JP2015099204A - Image tremor correction device, lens barrel, camera body and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact image tremor correction device, lens barrel, camera body and imaging device that have a viscosity attenuation characteristic and are excellent in drive efficiency.SOLUTION: An image tremor correction device (100) includes: a movement part (300) that is relatively movable to a stationary part (200); a tremor correction optical system (L3) that corrects a tremor of an image formed by an optical system provided in the movement part (300); a coil (302) that is provided in the movement part (300); a magnet (202) that has a first area supplying magnetic force of an N pole to the coil (302) and a second area supplying magnetic force of an S pole to the coil (302), and is provided in the stationary part (200); a protrusion part (212) that is provided between the first area and the second area; and a magnetic fluid (260) that is provided in at least one of the first area and the second area.

Description

  The present invention relates to an image blur correction device, a lens barrel, a camera body, and a photographing device.

  Various devices are known as shake correction devices that suppress blurring of a captured image due to camera shake or the like. For example, Patent Document 1 discloses a shake correction device using a magnet and a coil. In the shake correction apparatus of Patent Document 1, a magnetic fluid is disposed between the moving member and the fixed member so as to impart viscous damping to the relative movement of the moving member with respect to the fixed member.

  However, in the shake correction apparatus of Patent Document 1, since the magnetic fluid is disposed so as to straddle between both poles of the magnet, the magnetic flux of the magnetic circuit passes through the magnetic fluid and moves from the N pole to the S pole. There was a problem. As a result, the shake correction apparatus disclosed in Patent Document 1 has a problem in that the driving efficiency deteriorates because the magnetic force supplied to the coil decreases.

JP2008-58391

  An object of the present invention is to provide a compact image blur correction device, a lens barrel, a camera body, and a photographing device that have viscous damping characteristics and excellent driving efficiency.

In order to achieve the above object, an image blur correction device (100) of the present invention includes:
A moving part (300) movable relative to the fixed part (200);
A blur correction optical system (L3) that corrects blur of an image formed by the optical system provided in the moving unit (300);
A coil (302) provided in the moving unit (300);
A magnet (202) provided in the fixed portion (200) has a first region for supplying N-pole magnetic force to the coil (302) and a second region for supplying S-pole magnetic force to the coil (302). )When,
A protrusion (212) provided between the first region and the second region;
A magnetic fluid (260) provided in at least one of the first region and the second region.

  In order to explain the present invention in an easy-to-understand manner, the description has been made in association with the reference numerals of the drawings showing the embodiments, but the present invention is not limited to this. The configuration of the embodiment described later may be improved as appropriate, or at least a part of the configuration may be replaced with another configuration. Further, the configuration requirements that are not particularly limited with respect to the arrangement are not limited to the arrangement disclosed in the embodiment, and can be arranged at a position where the function can be achieved.

FIG. 1 is a schematic block diagram of a camera according to an embodiment of the present invention. 2 is an exploded perspective view of the image blur correction apparatus shown in FIG. FIG. 3 is a control block diagram showing an example of control of the camera shake correction operation of the camera shown in FIG. 4 is a cross-sectional view of the image blur correction apparatus shown in FIG. 1 and FIG. FIG. 5 is a cross-sectional view of the image blur correction apparatus shown in FIG. 6A shows an example of the magnetic circuit of the image blur correction apparatus shown in FIGS. 4 and 5, and FIG. 6B shows a comparative example thereof. FIG. 7A shows the frequency characteristics of the image blur correction apparatus shown in FIG. 4 and FIG. FIG. 7B is a schematic diagram for explaining the operational effect when the image stabilization operation is off in the image stabilization apparatus shown in FIGS. 4 and 5. FIG. 8 is a cross-sectional view of an image blur correction apparatus according to another embodiment. FIG. 9 is a cross-sectional view of the image blur correction apparatus shown in FIG. FIGS. 10A and 10B show examples of the magnetic circuit of the image blur correction apparatus shown in FIGS. FIG. 11 is a cross-sectional view of an image blur correction apparatus according to another embodiment. FIG. 12 is a cross-sectional view of the image blur correction apparatus shown in FIG. FIG. 13 is a cross-sectional view of an image blur correction apparatus according to another embodiment. 14 is a cross-sectional view of the image blur correction apparatus shown in FIG. FIG. 15 shows an example of the moving unit of the image blur correction apparatus shown in FIG.

First Embodiment As shown in FIG. 1, a camera 1 according to an embodiment of the present invention is a so-called single-lens reflex digital camera, and a camera body 1a and a lens barrel 2 are configured to be detachable. In the following embodiments, a single-lens reflex digital camera will be described as an example, but the present invention is not limited to this. For example, a compact digital camera in which the lens barrel 2 and the camera body 1a are integrally formed may be used. Furthermore, a mirrorless type camera that omits the mirror mechanism may be used. Further, the present invention is not limited to single-lens reflex digital cameras and compact digital cameras, and can also be applied to optical devices such as video cameras, binoculars, microscopes, telescopes, and mobile phones.

