JP4835095B2 - Lens barrel - Google Patents

Description

  The present invention relates to a lens barrel that houses a photographing lens group of a camera.

A so-called collapsible lens barrel is known in which the camera lens barrel is shortened in the optical axis direction and stored in the camera body when not in use.
In such a retractable lens barrel, in order to further reduce the total length during storage, a part of the plurality of lens groups is rotated around a rotation axis fixed to the lens barrel to thereby rotate the optical axis. There is known one in which another lens group is accommodated in a space portion formed by retreating in a direction orthogonal to (for example, Patent Document 1).

  A camera lens barrel having an optical shake correction device is known. The shake correction device detects vibration applied to the optical system by an angular velocity sensor or the like, and in response to the vibration, some lens groups (blur correction lens groups) are within a plane orthogonal to the optical axis. By driving, image blur on the imaging plane is reduced.

Even if the lens barrel is provided with such a blur correction device, as described above, it is desired to retract a part of the lens group from the optical axis at the time of shooting and store it in a compact manner. .
However, depending on the lens group configuration, it may be necessary to retract the image stabilization lens group in order to store the lens barrel compactly. In this case, the image stabilization lens group is used during image stabilization control during shooting. It is necessary to perform both the shift displacement and the retracting operation when the lens barrel is accommodated, and the support mechanism becomes complicated.
JP 2003-315861 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a lens barrel in which a shake correction optical system can be retracted from the optical axis of another optical system with a simple configuration and can be accommodated in a compact manner.

The present invention solves the above problems by the following means.
The invention of claim 1, motion compensation optical supported a driven member driven by the optical axis substantially perpendicular to a plane, the relative movement can and the driven member against the driven member in response to vibration In a lens barrel having a system and a normal optical system arranged in the optical axis direction with respect to the shake correction optical system in use, the shake correction optical system moves relative to the driven member. Thus, the use position that enters the optical axis of the normal optical system and is movable in a plane that is integrated with the driven member and substantially perpendicular to the optical axis, and the light of the normal optical system when not in use. A lens barrel that moves between a retracted position retracted from an axis.

According to a second aspect of the present invention, in the lens barrel according to the first aspect, at least a part of the normal optical system is in the optical axis direction of the normal optical system with respect to the blur correction optical system at the retracted position. The lens barrel is housed in a state where the positions overlap each other.
According to a third aspect of the present invention, in the lens barrel according to the first or second aspect, the blur correction optical system is rotatably supported around a rotation axis provided in the driven member. This is a featured lens barrel.
According to a fourth aspect of the present invention, in the lens barrel according to any one of the first to third aspects, the driven lens is moved when the blur correction optical system moves from the use position to the retracted position. A lens barrel comprising a guide portion that moves a member in a plane substantially orthogonal to the optical axis of the blur correction optical system and guides the member to a predetermined storage position.
According to a fifth aspect of the present invention, in the lens barrel according to the fourth aspect of the invention, the guide portion is configured to move with respect to the driven member when the blur correction optical system moves from the use position to the retracted position. The lens barrel includes a slope portion that is fixed to a relative movement member that relatively moves in a direction close to the optical axis direction and guides the driven member in conjunction with the relative movement.

According to the present invention, the following effects can be obtained.
(1) The shake correction optical system is supported so as to be relatively movable with respect to a driven member driven in accordance with vibration, and the shake correction optical system is retracted from the optical axis of the normal optical system by this relative movement. Thus, the mechanism that supports the shake correction optical system so as to be retractable by driving the driven member is not affected, and the structure can be simplified.
(2) Since the driven member is guided to a predetermined position when the blur correction optical system moves to the retracted position, rattling of the driven member when the lens barrel is stored is prevented. In addition, when the movement of the blur correction optical system is performed by a known cam mechanism or the like, the operation can be ensured.
(3) The guide portion has a slope portion fixed to the relative movement member that moves relative to the driven member in the optical axis direction, thereby guiding the driven member with a simple configuration. be able to.

  An object of the present invention is to provide a lens barrel that can retract a shake correction optical system from the optical axis of another optical system with a simple configuration and can be accommodated in a compact manner. This is realized by pivotally supporting the blur correction lens group with respect to the frame and retracting the blur correction lens group from the optical axis of the other lens groups by this rotation.

