JP2008197388A - Image shake correction device, lens barrel, and optical apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact image shake correction device, a lens barrel and an optical apparatus. <P>SOLUTION: The image shake correction device 90 includes: a base part 91; a second holding frame 92 movable within a plane perpendicular to the optical axis O2 of a photographing optical system relative to the base part 91; a driving section including a first VCM 94 disposed on a first axis perpendicular to the optical axis O2 and a second VCM 95 disposed on the second axis perpendicular to the optical axis O2 and across the first axis, and used to drive the second holding frame 92 during the image shake correction; hole elements 96b and 97b disposed opposite the driving section with the optical axis O2 between them, and used to detect displacement of the second holding frame 92 relative to the base part 91; and a notch 98 disposed in the driving area of an area sandwiched between the first and second axes and used to dispose a focus motor 80 therein. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image blur correction device, a lens barrel, and an optical apparatus.

An image blur correction device provided in a camera or the like is known that includes a magnetic sensor that detects the position of an image blur correction lens group or the like before and after performing an image blur correction operation (see, for example, Patent Document 1). .
JP 2002-229090 A

Here, when the electromagnetic motor is disposed close to the magnetic sensor, the detection accuracy may decrease due to a change in the magnetic field around the electromagnetic motor. For this reason, it is necessary for the image blur correction device to be arranged with the magnetic sensor and the electromagnetic motor separated from each other, or to place a magnetic shield around the magnetic sensor. These are factors that hinder downsizing of the image blur correction device. It was.
An object of the present invention is to provide a downsized image blur correction device, a lens barrel, and an optical apparatus.

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
The invention of claim 1 is characterized in that the fixed portion (91), the moving portion (92) movable in a plane perpendicular to the optical axis (O2) of the photographing optical system with respect to the fixed portion, and the optical axis. A first actuator (94) disposed on a first axis, and a second actuator (95) disposed on a second axis perpendicular to the optical axis and intersecting the first axis And a drive unit (94, 95) for driving the moving unit with respect to the fixed unit during image blur correction, and disposed on the opposite side of the drive unit across the optical axis, and during the image blur correction, A magnetic sensor (96b, 97b) for detecting displacement of the moving part relative to the fixed part; and an electromagnetic motor provided in an area on the drive part side of an area sandwiched between the first axis and the second axis. Electromagnetic motor arrangement possible area (98) in which (80) can be arranged An image blur correction apparatus including a (90).

  According to a second aspect of the present invention, in the image blur correction device according to the first aspect, the electromagnetic motor arrangement possible region (98) is provided in at least one of the fixed portion (91) and the moving portion (92). The image blur correction device (90) is a space, and the space can accommodate at least a part of the electromagnetic motor (80).

A third aspect of the invention includes the image blur correction device (90) according to the first or second aspect and the electromagnetic motor (80), and the electromagnetic motor emits light to the image blur correction device. The lens barrel (1) is provided so as to be relatively movable in an axial direction, and is disposed in the electromagnetic motor disposition region when approaching the image blur correction device.
According to a fourth aspect of the present invention, in the lens barrel according to the third aspect, the electromagnetic motor drives a motor (80) for driving the focus lens group (L1), a motor for driving the zoom lens group, and a shutter unit. A lens barrel (1) including at least one of motors.
According to a fifth aspect of the present invention, in the lens barrel according to the third or fourth aspect of the present invention, the lens barrel includes a cylindrical body (50) that houses the image blur correction device (90), and the optical axis (O2) of the photographing optical system. ) Is biased toward one region side of the cylindrical body, and the electromagnetic motor-arrangeable region (98) is provided on the other region side of the cylindrical body. It is.

The invention of claim 6 is an optical apparatus (2) including the image blur correction device (90) according to claim 1 or claim 2.
A seventh aspect of the invention is an optical apparatus (2) including the lens barrel (1) according to any one of the third to fifth aspects.
Note that the configuration described with reference numerals may be modified as appropriate, and at least a part of the configuration may be replaced with another component.

  According to the present invention, it is possible to provide a downsized image blur correction device, a lens barrel, and an optical apparatus.

Hereinafter, the present invention will be described in more detail with reference to the drawings and the like. In the following embodiments, a lens barrel will be described as an example of an optical apparatus including an image blur correction device.
FIG. 1 is a cross-sectional view including the optical axis of the lens barrel of the embodiment, and is a diagram illustrating a housing state of the lens barrel.
FIG. 2 is a diagram illustrating a state in which the lens barrel of FIG. 1 is extended toward the objective side in the optical axis direction.
FIG. 3 is a front view of the image blur correction device provided in the lens barrel of FIG. 1 as viewed from the objective side in the optical axis direction. Here, FIG. 1 is a cross-sectional view taken along the line AA in FIG. 3, and FIG. 2 is a cross-sectional view taken along the line BB in FIG.