  The lens barrel 2 includes an imaging optical system configured by arranging a zoom lens group L1, a focus lens group L2, and a shake correction lens group L3 in order from the subject side. Behind the shake correction lens group L3 (image plane side), an image sensor 3 represented by a CCD or a CMOS is provided.

  The zoom lens group L1 is provided on the most object side in the imaging optical system, and is driven to be movable in the direction along the optical axis L by the drive mechanism 6 so that zooming is possible. The focus lens group L2 is driven by the drive mechanism 8 so as to be movable in the direction along the optical axis L, and focusing is possible.

  The shake correction lens unit L3 constitutes a part of the image blur correction apparatus 100. The shake correction lens unit L3 is moved in a plane intersecting the optical axis L by the image blur correction apparatus 100 that has received a signal from the CPU 14, and reduces image blur due to the movement of the camera.

  The aperture mechanism 4 is disposed between the shake correction lens group L3 and the image sensor 3, and is driven by the drive mechanism 10 so as to control the amount of subject light.

  The quick return mirror 26 is configured to project an image on the viewfinder 32 at the time of composition determination, and retracts from the optical path during exposure. The quick return mirror 26 is driven by a mirror driving unit (not shown) (for example, a DC motor). The shutter 28 is configured to control the exposure time, and is driven by a shutter driving unit (not shown) (for example, a DC motor).

  The imaging element 3 generates an electrical image output signal based on the light of the subject image formed on the imaging surface by the imaging optical system. The image output signal is A / D converted or noise-processed by the signal processing circuit 16 and input to the CPU 14.

  The lens barrel 2 incorporates an angular velocity sensor 12 such as a gyro sensor, and the angular velocity sensor 12 detects an angular velocity caused by camera shake or the like generated in the camera 1 and outputs it to the CPU 14. The CPU 14 also receives a detection signal from the AF sensor 18 and controls the drive mechanism 8 based on the detection signal to realize an autofocus (AF) mechanism. The angular velocity sensor 12 may be provided in the camera body 1a.

  A storage medium 20, a nonvolatile memory 22, various operation buttons 24 and the like are connected to the CPU 14. The storage medium 20 is a memory that receives an output signal from the CPU 14 and stores or reads a photographed image. For example, the storage medium 20 is a detachable card memory. There are various types of removable memory such as an SD card, but there is no particular limitation.

  The nonvolatile memory 22 stores adjustment value information such as a gain value of the gyro sensor, and is configured by a semiconductor memory built in the camera together with the CPU 14. Examples of the various operation buttons 24 include a release switch. When the release switch is half-pressed or fully pressed, the signal is input to the CPU 14.

  The configuration of the image blur correction apparatus 100 shown in FIG. 1 will be described with reference to the exploded perspective view of FIG. The image blur correction apparatus 100 includes a fixed unit 200, a moving unit 300, a lid member 400, and a lock ring 500. Although not shown in FIG. 2, the moving unit 300 includes the shake correction lens unit L3 shown in FIG. 1 at the center thereof, and X that intersects the optical axis L so as to correct image blurring. -Move on the Y plane. In the following description, the shake correction lens unit L3 will be described as one shake correction lens L3 in order to facilitate understanding of the present embodiment. In the following description, an axis substantially parallel to the optical axis L is a Z axis, and axes perpendicular to the Z axis and perpendicular to each other are an X axis and a Y axis.

  The moving part 300 is attached to the fixed part 200 by two tension coil springs 74. The tension coil spring 74 urges the moving unit 300 in a direction to approach the fixed unit 200 so that the center of the shake correction lens L3 is returned to the optical axis L side on a plane intersecting the optical axis L. A force is applied to the moving unit 300.

  The moving unit 300 slides through the three ceramic balls 72 to fix a plane intersecting the optical axis L (for example, a plane including the X axis and the Y axis, a plane orthogonal to the optical axis L). It can move relative to the part 200. The numbers of the tension coil springs 145 and the ceramic balls 148 can be changed as appropriate according to the shapes of the moving unit 300 and the fixed unit 140.

  The moving unit 300 is driven by the driving force generated by the interaction between the first coil 302 and the second coil 303 provided in the moving unit 300 and the first magnet 202 and the second magnet (not shown) provided in the fixed unit 200. , Move on a plane intersecting the optical axis L.

  The first coil 302 and the first magnet 202 are arranged so as to face each other along the Z-axis direction, and constitute a first VCM 252. Further, the second coil 303 and the second magnet (not shown) are arranged so as to face each other along the Z-axis direction, and constitute the second VCM 254. VCM is an abbreviation for voice coil motor. In the present embodiment, the moving unit 300 includes a first coil 302 and a second coil 303, and the fixed unit 200 includes a first magnet 202 and a second magnet (not shown). However, the moving unit includes a magnet. The fixing unit may include a coil.

