JP2007108557A - Lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact lens barrel having good working efficiency where a blur correcting optical system can be movably supported with a small load, dispensing with a tension coil spring. <P>SOLUTION: A leaf spring part 10a formed of a metallic thin plate being a spring member is provided to a cover member 10 so as to support a holding frame 20. Further, an actuator support piece part 10c is provided, and by holding the actuator support piece part 10c between a magnet 11 and a yoke 12, the magnet 11 and the yoke 12 are supported with the cover member 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lens barrel provided with a blur correction optical system for correcting image blur.

In this type of lens barrel, vibration caused by camera shake applied to the camera and the lens barrel is detected, and image blur caused by this vibration is reduced by driving a blur correction optical system.
Many blur correction optical systems are driven to shift in a direction substantially perpendicular to the optical axis of the photographing optical system. The blur correction optical system is desirably capable of moving smoothly and with a light load in a plane perpendicular to the optical axis. For example, in Patent Document 1, a blur correction optical system and its holding frame are formed using a tension coil spring and a ball. The form which supports is shown.

However, when a tension coil spring is used, an opening is required as a spring hook on the base member that is the base of the shake correction unit in order to hook the hook formed at the end of the spring, and this opening is unnecessary. There is a problem that light passes through and causes light leakage. And when it was going to block this opening part, there existed a problem that a new component had to be added.
In addition, since the spring hook is always loaded by the tension coil spring, the area around the spring hook is enlarged to ensure its strength, resulting in an increase in the size of the lens barrel. There was a problem that.
Further, when the tension coil spring is assembled, there is a problem that workability is very poor because the assembly is performed while stretching the spring against the spring force.

On the other hand, in this type of lens barrel, a voice coil motor is often used as an actuator for driving the blur correction optical system. This voice coil motor is provided with a magnet, a coil, a yoke, and the like, and an adhesive is often used for fixing them.
However, if the components of the voice coil motor are fixed using adhesives, there will be a waiting time for adhesive curing during assembly work, and a large amount of units being cured will be stored, resulting in poor workability and production efficiency. There was a problem that became very bad.
Moreover, workability | operativity at the time of repair etc. is bad, and there existed a problem that the reuse of the member once adhere | attached was difficult.
JP-A-6-289453 (FIGS. 7 and 8)

  SUMMARY OF THE INVENTION An object of the present invention is to provide a small lens barrel that supports a blur correction optical system stably and with a light load without using a tension coil spring and has good workability.

In order to solve the above-mentioned problem, the invention of claim 1 is at least a part of a photographing optical system, and is a blur correction optical system that corrects image blur by moving in a direction substantially orthogonal to the optical axis, and A holding frame that holds the shake correction optical system and is movable in a direction substantially orthogonal to the optical axis, a base member that serves as a base for supporting the shake correction optical system and the holding frame, the shake correction optical system, and the A part of the actuator and the holding member are fixed to the base member at a position sandwiching the shake correction optical system and the holding frame between the base member and an actuator that generates a driving force for driving the holding frame. And a lid member formed of a metal plate material that supports at least one of the frames.
According to a second aspect of the present invention, in the lens barrel according to the first aspect, the lid member is formed of a member having a spring property and supports the holding frame in a direction parallel to the optical axis. A lens barrel characterized by having a spring portion.
According to a third aspect of the present invention, in the lens barrel according to the second aspect, the leaf spring portion supports the holding frame via a leaf spring side ball provided between the holding frame and the lens barrel. 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, a base member-side ball is provided between the holding frame and the base member. This is a lens barrel characterized by that.
According to a fifth aspect of the present invention, in the lens barrel according to the first aspect, the actuator is a voice coil motor including a magnet, a coil, and a yoke, and the lid member is connected to the magnet and the yoke. The lens barrel includes an actuator support piece for supporting a part of the voice coil motor by being sandwiched.
According to a sixth aspect of the present invention, in the lens barrel according to the fifth aspect, the lid member has a through hole into which a part of the magnet can be inserted, and the actuator support piece is a part of the through hole. The lens barrel is characterized in that it is a portion protruding from the portion.
A seventh aspect of the present invention is the lens barrel according to the sixth aspect, wherein the yoke has a half-cut portion having a size substantially equal to a plate thickness of the lid member at a position corresponding to the actuator support piece portion. This is a lens barrel characterized by the following.

  According to the present invention, since the lid member formed of a metal plate material that supports at least one of the actuator and the holding frame is used, the blur correction optical system can be used without using a tension coil spring. A small lens barrel that can be stably moved with a light load and can be moved and has good workability.

  The object of the present invention is to provide a small lens barrel that supports a shake correction optical system stably and with a light load, without using a tension coil spring, and has good workability. This is realized by forming a lid member with a plate material and providing a leaf spring portion and an actuator support piece portion on the lid member.

