JP2013003347A - Lens barrel and imaging apparatus - Google Patents

Abstract

The present invention provides a mechanism for reducing the size of a lens barrel by improving the space efficiency in which the drive units of a plurality of light amount adjusting members of a base plate on the outer peripheral side of a correction lens are arranged.
The lens barrel is provided with a base plate 4 on which driving units 3, 5 and 6 of a plurality of light quantity adjusting members are arranged, and is movable with respect to the base plate 4 in a direction perpendicular to the optical axis. On the outer peripheral side of the correction lens 1 of the holding member 2 for holding the correction lens 1, the ellipsoidal coils 7 a and 7 b that are spaced apart from each other in the circumferential direction with respect to the base plate 4, and the holding member 2. A correction lens driving unit having magnets 2a and 2b provided at positions facing the coils 7a and 7b in the optical axis direction and moving the holding member 2 in a direction perpendicular to the optical axis with respect to the base plate 4. Prepare. In the coils 7 a and 7 b, the line X extending in the long axis direction of one coil 7 a and the line Y extending in the long axis direction of the other coil 7 b intersect on the surface of the ground plane 4 on the outer peripheral side of the correction lens 1. One driving unit 5 among the driving units 3, 5 and 6 of the plurality of light quantity adjusting members is arranged on the intersecting surface.
[Selection] Figure 4

Description

  The present invention relates to a lens barrel equipped with an image blur correction mechanism and mounted on an imaging device such as a digital camera, and an imaging device equipped with a lens barrel.

  Some imaging apparatuses such as digital cameras include an image blur correction mechanism that detects camera shake during shooting and corrects image blur by displacing a correction lens in a direction orthogonal to the optical axis according to the detection result.

  By the way, the shutter blades of the shutter mechanism which are necessary when taking a still image with a digital camera or the like are arranged at a position where the photographing light beam is narrowed in order to avoid an increase in the size of the lens barrel. In addition, if the weight of the correction lens of the image blur correction mechanism is heavy, the drive unit that drives the correction lens becomes large, so that the correction lens is also arranged at a position where the photographing light flux is reduced as much as possible.

  Therefore, the position of the shutter blade and the position of the correction lens are close to each other. As a result, the shutter blade driving unit and the correction lens driving unit are also close to each other. In order to reduce the size of the lens barrel, it is desirable that an aperture for adjusting the light amount, an ND filter (a neutral density filter), and the like are also arranged at a position where the imaging light flux is reduced.

  Conventionally, a technique for holding a shutter mechanism in a holder that holds an image blur correction mechanism has been proposed (Patent Document 1). In addition, a technique has been proposed in which an image blur correction mechanism drive unit, a shutter mechanism drive unit, and an ND filter drive unit are arranged on the same ground plane (Patent Document 2).

Japanese Patent Laid-Open No. 11-305280 JP 2007-219338 A

  However, in Patent Document 1, the ground plate of the image blur correction mechanism and the ground plate of the shutter mechanism are independent, and the drive unit of the image blur correction mechanism and the drive unit of the shutter mechanism protrude radially outward. The thickness in the direction of the optical axis is increased, which is a cause of hindering downsizing of the lens barrel.

  Further, in Patent Document 2, in addition to the image blur correction mechanism drive unit, the shutter mechanism drive unit, and the ND filter drive unit on the ground plate, when an attempt is made to dispose the aperture drive mechanism drive unit, the space is reduced. It is difficult to secure.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a mechanism for reducing the size of a lens barrel by improving the space efficiency in which the drive units of a plurality of light quantity adjusting members of a ground plane on the outer peripheral side of a correction lens are arranged.

  In order to achieve the above object, the lens barrel of the present invention is provided with a ground plate on which driving units of a plurality of light amount adjusting members are arranged, and is movably provided in a direction perpendicular to the optical axis with respect to the ground plate. A holding member that holds the lens, a pair of oblong or rectangular coils that are spaced apart from each other in the circumferential direction with respect to the ground plate, and the pair of coils on the outer peripheral side of the correction lens of the holding member And a correction lens driving unit that moves the holding member, and the pair of coils is in the direction of the long axis or the long side of one of the coils. And the line extending in the long axis direction or the long side direction of the other coil are arranged so as to intersect on the surface of the ground plane on the outer peripheral side of the correction lens, and the plurality of light quantity adjusting members are arranged on the intersecting surfaces. Out of the drive unit Characterized in that one is located.

  According to the present invention, it is possible to improve the space efficiency in which the drive units of the plurality of light quantity adjusting members of the ground plane on the outer peripheral side of the correction lens can be improved, so that the lens barrel can be downsized.