  The fixed unit 200 or the moving unit 300 includes a position detection sensor (not shown) that detects a relative position of the moving unit 300 with respect to the fixed unit 200. The position detection sensor is, for example, an optical sensor such as a PSD or a magnetic sensor such as a hall element.

  The lid member 400 is disposed so as to sandwich the moving unit 300 between the lid member 400 and the fixing unit 200, and is fixed to the fixing unit 200 with screws 76. The lock ring 500 has a substantially annular shape, and locks the moving unit 300 so as not to move relative to the fixed unit 200 when blur correction is not performed.

  An example of the blur correction operation by the image blur correction apparatus 100 shown in FIGS. 1 and 2 is shown in FIG. Hereinafter, a case where the shake correction lens L3 is driven in the X-axis direction will be described as an example based on the angular velocity information regarding the X-axis direction output from the angular velocity sensor 12 illustrated in FIG.

  The angular velocity = 0 algorithm 50 calculates the center value (value of ω = 0 (zero)) from the output signal (angular velocity information) ω of the angular velocity sensor 12. If the output signal ω of the angular velocity sensor 12 fluctuates while the camera body 1a and the lens barrel 2 are stationary, the CPU 14 misidentifies that the camera body 1a and the lens barrel 2 are blurred, and the shake correction lens L3. Try to correct the blur. For this purpose, it is necessary to calculate the center value of the output signal ω of the angular velocity sensor 12 by the angular velocity = 0 algorithm 50. The angular velocity = 0 algorithm 50 subtracts the calculated center value from the output signal ω of the angular velocity sensor 12 to calculate angular velocity information that needs to be corrected. Angular Velocity Information Angular Velocity = 0 The algorithm 50 calculates a center value by a moving average method, a digital filter, or the like.

  The integrator 51 is for integrating the angular velocity information that needs to be corrected into the angle information θ. The overflow prevention table 52 prevents an integral overflow when the angular velocity sensor 12 detects a blur of the camera body 1a and the lens barrel 2 as an angular velocity component in the same direction for a long time. The overflow prevention table 52 prevents the overflow by subtracting the generated output signal from the angular velocity information. The overflow prevention table 52 is not used during the exposure operation. When the overflow prevention table 52 is used in a situation where the angle information θ is about to be saturated, the angular velocity information varies depending on the output signal. As a result, the CPU 14 erroneously recognizes this fluctuation value as blurring of the camera body 1a and the lens barrel 2 and corrects the shake correction lens L3.

The ideal target position conversion unit 53 converts the integrated angle information θ into ideal target drive position information (hereinafter referred to as target drive position information) X of the shake correction lens L3. The ideal target position conversion unit 53 calculates target drive position information X based on the focal length information f, the blur correction coefficient α, and the subject distance information D. Here, the blur correction coefficient α is the ratio of the correction amount on the imaging surface to the drive amount of the shake correction lens L3. The greater the value of the blur correction coefficient α, the smaller the drive amount of the shake correction lens L3 is required for the same blur. The blur correction coefficient α is expressed as a function of the focal length f. The target drive position information X is expressed by the following expression when the subject is far away.
X = f × θ × β / α (f)
Here, θ is the blur angle, and β is a constant. When the subject is close, the blur correction amount is changed using the subject distance information D. The ideal target position conversion unit 53 outputs the calculated target drive position information X to the comparator 54.

  The comparator 54 counts the number of times that the target drive position information X exceeds the comparison values Xmax and Xmin. The comparator 54 compares the target drive position information X with preset comparison values (set values) Xmax and Xmin, and outputs the target drive position information X as it is. Target drive position information X ′ obtained by subtracting the output signal of the position bias table 56 from the target drive position information X is input to the movable range limiter 55.

  The movable range limiter 55 restricts the drive range (movable range) of the shake correction lens L3 in terms of software. The movable range limiter 55 is provided inside a mechanical limit that mechanically regulates the drive range of the shake correction lens L3, and its soft limit value is set to ± L. The movable range limiter 55 outputs target drive position information X ′ to the PID control unit 58. The PID control unit 58 drives the first VCM 252 shown in FIG. 2 so as to move the shake correction lens L3 based on the target drive position information X ′.

  The position bias table 56 corrects and distorts the target drive position information X when large target drive position information X is input, so that the shake correction lens L3 does not cause a rapid speed change. The drive position is corrected.

  When the shake correction lens L3 is driven around a position deviated from the center of the movable range, the speed bias table 57 is adjusted to the center of the movable range or its vicinity by correcting the drive speed of the shake correction lens L3. The shake correction lens L3 is pulled back. The output signal of the velocity bias table 57 is subtracted from the angular velocity information that needs to be corrected. As a result, the shake correction lens L3 that drives a position deviated from the center of the movable range is pulled back to the center of the movable range or the vicinity thereof.

  Next, the configuration of the image blur correction apparatus 100 according to the present embodiment will be described in detail with reference to FIGS. 4 and 5. 4 is a cross-sectional view of the first VCM 252 shown in FIG. 2, and FIG. 5 is a cross-sectional view taken along line A-A ′ of FIG. The second VCM 254 may have the same configuration as the first VCM 252.