The lens barrel 1 is provided in a non-lens-changeable digital camera 2 (hereinafter referred to as camera 2). The lens barrel 1 is between a state in which it is accommodated in the camera body 3 (see FIG. 1) and a state in which the entire length in the optical axis direction extends and a part of the lens barrel 1 protrudes from the camera body 3 (see FIG. 2). This is a so-called collapsible lens barrel that can be shifted.
The lens barrel 1 includes a first lens group L1, a second lens group L2, a CCD 10, a shutter unit 20, a CCD base 30, a cam cylinder 40, a first group cylinder 50, a first group holding frame 60, a rectilinear guide key 70, a focus motor. 80 and an image blur correction device 90 (see FIG. 2 for the focus motor 80).

  The first lens group L1 and the second lens group L2 cooperate to form a zoom lens having a two-group configuration, and are arranged in this order from the objective side to the image side in the optical axis direction. The first lens unit L1 functions as a focus lens, and the second lens unit L2 functions as an image blur correction lens.

  The optical axes O2 of the first lens group L1 and the second lens group L2 are disposed below the center axis O1 of the cam cylinder 40 described later at the normal position of the camera 2 (see FIG. 3). Here, in this specification, the normal position of the camera 2 refers to the position of the camera 2 when taking a horizontally long image with the optical axis O2 being horizontal. Hereinafter, the description regarding the arrangement of each element provided in the camera 2 is based on this normal position.

The CCD 10 is a photoelectric conversion element arranged on the image side in the optical axis direction of the second lens group L2, and converts image light that has passed through the first lens group L1 and the second lens group L2 into an electrical signal. is there.
The shutter unit 20 adjusts the exposure time of image light to the CCD 10 and is disposed between the second lens group L2 and the CCD 10. The shutter unit 20 also includes a diaphragm unit that adjusts the amount of image light.

The CCD base 30 fixes the CCD 10 to the camera body 3 and is provided at the end of the lens barrel 1 on the image side in the optical axis direction. The shutter unit 20 described above is also fixed to the CCD table 30.
The cam cylinder 40 is formed in a cylindrical shape, and is provided so as to be rotatable around its central axis O1. The cam cylinder 40 has cam grooves 41 and 42 that can be engaged with cam follower pins 51 and 99 provided in a first group cylinder 50 and an image blur correction device 90, which will be described later, on the inner peripheral surface thereof.

The first group cylinder 50 is a cylinder disposed on the inner diameter side of the cam cylinder 40 and is provided substantially coaxially with the cam cylinder 40.
The first group cylinder 50 includes a cam follower pin 51 that protrudes from the outer peripheral surface to the outer diameter side. For example, three cam follower pins 51 are provided at substantially equal intervals in the circumferential direction of the first group cylinder 50. The cam follower pin 51 has a tip inserted into a cam groove 41 formed in the cam cylinder 40, and the first group cylinder 50 moves forward and backward in the optical axis direction according to the rotation of the cam cylinder 40. ing.

The first group cylinder 50 includes a front surface portion 52. The front surface portion 52 is a surface portion that is formed so as to protrude from the end on the optical axis direction objective side of the first group cylinder 50 to the inner diameter side, and is incident on the first lens group L1 and the second lens group L2. A substantially circular opening centered on the optical axis O2 is formed so as not to block the optical path of light.
The first group holding frame 60 is a frame that holds the first lens group L1, and a part of the first group holding frame 60 is disposed on the inner diameter side of the opening formed in the front surface portion 52 of the first group cylinder 50.

  The rectilinear guide key 70 is disposed between the cam cylinder 40 and the first group cylinder 50 and includes a key groove 71 formed so as to extend substantially parallel to the optical axis O2. Cam follower pins 51 and 99 provided in the first group cylinder 50 and the image blur correction device 90 are inserted into the cam grooves 41 and 42 while being engaged with the key grooves 71 of the linear guide key 70, respectively. As a result, the first group cylinder 50 and the image blur correction apparatus 90 do not rotate around the central axis O1 even when the cam cylinder 40 rotates, but go straight in the optical axis direction.

The focus motor 80 is, for example, a stepping motor that drives the first lens unit L1 in the optical axis direction according to a pulse signal output from a control unit (not shown) during a focusing operation such as autofocus.
The focus motor 80 is an electromagnetic motor including a permanent magnet and a rotor (not shown). Here, in this specification, an electromagnetic motor means an electric actuator that obtains a driving force by a change in a magnetic field.

