KR101464533B1 - Image stabilizer for camera - Google Patents

Abstract

An image stabilizer for a camera according to the present invention includes a correction lens disposed on an optical axis of a plurality of lenses, a lens support plate for supporting the correction lens, a lens support plate having a first direction perpendicular to the optical axis, And a base movably supporting the lens in a second direction perpendicular to the first direction, and a base which is symmetrical with respect to the correction lens on a straight line perpendicular to the optical axis and at an acute angle to the first direction, And a second driving unit disposed between the base and the lens support plate and driving the lens support plate on the outside of the correction lens on the straight line coinciding with the second direction.

Description

[0001] Image stabilizer for camera [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a camera shake correction apparatus, and more particularly, to an optical shake correction apparatus that allows a lens barrel to be designed for a compact camera.

A digital camera is a device capable of storing an image of a subject as a digital file of a photograph or a moving image, and is a digital still camera (DSC), a digital video camera (DVC) Modules and the like.

In recent years, in order to realize the miniaturization and thinning of a camera, an optical axis (light axis) of light representing a subject image is formed in a direction orthogonal to the optical axis by using a prism so as to secure an optical path length required from the subject to an image pickup element (photoelectric conversion element) A refractive optical system for refracting light is used.

On the other hand, technologies for correcting the shaking used in digital cameras are classified into two technologies, namely, electronic image stabilization technology and OIS (automatic image stabilization) technology.

Such a camera-shake correction technique can also be applied to a digital camera employing a refractive optical system. The optical image stabilization technology is a technique for correcting an image of a subject formed on a photoelectric conversion element so that there is no blur even if there is a shake of the photographing device by detecting the shaking of the user and changing the position of the optical lens or the photoelectric conversion element.

When the optical image stabilization technique of changing the position of the optical lens to the refractive optical system is applied, the size of the lens barrel is determined according to the structure of the image stabilization module. However, in the conventional digital camera adopting the refractive optical system, due to the structure of the actuator arranged in the lens barrel of the refractive optical system for moving the optical lens, the size of the lens barrel increases, which has been a limiting factor in downsizing and thinning of the digital camera.

The conventional camera shake correction module has a structure in which two driving means are disposed with a correction lens interposed therebetween. One driving means of the camera shake correction module generates a thrust in a horizontal direction (yaw direction), and the other driving means generates a thrust in a vertical direction (pitch direction). By thus adjusting the magnitude of the force generated by the two driving means, it is possible to determine the direction in which the correction lens is moved according to the direction of the vibration generated in the camera.

However, according to the conventional camera shake correction module, since the two driving units must be able to drive the correction lens only by combination, there is a problem in that the size of the driving means of the shake correction module is increased in order to generate sufficient force. That is, there has been a problem that the size of the barrel increases due to an increase in the size of the magnets and coils constituting the driving means so as to generate a force capable of driving the correction lens.

An object of the present invention is to provide a camera shake correction apparatus using an optical camera shake correction technique for changing the position of an optical lens.

Another object of the present invention is to provide a camera-shake correction device that enables the design of a lens barrel suitable for a small camera because it occupies a small space.

The present invention provides a camera-shake correction apparatus for facilitating the design of a small-sized lens barrel, in which the first driving unit for moving the correction lens in the first direction is disposed in a diagonal direction deviated from the first direction.

An image stabilizer for a camera according to the present invention includes a correction lens disposed on an optical axis of a plurality of lenses, a lens support plate for supporting the correction lens, a lens support plate having a first direction perpendicular to the optical axis, And a base movably supporting the lens in a second direction perpendicular to the first direction, and a base which is symmetrical with respect to the correction lens on a straight line perpendicular to the optical axis and at an acute angle to the first direction, And a second driving unit disposed between the base and the lens support plate outside the correction lens on the straight line coinciding with the second direction to drive the lens support plate.

In the present invention, the first driving unit may include first coils disposed on one of the base and the lens support plate, first magnets disposed on the other one of the base and the lens support plate to correspond to the first coils, The second driving unit may include a second coil disposed on one of the base and the lens support plate, and a second magnet disposed on the other one of the base and the lens support plate to correspond to the second coil.