Embodiments of a lens barrel to which the present invention is applied will be described below. The lens barrel of this embodiment is used as, for example, a photographing lens barrel of a digital still camera.
FIG. 1 is a cross-sectional view showing a shooting state (use state) on the wide end side of the lens barrel of the present embodiment. FIG. 2 is a cross-sectional view showing a photographing state at the tele end of the lens barrel. FIG. 3 is a view taken along the line III-III in FIG.

The lens barrel includes, for example, a multi-group zoom lens having a four-group configuration as a photographing lens group. The photographing lens group includes a first lens group L1 in order from the optical axis I direction image side in a photographing state. A second lens group L2, an image stabilization lens group (third lens group) L3, and a fourth lens group L4 are provided.
The first lens group L1 and the second lens group L2 are zooming lens groups that change the focal length of the photographing lens group by moving in the direction of the optical axis I, and each has a first annular lens frame. The lens group chamber 10 and the second lens group chamber 20 are fixed.
Note that the blur correction lens unit L3 and the fourth lens unit L4 also function as zoom lens lenses and move in the optical axis I direction.

The blur correction lens unit L3 reduces image blur on the imaging surface by displacing in a plane substantially orthogonal to the optical axis I in response to vibration applied to the lens barrel, and is an annular lens frame. The shake correction lens group chamber 30 is fixed to a vibration frame 210 of a shake correction unit 200 described later.
Here, the lens groups L1, L2, and L4 other than the blur correction lens group L3 are normal optical systems that do not perform such displacement.

The fourth lens group L4 is a focusing lens group that changes the photographing distance of the photographing lens group by movement in the optical axis I direction, and is fixed to a fourth lens group chamber 40 having an annular lens frame. Yes.
The fourth lens group chamber 40 is driven in the direction of the optical axis I by known AF control using a focusing mechanism (not shown).

The lens barrel includes a shutter unit 50, a CCD 60, and a low-pass filter (LPF) 70.
The shutter unit 50 is provided on the incident side of the vibration reduction lens group L3, and includes a shutter portion formed of a plurality of plastic thin pieces, and adjusts the exposure amount to the CCD 60.
The CCD 60 is a solid-state imaging device that converts an image formed by the photographing lens group into an electrical signal and outputs the electrical signal, and is provided on the exit side of the fourth lens group L4.
The LPF 70 is an optical type provided to prevent the occurrence of moire on the captured image, and is disposed between the fourth lens group L4 and the CCD 60.

  Further, the lens barrel includes a first lens group cylinder 110, a second lens group holding frame 120, a shake correction lens group holding frame 130, a fixed cylinder 150, a first cam cylinder 160, a second cam cylinder 170, a rectilinear key 180, A CCD base 190 is provided.

  The first lens group cylinder 110 is formed in a substantially cylindrical shape, and the first lens group chamber 10 is fixed to the inner diameter side thereof. The first lens group cylinder 110 is inserted on the inner diameter side of the second cam cylinder 170, and a cam mechanism formed between the first cam cylinder 170 and the second cam cylinder 170 is provided between the shooting state and the storage state of the lens barrel. It can be moved in the direction of the optical axis I at the time of transition and when the focal length is changed. As shown in FIGS. 1 and 2, it forms the tip of the lens barrel on the objective side in the photographing state.

The first lens group tube 110 includes a guide member 111 and a lens barrier unit 112.
The guide member 111 is a guide unit that guides a vibration frame 210 of the shake correction unit 200 described later, and light from an outer diameter side region of the first lens unit L1 on the objective-side end surface of the first lens unit tube 110. It is formed so as to protrude toward the image side in the axis I direction, and is formed in a tapered shape so that it gradually becomes narrower as it approaches the tip side (image side in the optical axis I direction). The guide operation by the guide member 111 will be described later.

The lens barrier unit 112 is provided on the objective side of the first lens group L1, and protects the incident-side surface portion of the first lens group L1 when the lens barrel is housed, and includes a barrier 113, a barrier drive ring 114, A barrier receiving plate 115 and a barrier cover 116 are provided.
The lens barrier unit 112 is fixed to the end of the first lens group cylinder 110 on the objective side.

The second lens group holding frame 120 is a frame mounted on the outer diameter side of the second lens group chamber 20, and is inserted on the inner diameter side of the first lens group cylinder 110, and between the first cam cylinder 160. Can be moved in the direction of the optical axis I independently of the first lens group tube 110 when the lens barrel is shifted between the photographing state and the housed state and when the focal length is changed. It has become.
Here, the second lens group chamber 20 has a flange portion formed so as to protrude in a collar shape on the outer peripheral surface portion, and the flange portion is fastened to the second lens group holding frame 120 by a nut 21. An adjustment washer 22 for finely adjusting the position of the second lens unit L2 is provided on the surface of the flange portion opposite to the nut 21.

