described above, the corresponding magnet can be further miniaturized.

INDUSTRIAL APPLICABILITY The present invention is applicable to a camera shake correction apparatus and a method for reducing the influence of the camera shake received by an imaging device.

Although the foregoing description has been focused on the novel features of the invention as applied to various embodiments, those skilled in the art will appreciate that the apparatus and method described above without departing from the scope of the invention. It will be understood that various deletions, substitutions, and changes in form and detail of the invention are possible. Accordingly, the scope of the invention is defined by the appended claims rather than in the foregoing description. All modifications within the scope of equivalents of the claims are to be embraced within the scope of the present invention.

As described above, according to the camera shake correction apparatus and method of the present invention, the driving force for rotating driving can be suppressed, and the space occupied by the configuration necessary for camera shake correction can be reduced, further miniaturizing, lowering cost, and lowering power consumption. It becomes possible.

Claims (10)

In a camera shake correction apparatus for camera shake correction of a rear focus zoom lens composed of four or more lens groups, Group 1 of the objective lens group; A second group for adjusting the focal length by moving back and forth with respect to the optical axis; A third group having a confocal lens constituting an afocal system and rotating with an axis orthogonal to the optical axis as a rotation axis, and a concave lens rotating with an axis orthogonal to the optical axis and perpendicular to the rotation axis of the convex lens; A fourth group for correcting image fluctuation accompanying the adjustment of the focal length of the second group; A hand shake detection unit detecting a hand shake angle; A rotation angle detector for detecting rotation angles of each of the third group of convex and concave lenses; A driving signal generator configured to generate driving signals of each of the third group of convex and concave lenses based on the detected shaking angle and the rotation angle; And And a rotation driver configured to rotationally drive each of the third group of convex and concave lenses in accordance with the generated drive signal. The method of claim 1, The rotation driving unit is formed of a coil and a magnet disposed to face the front surface perpendicular to the plane orthogonal to the rotation axis of the convex lens or the concave lens, and either of the coil or the magnet is fixed to the rotation shaft. Device. The method of claim 1, The rotation driving unit is formed of a coil and a magnet disposed to face in front of a plane parallel to the axis of rotation of the convex or concave lens, and either of the coil or the magnet is fixed to the axis of rotation. Device. The method of claim 1, The rotation angle detector is formed of a Hall element and a magnet disposed to face the surface perpendicular to the plane orthogonal to the rotation axis of the convex lens or the concave lens, and either one of the Hall element or the magnet is fixed to the rotation axis. Image stabilization device. The method of claim 1, The rotation angle detector is formed of a Hall element and a magnet disposed to face the surface parallel to the axis of rotation of the convex or concave lens, and either one of the Hall element or the magnet is fixed to the rotation axis. Image stabilization device. The method of claim 1, The rotation axis of the convex lens or the concave lens is formed to be spaced apart from the lens side toward the subject. The method according to any one of claims 1 to 6, And a fifth group having a convex lens rotating with an axis orthogonal to the optical axis as a rotation axis, and a concave lens rotating with an axis orthogonal to the optical axis and being orthogonal to the rotation axis of the convex lens, And the rotation angle detector and the rotation driver target the fifth group of convex and concave lenses instead of the third group of convex and concave lenses. In a camera shake correction method for camera shake correction of a rear focus zoom lens composed of four or more lens groups, A hand shake detection step of detecting a hand shake angle; A third group of convex lenses constituting an afocal system and having a convex lens rotating with an axis orthogonal to the optical axis as the rotation axis, and a concave lens orthogonal to the optical axis and rotating with an axis orthogonal to the axis of rotation of the convex lens as the rotation axis; A rotation angle detection step of detecting rotation angles of each of the concave lenses; A driving signal generation step of generating driving signals of each of the third group of convex and concave lenses based on the detected shake angle and the rotation angle; And And a rotation driving step of rotationally driving each of the third group of convex and concave lenses in accordance with the generated drive signal. In the image stabilization device for rotating the lens to shoot the image to correct the camera shake, A hand shake detection unit detecting a hand shake angle; A rotation angle detector for detecting a rotation angle of the lens; A driving signal generator configured to generate a driving signal of the lens based on the detected shaking angle and the rotation angle of the lens; And And a rotation driver configured to rotationally drive the lens according to the generated driving signal. In the image stabilization device image stabilizer, A first lens group; A second lens group disposed behind the first lens group and configured to adjust a focal length by moving back and forth with respect to the optical axis; A third lens group rotating using an axis orthogonal to the optical axis as a rotation axis; A hand shake detection unit detecting a hand shake angle; A drive signal generator configured to generate a drive signal of the third lens group based on the detected camera shake angle; And And a rotation driver configured to rotationally drive the third lens group according to the generated driving signal.

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