JP2012215697A - Vibration insulation unit and imaging device - Google Patents

Abstract

A magnetic drive unit of a vibration isolating unit is prevented from leaking to the outside.
An imaging apparatus includes a lens barrel unit having an optical system that forms incident light, an imaging element that captures an image formed by the optical system, and a magnetic drive unit that moves the imaging element. 22 and a cover 24 that constitutes an outer shell, the image stabilization unit 3 that corrects image blur by moving the image sensor, a housing 4 that houses the image stabilization unit and the optical system, And a magnetic shield plate 27 made of a magnetic material provided between the cover and the casing.
[Selection] Figure 6

Description

  The present invention relates to a vibration isolation unit and an imaging apparatus.

  An image pickup apparatus such as a digital camera is equipped with an image stabilization unit to suppress disturbance of a captured image (image blur) due to camera shake or the like. For example, in a camera unit built in a mobile phone, A device that is provided so as to be swingable and is moved according to camera shake or the like is known (for example, see Patent Document 1).

  Some recent digital cameras have a bending optical system that forms an image by bending incident light in the middle of the optical path, and the body has been downsized. Image blurring is suppressed by moving in a plane orthogonal to the axis (see, for example, Patent Document 2).

  In the above-described image stabilization unit, a voice coil motor including a magnet and a coil is generally used for a drive unit that moves the correction lens or the image sensor.

JP 2008-310172 A JP 2009-086322 A

  In a digital camera equipped with a bending optical system, a sensor shift type image stabilization unit that moves an image sensor is typically disposed along the bottom of the housing together with the image sensor, and a drive unit for moving the image sensor Is also arranged near the bottom of the housing. Accordingly, the magnetic flux of the magnet may leak to the outside of the housing. In this case, if the iron clip holder is placed near the bottom of the housing, the clip or the like may be sucked to the bottom of the housing.

  In particular, in recent years, a moving magnet type drive unit in which a small and lightweight magnet with excellent magnetic flux density is provided so as to be able to move integrally with the image sensor has been used. There is concern about an increase in magnetic flux.

  The anti-vibration unit described in Patent Document 1 is configured such that the cover that forms the outer shell of the anti-vibration unit functions as an electromagnetic shield, thereby reducing leakage magnetic flux. However, as the camera is reduced in size and weight, the vibration isolation unit is also required to be reduced in size and weight, and the cover of the vibration isolation unit is generally formed thin. For this reason, the cover may not be able to sufficiently reduce the leakage magnetic flux.

  Furthermore, since the cover is close to the magnet of the magnetic drive unit with the miniaturization of the vibration isolation unit, when the cover is an electromagnetic shield, the moving magnet type drive unit is In other words, there is a risk of hindering the movement of the image sensor.

  This invention is made | formed in view of the situation mentioned above, The objective is to prevent that the magnetic flux of the magnetic drive part of an anti-vibration unit leaks outside.

(1) An image stabilization unit that includes an image sensor, a magnetic drive unit that moves the image sensor, and a cover that forms an outer shell, and that corrects image blur on the image sensor by moving the image sensor. An anti-vibration unit having a magnetic shield plate made of a magnetic material provided on the outer surface of the cover.
(2) A lens barrel unit having an optical system that forms an incident light, an imaging element that captures an image formed by the optical system, a magnetic drive unit that moves the imaging element, and a cover that constitutes an outer shell An image stabilization unit that corrects image blur on the image sensor by moving the image sensor, a housing that houses the image stabilization unit and the lens barrel unit, a cover, and the housing And a magnetic shield plate made of a magnetic material provided between the two.

  According to the present invention, it is possible to prevent the magnetic flux of the magnetic drive unit of the image stabilization unit from leaking to the outside without hindering the movement of the image sensor.