In the present invention, the shaking motion compensating device further includes a vibration detecting device for detecting vibration, and the first driving part and the second driving part can move the lens supporting plate according to the detection result of the vibration detecting device.

In the present invention, it is possible to further include a position detecting device for detecting the position of the lens support plate.

In the present invention, the position detecting device may include a first position detecting device for detecting the position of the lens supporting plate in the first direction and a second position detecting device for detecting the position in the second direction.

In the present invention, the first position detecting device and the second position detecting device may each include a hall sensor.

The camera shake correction apparatus of the present invention as described above includes a first driving unit for moving the correction lens in the first direction and includes a set of two coils and magnet units symmetrical about the correction lens, Optical image stabilization technology can be implemented using magnets and coils.

In addition, since the width of the first driving unit that is disposed in the diagonal direction deviating from the first direction and occupied by the first driving unit that moves the correction lens in the first direction is minimized, it is possible to design the lens barrel suitable for a compact camera.

Hereinafter, the configuration and operation of the camera-shake correction apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic view schematically showing an optical system of a camera in which a camera shake correction apparatus according to an embodiment of the present invention is used.

In recent years, the performance of image capture devices such as digital still cameras and video cameras has been remarkably improved, allowing ordinary users, not experts, to easily shoot still images and moving images of high quality and high efficiency. The improvement in the performance of the image pickup apparatus is due to the high performance of the functions of the camera components such as the lens, the CCD, and the image processing circuit. However, even if the performance of a lens, a CCD, or the like is improved, blurring occurs in a high-resolution image and the quality of a photographed image is deteriorated if a camera shakes due to the hand of a person using the camera.

An image stabilizer developed for the purpose of solving such a problem is initially provided in a relatively expensive camera, but recently it is also provided in a compact automatic camera of a popular type. The camera shake correcting apparatus according to an embodiment of the present invention can be manufactured in a small size and occupies a small space, thus making it possible to design a lens barrel suitable for a small camera.

The optical system 10 of the camera shown in Fig. 1 includes a camera shake correcting device 20 that corrects a phenomenon in which an image is shaken by the influence of vibration caused by camera shake of a user who operates the camera. The optical system 10 of the camera of Fig. 1 is a refractive optical system which includes a plurality of lens assemblies 11, 12, 13, 14 and 15 arranged on one optical axis L, a photoelectric conversion unit 18, And an image stabilization device (20).

The plurality of lens assemblies include first to fifth lens assemblies 11, 12, 13, 14 and 15 and are arranged so that the image of a subject incident on the photoelectric conversion unit 18 between the subject and the photoelectric conversion unit 18 And adjusts the zoom and focus of the camera.

The photoelectric conversion unit 18 includes an optical low pass filter 16 and an image pickup device 17 and converts the incident light into an electrical signal representing an image of a subject.

The camera-shake correcting device 20 performs a camera-shake correction function, which is a function of correcting the phenomenon that the image of the camera optical system 10 is blurred due to vibration such as camera shake of the camera user.

The optical axis of the correction lens 21 of the shake correction apparatus 20 coincides with the optical axis L of the optical system 10 in a normal state without any camera shake. The correction lens 21 is supported by the lens support plate 30 and can move in a direction across the optical axis L. [ Therefore, in the case where an image formed on the image pickup element 17 is blurred due to a vibration such as an unintentional hand movement, the correction lens 21 moves in a direction crossing the optical axis L, so that the image blur can be corrected.

The plurality of lens assemblies 11, 12, 13, 14, 15 includes five lens assemblies. The first lens assembly 11, the third lens assembly 13 and the fifth lens assembly 15 are arranged in a fixed state and the second lens assembly 12 and the fourth lens assembly 14 are arranged in a fixed state, and can be moved for zooming and auto focusing.

The first lens assembly 11 includes a first lens 11a as an objective lens arranged to face the subject, a second lens 11c arranged at an angle of about 90 degrees with respect to the first lens 11a, And a prism 11b that converts the path of the light incident through the first lens 11a to the second lens 11c. Therefore, the first lens assembly 11 changes the optical path of the image light incident from the subject by about 90 degrees.