FIG. 1 is a diagram showing an embodiment of a camera including a lens barrel according to the present invention.
The camera 1 is a digital still camera that has a lens barrel 2 and images the image light that has passed through the lens barrel 2 on an image pickup device 3 for imaging. In the present embodiment, the lens barrel 2 is built in the camera 1 and described with reference to an example in which the lens cannot be replaced. However, a lens barrel used in a camera system in which the lens can be replaced may be used.
The lens barrel 2 has a photographing optical system composed of lens groups L1, L2, and L3. Among these, the lens group L2 is provided in the shake correction unit 100, and is moved to correct image blur on the image pickup device 3 by shifting in a direction orthogonal to the optical axis I. It is a system.

FIG. 2 is an exploded perspective view showing main members of the blur correction unit 100 from the image sensor side.
FIG. 3 is an exploded perspective view showing main members of the shake correction unit 100 from the subject side.
1 to 3 show common XYZ coordinate axes for the sake of explanation.
The shake correction unit 100 includes a lid member 10, a holding frame 20, and a base member 30 from the subject side.
The holding frame 20 holds the lens group L2, and is provided with a coil 21 and a flexible printed wiring board 22. Two coils 21 for driving in the X direction and for driving in the Y direction are fixed to the coil 21 so that the holding frame 20 can be driven in an arbitrary direction within a plane orthogonal to the optical axis (in the XY plane). . The flexible printed wiring board 22 supplies power to the X-direction driving coil 21 and the Y-direction driving coil 21 so as to surround the lens group L2.
Further, the flexible printed wiring board 22 is arranged in a direction in which a virtual line connecting the external connection end 22a and the coil connection end 22b forms an angle of about 45 degrees with the X axis and the Y axis. By arranging the flexible printed wiring board 22 in this way, it is possible to prevent the rigidity of the flexible printed wiring board 22 from being an excessive load with respect to the movement of the holding frame 20 within the movable range of the holding frame 20.

The base member 30 is a member serving as a base of the shake correction unit 100, and the holding frame 20 and the lid member 10 are attached to the base member 30.
A yoke 31 is fixed to the base member 30 at positions corresponding to the two coils 21 for driving in the X direction and driving in the Y direction. A cam pin 30a that engages with a cam groove provided in a cam cylinder (not shown) is fixed to the base member 30, and the shake correction unit moves in the optical axis I direction by the rotation of the cam cylinder.
In addition, the base member 30 is formed with two engaging convex portions 30b with which a hook portion 10b of the lid member 10 described later is engaged.

The lid member 10 is a member that is fixed to the base member 30 so as to sandwich the holding frame 20 with the base member 30 and is formed of a metal plate material having spring properties. Specifically, the lid member 10 is formed of a phosphor bronze thin plate having a thickness of 0.25 mm. In addition, the material of the lid member is not limited to this, and other copper-based materials, steel materials such as stainless steel may be used, and the thickness is appropriately changed to adjust the biasing force of the leaf spring portion 10a described later. Good.
The lid member 10 has two hook portions 10b. The hook portions 10b engage with the engaging convex portions 30b and are fixed to the base member 30 using screws 50.
On the base member 30 side of the lid member 10, there is provided a leaf spring portion 10 a that is formed by folding back a portion that protrudes in a substantially rectangular arm shape in the outer circumferential direction of the lid member 10. The leaf spring portion 10 a has a role of supporting the holding frame 20 in a direction parallel to the optical axis I via the ball 40. The ball 40 includes a leaf spring side ball provided between the leaf spring portion 10a and the holding frame 20, and a base member side ball provided between the holding frame 20 and the base member 30. Two spring side balls and three base member side balls are provided.

FIG. 4 is a diagram showing the main part of the shake correction unit 100 of the present embodiment in comparison with the shake correction unit 1000 of the comparative example. FIG. 4A shows a shake correction unit 1000 of a comparative example, and FIG. 4B shows a shake correction unit 100 of the present embodiment.
In the comparative example shown in FIG. 4A, the holding frame 1020 is supported on the base member 1030 via the balls 1040 by hooking the tension coil spring 1060 between the holding frame 1020 and the base member 1030. Yes.
However, when the tension coil spring is used in this way, as described above, light leakage from the opening 1030a provided as a spring hook on the base member 1030, enlargement of the periphery of the spring hook, and assembly There was a problem that workability at the time was very bad.
In addition, the tension coil spring 1060 needs to have an appropriate length in order to obtain a necessary urging force. Therefore, it is necessary to increase the distance between the spring hook of the holding frame 1020 and the spring hook of the base member 1030. There was a problem that it would increase in size.

On the other hand, in the shake correction unit 100 of the present embodiment, since the lid member 10 is formed of a thin plate, the size can be reduced accordingly.
Further, since the holding frame 20 is supported by pressing against the base member 30 by the urging force of the leaf spring portion 10a, the above-described problems due to the use of the tension coil spring 1060 do not occur, and the assembly is easier. Miniaturization can be achieved.

