JP4910589B2 - Imaging unit and imaging apparatus - Google Patents

Description

  The present invention relates to an imaging unit and an imaging apparatus, and more particularly, to an imaging unit and an imaging apparatus that rotate a photographic optical axis of a lens barrel using a polymer actuator.

  A compact image pickup device mounted on a mobile phone or the like is required to be downsized, low cost, and highly functional at the same time. Advanced functions are equipped with functions such as “autofocus function”, “automatic exposure function”, and “camera shake correction function” that are realized in digital cameras. An actuator for moving the system is required.

  On the other hand, in order to reduce the size, it is necessary to reduce the size of the members added for the above-mentioned high functionality, particularly the actuator, in addition to the reduction in the conventional functions, and space efficiency at all parts levels. Improvement is essential. Furthermore, in order to reduce costs, it is important not only to reduce the cost of parts, but also to reduce costs by facilitating assembly.

  From these viewpoints, there is a polymer actuator as an actuator that has been attracting attention in recent years. Polymer actuators have features such as high generation force, lightness, no sound, low-power drive, and the ability to make a free shape by molding because the material is resin.

  For example, it has been proposed that a driving unit of a calibration device of an imaging apparatus with a camera shake correction function can be configured using a polymer actuator as a driving source (see, for example, Patent Document 1).

There has also been proposed a method of eliminating image distortion by curving an image sensor in a concave shape using a polymer actuator as a drive source (see, for example, Patent Document 2).
JP 2004-282929 A JP 2005-278133 A

  However, Patent Document 1 merely describes that a polymer actuator is suitable for a drive unit of a calibration device of an imaging device with a camera shake correction function, and no specific means or method has been proposed. Therefore, feasibility has not been verified.

  In addition, although there is little direct relationship with the present invention, in the method of Patent Document 2, applying an external force to bend the semiconductor element such as an imaging element in a concave shape not only leads to cracking of the element but also due to distortion. This is not preferable because it causes a change in element characteristics and causes deterioration of characteristics.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a small, low-cost, high-performance imaging unit and imaging apparatus using a polymer actuator.

  The object of the present invention can be achieved by the following constitution.

In one aspect of the present invention, the imaging unit includes a lens barrel for supporting the imaging element that captures an image of the subject formed by the imaging optical system and the front SL imaging optical system for forming an image of an object together , a polymer actuator for rotating to the barrel photographing optical axis is inclined, in the image pickup unit provided with a holding portion for holding the polymer actuator, the polymer actuator is substantially planar shape, whereas The surface of the lens barrel faces the rear end of the lens barrel, the other surface faces the holding portion, and the polymer actuator is fixed to the holding portion so as not to extend. And a plurality of displaceable portions that are not fixed to the holding portion and extend, and each of the plurality of displaceable portions extends in a plane direction to project from the flat portion toward the rear end portion of the lens barrel. Protruding in the shape of that By the end moves the rear end of the barrel to push to the pressing direction, the optical axis of the imaging optical system you characterized by rotating the barrel so as to be inclined.

In the imaging unit described above, the displacement portion is a displacement portion of a protrusion protruding toward the rear end side of the lens barrel in a state before the displacement, and a distal end portion of the displacement portion is located behind the lens barrel. The lens barrel is in contact with an end portion and supports the lens barrel, and the distal end portion presses the rear end portion of the lens barrel and moves in the pressing direction when the displacement portion extends in the surface direction. Is preferred.

Further, in the above-described imaging unit, the displacement portion has a planar shape in a state before displacement, is on the same plane as the planar portion, and the polymer actuator is in relation to the holding portion and the polymer actuator. It is sandwiched between the holding part and the restricting part arranged on the opposite side,
  It is preferable that the holding portion is restricted from projecting the displacement portion toward the holding portion by extending the restricting portion to a part of a portion where the polymer actuator is not sandwiched.

Further, in the above-described image pickup unit is disposed on the opposite side of the polymer actuator relative to said barrel further includes a biasing means for biasing the polymer actuator to the holding portion through the barrel it is preferably characterized by a.

Further, in the above-described imaging unit, the polymer actuator is also arranged on the front end side of the lens barrel so that the distal end portion of the displacement portion presses the front end portion of the lens barrel. It is preferable.
Further, in one embodiment according to the present invention, an imaging device, e Bei either Kano imaging unit described above, the camera shake detection means for detecting a shake of the image pickup device, the polymer based on a detection result of the camera shake detection means And a camera shake correction unit configured to drive the actuator to correct the camera shake.