  The moving unit 300 includes a shake correction lens L <b> 3 and is disposed between the fixed unit 200 and the lid member 400. The moving unit 300 can move relative to the fixed unit 130 on a plane intersecting the optical axis L.

  The lid member 400 includes a first yoke 402. The first yoke 402 forms a magnetic circuit together with the first drive magnet 202a, the second drive magnet 202b, and the second yoke 206 provided in the fixed portion 200 (see FIG. 6 and the like). The first yoke 402 is attached to the lid member 400 so as to face the moving unit 300.

  The moving part 300 has a recess 306 formed on the lid member 400 side. The first yoke 402 included in the lid member 400 is disposed so as to enter the recess 306. Moreover, the moving part 300 has a coil attachment part 304 on the fixed part 200 side. The coil 302 is attached to the coil attachment portion 304 so as to face the first drive magnet 202a and the second drive magnet 202b of the fixed portion 200. The moving unit 300 and the coil attachment unit 304 may be integrated.

  The fixing unit 200 includes a first drive magnet 202a, a second drive magnet 202b, a second yoke 206, and a protrusion 212. The first drive magnet 202 a is arranged in the fixed part 200 so as to supply the N pole magnetic force to the coil 302, and the second drive magnet 202 b is fixed so as to supply the S pole magnetic force to the coil 302. The unit 200 is arranged. The first drive magnet 202a and the second drive magnet 202b are arranged at a distance from each other with the convex part 214 of the fixed part 200 interposed therebetween.

  The protrusion 212 is disposed between the first drive magnet 202a and the second drive magnet 202b. The protruding portion 212 is attached to the convex portion 214 of the fixed portion 200 and protrudes from the fixed portion 200 toward the moving portion 300 so as to enter the inside (coil portion) of the coil 302. The protrusion 212 is configured so as not to contact the coil 302 inside the coil 302. The protrusion 212 is made of a nonmagnetic material. The nonmagnetic material is not particularly limited, and includes all materials other than magnetic materials. Examples thereof include nonmagnetic metals (magnesium alloy, aluminum alloy), ceramics, and resins.

  A magnetic fluid 260 having magnetism is disposed between the fixed unit 200 and the moving unit 300. The magnetic fluid 260 is held on the first drive magnet 202a and the second drive magnet 202b by the magnetic force generated by the N pole of the first drive magnet 202a and the magnetic force generated by the S pole of the second drive magnet 202b. . The magnetic fluid 260 imparts viscous resistance to the moving unit 300 that moves relative to the fixed unit 200. Further, the magnetic fluid 260 applies a force so as to return the moving unit 300 to the initial position (optical center) by the magnetic force of the first drive magnet 202a and the second drive magnet 202b.

  The magnetic fluid 260 is in contact with the coil 302 and enters the inside of the coil 302. Inside the coil 302, the tip 212 a of the protrusion 212 protrudes toward the moving part 300 from the magnetic fluid 260.

  The magnetic fluid 260 is arranged in the first magnetic fluid 262 arranged in the first region closer to the first drive magnet 202a than the protrusion 212 and in the second region closer to the second drive magnet 202b than the protrusion 212. Second magnetic fluid 264. That is, the magnetic fluid 260 includes the first magnetic fluid 262 held by the N pole of the first drive magnet 202a and the second magnetic fluid 264 held by the S pole of the second drive magnet 202a by the protrusion 212. Preferably, the magnetic fluid 260 is completely separated into the first magnetic fluid 262 and the second magnetic fluid 264 by the protrusion 212.

  The magnetic fluid is, for example, a fluid that has magnetism and is attracted to the magnet while being a fluid. The magnetic fluid is not particularly limited. For example, the magnetic fluid is a magnetic colloid solution composed of ferromagnetic fine particles such as magnetite and manganese zinc ferrite, a surfactant covering the surface, a base liquid (water and oil), and the like. The ferromagnetic fine particles in the magnetic fluid maintain a stable dispersion state without being aggregated or settled in the base liquid due to, for example, the affinity between the surfactant and the base liquid and the repulsive force between the surfactants.

  In the present embodiment configured as described above, a suitable magnetic circuit can be formed as shown in FIG. This is because the protrusion 212 made of a non-magnetic material causes the magnetic fluid 260 to flow more than the first magnetic fluid 262 and the protrusion 212 disposed in the first region closer to the first drive magnet 202a than the protrusion 212. The second magnetic fluid 264 is disposed in the second region on the second drive magnet 202b side. For this reason, in this embodiment, the problem that the magnetic flux of the magnetic circuit passes through the magnetic fluid 260 and goes directly from the north pole of the first drive magnet 202a to the south pole of the second drive magnet 202b is solved. As a result, in the present embodiment, the magnetic force of the first drive magnet 202a and the second drive magnet 202b can be suitably supplied to the coil 302, so that the VCM can be driven efficiently.