It is the external appearance perspective view which looked at the digital camera which is an example of embodiment of an imaging device provided with the lens barrel of this invention from the front side. It is the figure which looked at FIG. 1 from the back side. It is a block diagram which shows the control system of a digital camera. It is the figure which looked at the image blurring correction mechanism mounted in a lens barrel from the optical axis direction. FIG. 5 is a side view of FIG. 4. It is a perspective view which shows the relationship between a main plate, an aperture stop, and an aperture drive part. FIG. 5 is a rear view of FIG. 4. It is a block diagram which shows the principal part of the structure of.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an external perspective view of a digital camera, which is an example of an embodiment of an imaging apparatus including a lens barrel of the present invention, as viewed from the front side, and FIG. 2 is a diagram of FIG.

  As shown in FIG. 1, the digital camera 15 of the present embodiment has a finder 16 for determining the composition of an object, an auxiliary light source 14 for performing photometric distance measurement, a strobe 17 and a lens barrel 18 on the front. Yes. The lens barrel 18 is of a zoom type that moves in the optical axis direction between the shooting position and the storage position to change the shooting magnification.

  A release button 11, a power switch button 13, and a zoom switch 12 are disposed on the top surface of the digital camera 15. As shown in FIG. 2, operation buttons 21 to 26, a display 20 such as an LCD, and a viewfinder eyepiece 19 are arranged on the back of the digital camera 15.

  FIG. 3 is a block diagram showing a control system of the digital camera 15 of the present embodiment.

  The bus 38 includes a CPU 40, a ROM 39, a RAM 41, a release button 11, operation buttons 21 to 36, a display 20, a power switch button 13, a zoom switch 12, a memory 34, a compression / expansion unit 35, a memory card drive 36, and a drive circuit 37. Is connected.

  The driving circuit 37 includes a zoom driving unit 27 that zooms the lens barrel 18, a focus driving unit 29 that drives the focus lens 28, a shutter driving unit 3 that drives the shutter unit 8, and an aperture driving unit 6 that drives the diaphragm 10. Is connected.

  The drive circuit 37 includes an ND drive unit 5 that drives the ND filter 9, correction lens drive units 2a, 2b, 7a, and 7b that drive the correction lens 1, an image sensor 30 such as a CCD sensor or a CMOS sensor, and a strobe. 17 is connected. Drive of each unit connected to the drive circuit 37 is controlled via the drive circuit 37 based on a signal from the CPU 40.

  Various control programs and the like are stored in the ROM 39, and data necessary for the various control programs is stored in the RAM 41. The analog signal processing unit 31 performs analog processing on the image data output from the image sensor 30 and outputs the processed image data to the A / D conversion unit 32.

  The A / D conversion unit 32 converts analog data captured from the image sensor 30 into digital data and outputs the digital data to the digital signal processing unit 33. The digital signal processing unit 33 performs predetermined processing on the digital data converted by the A / D conversion unit 32 and outputs the processed data to the memory 34 as image data.

  The image data stored in the memory 34 is subjected to compression processing such as JPEG or TIFF by the compression / decompression unit 35, and then is output to and stored in a memory card attached to the memory card drive 36.

  Further, the image data stored in the memory 34 or the image data stored in the memory card drive 36 can be expanded by the compression / decompression unit 35 and then displayed on the display 20 via the bus 38. If the user determines that the image displayed on the display 20 is unnecessary by viewing the image, the image can be erased by operating the operation button 24.

  4 is a view of the image blur correction mechanism mounted on the lens barrel 18 as viewed from the optical axis direction, FIG. 5 is a side view of FIG. 4, and FIG. 6 shows the relationship among the base plate 4, the diaphragm 10, and the diaphragm drive unit 6. FIG. 7 is a rear view of FIG. 4.

  As shown in FIGS. 4 and 5, the image blur correction mechanism is provided such that the holding member 2 that holds the correction lens 1 with respect to the base plate 4 is movable in a direction orthogonal to the optical axis. The ground plane 4 is provided with a pair of oval coils 7a and 7b spaced apart from each other by approximately 90 ° in the circumferential direction. The coils 7a and 7b have an oval shape as an example, but may have a rectangular shape as another form.

  A pair of magnets 2a and 2b are provided on the outer peripheral side of the correction lens 1 of the holding member 2 at positions facing the pair of coils 7a and 7b in the optical axis direction. Here, the magnets 2a and 2b and the coils 7a and 7b constitute a correction lens driving unit that drives the correction lens 1.

  Then, when the coils 7a and 7b are energized, a magnetic field is generated, and a driving force is generated in the magnet 2a in the left-right direction in FIG. 4 and in the magnet 2b in the up-and-down direction in FIG. 2 to move in a direction perpendicular to the optical axis.