  According to the present invention, camera barrel correction is realized by rotating a lens barrel that integrally supports an imaging optical system and an imaging element around a photographing optical axis using a polymer actuator, and has good assembly properties. By realizing the actuator, it is possible to provide a small, low-cost, high-performance imaging unit and imaging apparatus.

  Hereinafter, the present invention will be described based on the illustrated embodiment, but the present invention is not limited to the embodiment. In the drawings, the same or equivalent parts are denoted by the same reference numerals, and redundant description is omitted.

  First, an imaging apparatus according to the present invention will be described with reference to FIG. FIG. 1 is a schematic diagram illustrating a configuration of the imaging apparatus 1.

  In FIG. 1, the imaging device 1 includes an imaging unit 350 and an imaging circuit 300. The imaging unit 350 includes an imaging unit 330 and a camera shake detection unit 301. The imaging unit 330 includes an imaging optical system 211, an imaging element 162, a lens barrel 201, and a moving mechanism 331. An imaging optical system 211 is fixed inside the lens barrel 201, and the imaging element 162 is disposed so that the imaging surface of the imaging element 162 is positioned at the imaging plane position of the imaging optical system 211 and bonded to the lens barrel 201. It is fixed by screwing.

  Here, the imaging optical system 211 and the imaging element 162 are described as being fixed to the lens barrel 201, but may be attached to the lens barrel via autofocus means. The camera shake detection unit 301 includes a vertical shake sensor 301P (Pitch) and a left / right shake sensor 301Y (Yaw).

  The imaging circuit 300 includes a shake detection circuit 303, a camera shake correction unit 305, an actuator control unit 315, a drive circuit unit 313, an imaging control unit 161, an analog / digital (A / D) converter 163, an image processing unit 165, and an image recording unit 181. The operation unit 111 and the image display unit 131 are configured. The drive circuit unit 313 includes a booster circuit, and generates a voltage necessary for driving the polymer actuator constituting the moving mechanism 331.

  The imaging apparatus 1 in FIG. 1 is roughly divided into two functions. One is an imaging function, and the other is a camera shake correction function. First, the imaging function will be described. An image of a subject is formed on the imaging surface of the imaging element 162 by the imaging optical system 211, and the subject image is photoelectrically converted by the imaging element 162 and output as imaging data 162k. The output imaging data 162k is converted into digital data by the A / D converter 163, subjected to image processing such as white balance processing and gamma conversion in the image processing unit 165, and is recorded in the image recording unit 181 as image data 161g. And displayed on the image display unit 131 as appropriate. A series of these imaging operations are controlled by the imaging control unit 161.

  On the other hand, in the camera shake correction function, camera shake of the imaging apparatus 1 is detected by the sensors 301P and 301Y of the camera shake detection unit 301 and the shake detection circuit 303, and the amount of camera shake correction is calculated by the camera shake correction unit 305. An electric field is applied to the polymer actuator constituting the moving mechanism 331 by the actuator control unit 315 and the drive circuit unit 313 according to the calculated camera shake correction amount, and the lens barrel 201 moves in the vertical (Pitch) direction (hereinafter, P direction). And the left and right (Yaw) direction (hereinafter referred to as the Y direction), the photographing optical axis 200 of the lens barrel 201 is rotated in the direction opposite to the camera shake, and the camera shake is corrected. Here, the shake detection circuit 303, the shake correction unit 305, the actuator control unit 315, the drive circuit unit 313, and the moving mechanism 331 function as a shake correction unit in the present invention.

  The moving mechanism 331 will be described in detail after FIG.

  Next, the operation principle of the polymer actuator used in the present invention will be described with reference to FIG. FIG. 2 is a schematic diagram for explaining the operating principle of the polymer actuator.

  In FIG. 2, a polymer actuator 401 includes an extension portion 403 made of a dielectric polymer (silicon resin or acrylic resin), and an electrode 405 made of a polymer material mixed with conductive carbon particles provided on both sides of the extension portion 403. Consists of. When an electric field E is applied between the electrodes 405 provided on both surfaces of the extension portion 403, an electrostatic attraction force is generated between the electrodes and the electrodes are attracted. As a result, the extension made of a dielectric polymer that is an elastic body is generated. The unit 403 extends in the direction of the arrow in the figure. The magnitude of the extension is approximately proportional to the magnitude of the applied electric field E.