It is a figure showing typically an example of an imaging device for explaining an embodiment of the present invention. It is a figure which shows the external appearance of the lens barrel unit and vibration proof unit of the imaging device of FIG. It is a figure which shows the external appearance of the image stabilization unit of the imaging device of FIG. It is a figure which shows the external appearance of the image stabilization unit of the imaging device of FIG. It is a figure which decomposes | disassembles and shows the anti-vibration unit of the imaging device of FIG. It is a figure which shows the VI-VI line cross section of the vibration isolator unit in FIG. It is a figure which shows the VII-VII line cross section of the vibration isolator unit in FIG. It is a figure which shows the support mechanism of the element in the vibration proof unit of FIG.

  FIG. 1 schematically shows an example of an imaging apparatus for explaining an embodiment of the present invention.

  The imaging apparatus shown in FIG. 1 is a digital camera, and the camera 1 captures an image formed by a lens barrel unit 2 having an optical system that forms incident light and an optical system of the lens barrel unit 2. An anti-vibration unit 3 having an image sensor, and a lens barrel unit 2 and a housing 4 for housing the anti-vibration unit 3 are provided. The image stabilization unit 3 corrects the image blur by moving the image sensor.

  The optical system of the lens barrel unit 2 is a so-called bending optical system, which bends incident light incident along the first optical axis A1 extending in the Y direction and along the second optical axis A2 extending in the Z direction. The light is guided and imaged on the image sensor of the image stabilization unit 3.

  The anti-vibration unit 3 is disposed along the bottom of the housing 4.

  FIG. 2 shows the external appearance of the lens barrel unit 2 and the vibration isolation unit 3.

  The lens barrel unit 2 includes the above-described optical system and a lens barrel 10 that houses the optical system. The optical system includes, for example, a plurality of lenses such as an objective system, a focusing system, a zooming system, and a correction system including a lens L1 exposed outside the housing 4 and a prism (not shown) that bends light incident on the lens. Composed by groups.

  The vibration isolation unit 3 is assembled to the lens barrel unit 2 by engaging a plurality of engaging portions 24 a provided on the cover 24 constituting the outer shell with the emission side end portion of the lens barrel 10.

  3 and 4 show the appearance of the image stabilization unit 3, FIG. 5 shows an exploded view of the image stabilization unit 3, and FIGS. 6 and 7 show a cross section of the image stabilization unit 3. FIG.

  The image stabilization unit 3 includes an imaging element 20 that captures an image formed by the optical system of the lens barrel unit 2, and a plane (XY plane) orthogonal to the second optical axis A2 (see FIG. 1) of the optical system. A support mechanism that movably supports the image sensor 20 in the interior, a magnetic drive unit 22 that moves the image sensor 20 by moving the support mechanism, a unit base 23 that holds the support mechanism and the magnetic drive unit 22, and a unit And a cover 24 constituting the outer shell.

  The support mechanism described above extends in parallel to the X direction, a pair of first guide shafts 31a and 31b fixed to the unit base 23, a slider 32, and a pair of second guides extending in parallel to the Y direction. And a holder 34 to which guide shafts 33a and 33b are fixed. The image sensor 20 is attached to the holder 34.

  The slider 32 is slidably engaged with the first guide shafts 31a and 31b, and is supported so as to be movable in the X direction with respect to the unit base 23 to which the first guide shafts 31a and 31b are fixed. Has been. The slider 32 is slidably engaged with the second guide shafts 33a and 33b, and the holder 34 to which the second guide shafts 33a and 33b are fixed moves in the Y direction with respect to the slider 32. It is supported freely. The imaging element 20 attached to the holder 34 is movable in the XY plane by a combination of the movement of the slider 32 in the X direction with respect to the unit base 23 and the movement of the holder 34 in the Y direction with respect to the slider 32.

  The magnetic drive unit 22 includes a first drive unit 40 for moving the holder 34 in the X direction and a second drive unit 41 for moving the holder 34 in the Y direction. The first drive unit 40 includes a magnet 42, a coil 43, and a hall element 44 that detects the magnetic field of the magnet 42. Similarly, the second drive unit 41 includes a magnet 45, a coil 46, and a hall element 47 that detects the magnetic field of the magnet 45.

  In the first drive unit 40, the magnet 42 is attached to the holder 34 and moves together with the holder 34. The coil 43 is disposed on the upper side of the magnet 42 so as to face the magnet 42, and is fixed to the unit base 23. The hall element 44 is disposed below the magnet 42 and opposed to the magnet 42, and is fixed to the unit base 23 via a holding plate 48.