  Here, referring to FIG. 4, the pair of coils 7 a and 7 b is configured such that a line X extending in the major axis direction of one coil 7 a and a line Y extending in the major axis direction of the other coil 7 b are the outer periphery of the correction lens 1. It arrange | positions so that it may cross | intersect on the surface of the side ground plane 4. FIG. And the ND drive part 5 which drives the ND filter 9 is arrange | positioned in this intersection surface. The long axis direction is the long side direction when the coils 7a and 7b are rectangular.

  On the surface of the base plate 4 other than the surface on which the ND driving unit 5 is provided, the shutter driving unit 3 that drives the shutter unit 8 and the diaphragm driving unit 6 that drives the diaphragm 10 are located on the outer peripheral side of the correction lens 1. Arranged. Here, the ND filter 9, the shutter unit 8, and the diaphragm 10 correspond to an example of a plurality of light amount adjusting members of the present invention.

  Further, the ND driving unit 5, the shutter driving unit 3, the diaphragm driving unit 6, and the coils 7a and 7b are arranged on substantially the same plane in a direction orthogonal to the optical axis. Thereby, the drive parts 3, 5, and 6 do not protrude from the outer shape part of the main plate 4, and the thickness in the optical axis direction can be reduced.

  In the present embodiment, the diaphragm driving unit 6 is provided integrally with the diaphragm 10 in a state of protruding from the diaphragm 10 in the optical axis direction, as shown in FIG. When the diaphragm 10 is coaxially arranged with respect to the base plate 4, the diaphragm drive unit 6 is arranged at a position adjacent to the shutter drive unit 3 on the outer peripheral side of the correction lens 1. It may be fixed integrally with the.

  Then, as shown in FIG. 7, the shutter drive unit 3 opens and closes the shutter blades 8a and 8b of the shutter unit 8 to manage the incident time of the photographing light beam, and the ND drive unit 5 opens and closes the ND filter 9. By doing so, the luminance of the photographing light beam can be changed.

  As described above, in the present embodiment, the line X extending in the long axis direction of the coil 7a and the line Y extending in the long axis direction of the coil 7b intersect on the surface of the ground plane 4 on the outer peripheral side of the correction lens 1. The coils 7a and 7b are arranged on the crossing surface, and the ND driving unit 5 is arranged on the intersecting surface.

  Thereby, the space efficiency which arrange | positions the drive part of the some light quantity adjustment member of the base plate 4 in the outer peripheral side of the correction | amendment lens 1 can be improved. As a result, it is possible to dispose a larger number of drive units of the light amount adjusting members on the surface of the base plate 4 than in the past, and the lens barrel 18 can be downsized.

  The configuration of the present invention is not limited to that exemplified in the above embodiment, and the material, shape, dimensions, form, number, arrangement location, and the like can be changed as appropriate without departing from the scope of the present invention. It is.

  For example, in the above-described embodiment, the ND filter 9, the shutter unit 8, and the diaphragm 10 are exemplified as the plurality of light amount adjusting members. However, the number of light amount adjusting members is not limited thereto.

  Moreover, in the said embodiment, although the ND drive part 5 was arrange | positioned on the surface of the ground plane 4 where the line X extended in the major axis direction of the coil 7a and the line Y extended in the major axis direction of the coil 7b crossed, it is limited to this. Instead, the shutter drive unit 3, the aperture drive unit 6 and the like may be arranged.

DESCRIPTION OF SYMBOLS 1 Correction lens 2 Holding member 2a, 2b Magnet 3 Shutter drive part 4 Base plate 5 ND drive part 6 Aperture drive part 7a, 7b Coil 8 Shutter mechanism 9 ND filter 10 Aperture

Claims (3)

A ground plate on which the drive units of the plurality of light amount adjusting members are disposed;
A holding member that is provided so as to be movable in a direction perpendicular to the optical axis with respect to the base plate, and that holds a correction lens;
A pair of oval or rectangular coils that are spaced apart from each other in the circumferential direction with respect to the base plate, and positions that face the pair of coils in the optical axis direction on the outer peripheral side of the correction lens of the holding member A correction lens driving unit that moves the holding member.
In the pair of coils, a line extending in the long axis or long side direction of one coil and a line extending in the long axis or long side direction of the other coil intersect on the surface of the ground plane on the outer peripheral side of the correction lens. The lens barrel is characterized in that one of the drive units of the plurality of light quantity adjusting members is arranged on the intersecting surface.   2. The lens according to claim 1, wherein the plurality of light amount adjusting members are at least an ND filter, a shutter unit, and a diaphragm, and a driving unit that drives the ND filter is disposed on the intersecting surface. A lens barrel. An imaging device equipped with a lens barrel,
An imaging apparatus comprising the lens barrel according to claim 1 or 2 mounted as the lens barrel.

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