  If the electrode 405 is a partial electrode, only the extending portion 403 immediately below the partial electrode extends. Therefore, the electrode 405 is divided into a plurality of partial electrodes, and each of them is driven separately to arrange a plurality of polymer actuators. A so-called actuator array can be created. Polymer actuators are characterized by high power generation, lightness, no sound, low-power drive, the ability to make a free shape by molding because the material is resin, and the ability to form multiple actuators integrally. is there.

  Next, a first embodiment of the moving mechanism 331 using the polymer actuator 401 described above will be described with reference to FIGS. FIG. 3 is a schematic diagram showing the configuration of the first embodiment of the moving mechanism 331. FIG. 3A is parallel to the photographing optical axis 200 of the moving mechanism 331 and passes through Y1-Y2 in FIG. 3B. FIG. 3B is a schematic view showing the shape of the polymer actuator 401 used in the first embodiment.

  In FIG. 3A, the image pickup device 162 is disposed at the image forming position of the image pickup optical system 211, and the image pickup optical system 211 and the image pickup device 162 are integrally attached to the lens barrel 201. The lens barrel 201 is disposed in a space formed by the holding portion 331a and the regulating member 331b of the moving mechanism 331. A polymer actuator 401 is disposed between the lens barrel 201 and the holding portion 331a, and is in the + F direction of the imaging optical axis 200 direction (hereinafter referred to as the F direction) with respect to the end surface of the lens barrel 201 on the imaging element 162 side. Apply force.

  The polymer actuator 401 has a flat surface portion 401 a and a plurality of protruding displacement portions 401 b, and the displacement portion 401 b is disposed so as to contact the bottom surface portion of the lens barrel 201. As described with reference to FIG. 2, since the magnitude of the extension of the polymer actuator is substantially proportional to the magnitude of the applied electric field E, the displacement portion 401 b is a plane in order to efficiently use the applied electric field E. It is desirable that the thickness be equal to that of the portion 401a.

  The flat surface portion 401a and the side portion of the displacement portion 401b of the polymer actuator 401 are sandwiched between the holding portion 331a and the regulating member 331b fixed to the holding portion 331a, and are regulated so that they cannot expand even when an electric field is applied. . The back surface concave portion of the portion of the displacement portion 401b that contacts the lens barrel 201 is in contact with the protrusion of the holding portion 331a with a gap corresponding to the amount of movement of the lens barrel 201.

  The opposite surface of the lens barrel 201 that is in contact with the displacement portion 401b of the polymer actuator 401 across the imaging optical system 211 is biased in the -F direction by a biasing spring 331c that functions as a biasing member in the present invention. The lens barrel 201 is sandwiched between the biasing spring 331c and the displacement portion 401b of the polymer actuator 401.

  When the moving mechanism 331 is actually assembled, the polymer actuator 401 is placed inside the shallow cup-shaped holding portion 331a, and the regulating member 331b is placed thereon and fixed to the holding portion 331a. Next, it is only necessary to drop the lens barrel 201 into the regulating member 331b and press the lens barrel 201 with a biasing spring 331c from above, which makes it possible to assemble very easily and to reduce assembly costs at a low cost.

  In FIG. 3B, the polymer actuator 401 is integrally formed by, for example, injection molding, and four projecting displacement portions 401b are arranged on a rectangular sheet-like plane portion 401a. In the figure, the + side displacement part in the P direction is 401 bp1, the − direction displacement part in the P direction is 401 bp2, the + direction displacement part in the Y direction is 401 by1, and the − side displacement part in the Y direction is 401 by2.

  The flat surface portion 401a is inserted so as to follow the inner surface of the holding portion 331a. The shape is not limited to the one shown here, and may be any shape according to the space to be inserted. For example, the electrode 405 shown in FIG. 2 is provided as a partial electrode on the entire surface of the displacement portion 401b excluding the top contacting the imaging device package 162a on the paper surface side of the drawing, and the back surface side of the drawing is a concave portion of the displacement portion 401b. Is provided on the entire surface.