The light incident through the first lens 11a of the first lens assembly 11 is converted into an optical axis by the prism 11b by 90 degrees and is incident on the second lens assembly 12 through the second lens 11c . The incident light is focused by the movement of the second lens assembly 12 and the fourth lens assembly 14, and is incident on the photoelectric conversion unit 18.

Since the refracting optical system is configured to convert the optical path of the light incident on the lens barrel to the 90 degree direction by the prism 11b, it is not necessary to arrange all the lenses in the direction in which the light is incident, .

The present invention is not limited by the number, shape, arrangement order of the lenses provided in the optical system 10 shown in Fig. 1, and the type of lens assembly and movable lens assemblies that are fixed. Therefore, the range of the optical system 10 in which the shake correction apparatus 20 of the present invention can be used is not limited to the embodiment shown in FIG. 1, but a person skilled in the art But may also include optical systems of a range that can be used.

FIG. 3 is a perspective view showing a state in which the image stabilization device of FIG. 2 is engaged, FIG. 4 is a perspective view of the correction lens of the image stabilization device of FIG. 2, Fig. 7 is a plan view showing the lens supporting plate.

2 to 4 includes a correction lens 21, a lens support plate 30, a base 40 for movably supporting the lens support plate 30, And a first driving unit 50 and a second driving unit 60 that drive the lens support plate 30.

The correction lens 21 is a lens disposed on the optical axis L of the optical system 10 of Fig. 1 and the correction lens 21 is supported by the lens support plate 30. Fig. The lens holding plate 30 is provided with a lens mounting hole 31 so that the correction lens 21 is engaged.

The lens support plate 30 is fixed to the base 40 so as to be movable along a first direction (Y-axis direction) perpendicular to the optical axis L and a second direction (X-axis direction) perpendicular to the optical axis L and the first direction. . The base 40 includes a first support portion 41 for movably supporting the lens support plate 30 along the first direction and a second support portion 45 for movably supporting the lens support plate 30 along the second direction ).

Referring to FIG. 3, the first direction perpendicular to the optical axis L corresponds to the Y axis direction, and the second direction perpendicular to the optical axis L and the Y axis corresponds to the X axis direction. The X axis and the Y axis are orthogonal to each other through the center of the correcting lens 21.

2, among the axes shown with the lens support plate 30, the first support portion 41 and the second support portion 45, Y1 and Y2 axes are axes in the same direction as the Y axis in FIG. 3, and X1, X2, and X3 are all axes in the same direction as the X-axis in Fig. The Y1 and Y2 axes and the X1, X2 and X3 axes are the names of axes marked for convenience in accordance with what is shown in FIG. Therefore, when the lens support plate 30, the first support portion 41 and the second support portion 45 of FIG. 2 are combined and assembled in the coupled state of FIG. 3, the Y1 and Y2 axes shown in FIG. And the X1, X2, and X3 axes become the X-axis in Fig.

The first sliding rails 32a and 32b are provided on the outer side of the lens supporting plate 30 to extend in the Y1-axis direction. The first slide support plates 42a and 42b having through holes 43a and 43b are formed at positions corresponding to the first slide rails 32a and 32b at both side edges of the first support portion 41 in the Y2 axis direction Respectively. When the lens support plate 30 is coupled to the first support portion 41, each of the first slide rails 32a and 32b is slidably inserted into the first slide support plates 42a and 42b, The support plate 30 can move in the Y-axis direction with respect to the first support portion 41. [

Second slide rails 44a and 44b are provided on the outer side of the first support portion 41 so as to protrude in the X2 axis direction. Second sliding support plates 47a and 47b having through holes (not shown) are provided at both side edges of the second support portion 45 at positions corresponding to the second slide rails 44a and 44b. Therefore, when the first support portion 41 is engaged with the second support portion 45, each of the second slide rails 44a and 44b is slidably inserted into the second slide support plates 47a and 47b, 1 support portion 41 can move in the X-axis direction with respect to the second support portion 45. [

The direction of movement of the first slide rails 32a and 32b is directed to the Y axis direction perpendicular to the X axis direction which is the sliding movement direction of the first support portion 41. [ The first sliding rails 32a and 32b of the lens supporting plate 30 are moved in the X-axis direction with respect to the second supporting portion 45 in the first supporting portion 41, The lens support plate 30 is not affected by the movement of the first support portion 41 because the inserted state is maintained in the sliding support plates 42a and 42b.