  When a current is supplied to the coil 43, a magnetic field is formed by the coil 43, and the holder 34 is moved in the X direction by an attractive force or a repulsive force acting between the magnetic field of the coil 43 and the magnetic field of the magnet 42. As the holder 34 moves in the X direction, the magnetic field of the magnet 42 at the position of the Hall element 44 changes, and this change in the magnetic field is detected by the Hall element 44. Based on a change in the magnetic field detected by the Hall element 44, a current supplied to the coil 43 is controlled by a control unit (not shown), thereby controlling movement of the holder 34 in the X direction.

  Similarly, in the second drive unit 41, the magnet 45 is attached to the holder 34 and moves together with the holder 34. The coil 46 is disposed above the magnet 45 so as to face the magnet 45 and is fixed to the unit base 23. The hall element 47 is below the magnet 45 and is fixed to the unit base 23 via a holding plate 48.

  When a current is supplied to the coil 46, a magnetic field is formed by the coil 46, and the holder 34 is moved in the Y direction by attractive force or repulsive force acting between the magnetic field of the coil 46 and the magnetic field of the magnet 45. As the holder 34 moves in the Y direction, the magnetic field of the magnet 45 at the position of the Hall element 47 changes, and this change in the magnetic field is detected by the Hall element 47. Based on the change in the magnetic field detected by the Hall element 47, the current supplied to the coil 46 is controlled by a control unit (not shown), and thereby the movement of the holder 34 in the Y direction is controlled.

  As described above, in each of the first driving unit 40 and the second driving unit 41, the coil, the magnet, and the Hall element are arranged in a line in this order, and the driving by the coil and the magnetic field detection by the Hall element are performed. And the magnet is shared, and miniaturization of the drive part is achieved.

  The first drive unit 40 and the second drive unit 41 are arranged side by side in the X direction together with the imaging device 20. Thereby, the size of the image stabilizing unit 3 is reduced in the Y direction corresponding to the thickness direction of the camera 1. The first drive unit 40 and the second drive unit 41 may be arranged on both sides of the image sensor 20 so as to sandwich the image sensor 20 therebetween. They are arranged on the same side.

  The image sensor 20 is mounted on the end of the FPC 25. A holding plate 26 is provided at a position overlapping the image sensor 20 on the back surface of the FPC 25 opposite to the surface on which the image sensor 20 is mounted. The holding plate 26 functions as a grip portion when the image pickup device 20 is attached to the holder 34 and also functions as a buffer material that reduces an impact that acts on the image pickup device 20 when the camera 1 is dropped.

  The image pickup device 20 is attached to the holder 34 by, for example, aerial bonding. Specifically, the holding plate 26 is gripped using an appropriate jig, and the support mechanism including the holder 34 is attached to the unit base 23. In the held state, the position of the image pickup device 20 in the X, Y, and Z axial directions and the angle of the image pickup device 20 around each axis are adjusted, and the image pickup device 20 is placed in the holder 34 with these adjustments being made. Glued. According to such a method, it is possible to absorb an error between elements constituting the support mechanism and arrange the imaging element 20 at the imaging position of the optical system of the lens barrel unit 2 with high accuracy.

  The FPC 25 extends in the X direction in which the first drive unit 40, the second drive unit 41, and the image sensor 20 are arranged, and is appropriately folded at the end portion in the X direction of the image stabilizing unit 3, and is controlled by a control unit (not shown). )It is connected to the. In particular, as in the illustrated example, when the first drive unit 40 and the second drive unit 41 are arranged on the same side with respect to the imaging element 20, the wiring length along the X direction of the FPC 25 is set. It can be secured sufficiently. Thereby, the stress which acts on each part of FPC25 resulting from the bending at the time of following the movement of the image pick-up element 20 in the Y direction can be relieved.

  FIG. 8 shows the support mechanism for supporting the image sensor 20 in detail.