  As described above, the polymer actuator 401 can integrally form the four displacement portions by molding or the like, and the shape is arbitrary according to the shape of the counterpart to be incorporated, and can be manufactured easily and inexpensively.

  FIG. 4 is a timing chart showing the relationship between the electric field E applied to the four displacement portions 401 bp 1, 401 bp 2, 401 by 1, and 401 by 2 described in FIG. 3 and the displacement in the P direction and the Y direction of the image sensor 162.

  In FIG. 4, when the electric field of + E is applied to the displacement part 401bp1 shown in FIG. 3 at timing T1, the part other than the displacement part 401b of the polymer actuator 401 is sandwiched between the regulating member 331b and the holding part 331a. Since it cannot extend, the displacement portion 401 bp 1 extends and pushes the contact portion of the lens barrel 201 in the + F direction. Since the lens barrel 201 is urged in the −F direction by the urging spring 331c, only the side in contact with the displacement portion 401bp1 is pushed up in the + F direction. As a whole, the lens barrel 201 is supported with the displacement portion 401bp2 as a fulcrum. It is rotated in the -P direction. However, as the lens barrel 201 rotates in the −P direction, the top of the displacement portion 401 bp 2 is pushed and deformed by the end portion of the lens barrel 201, so the displacement portion 401 bp 2 is not a complete fulcrum.

  Similarly, when an electric field of + E is applied to the displacement portion 401 bp 2 at timing T 2, the displacement portion 401 bp 2 expands and pushes the contact portion of the lens barrel 201 in the + F direction, so that the lens barrel 201 rotates in the + P direction as a whole. Moved.

  When the electric field of + E is applied to the displacement portion 401by1 at timing T3, the displacement portion 401by1 expands and pushes the contact portion of the lens barrel 201 in the + F direction, and the lens barrel 201 is rotated in the −Y direction as a whole. The

  Similarly, when an electric field of + E is applied to the displacement portion 401by2 at timing T4, the displacement portion 401by2 expands and pushes the contact portion of the lens barrel 201 in the + F direction, and the lens barrel 201 rotates in the + Y direction as a whole. Moved.

  When the electric fields at the timings T1 and T3 are applied simultaneously, the lens barrel 201 is rotated in the −P / −Y direction. Similarly, when the electric fields at timings T1 and T4 are applied simultaneously, the lens barrel 201 is rotated in the -P / + Y direction, and when the electric fields at timings T2 and T3 are applied simultaneously, the lens barrel 201 is rotated in the + P / -Y direction. When the electric fields at timings T2 and T4 are applied simultaneously, the lens barrel 201 is rotated in the + P / + Y direction.

  As described above, according to the first embodiment, the polymer actuator 401 can integrally form the four displacement portions 401 bp 1, 401 bp 2, 401 by 1 and 401 by 2, and the lens barrel 201 and the moving mechanism 331 can be formed integrally. Since it can arrange | position in the slight clearance gap between the holding | maintenance parts 331a, space efficiency is very good and an assembly is easy. Further, since the lens barrel 201 is held by the elasticity of the biasing spring 331c and the polymer actuator 401, it is resistant to impact. Furthermore, the drive is very simple by simply applying the electric field E, and since it does not have a resonance peak as in a piezoelectric actuator, for example, control is very easy.

  In FIG. 3, the lens barrel 201 is biased in the −F direction by the biasing spring 331 c, but a polymer actuator 401 is also provided on the lens 211 side of the lens barrel 201, and both from above and below the lens barrel 201. You may drive using the polymer actuator 401. FIG. This example will be described with reference to FIG. 5 as a second embodiment of the moving mechanism 331. FIG. 5 is a schematic diagram showing the configuration of the third embodiment of the moving mechanism 331. FIG. 5A is a plane parallel to the photographing optical axis 200 of the moving mechanism 331 and passing through Y1-Y2 in FIG. 5B. FIG. 5B is a schematic view showing the shape of the polymer actuator 401 provided on the upper part of the lens barrel of the second embodiment.

  In FIG. 5A, the moving mechanism 331 on the lens barrel 201 and the image sensor 162 side is the same as that shown in FIG. In the present embodiment, on the lens side of the lens barrel 201, the polymer actuator 401 having the displacement portions 401by3, 401by4, 401bp3, 401bp4 shown in FIG. 5B and having a hole in the center, and the holding portion 331d. The lens barrel 201 is sandwiched by the polymer actuator 401 from + F and −F directions substantially parallel to the photographing optical axis 200, and the polymer actuator 401 is substantially parallel to the photographing optical axis 200. In addition, force is applied to the lens barrel 201 from the opposite direction.