The second sliding rails 44a and 44b of the first supporting portion 41 are kept inserted into the second supporting portion 45 and the influence of the second sliding rails 44a and 44b on the first supporting portion 41 I do not accept.

A through hole 48 having a size corresponding to the correcting lens 21 coupled to the lens supporting plate 30 is formed at the center of the first supporting portion 41 and a correcting lens 21 is provided at the center of the second supporting portion 45, The through hole 46 having a size corresponding to that of the through hole 46 is formed. Therefore, the light that has passed through the correction lens 21 can pass through the through holes 41 and 46.

A first driving part 50 and a second driving part 60 for driving the lens supporting plate 30 are disposed between the base 40 and the lens supporting plate 30. The first driving part 50 functions to move the lens supporting plate 30 in the first direction (Y axis direction) and the second driving part 60 functions to move the lens supporting plate 30 in the second direction .

The first driving part 50 includes first coils 51a and 51b disposed in the mounting grooves 38a and 38b of the lens supporting plate 30 and first coils 51a and 51b disposed in the first supporting part 41, (52a, 52b). The first coils 51a and 51b are arranged on both sides of the correcting lens 21 on a straight line M1 perpendicular to the optical axis L and forming an acute angle alpha with the first direction (Y axis direction). That is, the first coils 51a and 51b are arranged symmetrically on the straight line M1 about the correcting lens 21. The positions of the first magnets 52a and 52b correspond to the positions of the first coils 51a and 51b so that the position of the first magnets 52a and 52b on the straight line M2 perpendicular to the optical axis L and forming the acute angle? And is disposed on both sides of the correction lens 21.

The straight lines M1 and M2 shown in Fig. 2 are straight lines perpendicular to the optical axis L in Fig. 3 and in the same direction as the straight line M forming the acute angle alpha with the first direction (Y axis direction). In FIG. 2, different reference numerals of M1 and M2 are used to compare the positions of the components shown separately. When the components of FIG. 2 are combined and assembled into the state of FIG. 3, the straight lines M1 and M2 Coincide with each other to form a straight line M in Fig. The straight line M in FIG. 3 is a straight line passing through the intersection of the X axis and the Y axis, that is, passing through the center of the correcting lens 21 and perpendicular to the optical axis L.

According to the first driving unit 50 having the above-described arrangement structure, by controlling the current value supplied to the first coils 51a and 51b, the first coils 51a and 51b and the first magnets 52a , And 52b of the first and second guide members 52a and 52b. The lens support plate 30 moves relative to the first support portion 41 when an attractive force or a repulsive force acts between the first coils 51a and 51b and the first magnet portions 52a and 52b. That is, due to the influence of the components of the first direction (Y-axis direction) of the magnetic force acting between the first coils 51a, 51b and the first magnet portions 52a, 52b, the lens supporting plate 30 moves in the first direction As shown in Fig.

The first sliding rails 32a and 32b are inserted into the first sliding support plates 42a and 42b of the first supporting portion 41 to restrict movement in the second direction (X axis direction) 51a, 51b and the first magnet portions 52a, 52b can not move the lens support plate 30 in the second direction.

Since the magnet and the coil are arranged on the Y axis in order to drive the correcting lens in the first direction (Y axis direction) and the combination of one coil and the magnet is arranged outside the correcting lens in the conventional camera shake correction apparatus, There is a problem that the width of the barrel in the Y-axis direction increases due to the size of the coil and the magnet portion occupying.

However, in the camera-shake correcting apparatus according to the embodiment of the present invention, the first driving unit 50 is provided with the two first coils 51a and 51b and the first magnet units 51a and 51b for moving the lens supporting plate 30 in the first direction, 52a and 52b is used, the same object can be achieved by using magnets and coils having a size smaller than the size of the magnet portion and the coil required when using a combination of one magnet portion and a coil.

Since the first coils 51a and 51b and the first magnets 52a and 52b are disposed in the oblique direction (the direction of the straight line M) deviating from the first direction (Y axis direction) The width occupied by the first driving unit 50 for moving the correction lens can be minimized. This has the advantage that the size of the mechanism for moving the correction lens can be reduced.