The focus motor 80 is disposed on the inner diameter side of the first group cylinder 50 and above the first lens group L1 (see FIG. 3). The focus motor 80 is fixed to a surface portion facing the image side in the optical axis direction of the front surface portion 52, and its output axis (not shown) is orthogonal to a vertical plane (BB cross section) including the optical axis O2. Yes.
The output shaft of the focus motor 80 and the first group holding frame 60 described above are each provided with a gear (not shown). The first group holding frame 60 is driven in the optical axis direction by transmitting the output of the focus motor 80 via a gear train (not shown) provided between these gears.

For example, the image blur correction device 90 drives the second lens unit L2 in a direction that cancels a change in the posture of the camera caused by a camera shake of the photographer. It corrects image blur.
The image blur correction device 90 includes a base 91, a second group holding frame 92, a ball 93, a first voice coil motor (VCM) 94, a second VCM 95, a first position detector 96, and a second position detector 97. , And a notch 98 is provided.

The base 91 is a disk-shaped member disposed substantially concentrically with the first group cylinder 50, and includes a cam follower pin 99 that is inserted into a cam groove 42 formed in the cam cylinder 40. Similar to the first group cylinder 50, the base 91 moves forward and backward in the optical axis direction according to the rotation of the cam cylinder 40.
Here, the zoom lens is between a state where the focal length is maximized (hereinafter referred to as a tele state (see FIG. 2)) and a state where the focal length is minimized (hereinafter referred to as a wide state). The focal length is changed.
When the zoom lens shifts from the wide state to the tele state, the image blur correction device 90 and the first group holding frame 60 relatively move in the approaching direction, and when the zoom lens shifts from the tele state to the wide state, It moves relative to the direction of separation.

The second group holding frame 92 is a disk-shaped member arranged on the subject side in the optical axis direction with respect to the base 91. The second group holding frame 92 includes a substantially circular opening centered on the optical axis O2, and the second lens group L2 is attached to this opening.
The ball 93 supports the second group holding frame 92 with respect to the base 91, and is disposed between the base 91 and the second group holding frame 92. For example, three balls 93 are formed of, for example, steel, ceramics, and the like, and are provided at substantially equal intervals in the circumferential direction of the base 91. Thereby, the second group holding frame 92 is movable in a plane perpendicular to the optical axis O2 with respect to the base 91.

The first VCM 94 and the second VCM 95 are electromagnetic actuators that drive the second group holding frame 92 with respect to the base portion 91 singly or in cooperation, and function as drive units.
As shown in FIG. 3, the first VCM 94 and the second VCM 95 are arranged above the horizontal plane including the optical axis O2 when the lens barrel 1 is viewed from the objective side in the optical axis direction. Further, the first VCM 94 is arranged on the left side of the vertical plane including the optical axis O2 when the lens barrel 1 is viewed from the objective side in the optical axis direction, and the second VCM 95 is a vertical including the optical axis O2. When the lens barrel 1 is viewed from the objective side in the optical axis direction than the surface, the lens barrel 1 is arranged on the right side.
The first VCM 94 and the second VCM 95 are arranged so that their thrusts are generated in directions orthogonal to each other. The first VCM 94 and the second VCM 95 are arranged such that the thrust acts on the center of the second lens unit L2, and the direction of the thrust is, for example, an angle of 45 ° with respect to the horizontal direction. It has come to make.

As shown in FIG. 1, the first VCM 94 includes a magnet 94a, a coil 94b, a magnet yoke 94c, and a coil yoke 94d.
The magnet 94 a is a permanent magnet fixed to the second group holding frame 92 in a state of facing the base portion 91.
The coil 94b is fixed to the base 91 in a state of facing the magnet 94a.
The magnet yoke 94c and the coil yoke 94d are magnetic bodies formed in a plate shape from, for example, an iron-based metal material. The magnet yoke 94c is provided so as to face the surface of the magnet 94a opposite to the surface facing the coil 94b. The coil yoke 94d is provided so as to face the surface of the coil 94b opposite to the surface facing the magnet 94a.
The second VCM 95 is also provided with a magnet 95a, a coil 95b, a magnet yoke 95c, and a coil yoke 95d (the magnet yoke 95c and the coil yoke 95d are not shown) in the same manner as the first VCM 94 described above. Its function is the same as that of the first VCM 94 except that the thrust direction is different.