  FIG. 6B shows a comparative example of this embodiment. The comparative example shown in FIG. 6B is the same as the present embodiment except that the protrusion 212 is not provided. In the comparative example, the magnetic flux of the magnetic circuit passes through the magnetic fluid 260 toward the south pole of the second drive magnet 202b from the north pole of the first drive magnet 202a. As a result, in the comparative example, since the magnetic force supplied to the coil 302 is reduced, the driving efficiency of the VCM is deteriorated.

  In addition, as shown in FIG. 4, you may provide the 1st scattering prevention member 208 and / or the 2nd scattering prevention member 308 in this embodiment. The first scattering prevention member 208 is provided in the fixing unit 200. The first scattering prevention member 208 protrudes toward the moving unit 300 and prevents the magnetic fluid 260 from scattering. The first scattering prevention member 208 is attached at least to the shake correction lens L3 side of the fixed part 200, and more preferably, is attached to the fixed part 200 so as to surround the magnetic fluid 260. The first scattering prevention member 208 may be formed integrally with the fixing portion 200. As shown in FIG. 5, the gap g1 in the optical axis L direction between the first scattering prevention member 208 and the moving part 300 is configured to be narrower than the gap g2 in the optical axis L direction between the coil 302 and the fixed part 200. can do. This is because the gap g1 in the optical axis L direction between the first scattering prevention member 208 and the moving unit 300 corresponds to the size of the ceramic ball 72 (FIG. 2) disposed between the fixed unit 200 and the moving unit 300. ing. The ceramic ball 72 shown in FIG. 2 may be disposed between the first scattering prevention member 208 and the moving unit 300 shown in FIG.

  The second scattering prevention member 308 is provided in the moving unit 300. The second scattering prevention member 308 protrudes toward the fixed portion 200 and prevents the magnetic fluid 260 from scattering. The second scattering prevention member 308 is formed at least on the shake correction lens L3 side of the moving unit 300, and more preferably fixed from the moving unit 300 so as to surround the magnetic fluid 260 and the first scattering preventing member 208. It is formed so as to protrude to the part 200 side. The moving unit 300 and the second scattering prevention member 308 may have different configurations.

  FIG. 7A shows frequency characteristics of the shake correction apparatus 100 according to the present embodiment. In FIG. 7A, the frequency characteristic of the shake correction apparatus 100 of the present embodiment is indicated by a solid line, and the comparative example is indicated by a dotted line. In the comparative example, the configuration is the same as that of the shake correction apparatus 100 according to the present embodiment except that the magnetic fluid 260 is not disposed between the fixed unit 200 and the moving unit 300.

  As shown in FIGS. 7A (a) and 7A (b), in the comparative example of the present embodiment, the gain suddenly rises and the phase suddenly changes near the frequency f1 [Hz]. The operation is unstable in the band. On the other hand, the shake correction apparatus 100 according to the present embodiment has a small change in gain and phase even near the frequency f1 [Hz], and is more stable in operation than the comparative example.

  As described above, in the shake correction apparatus 100 according to the present embodiment, since the magnetic fluid 260 is disposed between the fixed unit 200 and the moving unit 300, the moving unit 300 moves relative to the fixed unit 200. At this time, viscous resistance by the magnetic fluid 260 can be applied to the moving unit 300. That is, in the present embodiment, the magnetic fluid 260 is in contact with the first drive magnet 202a, the second drive magnet 202b, the coil 302, and the protrusion 212, and the viscous damping corresponding to the contact area with these is applied to the moving unit 300. Can be given to relative movements. As a result, in the present embodiment, it is possible to provide a shake correction apparatus having a suitable frequency characteristic with a simple and small configuration. The viscosity damping characteristic can be adjusted by appropriately adjusting the injection amount and viscosity of the magnetic fluid 260.

  In the present embodiment, the magnetic fluid 260 has the first magnetic fluid 262 held by the N pole of the first drive magnet 202a and the S pole of the second drive magnet 202a by the protrusion 212 made of a non-magnetic material. Is separated from the second magnetic fluid 264 held therein. For this reason, in this embodiment, the problem that the magnetic flux of the magnetic circuit passes through the magnetic fluid 260 and goes directly from the north pole of the first drive magnet 202a to the south pole of the second drive magnet 202b is solved. As a result, in the present embodiment, the magnetic force of the first drive magnet 202a and the second drive magnet 202b can be suitably supplied to the coil 302, so that the VCM can be driven efficiently.

  In the above embodiment, the magnetic fluid 260 includes the first magnetic fluid 262 and the second magnetic fluid 264. However, either the first magnetic fluid 262 or the second magnetic fluid 264 is disposed. Also good. Even in this case, the same effect as that of the above embodiment can be obtained.

  In the present embodiment, the magnetic fluid 160 is provided together with the protrusion 212, so that the blur correction (VR) is not activated (referred to as VR_off (blur correction off) or anti-vibration off). Has the following effects. The explanation is described below.