The second driving portion 60 includes a second coil 61 disposed in the mounting groove 39 of the lens supporting plate 30 and a second magnet portion 62 disposed in the second supporting portion 45 do. The second coil 61 is disposed outside the correcting lens 21 on a straight line X1 coinciding with the second direction (X-axis direction). The position of the second magnet portion 62 corresponds to the arrangement position of the second coil 61 and is disposed on the outer side of the correcting lens 21 from above the straight line X2 that coincides with the second direction .

The second drive unit 60 having the above-described arrangement structure can control the current value supplied to the second coil 61 so that a desired amount of magnetic field is generated between the second coil 61 and the second magnet unit 62 The pulling force or the repulsive force of the pushing force can be applied. The first support portion 41 moves relative to the second support portion 45 when a pulling force or a repulsive force acts between the second coil 61 and the second magnet portion 62. [ The first support portion 41 is moved in the second direction along the second direction by the influence of the components in the second direction (X-axis direction) of the magnetic force acting between the second coil 61 and the second magnet portion 62, It can slide back and forth with respect to the support portion 45. [

The lens support plate 30 may be provided with position detection devices 71 and 72 for detecting the position of the lens support plate 30 with respect to the first support portion 41 and the second support portion 45. A hall sensor using the principle that the magnitude of the current (or voltage) induced according to the intensity of the magnetic field changes may be used for the position detecting devices 71 and 72.

The first position detecting device 71 can detect the position of the lens supporting plate 30 in the first direction by detecting the position of the lens supporting plate 30 with respect to the first supporting portion 41. [ The second position detecting device 72 can detect the movement position of the lens supporting plate 30 in the second direction by detecting the position of the lens supporting plate 30 with respect to the second supporting portion 45. [

FIG. 5 is a block diagram showing a schematic configuration of a camera provided with the shaking motion correction apparatus of FIG. 1;

The camera shown in Fig. 5 includes a lens unit 1 including a correction lens 21, an imaging element 17, a control unit 80, a first driving unit 50 for moving the correction lens 21, A second driving unit 60, and the like.

A lens unit (1) installed in a camera includes a plurality of lens assemblies, and receives image light of a subject to form an image into an image.

The image pickup element 17 is disposed at a position where image light passing through the lens unit 1 is imaged into an image and functions to convert an image formed by the lens unit 1 into an electrical signal. Therefore, the imaging element 17 performs a central function in photographing using a camera. The image pickup device 17 is electrically connected to the control unit 80 and receives signals from the control unit 80 to operate.

The control unit 80 is built in the camera and is electrically connected to various components such as the image pickup device 17, the first drive unit 50 and the second drive unit 60, Control signals are exchanged with these components for control, and data processing is performed. The control unit 80 includes an image processing unit 81, a memory control unit 82, a shaking motion correction calculation unit 83, a drive circuit unit 84 and a plurality of amplification units 85, 86 and 87.

The image pickup element 17 receives the image light of the object and generates an image signal which is an electrical signal. The image processing unit 81 of the control unit 80 converts the image signal input from the image pickup element 17 into image data representing an image. The image data converted by the image processing unit 81 can be stored in the memory 2 via the memory control unit 82. [

The shaking motion correction calculation unit 83 is connected to the vibration detection device 90 through the amplification unit 85. [ The vibration detecting device 90 is a device capable of detecting vibration due to camera shake or the like acting on the camera. A gyro sensor for detecting the amount of displacement caused by hand shake can be used for the vibration detection device 90. [ Therefore, the shaking motion correction calculating section 83 calculates a correction amount for moving the position of the correction lens 21 in order to correct the shaking motion, based on the detection result of the vibration detecting device 90. [

The first position detecting device 71 is connected to the driving circuit part 84 of the control part 80 through the amplifying part 86 and the second position detecting device 72 is connected via the amplifying part 87. [ Since the first position detecting device 71 detects the position of the lens supporting plate 30 in the first direction relative to the base 40 shown in Figs. 1 to 4, the driving circuit part 84 detects the position of the lens supporting plate 30 in the first direction, The position of the correcting lens 21 in the first direction can be confirmed from the detection result of the correcting lens 71. The second position detecting device 72 detects the position of the lens supporting plate 30 with respect to the base 40 in the second direction so that the driving circuit portion 84 detects the position of the lens supporting plate 30 in the second direction from the detection result of the second position detecting device 72 The position of the correcting lens 21 in the second direction can be confirmed.