  When the moving mechanism 331 is actually assembled, the polymer actuator 401 is placed inside the shallow cup-shaped holding portion 331a, and the regulating member 331b is placed thereon and fixed to the holding portion 331a. Next, the lens barrel 201 is dropped into the regulating member 331b. Next, a polymer actuator 401 having a hole in the center is dropped into a shallow cup-shaped holding member 331d having a hole in the center, and a regulating member 331e having a hole in the center is placed thereon and held. By fixing what is fixed to the portion 331d from the lens 211 side of the lens barrel 201 and fixing it to the holding member 331b, it is possible to assemble very easily and to reduce assembly costs at a low cost.

  As a driving method of the moving mechanism 331, the displacement portions 401bp1 and 401bp4, 401bp2 and 401bp3, 401by1 and 401by4, 401by2 and 401by3 are respectively paired and applied to the displacement portions 401bp1, 401bp2, 401by1, and 401by2 shown in FIG. If the applied electric field E is applied, the same operation as in FIG. 4 can be performed.

  In the present embodiment, as shown in FIG. 3B and FIG. 5B, the displacement portion 401by3 is disposed on the opposite side of the lens barrel 201 of the displacement portion 401by1, and similarly on the opposite side of the displacement portion 401by2. Displacement part 401by3, displacement part 401bp3 and displacement part 401bp4 are arranged on the opposite side of displacement part 401by4 and displacement part 401bp1, for example. They may be shifted by °.

  Further, in this embodiment, the two polymer actuators 401 sandwiching the lens barrel 201 are separated as shown in FIGS. 3B and 5B, but FIG. The two polymer actuators 401 shown in FIG. 5B may be integrated by providing a connecting portion that follows the holding portion 331b.

  As described above, according to the second embodiment, similarly to the first embodiment, the polymer actuator 401 can integrally form four displacement portions and move with the lens barrel 201. Since it can arrange | position in the slight clearance gap between the holding parts 331a of the mechanism 331, space efficiency is very good and an assembly is easy. Further, since the lens barrel 201 is sandwiched between the polymer actuators 401 and held by its elasticity, it is strong against impacts, and each displacement portion can be miniaturized and further space saving can be achieved. Furthermore, the drive is very simple by simply applying the electric field E, and since it does not have a resonance peak as in a piezoelectric actuator, for example, control is very easy.

  Next, a third embodiment of the moving mechanism 331 using the polymer actuator 401 will be described with reference to FIGS. FIG. 6 is a schematic diagram showing the configuration of the third embodiment of the moving mechanism 331. FIG. 6A is a top view of the imaging optical axis 200 of the third embodiment viewed from the + F direction to the −F direction. FIG. 6B is a cross-sectional view taken along the line AA ′ of FIG. In the third embodiment, unlike the first embodiment, the polymer actuator 401 has three displacement portions 401b arranged at the positions of the vertices of an equilateral triangle.

  6 (a) and 6 (b), the polymer actuator 401 in which the flat surface portion 401a and the three displacement portions 401b are integrally formed in a sheet shape is dropped into the bottom of the shallow cup-shaped holding portion 331a. The portions other than the three displacement portions 401b are arranged so as to be sandwiched between the holding portion 331a and the restricting member 331b, so that they are restricted so that they cannot expand even when an electric field is applied. It is desirable that the three displacement portions 401b have the same thickness as the flat portion 401a.

  The lens barrel 201 that integrally supports the imaging optical system 211 and the imaging element 162 is disposed inside the regulating member 331b, and the end surface on the side where the imaging element 162 is attached has three displacement portions 401b of the polymer actuator 401. It is in contact with the tip. The end surface of the lens barrel 201 that is not in contact with the displacement portion 401b is in contact with the tip of an urging spring 331c attached to the restricting member 331b, whereby the lens barrel 201 is urged in the −F direction. ing.

  The three displacement parts 401b1, 401b2, and 401b3 of the polymer actuator 401 are arranged at the positions of the vertices of equilateral triangles that are 120 degrees apart from each other with respect to the imaging optical axis 200, and the three displacement parts 401b1, 401b2, and 401b3 The lens barrel 201 can be freely rotated inside the moving mechanism 331 by appropriately controlling the magnitude of the applied electric field E individually.