The lid member 10 includes an actuator support piece 10c that supports a part of a voice coil motor that is an actuator that drives the holding frame 20 by being sandwiched between the magnet 11 and the yoke 12.
FIG. 5 is a view of the vicinity of the actuator support piece 10c of the lid member 10 and the yoke 12 as viewed from the subject side (Z plus side). FIG. 5A shows only the lid member 10, FIG. 5B shows only the yoke 12, and FIG. 5C shows a state where the yoke 12 is assembled to the lid member 10.
FIG. 6 is a cross-sectional view of the vicinity of the voice coil motor.
The lid member 10 of the present embodiment is provided with a substantially square through hole 10d into which a part of the magnet 11 can be inserted, and the actuator support piece protrudes into a part of the through hole 10d to form four corners. Is provided. The yoke 12 has a semi-cut portion 12a that is semi-cut by a dimension substantially equal to the plate thickness (0.25 mm) of the lid member 10 at a position corresponding to the actuator support piece 10c. The half-cut portion 12a can be easily formed by pressing, but a step having a dimension substantially equal to the plate thickness of the lid member 10 may be formed on the yoke 12 by cutting.

  Even if the lid member 10 is sandwiched between the yoke 12 and the magnet 11, the yoke 12 and the magnet 11 are provided by providing the yoke 12 with the half-cut portion 12a and sandwiching the actuator support piece 10c between the magnet 11 at this position. And can be in close contact. Therefore, the magnet 11 and the yoke 12 can be supported by the lid member 10 only by the attractive force due to the magnetic force of the magnet 11.

In the case of the comparative example shown in FIG. 4A, the support of the magnet and the yoke was performed by adhesion, so that the workability at the time of repair was bad, but in this embodiment, the rework such as repair was performed. Even when performing, the workability is good and the parts can be reused.
In the present embodiment, a standing bent portion 10e is provided in a portion where the through hole 10d is formed. Although the standing bent portion 10e of the present embodiment is bent at approximately 90 degrees, this portion is formed so as to be slightly tilted to the inside of the through hole 10d, and the bent portions 10e are formed at intervals narrower than the width of the magnet 11. It may be present. By doing in this way, the clearance gap between the cover member 10 and the magnet 11 can be eliminated using the spring biasing force of the standing bent part 10e, and the magnet 11 and the yoke 12 can be supported without play. At this time, a bent portion may be further provided at the tip of the standing bent portion 10e so that the magnet 11 can be easily inserted.

  According to the present embodiment, it is possible to provide a small lens barrel that can stably support the blur correction optical system in a light load without using a tension coil spring. Further, since no adhesion is used, a lens barrel having good workability can be obtained both during assembly and during repair.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the equivalent scope of the present invention.
For example, in the present embodiment, the cover member 10 has shown an example in which the holding frame 20 and the voice coil motor are supported. However, the present invention is not limited to this, and only one of them is supported. May be.

  In the present embodiment, the lens barrel of the digital still camera has been described as an example. However, the present invention is not limited to this. For example, a video camera mainly used for moving image shooting may be used. The camera may be capable of any shooting.

It is a figure which shows the Example of the camera containing the lens-barrel by this invention. FIG. 2 is an exploded perspective view showing main members of the shake correction unit 100 from the image sensor side. FIG. 3 is an exploded perspective view showing main members of the shake correction unit 100 from the subject side. It is the figure which showed the main part of the blurring correction unit 100 of a present Example compared with the blurring correction unit 1000 of a comparative example. It is the figure which looked at the actuator support piece part 10c vicinity of the cover member 10, and the yoke 12 from the to-be-photographed object side (Z plus side). It is sectional drawing of a voice coil motor vicinity.

Explanation of symbols

10: lid member, 10a: leaf spring, 11: magnet, 12: yoke, 20: holding frame, 30: base member, 40: ball

Claims (7)

A blur correction optical system that corrects image blur by moving in a direction substantially orthogonal to the optical axis, at least part of the photographing optical system;
A holding frame that holds the blur correction optical system and is movable in a direction substantially perpendicular to the optical axis;
A base member serving as a base for supporting the blur correction optical system and the holding frame;
An actuator for generating a driving force for driving the blur correction optical system and the holding frame;
A metal member that is fixed to the base member at a position between the base member and the shake correction optical system and the holding frame, and that supports at least one of a part of the actuator and the holding frame. A lid member formed of a plate material;
Lens barrel with The lens barrel according to claim 1,
The lid member is formed of a springy member,
Having a leaf spring portion for supporting the holding frame in a direction parallel to the optical axis;
A lens barrel characterized by The lens barrel according to claim 2,
The leaf spring part supports the holding frame via a leaf spring side ball provided between the holding frame and the holding frame;
A lens barrel characterized by The lens barrel according to any one of claims 1 to 3, wherein
A base member side ball is provided between the holding frame and the base member;
A lens barrel characterized by The lens barrel according to claim 1,
The actuator is a voice coil motor including a magnet, a coil, and a yoke,
The lid member has an actuator support piece for supporting a part of the voice coil motor by being sandwiched between the magnet and the yoke;
A lens barrel characterized by In the lens barrel according to claim 5,
The lid member has a through hole into which a part of the magnet can be inserted,
The actuator support piece is a portion protruding into a part of the through hole;
A lens barrel characterized by The lens barrel according to claim 6, wherein
The yoke has a half-cut portion whose position corresponding to the actuator support piece is approximately equal to the plate thickness of the lid member;
A lens barrel characterized by

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