The first position detection unit 96 and the second position detection unit 97 are position sensors that detect the displacement of the second group holding frame 92 with respect to the base 91 in a plane orthogonal to the optical axis O2.
The first position detection unit 96 is provided in a region opposite to the first VCM 94 across the second lens group L2, and detects the movement of the second group holding frame 92 in the thrust direction of the first VCM 94. is there.
The second position detection unit 97 is provided in a region opposite to the second VCM 95 across the second lens group L2, and detects the movement of the second group holding frame 92 in the thrust direction of the second VCM 95. is there.

As shown in FIG. 1, the first position detector 96 includes a magnet 96a, a Hall element 96b, and a yoke 96c.
The magnet 96 a is a permanent magnet fixed to the second group holding frame 92 in a state of facing the base portion 91.
The hall element 96b is a magnetic sensor mounted on the flexible printed circuit board 96d and fixed to the base 91 in a state of facing the magnet 96a. The hall element 96b detects and outputs a change in the magnetic field from the magnet 96a when the second group holding frame 92 moves with respect to the base 91, and the image blur correction device 90 includes the hall element 96b. The amount of movement of the second lens unit L2 relative to the base 91 is calculated based on the output of.
The yoke 96c is, for example, a magnetic body formed in a plate shape using an iron-based metal material or the like, and is provided to face a surface of the magnet 96a opposite to the surface facing the hall element 96b.
The second position detection unit 97 also includes a magnet 97a, a Hall element 97b, and a yoke 97c (the yoke 97c is not shown in the figure) in the same manner as the first position detection unit 96 described above. This is the same as the position detector 96.

The notch 98 is for avoiding interference between the focus motor 80 and the image blur correction device 90 in a state where the image blur correction device 90 and the focus motor 80 are close to each other. The notch 98 is orthogonal to the optical axis O2 and extends in the thrust direction of the first VCM 94 (line A1 in FIG. 3), and is orthogonal to the optical axis O2 and thrust of the second VCM 95. The first VCM 94 and the second VCM 95 (drive unit) are provided in a region sandwiched between the second axis (line A2 in FIG. 3) extending in the direction.
Here, in the present specification, of the regions sandwiched between the first axis and the second axis, the region on the drive unit side is the region sandwiched between the first axis and the second axis. It means a region in the vicinity of the drive unit (first VCM 94 and second VCM 95), that is, a region farthest from the first position detection unit 96 and the second position detection unit 97. Specifically, It means an area sandwiched between the first VCM 94 and the second VCM 95, the vicinity of this area, and the like.

  The cutout portion 98 is a part of the second group holding frame 92 and is formed such that a portion above the second lens group L2 is cut out in a substantially U shape when viewed from the front shown in FIG. The second group holding frame 92 is open at the peripheral edge. The notch 98 is a space formed at a position overlapping the focus motor 80 when the lens barrel 1 is viewed from the optical axis direction (see FIG. 3), and is formed with a dimension larger than the outer dimension of the focus motor 80. .

Next, the operation of the lens barrel 1 will be described.
The lens barrel 1 is in the accommodated state shown in FIG. When a power button or the like (not shown) is operated from this accommodated state in the lens barrel 1, the cam barrel 40 is rotated and the first group cylinder 50 is propelled toward the objective side in the optical axis direction, and is ready for photographing. At this time, the zoom lens is in the wide state, and the image blur correction device 90 is separated from the first group holding frame 60 (not shown).
When the photographer performs a zoom-up operation in the wide state, the lens barrel 1 shifts to a tele state in which the first lens unit L1 and the second lens unit L2 illustrated in FIG.
In the tele state shown in FIG. 2, a part of the focus motor 80 is accommodated in a notch portion 98 formed in the second group holding frame 92, and the notch portion 98 functions as an electromagnetic motor placement region.

According to the lens barrel 1 of the present embodiment described above, the following effects can be obtained.
(1) Since the focus motor 80, which is an electromagnetic motor, is arranged on the opposite side of the Hall elements 96b and 97b with the optical axis O2 interposed therebetween, the focus motor 80 and the Hall elements 96b and 97b are separated from each other. Is less susceptible to magnetic field fluctuations around the focus motor 80. Therefore, each of the first position detection unit 96 and the second position detection unit 97 can accurately detect the amount of movement of the second group holding frame 92 relative to the base 91, and the image blur correction accuracy of the image blur correction device 90 is improved. .
Furthermore, since the focus motor 80 and the Hall elements 96b and 97b are separated from each other, it is not necessary to provide a magnetic shield material around the Hall elements 96b and 97b to reduce the influence of the magnetic field, and the cost can be reduced. The image blur correction device 90 can be reduced in size.