  In the shake correction apparatus that does not include the protrusion 212 and the magnetic fluid 160, a mechanism that mechanically locks the image stabilization lens (the shake correction lens group L3) is provided in a state where VR_off is set (for example, Lock ring 500 shown in FIG. However, since the backlash also exists in the lock mechanism, the anti-vibration lens can move within the backlash even in the locked state.

  For this reason, when the release switch is pressed and a shock is applied due to mirror up or shutter drive, the vibration-proof lens itself moves due to the shock (within the lock backlash). This effect is particularly noticeable when the tripod is fixed. An example is shown below (tripod fixation, vibration during VR_off).

  FIG. 7B (a) is a waveform showing the shake on the imaging surface due to the vibration of the entire camera due to the release shock (mirror drive, shutter drive). The mirror is driven at time t1, and then the shutter is driven at time t2, and exposure is started. In addition, the anti-vibration lens may be vibrated in the rock play due to the impact (FIG. 7B (b)). FIG. 7B (c) shows a blur waveform on the imaging surface when the vibrations of FIG. 7B (a) and FIG. 7 (b) are applied. Since the vibration is applied even after the start of exposure, the photographed image is deteriorated due to the shake.

  On the other hand, in the present embodiment, since the magnetic fluid 160 is provided together with the protrusion 212, the blur due to the movement of the lens shown in FIG. 7B (b) is reduced. This is because viscous damping characteristics are added to the vibration-proof lens. As a result, the shake on the imaging surface when an impact at the time of release is applied is only the influence of the vibration of the camera itself shown in FIG. 7B (a). By arranging the magnetic fluid, the vibration is off. However, there is an effect that the blur due to the movement of the lens is reduced.

Second Embodiment The second embodiment is the same as the first embodiment except that the projection 212 is attached to the moving unit 300 as shown in FIGS. 8 and 9, except that the projection 212 is different from the first embodiment. is there. In the following description, the description of the same part as the above embodiment is omitted.

  In the present embodiment, as shown in FIGS. 8 and 9, the protrusion 212 is attached to the coil attachment portion 304 of the moving portion 300 so as to enter between the first drive magnet 202a and the second drive magnet 202b. It protrudes from the moving part 300 to the fixed part 200 side. Note that the protruding portion 212 may be attached to the moving portion 300 at a position different from the coil attaching portion 304. Further, the protruding portion 212 may be integrated with the moving portion 300.

  In the present embodiment, as shown in FIGS. 10A and 10B, a suitable magnetic circuit can be formed. That is, in the example shown in FIG. 10A, the protrusion 212 made of a non-magnetic material enters between the first drive magnet 202a and the second drive magnet 202b, and the magnetic flux of the magnetic circuit is The phenomenon of passing through the magnetic fluid 260 and going directly from the north pole of the first drive magnet 202a to the south pole of the second drive magnet 202b is greatly suppressed. More preferably, as shown in FIG. 10B, the protrusion 212 protrudes toward the fixed portion 200 from the N pole of the first drive magnet 202a and the S pole of the second drive magnet 202b. In this case, the phenomenon in which the magnetic flux of the magnetic circuit passes through the magnetic fluid 260 and travels from the N pole of the first drive magnet 202a to the S pole of the second drive magnet 202b can be more preferably suppressed. Therefore, in this embodiment, the magnetic force of the first drive magnet 202a and the second drive magnet 202b can be suitably supplied to the coil 302, so that the VCM can be driven efficiently.

Third Embodiment In the third embodiment, as shown in FIGS. 11 and 12, the fixing unit 200 includes a coil 302, the moving unit 300 includes a magnet 202 and a projection 212, and the magnet 202 has one drive magnet 202. This is the same as the first embodiment except that it is different from the first embodiment. In the following description, the description of the same part as the above embodiment is omitted.

  In the present embodiment, the fixing unit 200 includes a coil 302. The coil 302 is attached to the fixed part 200 via the convex part 214 of the fixed part 200. The moving unit 300 includes a drive magnet 202 and a protrusion 212. The drive magnet 202 is attached to the moving unit 300 and supplies N-pole and S-pole magnetic forces to the coil 302. The protrusion 212 is attached to the drive magnet 202 between the N pole and the S pole of the drive magnet 202 and protrudes from the moving part 300 toward the fixed part 200 so as to enter the inside of the coil 302.

  The magnetic fluid 260 is held on the drive magnet 202 by a magnetic field generated by the drive magnet 202. The magnetic fluid 260 is disposed in the first magnetic fluid 262 disposed in the first region on the south pole side of the driving magnet 202 relative to the protrusion 212 and in the second region on the north pole side of the driving magnet 202 relative to the protrusion 212. Second magnetic fluid 264. That is, the magnetic fluid 260 is separated into the first magnetic fluid 262 held by the N pole of the drive magnet 202 and the second magnetic fluid 264 held by the S pole of the drive magnet 202 by the protrusion 212. For this reason, in this embodiment, the problem that the magnetic flux of the magnetic circuit passes through the magnetic fluid 260 and goes directly from the N pole of the drive magnet 202 to the S pole is solved. As a result, in this embodiment, the magnetic force of the drive magnet 202 can be suitably supplied to the coil 302, so that the VCM can be driven efficiently.