  FIG. 7 is a timing chart showing the relationship between the electric field E applied to the three displacement portions 401b1, 401b2, and 401b3 described in FIG. 6 and the displacement in the P direction and the Y direction of the lens barrel 201.

  In FIG. 7, when an electric field of + E is applied to the displacement part 401b1 at the timing T11, the part of the lens barrel 201 that contacts the displacement part 401b1 is pushed in the + F direction, and the mirror is balanced with the force of the biasing spring 331c. The barrel 201 is rotated in the −P direction. When an electric field of + E is applied to the displacement portion 401b2 at timing T12, the portion of the lens barrel 201 that contacts the displacement portion 401b2 is pushed in the + F direction, and the lens barrel 201 is + Y due to the balance with the force of the biasing spring 331c. And also slightly rotated in the + P direction.

  When an electric field of + E is applied to the displacement portion 401b3 at timing T13, the portion of the lens barrel 201 that contacts the displacement portion 401b3 is pushed in the + F direction, and the lens barrel 201 is-due to the balance with the force of the biasing spring 331c. It is rotated in the Y direction and slightly in the + P direction. When a + E electric field is applied to the displacement portions 401b2 and 401b3 at timing T14, the portion of the lens barrel 201 that contacts the displacement portions 401b2 and 401b3 is pushed in the + F direction, and is balanced with the force of the biasing spring 331c. The lens barrel 201 is rotated in the + P direction.

  When an electric field of + E is applied to the displacement portion 401b2 at timing T15 and an electric field smaller than + E is applied to the displacement portion 401b1, the portion that contacts the displacement portions 401b1 and 401b2 of the lens barrel 201 is pushed in the + F direction. The lens barrel 201 is rotated in the + Y direction by the balance with the force of the biasing spring 331c. When an electric field of + E is applied to the displacement part 401b3 at timing T16 and an electric field smaller than + E is applied to the displacement part 401b1, the part that contacts the displacement parts 401b1 and 401b3 of the lens barrel 201 is pushed in the + F direction. The lens barrel 201 is rotated in the −Y direction by balance with the force of the biasing spring 331c.

  According to the third embodiment, in addition to the effect of the first embodiment, the three displacement portions 401b1, 401b2, and 401b3 apply force to the end surface of the lens barrel 201 at three points, thereby taking an image. The lens barrel 201 can be stably and freely rotated about the optical axis 200 in the P direction and the Y direction.

Next, a fourth embodiment of the moving mechanism 331 using the polymer actuator 401 will be described with reference to FIGS. FIG. 8 is a schematic diagram showing a second example of the configuration of the polymer actuator 401 used in the third embodiment of the moving mechanism 331. FIG. 8A is a cross-section when the electric field E is not applied. FIG. 8 and FIG. 8B are cross-sectional views when the electric field E is applied.

  In the first, second, and third embodiments of the moving mechanism 331 described above, the polymer actuator 401 includes, for example, a flat surface portion 401a, a protruding displacement portion 401b, as shown in FIG. The electrode 405 is provided as a partial electrode on the entire surface of the displacement portion 401b excluding the top contacting the image sensor package 162a on the paper surface side of the drawing, and the back surface side of the drawing includes the concave portion of the displacement portion 401b. The displacement portion 401b expands to operate as an actuator when an electric field is applied between the electrodes.

  On the other hand, in the second example of the configuration of the polymer actuator 401 described with reference to FIG. 8, the polymer actuator 401 has a planar shape and does not have the protruding displacement portion 401b. Therefore, the electrode 405 can be easily formed by printing or the like, and it is easier to incorporate the polymer actuator 401 into the moving mechanism 331.

  In FIG. 8A, a polymer actuator 401 includes a planar extension 403 made of a dielectric polymer (silicon resin or acrylic resin), an upper surface electrode 405a made of a polymer material in which conductive carbon particles are mixed, and It is comprised with the lower surface electrode 405b. In this example, the upper electrode 405a is a partial electrode, and the lower electrode 405b is a full electrode. A region sandwiched between the upper surface electrode 405a and the lower surface electrode 405b is an action portion 401x that acts as an actuator.