  The blur correction lens group holding frame 130 is a frame body that holds the blur correction unit 200 including the blur correction lens group L3 and the blur correction lens group chamber 30, and is inserted on the inner diameter side of the first lens group cylinder 110. A cam mechanism formed between the cam barrel 160 and the cam barrel 160 is movable in the direction of the optical axis I at the time of transition between the photographing state and the retracted state of the lens barrel.

The fixed barrel 150 is a base portion of a lens barrel that is fixed to the body side of a camera (not shown), is formed in a substantially cylindrical shape, and is disposed on the outermost diameter side of the lens barrel.
The first cam cylinder 160 and the second cam cylinder 170 are each formed in a cylindrical shape, and can be rotated around the optical axis I with respect to the fixed cylinder 150 by an interlocking mechanism (not shown).
The first cam cylinder 160 is inserted on the inner diameter side of the fixed cylinder 150, a cam follower is formed on the outer peripheral surface portion thereof and inserted into a cam groove formed on the inner peripheral surface of the fixed cylinder 150, and the second lens is formed on the inner peripheral surface portion. Cam grooves into which cam followers respectively formed on the group holding frame 120 and the shake correction lens group holding frame 130 are inserted are formed.
The second cam cylinder 170 is further inserted on the inner diameter side of the first cam cylinder 160, and the first lens group cylinder 110 is inserted on the inner diameter side thereof. The second cam cylinder 170 is formed with a cam groove on the inner peripheral surface thereof into which a cam follower formed on the outer diameter side of the first lens group cylinder 110 is inserted.

The rectilinear key 180 moves the first lens group cylinder 110, the second lens group holding frame 120, and the shake correction lens group holding frame 130 relative to the fixed cylinder 150 regardless of the rotation of the first cam cylinder 160 and the second cam cylinder 170. Thus, it is guided straight in the direction of the optical axis I.
The CCD table 190 is a surface portion that is fixed to the end of the fixed cylinder 150 on the image side in the optical axis I direction and closes the opening end, and to which the CCD 60 and the LPF 70 are fixed.

  The shake correction unit 200 includes a vibration frame 210, a voice coil motor (VCM) 220, a position detector 230, a shake correction unit cover 240, and a flexible printed circuit board (FPC) 250.

The vibration frame 210 is provided on a surface portion of the image stabilization lens group holding frame 130 on the image side in the optical axis I direction, and is supported by the image stabilization lens group holding frame 130 so as to be movable in a plane perpendicular to the optical axis I. Has been. The vibration frame 210 is a driven member that is driven in a plane orthogonal to the optical axis I by known blur correction control.
The vibration frame 210 is formed by recessing the outer peripheral edge thereof, and is provided with a recess 210a into which the above-described guide member 111 is inserted.
Further, the vibration frame 210 includes a rotation shaft 211, a spring 212, and a rotation stopper 213.
The rotation shaft 211 is a pin-shaped portion that protrudes from the surface of the vibration frame 210 on the image side in the optical axis I direction, and is an arm portion 31 that protrudes to the outer diameter side of the shake correction lens group chamber 30. The tip of the shaft is rotatably supported. The central axis of the rotation axis 211 is disposed substantially parallel to the optical axis I. The rotating shaft 211 is disposed obliquely above the optical axis I during normal shooting.
In this specification, the term “normal photographing” refers to a state in which photographing is performed with the optical axis I and the long side direction of the screen being substantially horizontal.

The spring 212 is provided at a connection portion between the rotation shaft 211 and the shake correction lens group chamber 30, and the shake correction lens group chamber 30 is placed in a predetermined direction around the rotation axis 211 with respect to the vibration frame 210 (in this embodiment). Is urged to rotate clockwise as viewed from the image side in the optical axis I direction.
The rotation stopper 213 is a convex portion that is formed to protrude from the surface of the vibration frame 210, is on the outer diameter side of the shake correction lens group chamber 30, and is disposed substantially symmetrically with respect to the optical axis. By abutting against the protruding portion 32, the rotation of the blur correction lens group chamber 30 due to the biasing force of the spring 212 is restricted.