Fourth Embodiment In the fourth embodiment, as shown in FIGS. 13 and 14, the lid member 400 includes the third drive magnet 404 a and the fourth drive magnet 404 b, and the protrusion 212 is provided on the fixed portion 200 and the lid member 400. It is the same as the first embodiment except that it is different from the first embodiment in that it is fixed. In the following description, the description of the same part as the above embodiment is omitted.

  In the present embodiment, as shown in FIGS. 13 and 14, the lid member 400 further includes a third drive magnet 404a and a fourth drive magnet 404b. The third drive magnet 404 a is disposed on the lid member 400 so as to supply the south pole magnetic force to the coil 302, and the fourth drive magnet 404 b is a lid so as to supply the north pole magnetic force to the coil 302. The member 400 is disposed. The third drive magnet 404a and the fourth drive magnet 404b are arranged at a distance from each other with the convex portion 410 of the lid member 400 interposed therebetween.

  The first drive magnet 202a, the second drive magnet 202b, the second yoke 206, the third drive magnet 404a, the fourth drive magnet 404b, and the first yoke 402 form a magnetic circuit and supply magnetic force to the coil 302. ing.

  The protruding portion 212 is fixed so as to pass through the inside (air core portion) of the coil 302 and the through hole 310 of the moving portion 300 so as to connect the convex portion 214 of the fixing portion 200 and the convex portion 410 of the lid member 400. It is.

  The magnetic fluid 260 includes the magnetic force generated by the N pole of the first drive magnet 202a, the magnetic force generated by the S pole of the second drive magnet 202b, the magnetic force generated by the S pole of the third drive magnet 404a, and the magnetic force generated by the fourth drive magnet 404b. The magnetic force generated by the N pole is held between the fixed portion 200 and the lid member 400. The magnetic fluid 260 is disposed so as to contact the inside of the coil 302 and the inner peripheral surface of the through hole 310 of the moving unit 300.

  The magnetic fluid 260 includes a first magnetic fluid 262 disposed in a first region closer to the first drive magnet 202a and the third drive magnet 404a than the protrusion 212, and the second drive magnet 202b and the fourth than the protrusion 212. And a second magnetic fluid 264 disposed in the second region on the drive magnet 404b side. That is, the magnetic fluid 260 has the first magnetic fluid 262 and the S pole of the second drive magnet 202a held by the N pole of the first drive magnet 202a and the S pole of the third drive magnet 404a by the non-magnetic projection 212. And the second magnetic fluid 264 held by the fourth drive magnet 404bN pole. For this reason, in this embodiment, a magnetic circuit can be formed suitably. As a result, in the present embodiment, since the magnetic force of the magnet can be suitably supplied to the coil 302, the VCM can be driven efficiently.

  In the above-described embodiment, the fixing unit 200 and the lid member 400 are configured to include a magnet. However, the present embodiment is not limited to this, and either the fixing unit 200 or the lid member 400 includes a magnet. It may be.

  In the above-described embodiment, the first magnetic fluid 262 disposed in the first region on the first drive magnet 202 a and the third drive magnet 404 a side with respect to the protrusion 212 and the second drive magnet 202 b with respect to the protrusion 212. And the second magnetic fluid 264 disposed in the second region on the fourth drive magnet 404b side, but the present embodiment is not limited to this. For example, the first magnetic fluid 262 disposed in the first region closer to the first drive magnet 202a and the third drive magnet 404a than the protrusion 212, or the second drive magnet 202b and the fourth drive magnet relative to the protrusion 212. The configuration may include any of the second magnetic fluids 264 disposed in the second region on the 404b side. Further, any one of the first drive magnet 202a, the second drive magnet 202b, the third drive magnet 404a, and the fourth drive magnet 404b may hold the magnetic fluid 260.

  In addition, this invention is not limited to said embodiment.

  In the above-described embodiment, the optical system movement type blur correction apparatus that drives the shake correction lens L3 is used. However, the present invention can also be applied to an image sensor movement type blur correction apparatus that moves the image sensor 3.

  In the above embodiment, as shown in FIG. 15A, the first coil 302 and the second coil 304 are arranged in parallel to the X axis and the Y axis, respectively. Not. For example, as shown in FIG. 15B, the first coil 302 and the second coil 304 may be arranged to be inclined with respect to the X axis and the Y axis. For example, the inclination angle θ1 (90 degrees or more or 90 degrees or less) of the first coil 302 and the second coil 304 can be determined according to the viscous resistance of the magnetic fluid 260. For example, when the viscous resistance of the magnetic fluid 260 is high, the inclination angle θ1 of the first coil 302 and the second coil 304 is increased.