  In the illustrated example, the first drive unit 40 and the second drive unit 41 are arranged on the same side with respect to the image sensor 20, and the image sensor 20 is one end in the X direction of the holder 34 of the support mechanism. Is provided. The first guide shafts 31 a and 31 b and the second guide shafts 33 a and 33 b for supporting the holder 34 movably in the X direction and the Y direction are arranged in the X direction of the holder 34 on the side opposite to the imaging device 20. It is arranged on the other end side. In other words, the image pickup device 20 is attached to a portion of the holder 34 that is overhanging in the X direction by removing from the portion supported by the first guide shafts 31a and 31b and the second guide shafts 33a and 33b. It has been.

  Assuming that the image sensor 20 is provided in a portion supported by the first guide shafts 31a and 31b and the second guide shafts 33a and 33b, the first guide shaft 31a and 31b is provided with the FPC 25 extending from the image sensor 20 for the first reason. The guide shafts 31 a and 31 b and the second guide shafts 33 a and 33 b are generally arranged so as to surround the image sensor 20. Therefore, extra space is required in the X direction or the Y direction. On the other hand, the image pickup device 20 is attached to the overhanging portion of the holder 34 as described above, so that the vibration-proof unit 3 is small in the Y direction corresponding to the thickness direction of the camera 1. It is planned.

  The anti-vibration unit 3 configured as described above is disposed along the bottom of the housing 4. And between the cover 24 which comprises the outer shell of the vibration isolator 3 and the bottom part of the housing | casing 4, it overlaps with the magnets 42 and 45 in the opposing direction of the coils 43 and 46 corresponding to the magnets 42 and 45. A magnetic shield plate 27 is provided. The magnetic shield plate 27 is made of, for example, a magnetic material such as pure iron or SUS400 series ferrite-based or martensitic stainless material.

  As the vibration isolation unit 3 is disposed along the bottom of the housing 4, the magnets 42 and 45 included in the first driving unit 40 and the second driving unit 41 of the magnetic driving unit 22 are also included in the housing. Although arranged near the bottom of the body 4, the magnetic shield plate 27 prevents or reduces the magnetic flux of the magnets 42 and 45 from leaking outside the housing 4.

  The magnetic shield plate 27 is disposed outside the cover 24 and a certain distance is secured between the magnets 42 and 45. Therefore, the magnets 42 and 45 are weakly attracted to the magnetic shield plate 27, and the movement of the magnets 42 and 45, that is, the movement of the image sensor 20 is smoothly performed. The distance between the magnetic shield plate 27 and the magnets 42 and 45 depends on the magnetic flux density of the magnets 42 and 45, but is preferably 4 mm or more.

  Furthermore, in this example, the cover 24 is made of a nonmagnetic material such as aluminum or austenitic stainless steel of SUS300 series. The cover 24 is closer to the magnets 42 and 45 than the magnetic shield plate 27. However, the magnets 42 and 45 are not attracted to the cover 24 by forming them with a nonmagnetic material. Movement, that is, movement of the image sensor 20 is performed smoothly.

  In the above-described example, the magnetic shield plate 27 is attached to the outer surface of the cover 24 of the vibration isolation unit 3, but it may be disposed between the cover 24 and the bottom of the housing 4. It may be attached to the inner surface of the bottom of the body 4.

  As described above, the present specification discloses the following anti-vibration units (1) to (4) and the following imaging devices (5) to (11).