  In addition, the blur correction lens group chamber 30 is provided with a cam surface portion 34 formed around the rotation shaft 211 at a connection portion with the rotation shaft 211. The cam surface portion 34 has a height along the longitudinal direction of the rotation shaft 211 that continuously changes in accordance with an angle around the rotation shaft 211, and the blur correction lens group chamber 30 includes a lens barrel. When the camera is shifted from the photographing state to the housed state, the cam surface 34 is pressed by the pin 33 fixed to the CCD base 190 so as to rotate around the rotation shaft 211.

The VCM 220 is an actuator that drives the vibration frame 210 in a direction orthogonal to the optical axis I in response to a control signal from a blur correction control unit (not shown). As shown in FIGS. 1 and 2, the coil 221 and the magnet 222 are used. , Yokes 223 and 224 are provided.
The coil 221 is fixed to the vibration frame 210.
The magnet 222 is a permanent magnet that is fixed to the shake correction lens group holding frame 130 and arranged to face the coil 221.
The yoke 223 is fixed to the surface of the magnet 222 opposite to the coil 221.
The yoke 224 is disposed on the optical axis I direction image side of the vibration frame 210 and is fixed to the shake correction unit cover 240 fixed to the shake correction lens group holding frame 130, and is opposite to the magnet 222 side of the coil 221. It is arrange | positioned facing the surface part.

In the present embodiment, the shake correction unit 200 performs shake correction corresponding to the pitching and yawing of the lens barrel, and the VCM 220 is provided to drive the vibration frame for pitching and yawing.
As shown in FIG. 3, the VCM 220P is disposed below the optical axis I during normal photographing. In addition, the VCM 220Y is disposed on the side of the optical axis I during normal photographing and at a position 90 ° apart from the VCM 220P at an angle around the optical axis I.

The position detector 230 includes a Hall element fixed to the vibration frame 210 and a magnet fixed to the shake correction lens group holding frame 130, and is caused by displacement of the vibration frame 210 with respect to the shake correction lens group holding frame 130. The position of the vibration frame 210 with respect to the shake correction lens group holding frame 130 is detected based on the change in the strength of the magnetic field detected by the Hall element.
The position detector 230P is arranged in the upper region of the VCM 220Y during normal shooting.
The position detector 230Y is disposed in a region opposite to the VCM 220Y with the optical axis I interposed therebetween.

  The FPC 250 is formed between the fixed cylinder 150 and the vibration frame 210 and supplies power to the coil 221 of the VCM 220 and transmits an output signal of the Hall element of the position detector 230.

Next, the operation when the lens barrel of the present embodiment shifts from the photographing state to the housed state will be described.
FIG. 3 is a cross-sectional view showing a state in which the lens barrel is in the transition from the photographing state to the housed state.
First, the lens barrel rotates the first cam cylinder 160 and the second cam cylinder 170 to move the first lens group cylinder 110 and the second lens group holding frame 120 to the optical axis I direction image side.
In conjunction with the movement of the first lens group cylinder 110, the guide member 111 fixed to the first lens group cylinder 110 has a minimum distance between the first lens group L1 and the third lens group L3 in the photographing state. Is inserted into a recess 210a formed in the vibration frame 210 of the shake correction unit 200.

  As described above, the guide member 111 is formed in a tapered shape that gradually increases in thickness from the tip end (optical axis I direction image side) to the base side (first lens group cylinder 110 side), and the surface portion thereof is the optical axis I. Since the insertion depth of the guide member 111 is increased, the vibration frame 210 is orthogonal to the optical axis I by sliding the inner surface of the recess 210a and the guide member 111. Finally, the optical axis of the vibration reduction lens group L3 is constrained to be in a state (centered state) substantially coincident with the optical axes of the other lens groups (FIG. 4).

  After the vibration reduction lens group L3 is constrained to the centered state as described above, the vibration reduction lens group holding frame 130 is moved to the image side in the optical axis I direction by further rotating the first cam cylinder 160. Start moving. By this movement, the pin 33 fixed to the CCD base 190 presses the cam surface portion 34 of the shake correction lens group chamber 30.

FIG. 5 is a cross-sectional view showing a stored state of the lens barrel. FIG. 6 is a cross-sectional view of the lens barrel in the housed state as cut along a plane including the optical axis.
As shown in FIG. 5, the shake correction lens group L3 is retracted from the optical axis I of the other lens groups when the cam surface portion 34 of the shake correction lens group chamber 30 is pressed.
The lens barrel moves the first lens group cylinder 110, the second lens group holding frame 120, and the blur correction lens group holding frame 130 further to the optical axis I direction image side after the end of the retraction of the blur correction lens group L3. As shown in FIG. 6, the fourth lens unit L4 and the blur correction lens unit L3 retracted from the optical axis I overlap with each other in the optical axis I direction.