The drive circuit unit 84 drives the correction lens 84 in the first direction or the second direction based on the detection results of the first position detection device 71 and the second position detection device 72 and the calculation result of the shake correction calculation unit 83. [ Determines a driving amount for moving the first driving part (21), and transmits a driving signal to the first driving part (50) and the second driving part (60). Therefore, the correction lens 21 is driven by the first driving unit 50 and the second driving unit 60, and the position of the correction lens 21 in the lens unit 1 is adjusted, so that the camera shake caused by the camera can be effectively corrected.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the appended claims.

1 is a schematic view schematically showing an optical system of a camera in which a camera shake correction apparatus according to an embodiment of the present invention is used.

Fig. 2 is an exploded perspective view specifically showing the shaking motion correcting device of Fig. 1;

Fig. 3 is a perspective view showing a state in which the shake correction apparatus of Fig. 2 is engaged. Fig.

4 is a plan view showing a correction lens and a lens support plate of the shake correction apparatus of Fig.

FIG. 5 is a block diagram showing a schematic configuration of a camera provided with the shaking motion correction apparatus of FIG. 1;

DESCRIPTION OF THE REFERENCE NUMERALS

1: lens unit 46, 48: through-hole

2: memory 50: first driving section

10: Optical system 60: Second driving part

11a: first lens 61: second coil

11c: second lens 62: second magnet portion

11b: prisms 32a, 32b: first sliding rails

11: first lens assembly 42a, 42b: first slide support plates

12: second lens assembly 43a, 43b:

13: Third lens assembly 44a, 44b: Second slide rail

14: fourth lens assembly 47a, 47b: second slide support plates

15: fifth lens assembly 51a, 51b: first lens

16: Optical low-pass filter 52a, 52b:

17: image pickup element 71: first position detecting device

18: photoelectric conversion unit 72: second position detection device

20: camera-shake compensation device 80:

21: Correction lens 81: Image processing section

30: lens support plate 82: memory control unit

31: lens mount hole 83: camera-shake correction calculating section

38a, 38b, 39: mounting groove 84:

40: base 85, 86, 87:

41: first supporting part 90: vibration detecting device

45: second support portion

Claims (6)

A correction lens disposed on an optical axis (optical axis) of the plurality of lenses; A lens supporting plate for supporting the correction lens; A second support portion movably supporting the lens support plate in a first direction perpendicular to the optical axis, and a second support portion movably supporting the first support portion along the optical axis and a second direction perpendicular to the first direction, A base having a support; First slide rails extending along the first direction and movably connecting the lens support plate to the first support portion along the first direction; Second sliding rails extending along the second direction and movably connecting the first supporting portion to the second supporting portion along the second direction; A pair of first lenses arranged on one of the base and the lens support plate so as to be symmetrical about the correction lens on a straight line passing through the center of the correction lens and having an acute angle with the first direction, A first driver for driving the lens supporting plate, the first driving unit including a pair of first magnets disposed on the other one of the base and the lens support plate to correspond to the first coils, And A second coil coinciding with the second direction and disposed on one side of the base and the lens support plate outside the correction lens on a straight line passing through the center of the correction lens; And a second driving unit for driving the lens supporting plate, the second driving unit including a second magnet disposed on the other one of the lens supporting plates. delete The method according to claim 1, Wherein the camera shake correction device further comprises a vibration detection device that detects vibration, and the first drive part and the second drive part move the lens support plate according to the detection result of the vibration detection device. The method according to claim 1 or 3, Further comprising a position detecting device for detecting a position of the lens supporting plate. 5. The method of claim 4, Wherein the position detecting device includes a first position detecting device for detecting a position of the lens supporting plate in a first direction and a second position detecting device for detecting a position in the second direction. 6. The method of claim 5, Wherein the first position detection device and the second position detection device each include a hall sensor.

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