(2) Since the focus motor 80 is housed in the notch 98 when the zoom lens is in the tele state, interference between the focus motor 80 and the second group holding frame 92 can be prevented, and within the movable range of the image blur correction device 90. A focus motor 80 can be disposed on the screen. Therefore, the total length of the lens barrel 1 in the optical axis direction can be shortened, and the lens barrel 1 and the camera 2 can be downsized.
(3) Since the optical axis O2 of the second lens unit L2, which is an image blur correction lens, is shifted downward with respect to the central axis O1 of the cam barrel 40, the optical axis direction of the notch 98 functioning as an electromagnetic motor arrangement region The area when viewed from the side can be set large. As a result, even a large focus motor 80 can be reliably accommodated in the notch 98.

[Deformation]
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the technical scope of the present invention.
(1) The configurations of the image blur correction device, the lens barrel, and the optical apparatus to which the present invention is applied are not limited to those described in the embodiments, and can be changed as appropriate. For example, in the embodiment, the electromagnetic motor is a focus motor, but the electromagnetic motor is not limited to this, and may be, for example, a shutter motor or a zoom motor.
(2) In the embodiment, the focus motor is accommodated in the cutout portion of the image blur correction device by moving the image blur correction device in the optical axis direction. The motor may be arranged in the notch, and an electromagnetic motor may be arranged in the notch regardless of the movement state of the image blur correction apparatus.
(3) In the embodiment, the electromagnetic motor is arranged by providing the cutout portion in the second group holding frame that is the moving portion. However, the present invention is not limited thereto, and the cutout portion may be provided also in the base portion that is the fixed portion. In this case, since the wrap length in the optical axis direction between the electromagnetic motor and the image blur correcting device can be increased, the lens barrel can be further reduced in size.
(4) Although the magnetic sensor of the embodiment is a Hall element, the magnetic sensor is not limited thereto, and may be, for example, an MI sensor, an MR sensor, a magnetic resonance type magnetic field detection element, or the like.
(5) The image blur correction apparatus of the embodiment corrects the image blur by moving the image blur correction lens. However, the image blur correction device is not limited to this, and the image sensor such as a CCD is moved to form an image on the image sensor. The image blur of the image may be corrected.
(6) Although the optical device of the embodiment is a lens barrel provided in a camera, the optical device is not limited thereto, and may be, for example, an interchangeable lens barrel.

It is sectional drawing containing the optical axis of the lens-barrel of embodiment, and is a figure which shows the accommodation state of a lens-barrel. It is a figure which shows the state by which the lens-barrel of FIG. 1 was extended to the optical axis direction objective side. It is the front view which looked at the image blurring correction apparatus with which the lens barrel of FIG. 1 was seen from the optical axis direction objective side.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Lens barrel: 2 Cameras: 80 Focus motor: 90 Image blur correction apparatus: 91 Fixed part: 92 Moving part: 94 1st VCM: 95 2nd VCM: 96b Hall element: 97b Hall element: 98 Notch part

Claims (7)

A fixed part;
A movable part movable in a plane perpendicular to the optical axis of the photographing optical system with respect to the fixed part;
A first actuator disposed on a first axis orthogonal to the optical axis, and a second actuator disposed on a second axis orthogonal to the optical axis and intersecting the first axis A driving unit that drives the moving unit with respect to the fixed unit during image blur correction;
A magnetic sensor disposed on the opposite side of the drive unit across the optical axis and detecting displacement of the moving unit relative to the fixed unit during image blur correction;
An image blur correction device comprising: an electromagnetic motor disposition area in which an electromagnetic motor can be disposed, which is provided in an area on the drive unit side in an area sandwiched between the first axis and the second axis. The image blur correction device according to claim 1,
The electromagnetic motor arrangement possible area is a space provided in at least one of the fixed part and the moving part,
The image blur correction device, wherein the space portion can accommodate at least a part of the electromagnetic motor. The image blur correction device according to claim 1 or 2,
Including the electromagnetic motor,
The electromagnetic mirror is provided so as to be relatively movable in the optical axis direction with respect to the image blur correction device, and is disposed in the electromagnetic motor placement area when approaching the image blur correction device. Tube. In the lens barrel according to claim 3,
The lens barrel includes at least one of a motor for driving a focus lens group, a motor for driving a zoom lens group, and a motor for driving a shutter unit. In the lens barrel according to claim 3 or 4,
Comprising a cylinder for housing the image blur correction device;
The optical axis of the photographing optical system is arranged to be biased toward one region side of the cylindrical body,
The region where the electromagnetic motor can be arranged is provided on the other region side of the cylindrical body. An optical apparatus comprising the image blur correction device according to claim 1. An optical apparatus comprising the lens barrel according to any one of claims 3 to 5.

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