  Further, as shown in FIG. 15C, the shake correction lens unit L3 included in the moving unit 300 moves linearly in the X-axis direction, and has an arc shape (substantially Y-axis) about the guide pin 350. The image blur correction apparatus 100 can be applied to a type that moves in the direction). Furthermore, in the above-described embodiment, two VCMs are applied as means for driving the moving unit 300. However, the present invention is not limited to this, and a configuration including two or more VCMs may be used.

DESCRIPTION OF SYMBOLS 100 ... Image blur correction apparatus 200 ... Fixed part 202 ... Magnet 212 ... Protrusion part 260 ... Magnetic fluid 300 ... Moving part 302 ... Coil L3 ... Blur correction optical system

Claims (19)

A moving part movable relative to the fixed part;
A blur correction optical system for correcting blur of an image formed in the moving unit and formed by the optical system;
A coil provided in the moving unit;
A first region for supplying N-pole magnetic force to the coil and a second region for supplying S-pole magnetic force to the coil;
A protrusion provided between the first region and the second region;
An image blur correction device comprising: a magnetic fluid provided in at least one of the first region and the second region. The image blur correction device according to claim 1,
The image blur correction apparatus according to claim 1, wherein the protrusion is a non-magnetic material. An image blur correction apparatus according to claim 1 or 2, wherein
The image blur correction apparatus, wherein the magnetic fluid is in contact with the coil. An image blur correction apparatus according to any one of claims 1 to 3, wherein
The image blur correction device, wherein the protrusion is fixed to the magnet. An image blur correction apparatus according to any one of claims 1 to 4, wherein
The image blur correction apparatus according to claim 1, wherein the magnetic fluid enters the inside of the coil. An image blur correction apparatus according to any one of claims 1 to 5,
The image blur correction apparatus, wherein the magnetic fluid provided in the first region and the magnetic fluid provided in the second region are separated by the protrusion. An image blur correction apparatus according to any one of claims 1 to 3, wherein
The image blur correction apparatus, wherein the protrusion is fixed to the moving unit. An image blur correction apparatus according to any one of claims 1 to 7,
The image blur correction apparatus, wherein the fixed portion includes a first scattering prevention member that protrudes toward the moving portion and prevents the magnetic fluid from scattering. An image blur correction device according to any one of claims 1 to 8,
The image blur correction apparatus according to claim 1, wherein the moving unit includes a second scattering prevention member that protrudes toward the fixed unit and prevents the magnetic fluid from scattering. An image blur correction device according to claim 8 or claim 9 subordinate to claim 8, comprising:
The gap in the optical axis direction of the optical system between the first scattering prevention member and the moving part is narrower than the gap in the optical axis direction between the coil and the fixed part. Correction device. An image blur correction apparatus according to any one of claims 1 to 3, wherein
The fixing unit includes a first fixing unit provided on one side of the moving unit in the optical axis direction of the optical system, and a second fixing unit provided on the other side of the moving unit in the optical axis direction. And
The image blur correction apparatus, wherein the protrusion is fixed to the first fixing portion and the second fixing portion. The image blur correction device according to claim 11,
The image blur correction apparatus according to claim 1, wherein the magnet is provided on one of the first fixing portion and the second fixing portion. The image blur correction device according to claim 11,
The magnet includes a first magnet having the first region and the second region and provided in the first fixing portion, a third region for supplying an N-pole magnetic force to the coil, and an S-pole for the coil. A fourth region for supplying a magnetic force, and a second magnet provided in the second fixed portion,
The image blur correction apparatus, wherein the magnetic fluid is provided in at least one of the first region and the second region, and at least one of the third region and the fourth region. A moving part movable relative to the fixed part;
A blur correction optical system for correcting blur of an image formed in the moving unit and formed by the optical system;
A coil provided in the fixed portion;
A first region for supplying N-pole magnetic force to the coil and a second region for supplying S-pole magnetic force to the coil;
A protrusion provided between the first region and the second region;
An image blur correction device comprising: a magnetic fluid provided in at least one of the first region and the second region. A moving part movable relative to the fixed part;
An image sensor provided in the moving unit;
A coil provided in the moving unit;
A first region for supplying N-pole magnetic force to the coil and a second region for supplying S-pole magnetic force to the coil;
A protrusion provided between the first region and the second region;
An image blur correction device comprising: a magnetic fluid provided in at least one of the first region and the second region. A moving part movable relative to the fixed part;
An image sensor provided in the moving unit;
A coil provided in the fixed portion;
A first region for supplying N-pole magnetic force to the coil and a second region for supplying S-pole magnetic force to the coil;
A protrusion provided between the first region and the second region;
An image blur correction device comprising: a magnetic fluid provided in at least one of the first region and the second region.   A lens barrel including the image blur correction device according to any one of claims 1 to 14.   A camera body including the image blur correction device according to claim 15.   An imaging device including the image blur correction device according to any one of claims 1 to 16.

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