(1) An image stabilization unit that includes an image sensor, a magnetic drive unit that moves the image sensor, and a cover that forms an outer shell, and that corrects image blur by moving the image sensor, An anti-vibration unit having a magnetic shield plate made of a magnetic material provided on the outer surface of the cover.
(2) The vibration isolating unit according to (1), wherein the magnetic drive unit includes a magnet that moves integrally with the imaging element, and a coil that is disposed to face the magnet, and the magnetic shield plate Is an anti-vibration unit that is arranged to overlap the magnet in the opposing direction of the magnet and the coil.
(3) The anti-vibration unit according to (2), wherein the magnetic shield plate and the magnet are separated by 4 mm or more.
(4) The vibration isolating unit according to any one of (1) to (3), wherein the cover is made of a nonmagnetic material.
(5) A lens barrel unit having an optical system for forming incident light, an image pickup device for picking up an image formed by the optical system, a magnetic drive unit for moving the image pickup device, and a cover constituting an outer shell A vibration-proof unit that corrects image blur by moving the image sensor, a housing that houses the vibration-proof unit and the lens barrel unit, and a cover that is provided between the cover and the housing. And a magnetic shield plate made of a magnetic material.
(6) In the imaging device according to (5), the magnetic drive unit includes a magnet that moves integrally with the imaging element, and a coil that is disposed to face the magnet, and the magnetic shield plate is An image pickup device arranged to overlap the magnet in the facing direction of the magnet and the coil.
(7) The imaging device according to (6), wherein the magnetic shield plate and the magnet are separated by 4 mm or more.
(8) The imaging apparatus according to any one of (5) to (7), wherein the cover is made of a nonmagnetic material.
(9) The imaging apparatus according to any one of (5) to (8), wherein the magnetic shield plate is provided on an outer surface of the cover.
(10) The imaging apparatus according to any one of (5) to (8), wherein the magnetic shield plate is provided on an inner surface of the casing.
(11) The imaging apparatus according to any one of (5) to (10), wherein the optical system bends incident light incident along a first optical axis, and An imaging device that guides light along an intersecting second optical axis to form an image.

1 Digital camera (imaging device)
2 Lens barrel unit 3 Anti-vibration unit 4 Housing 10 Lens barrel 20 Imaging element 22 Magnetic drive unit 23 Unit base 24 Cover 25 FPC
26 holding plate 31a first guide shaft 31b first guide shaft 32 slider 33a second guide shaft 33b second guide shaft 34 holder 40 first drive unit 41 second drive unit 42 magnet 43 coil 44 Hall element (Detection means)
45 Magnet 46 Coil 47 Hall element (detection means)
48 Retaining plate

Claims (11)

An image stabilization unit that includes an image sensor, a magnetic drive unit that moves the image sensor, and a cover that forms an outer shell, and that corrects image blur by moving the image sensor,
An anti-vibration unit having a magnetic shield plate made of a magnetic material provided on the outer surface of the cover. The anti-vibration unit according to claim 1,
The magnetic drive unit includes a magnet that moves integrally with the imaging device, and a coil that is disposed to face the magnet.
The said magnetic shield board is a vibration isolator unit arrange | positioned in the opposing direction of the said magnet and the said coil so that it may overlap with the said magnet. The vibration isolation unit according to claim 2,
The magnetic shield plate and the magnet are vibration-proof units separated by 4 mm or more. The anti-vibration unit according to any one of claims 1 to 3,
The cover is a vibration isolation unit made of a non-magnetic material. A lens barrel unit having an optical system for imaging incident light;
An image pickup device that picks up an image formed by the optical system, a magnetic drive unit that moves the image pickup device, and a cover that forms an outer shell, and prevents image blurring by moving the image pickup device. Vibration unit,
A housing for housing the vibration isolation unit and the lens barrel unit;
A magnetic shield plate made of a magnetic material provided between the cover and the housing;
An imaging apparatus comprising: The imaging apparatus according to claim 5,
The magnetic drive unit includes a magnet that moves integrally with the imaging device, and a coil that is disposed to face the magnet.
The imaging apparatus, wherein the magnetic shield plate is disposed so as to overlap the magnet in a facing direction of the magnet and the coil. The imaging apparatus according to claim 6,
The magnetic shield plate and the magnet are imaging devices separated by 4 mm or more. The imaging device according to any one of claims 5 to 7,
The cover is an imaging device made of a nonmagnetic material. The imaging device according to any one of claims 5 to 8,
The magnetic shield plate is an imaging device provided on an outer surface of the cover. The imaging device according to any one of claims 5 to 8,
The magnetic shield plate is an imaging device provided on an inner surface of the casing. The imaging apparatus according to any one of claims 5 to 10,
The imaging system is an imaging apparatus in which incident light incident along a first optical axis is bent and guided along a second optical axis that intersects the first optical axis to form an image.

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