JP5137036B2 - Image blur correction apparatus and imaging apparatus - Google Patents

Description

The present invention relates to an image blur correction apparatus and an imaging apparatus such as a video camera or a still camera provided with the image blur correction apparatus.

When shooting with a video camera or still camera held by hand, the shooting position fluctuates due to the minute rotation of the human hand. In the case of a video camera, the captured image is blurred. In this case, there is a problem that the captured image is blurred. For this reason, a mechanism having a function of preventing imaging position fluctuation has been known.

For example, as shown in FIG. 11, when a camera shake occurs, there is a mechanism for correcting image blur by driving the lens 10 in the vertical direction with a linear actuator such as a telescopic spring (see Japanese Patent Laid-Open No. 9-80556). Proposed.

In these structures, a method of decentering the correction optical system in the direction perpendicular to the optical axis is employed. In such a case, if the correction optical system is decentered, the optical performance deteriorates, so it is necessary to make the decentering as small as possible. However, since the correction optical system is always pulled by the gravity G, it is necessary to always drive the correction optical system with servo so as to overcome the gravity G and hold it at the center position.

In order to avoid the energy loss due to the servo drive as described above, as shown in FIG. 12, a rotational correction optical system (see Japanese Patent Laid-Open No. 6-197258) has also been proposed. Further, there is a problem that the structure becomes complicated because it is necessary to correct the vibration in the pitch direction with different correction optical systems.

Japanese Patent Laid-Open No. 9-80556 JP-A-6-197258

The present invention has been made in view of the above-described problems of the conventional image blur correction apparatus and imaging apparatus, and can correct the yaw direction and the pitch direction without being affected by gravity. An object of the present invention is to provide a new and improved image blur correction apparatus and image pickup apparatus that can realize image blur correction with low power consumption without requiring a large amount of energy.

In order to solve the above-described problems, according to a first aspect of the present invention, a lens fixing portion, a lens supporting portion that is biaxially rotatable in the yaw direction and the pitch direction with respect to the lens fixing portion, and a lens supporting portion are provided. A single lens that is supported and has at least one surface formed into a curved surface, a vibration detection device that detects vibration of the imaging device, and a lens support that corrects image point movement due to image blur according to the output of the vibration detection means A drive unit that rotates the member in at least one of the yaw direction and the pitch direction , and the lens support unit is configured such that the support point of the single lens and the center of gravity of the single lens coincide with each other. An image blur correction apparatus characterized by being controlled in rotation is provided.

According to such a configuration, the yaw direction and the pitch direction can be corrected by a single lens, and the influence of gravity is controlled by controlling the lens so that the support point of the lens and the center of gravity of the lens coincide. Therefore, image blur correction can be realized with low power consumption without requiring extra energy.

According to a first aspect of the present invention, further in the above structure, the center of rotation of the two axes of the lens support portion may be configured to the center of curvature and substantially aligned in a single lens surface. As a result, since no offset of the lens surface with respect to the optical axis occurs, the occurrence of aberration can be reduced, and image blur correction can be realized while maintaining good image quality.

In the above-described configuration, the driving unit is disposed on either the lens fixing unit or the lens support unit corresponding to each of the plurality of magnet members disposed on either the lens fixing unit or the lens support unit. The plurality of coil members and the yoke member can be configured. According to such a configuration, it is possible to easily drive the lens support unit and realize image blur correction by supplying a predetermined current to the coil according to the output of the vibration detection device. At this time, if the magnet member is disposed on the lens support portion side and the coil member and the yoke member are disposed on the lens fixing portion side, the driven portion can be configured freely, and the structure is simplified.

Further, if the circumferential length of each magnet member is configured to be approximately equal to the circumferential length of each corresponding yoke member, it is possible to control rotation in the circumferential direction without providing a special stopper. .

In addition, if a configuration in which a magnetic fluid is filled between the magnet member, the coil member, and the yoke member is adopted, the resonance amplitude at the main resonance can be suppressed, so that the controllability of the operating unit can be improved.