As described above, according to this embodiment, the following effects can be obtained.
(1) Since the rotation shaft 211 is fixed to the vibration frame 210 driven by the shake correction control, the shake correction lens group L3 is rotated around the rotation axis 211 and retracted from the optical axis I. Driving the vibration frame 210 does not affect the mechanism for retracting the blur correction lens group L3. For example, the structure is simpler than when the retract mechanism for the blur correction lens group is fixed to the lens barrel. be able to.
(2) When the lens barrel shifts from the use state to the retracted state, the tapered guide member 111 fixed to the first lens group tube 110 is inserted into the recess 210a of the vibration frame 210 for centering. Therefore, the vibration of the vibration frame 210 can be prevented from being shaken with a simple configuration, and the operation of the cam mechanism for rotating and retracting the third lens group chamber 30 can be ensured.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes can be made, and these are also within the equivalent scope of the present invention.
(1) The mechanism for retracting the blur correction optical system from the optical axis of the normal optical system is not limited to the configuration of the above-described embodiment, and may have other configurations. For example, when the blur correction optical system is rotated around the rotation axis and retracted, the rotation axis may be arranged to be inclined with respect to the optical axis. Moreover, it is not restricted to what is rotated and retracted, For example, you may make it retract by parallel movement etc.
(2) The configuration of the guide portion that guides the driven member such as the vibration frame is not limited to the above-described embodiment, and may be another configuration. For example, the guide portion may be provided on a member provided on the image side of the blur correction optical system.
(3) In the embodiment, for example, the third group of the zoom lens having a four-group configuration is a blur correction optical system, but the group configuration of the lens group and the arrangement of the blur correction optical system can be changed as appropriate. .
(4) The embodiment relates to a photographing lens barrel of a digital still camera, for example. However, the present invention is not limited to this, and a photographing lens barrel such as a movie camera or a film camera, or an optical device other than a camera. It may be provided in a device.

It is sectional drawing which shows the imaging | photography state in the wide end side of the Example of the lens-barrel to which this invention is applied. It is sectional drawing which shows the imaging | photography state in the tele side of the lens barrel of FIG. It is the III-III part arrow directional view of FIG. FIG. 2 is a cross-sectional view showing a state in which the lens barrel in FIG. FIG. 2 is a transverse cross-sectional view showing a storage state of the lens barrel of FIG. It is sectional drawing which shows the accommodation state of the lens-barrel of FIG.

Explanation of symbols

L1 first lens group, L2 second lens group, L3 lens group (third) lens group, L4 fourth lens group,
10 First lens group chamber, 20 Second lens group chamber, 30 Shake correction lens group chamber, 40 Fourth lens group chamber 50 Shutter unit, 60 CCD, 70 LPF
110 First lens group cylinder, 111 guide member, 130 shake correction lens group holding frame 200 shake correction unit, 210 vibration frame, 211 rotating shaft, 212 spring, 213 rotation stop

Claims (5)

A driven member driven in a plane substantially orthogonal to the optical axis in response to vibration;
A blur correction optical system in which the supported on relatively movable and said driven member against the driven member,
In a lens barrel comprising a normal optical system arranged in the optical axis direction with respect to the blur correction optical system in use,
The blur correction optical system moves relative to the driven member so that it enters the optical axis of the normal optical system and is integrated with the driven member in a plane substantially orthogonal to the optical axis. A lens barrel, wherein the lens barrel moves between a use position that can be moved at a retracted position and a retracted position that is retracted from the optical axis of the normal optical system when not in use. The lens barrel according to claim 1,
At least a part of the normal optical system is accommodated in a state where the position of the normal optical system in the optical axis direction overlaps the blur correction optical system at the retracted position. In the lens barrel according to claim 1 or 2,
The lens barrel, wherein the blur correction optical system is rotatably supported around a rotation axis provided in the driven member. The lens barrel according to any one of claims 1 to 3, wherein
When the blur correction optical system moves from the use position to the retracted position, the driven member is moved in a plane substantially perpendicular to the optical axis of the blur correction optical system and guided to a predetermined storage position. A lens barrel comprising a guide portion. The lens barrel according to claim 4,
The guide portion is fixed to a relative movement member that moves relative to the driven member in the direction along the optical axis direction when the blur correction optical system moves from the use position to the retracted position. And a slope portion for guiding the driven member in conjunction with the relative movement.

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