  The example shown in FIG. 8 is the most basic example. Similarly to the case shown in FIG. 3B, the top of the upper surface electrode 405a is partially removed to prevent deterioration of deformation characteristics due to electrode wear. In addition, various ideas such as determining the direction of deformation by creating a portion that is easily deformed are possible.

  In the polymer actuator 401, a portion other than the action portion 401x is sandwiched between the holding portion 331a and the regulating member 331b in order to increase the rigidity and stabilize the deformation. It is desirable that the holding portion 331a is extended to the vicinity of the action portion 401x rather than the regulating member 331b to the extent that the range of the action portion 401x or a part of the action portion 401x is applied.

  In FIG. 8B, when the switch Sw is turned on and an electric field E is applied between the upper surface electrode 405a and the lower surface electrode 405b, the action portion 401x is compressed by electrostatic force and extends in the lateral direction, and the holding portion 331a. Becomes an obstacle and cannot extend to the lower surface electrode 405b side, and as a result, it is deformed into a bowl shape convex toward the upper surface electrode 405a side as shown in the figure. Since the electrode 405 is also made of a flexible polymer material such as rubber like the extending portion 403, it extends together with the extending portion 403 and deforms into a convex shape.

  Since the polymer actuator 401 has characteristics similar to those of a capacitor in terms of its structure and material, once the electric field is applied and the action part 401x is deformed into a convex shape, the switch between the electrodes is turned off even if the switch Sw is turned off. The electric field is maintained and the deformation is also maintained. When the electric field is removed by short-circuiting the electrodes, the action part 401x returns to the original plane.

  FIG. 9 is a schematic diagram showing a fourth embodiment of the moving mechanism 331 applied to the first embodiment of the moving mechanism 331 shown in FIG. 3 in the second example of the polymer actuator 401 shown in FIG. FIG.

  In FIG. 9, the polymer actuator 401 is arranged in such a manner that it is dropped inside the holding part 331a. 9 illustrates an upper surface electrode 405a1 of the action portion 401x1 and an upper surface electrode 405a2 of the action portion 401x2 corresponding to the displacement portions 401by1 and 401by2 of FIG. The holding portion 331a is provided with an opening 407 as an air hole on the back surface of the upper surface electrodes 405a1 and 405a2 of the action portion. Similar to FIGS. 3 and 6, the polymer actuator 401 has a portion other than the upper surface electrode 405a of the action portion sandwiched between the holding portion 331a and the restriction member 331b, and is restricted so that it cannot expand even when an electric field is applied. Has been.

  The lens barrel 201 that integrally supports the image pickup optical system 211 and the image pickup element 162 is also arranged inside the regulating member 331b and is the end face on the side where the image pickup element 162 is attached, as in FIGS. Is in contact with the action portion 401 x of the polymer actuator 401. The end surface of the working portion of the lens barrel 201 that is not in contact with the upper surface electrode 405a is in contact with the tip of a biasing spring 331c attached to the restricting member 331b, whereby the lens barrel 201 is in the −F direction. It is energized.

  If the electric field E is applied between the upper surface electrode 405a2 and the lower surface electrode 405b of the action part 401x2 corresponding to the displacement part 401by2 in FIG. The portion 401x2 swells in a bowl shape convex toward the upper surface electrode 405a2, the portion of the barrel 201 that is in contact with the action portion 401x2 is pushed up, and the balance of the force of the biasing spring 331c causes the barrel 201 to move in the + Y direction. It is rotated. Although this state is illustrated in FIG. 9, the case where the electric field E is applied between the upper surface electrode 405a and the lower surface electrode 405b of the other action part 401x may be considered similarly to FIG. Further, it is possible to realize a configuration similar to that of FIG. 6 by using three action portions 401x.

  According to the fourth embodiment of the moving mechanism 331 described above, in addition to the effects of the first or third embodiment, since the polymer actuator 401 can be configured in a planar shape, the electrode 405 is printed or the like. In the case where the polymer actuator 401 is incorporated into the moving mechanism 331, it is only necessary to fit it inside the moving mechanism, which is very easy. In addition, it is possible to easily create an element that determines the directionality of deformation, such as by restricting the direction of deformation by the holding portion 331a or creating a portion that is easily deformed by partially removing the top of the upper surface electrode 405a. it can.