Furthermore, according to another aspect of the present invention, there is provided an imaging apparatus including the image blur correction apparatus having the above configuration.

According to such a configuration, the yaw direction and the pitch direction can be corrected by a single lens, and the influence of gravity is controlled by controlling the lens so that the support point of the lens and the center of gravity of the lens coincide. Therefore, image blur correction can be realized with low power consumption without requiring extra energy.

It is explanatory drawing explaining the principle of image blur correction. It is explanatory drawing explaining the principle of an image blur correction in case the curvature center of the spherical surface of a lens and the rotation center of a lens correspond. It is explanatory drawing explaining the principle of image blur correction in the plane side of a lens. 1 is a block diagram showing a schematic configuration of an image blur correction apparatus according to an embodiment of the present invention. It is a block diagram which shows schematic structure of the image blurring correction apparatus concerning the other embodiment of this invention. 1 is a schematic sketch of a correction drive system assembly according to an embodiment of an image blur correction device. FIG. 7 is a plan view of the correction drive system assembly shown in FIG. 6. It is AA sectional drawing of the correction | amendment drive system assembly shown in FIG. FIG. 7 is a cross-sectional view of the correction drive system assembly shown in FIG. It is explanatory drawing which shows operation | movement at the time of making the circumferential direction length of a magnet member correspond with the circumferential direction length of a coil member and a yoke member. It is explanatory drawing which shows schematic structure of the conventional image blurring correction apparatus. It is explanatory drawing which shows schematic structure of the conventional image blurring correction apparatus.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the following description and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.
First, the principle of an image blur correction apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 1A is a diagram when the entire camera is tilted due to camera shake. In this figure, since the lens is used as a reference, the incident light is shown tilted. At this time, the imaging position moves, but the imaging position can be returned to the original position by tilting the lens as shown in FIG.

This can be explained as follows. Since the lens can be considered as an assembly of prisms, in an extreme case, the incident side surface is considered as a spherical surface and the opposite side surface as a flat surface. Actually, one side does not need to be a complete plane. As shown in FIG. 2, when the center of curvature of the lens and the center of curvature of the spherical surface are made coincident and the lens is tilted at the center of curvature of the spherical surface of the lens, the spherical side does not change with the lens tilt, so it is necessary to consider However, it is sufficient to consider only the effect on the plane side.

As a result, as shown in FIG. 3, the image blur may be corrected in consideration of the effect on the plane side. When light is incident on a boundary surface having an inclination of α from a medium having a refractive index n, the following equation is established from Snell's law.

ここで角度は十分小さいので、次の様に近似できる。

レンズを傾ける役割はθ０が発生した時に、βを０にすることであるから、

となるようにα（レンズ傾き）を制御してやれば像点移動が無くなる。

Here, since the angle is sufficiently small, it can be approximated as follows.

Since the role of tilting the lens is to set β to 0 when θ0 occurs,

If α (lens tilt) is controlled so as to be, the image point movement is eliminated.

As described above, it is understood that the image point can be corrected by the lens tilt. In addition, according to the present embodiment, since the straight line connecting the contact point for rotation with the center of gravity can be made to coincide with the direction of gravity, the lens does not tilt due to gravity, so that the lens is There is no need to drive against the influence.

Next, the image blur correction device according to the present embodiment will be described in detail with reference to FIGS. 4 to 8. 4 and 5 are schematic block diagrams of the image blur correction apparatus, FIG. 6 is a schematic sketch of the correction drive system assembly in one embodiment of the image blur correction apparatus, and FIG. 7 is the correction drive system. 8 is a plan view of the assembly, FIG. 8 is a cross-sectional view taken along the line AA of the correction drive system assembly shown in FIG. 6, and FIG. 9 is a cross-sectional view taken along the line BB of the correction drive system assembly shown in FIG. Note that the image blur correction apparatus according to the present embodiment is applied to an imaging apparatus such as a video camera or a still camera, but a detailed configuration of the imaging apparatus is omitted.

As shown in FIG. 4, the image blur correction apparatus according to the present embodiment mainly includes a correction drive system assembly 100 and a correction control system 200.

The correction drive system 100 is supported by the lens fixing portion 110, the lens support portion 120 that can rotate biaxially in the yaw direction and the pitch direction with respect to the lens fixing portion 110, and the lens support portion 120 , and at least one surface is formed into a curved surface. The single lens L and the driving unit 130 that rotates the lens support unit in the yaw direction and / or the pitch direction are mainly configured.

The correction control system 200 corrects based on an image sensor 210 such as a CCD or CMOS, a vibration detection device 220 that detects vibration of the image pickup device in accordance with a signal from the image sensor 210, and a detection signal from the vibration detection device 220. The rotation control unit 230 mainly generates a drive signal for driving the drive system 100.

In the above embodiment, the correction control system 200 is configured to detect the vibration of the image pickup apparatus by the image pickup element 210 such as a CCD or a CMOS. However, as shown in FIG. Based on an angular velocity sensor 240 attached to the imaging device, a vibration detection device 220 that detects vibrations of the imaging device in accordance with a change in the angle of the imaging device detected by the angular velocity sensor 240, and a detection signal from the vibration detection device 220. A rotational drive control system that generates a drive signal for driving the correction drive system 100 can also be used.

Further, the configuration of the correction drive system 100 will be described with reference to FIGS. 6 to 9, the single lens L is omitted or indicated by a dotted line for the sake of simplicity.

The lens fixing part 110 is made of a rigid member such as plastic, and has a substantially circular hole for fitting the lens support part 120 in the center. The lens support 120 is a bowl-shaped member made of a rigid member such as plastic, and is provided with a substantially circular hole for fitting the single lens L at the center. The lens support unit 120 is attached to the lens fixing unit 110 so as to be biaxially rotatable in the yaw direction and the pitch direction.

Yaw direction drive unit 130Y for rotating lens support unit 120 in the yaw direction is provided with a yoke member 132Y provided in pairs on both sides of a hole provided in lens fixing unit 110 along the yaw direction rotation axis. And the coil member 134Y, and the magnet member 136Y provided on the lens support portion 120 side so as to correspond to each yoke member 132Y and the coil member 134Y. Similarly, the pitch direction drive unit 130P for rotationally driving the lens support unit 120 in the pitch direction is a yoke provided to form a pair on both sides of the hole provided in the lens fixing unit 110 along the pitch direction rotation axis. It is comprised from the magnet member 136P provided in the lens support part 120 side so that it may correspond to each member 132P and the coil member 134P, and each yoke member 132P and the coil member 134P.

Furthermore, a ball bearing 138 is attached between each yaw direction driving unit 130Y and the pitch direction driving unit 130P, and the lens support unit 120 is smoothly rotated. In the illustrated example, four ball bearings 138 are evenly arranged at intervals of 90 degrees, but the arrangement position and the number of ball bearings 138 are not limited thereto. Although illustration is omitted, if a configuration in which a magnetic fluid is filled between the magnet members 136Y and 136P and the coil members 134Y and 134P and the yoke members 132Y and 132P is adopted, the resonance amplitude at the main resonance can be suppressed. Controllability of the movable part can be improved.

By configuring the correction drive system 100 as described above, by controlling the current value supplied to the coil member 134Y or coil member 134P, the desired size is of attraction or repulsion generated, it is supported by the lens supporting unit 120 The single lens L can be rotationally driven in the yaw direction and / or pitch direction to correct image blur. At that time, according to the correction drive system 100 according to the present embodiment, the lens is controlled so that the support point of the lens and the center of gravity of the lens coincide with each other. Therefore, image blur correction can be realized with low power consumption without requiring extra energy.

In the above configuration, the magnet members 136Y and 136P are arranged on the lens support portion 120 side, and the coil members 134Y and 134P and the yoke members 132Y and 132P are arranged on the lens fixing portion 110 side, thereby being driven parts. The lens support part 120 is configured to be free. However, the present invention is not limited to this example, and the magnet members 136Y and 136P are arranged on the lens fixing portion 110 side, and the coil members 134Y and 134P and the yoke members 132Y and 132P are arranged on the lens fixing portion 120 side. A configuration may be adopted.