  As described above, according to the present invention, camera shake correction is realized by rotating the lens barrel that integrally supports the imaging optical system and the imaging device around the imaging optical axis using a polymer actuator. In addition, by realizing an actuator with good assemblability, it is possible to provide a high-performance imaging unit and imaging apparatus that are small and low in cost.

  It should be noted that the detailed configuration and detailed operation of each component constituting the imaging unit and the imaging apparatus according to the present invention can be changed as appropriate without departing from the spirit of the present invention.

It is a schematic diagram which shows the structure of an imaging device. It is a schematic diagram for demonstrating the operation principle of a polymer actuator. It is a schematic diagram which shows the structure of 1st Embodiment of a moving mechanism. It is a timing chart which shows the relationship between the electric field applied to the polymer actuator in 1st Embodiment, and the displacement of a lens barrel. It is a schematic diagram which shows the structure of 2nd Embodiment of a moving mechanism. It is a schematic diagram which shows the structure of 3rd Embodiment of a moving mechanism. It is a timing chart which shows the relationship between the electric field applied to the polymer actuator in 3rd Embodiment, and the displacement of a lens barrel. It is a schematic diagram which shows the 2nd example of a polymer actuator. It is a schematic diagram which shows the structure of 4th Embodiment of a moving mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Imaging device 111 Operation part 131 Image display part 161 Imaging control part 162 Image pick-up element 163 Analog digital (A / D) converter 165 Image processing part 181 Image recording part 200 Imaging optical axis 201 Lens barrel 211 Imaging optical system 300 Imaging circuit 301 Camera shake detection unit 303 Camera shake detection circuit 305 Camera shake correction unit 313 Drive circuit unit 315 Actuator control unit 330 Imaging unit 331 Movement mechanism 331a Holding unit 331b Restricting member 331c Energizing spring 331d Holding unit 331e Restricting member 350 Imaging unit 401 Polymer actuator 401a Plane Part 401b Displacement part 401x Action part 403 Extension part 405 Electrode 407 Opening part

Claims (6)

A lens barrel for supporting integrally an imaging device that captures an image of the imaged object by the imaging optical system and the front SL imaging optical system for forming an image of an object,
A polymer actuator that rotates the lens barrel so that the photographing optical axis is inclined ;
A holding part for holding the polymer actuator;
In an imaging unit comprising
The polymer actuator has a substantially planar shape, and one surface faces the rear end of the lens barrel, and the other surface faces the holding portion.
The polymer actuator includes a flat portion fixed so as not to extend to the holding portion and a plurality of displacement portions that are not fixed to the holding portion and can be extended.
Each of the plurality of displacement portions extends in a plane direction so as to protrude from the flat portion toward the rear end portion of the lens barrel, and the protruding tip portion presses the rear end portion of the lens barrel, An imaging unit , wherein the lens barrel is rotated so that an optical axis of the imaging optical system is inclined by moving in a pressing direction . The displacement portion is a displacement portion of a protruding portion that protrudes toward the rear end portion of the lens barrel in a state before displacement, and a distal end portion of the displacement portion abuts on a rear end portion of the lens barrel and the lens barrel Support
The imaging unit according to claim 1, wherein the distal end portion presses a rear end portion of the lens barrel and moves in the pressing direction when the displacement portion extends in a plane direction . The displacement part has a planar shape in a state before displacement, is on the same plane as the planar part,
  The polymer actuator is sandwiched between the holding unit and a regulating unit disposed on the opposite side of the holding unit with respect to the polymer actuator,
  The holding part is restricted from projecting the displacement part to the holding part side by extending the restricting part to a part of a portion that does not sandwich the polymer actuator. Item 2. The imaging unit according to Item 1. The biasing means is further provided on the opposite side of the polymer actuator with respect to the lens barrel and biases the polymer actuator toward the holding portion via the lens barrel. The imaging unit according to any one of 1 to 3 . 4. The polymer actuator according to any one of claims 1 to 3, wherein the polymer actuator is also disposed on the front end side of the lens barrel so that a distal end portion of the displacement portion presses a front end portion of the lens barrel . The imaging unit according to one item . In the imaging device provided with the imaging unit according to any one of claims 1 to 5 ,
Camera shake detection means for detecting camera shake of the imaging device;
An image pickup apparatus comprising: a camera shake correction unit that drives the polymer actuator based on a detection result of the camera shake detection unit to correct a camera shake.

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