In the above configuration, the rotational axes of the two axes of the lens support portion 120 are aligned with the rotational center of the lens L and the center of curvature of the spherical surface, as described with reference to FIG. If the lens L is tilted at the center of curvature, the spherical surface does not change with the tilt of the lens L, so that no offset occurs with respect to the optical axis of the lens surface, so that there is little aberration and the image quality is kept good. Image blur correction can be realized.

As shown in FIG. 10, if the circumferential lengths of the magnet members 136Y and 136P are configured to be approximately equal to the circumferential lengths of the corresponding yoke members 132Y and 132P, the yoke members 132Y of the magnet members 136Y and 136P. Because the return force is generated even if the magnet members 136Y and 136P are disengaged from the yoke members 132Y and 132P in the circumferential direction due to the attractive force with respect to 132P, the rotation in the circumferential direction is controlled without providing a special stopper. It becomes possible.

Next, the operation of the image blur correction apparatus configured as described above will be described. When the image detected by the image sensor 210 passing through the lens L is displaced due to camera shake or the like, the vibration detecting device 220 calculates the amount of displacement. The rotation control unit 230 supplies a predetermined amount of current to the yoke driving unit 130Y and / or the pitch driving unit 130P so as to correct the deviation amount calculated by the vibration detection device 220. The yoke driving unit 130Y and / or the pitch driving unit 130P rotationally drive the lens support unit 120 so as to correct image blur in the yoke direction and / or the pitch direction according to the supplied current. As a result, the lens L supported by the lens support unit 120 is also rotationally driven in the yoke direction and / or the pitch direction by a predetermined amount, and image blur can be corrected.

As described above, according to the image blur correction device according to the present embodiment, it is possible to correct the yaw direction and the pitch direction with a single lens so that the support point of the lens matches the center of gravity of the lens. By controlling the lens in a rotating manner, it is not affected by gravity, does not require extra energy, and can achieve image blur correction with low power consumption.

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such examples. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

The present invention is applicable to an image blur correction device and an imaging device such as a video camera or a still camera including the image blur correction device.

DESCRIPTION OF SYMBOLS 100 Correction drive system 110 Lens fixing part 120 Lens support part 130 (130Y, 130P) Drive part 132Y, 132P Yoke member 134Y, 134P Coil member 136Y, 136P Magnet member 138 Ball bearing 200 Correction control system 210 Imaging element 220 Vibration detection device 230 Rotation control unit L Lens

Claims (6)

A lens fixing part,
A lens support that is biaxially rotatable in the yaw direction and the pitch direction with respect to the lens fixing part;
A single lens supported by the lens support portion and having at least one surface formed into a curved surface;
A vibration detection device that detects vibration of the imaging device;
A drive unit that rotates the lens support member in at least one of the yaw direction and the pitch direction so as to correct the image point movement due to the image blur according to the output of the vibration detection unit;
With
The lens support is rotationally controlled so that the support point of the single lens and the center of gravity of the single lens coincide with each other ,
2. The image blur correction device according to claim 1, wherein each of the two rotation centers of the lens support portion substantially coincides with a curvature center of the curved surface of the single lens . The drive unit is
A plurality of magnet members disposed on either the lens fixing part or the lens support part;
A plurality of coil members and yoke members disposed on either the lens fixing portion or the lens support portion corresponding to the magnet members;
The image blur correction device according to claim 1 , comprising: The image blur correction apparatus according to claim 2 , wherein the magnet member is disposed on the lens support portion side, and the coil member and the yoke member are disposed on the lens fixing portion side. The circumferential length of each magnet member may be approximately equal to the circumferential length of the corresponding respective yoke member, image blur correction apparatus according to claim 2 or 3. Image blur correction apparatus according to any one of, wherein a magnetic fluid is filled, the preceding claims 2 4 between the magnet member and the coil member and the yoke member. Imaging apparatus characterized by comprising an image shake correction apparatus according to any one of claims 1 to 5.

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