JP2001013393A - Lens barrel for optical equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily drive a lens barrel driving plural moving barrels without making it larger in a radial direction. SOLUTION: The screw part 2d of a 1st feed screw 2 supported in parallel with an optical axis so as to rotate through a gear part 2a by a driving source in a camera main body 1 is screwed in a flange 6 fixed on the 1st moving barrel 5, and the two-way parts 2b and 2c of the screw part 2d are fit to slide in an axial direction in the square fitting hole 7a of a 2nd feed screw 7 rotatably supported in parallel with the optical axis by the flange 6, whereby the screw 7 is interlocked with the screw 2 in a rotating direction at the time of assembly, and supported movably in the optical axis direction. Then, the screw part 7f of the screw 7 is screwed in a flange 11 fixed on the 2nd moving barrel 9 and the tip part of the screw 7 turns an interlocking member 15 so as to close a barrier 13 by a driving member 14 at the time of callapsing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel structure of an optical instrument.

[0002]

2. Description of the Related Art Conventionally, there has been known a compact camera having a so-called zoom lens having at least two lens groups and varying a photographing magnification by changing a position in an optical axis direction. The lens barrel structure of such a zoom compact camera includes the following. 1. A mechanism for controlling the feed of the photographing lens group to a predetermined position in the optical axis direction by driving a cam pin provided on a holding member for holding the lens group by a combination of a known cam cylinder having a cam groove and a linear guide cylinder. It is. (Conventional example 1) 2. A lens barrel driving mechanism (conventionally known) that drives a movable cylinder that holds a taking lens and has a substantially square cross section orthogonal to the optical axis along the optical axis direction by, for example, a lever having a link mechanism, and determines the position of the taking lens group in the optical axis direction. Example 2) and JP-A-8-157
As described in Japanese Patent No. 43, zooming is performed by moving the entire barrel along the optical axis with a screw and changing the air gap between the two lens groups by a known differential cam mechanism arranged inside the barrel. (Conventional example 3). Separately, as described in Japanese Patent Application Laid-Open No. 7-28113, a moving cylinder holding a lens with a single focal length that does not perform a zooming operation is screwed into a nut having a female screw fixed outside thereof. There is a lens barrel driving mechanism (conventional example 4) that is driven along the optical axis by a mating screw rod to perform a focusing operation of a photographing lens.

[0003]

However, the aforementioned conventional lens barrel structure has the following problems. In the lens barrel structure in which the cross section orthogonal to the optical axis is cylindrical as in the above-described conventional example 1, the cross section orthogonal to the optical axis is circular, so that a film storage room or a film winding room located on the left and right of the camera can be used. Dead space occurs between the two.
This is because, when the film storage room and the film winding room are viewed from the front, they are substantially vertically elongated rectangles, and four gaps are formed between the lens housing and the lens barrel in the upper, lower, left and right corners. Further, as described above, since the optical component is moved back and forth by the combination of the cam cylinder and the straight guide cylinder, one set of two components is required in the radial direction. For this reason, the so-called multi-stage collapsible camera employed in recent high-magnification zoom cameras has a problem that its radial direction becomes large.

In the technique of driving a movable cylinder having a substantially quadrangular section perpendicular to the optical axis by a lever or the like having a link mechanism as in the above-described conventional example 2, at least two or more groups of optical components are simultaneously fed to a predetermined position. Therefore, there is a possibility that the link mechanism becomes complicated or that the optical component cannot be positioned at a required position. On the other hand, the mechanism shown in Conventional Example 3 requires the cam cylinder and the straight guide cylinder mechanism as described above, and is not suitable for reducing the size of the camera. Then, there is a problem that the mechanism as in the above-described conventional example 4 cannot be applied to a zoom lens barrel.

SUMMARY OF THE INVENTION It is a first object of the present invention to provide a lens barrel of an optical apparatus having a mechanism for feeding an optical component with a simple mechanism without increasing the size in the radial direction. And A second object of the present invention is to provide a lens barrel of an optical apparatus that can protect a front surface of a photographing lens, that is, can form a so-called barrier mechanism at low cost.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a first moving cylinder which moves back and forth by a first feed screw rotatably supported, and a rotatable rotation of the first moving cylinder. A second feed screw supported and rotated by the first feed screw is coaxially fitted, a second feed screw is used to move the second moving cylinder back and forth, and a barrier mechanism is operated by the second feed screw when retracted. It is to let.

[0007]

1 is a perspective view of a lens barrel of an optical apparatus according to a first embodiment of the present invention; FIG. A first moving cylinder screwed with the first moving cylinder in the optical axis direction, and a second feed screw rotatably held by the first moving cylinder and rotated by receiving a rotational force of the first feed screw A second screw that is screwed with the second feed screw and moves in the optical axis direction with respect to the first moving cylinder;
The moving barrel with a circular cross section orthogonal to the optical axis makes it possible to realize a multi-stage collapsible barrel without increasing the size of the moving barrel. A retractable lens barrel can be realized. According to the present invention as set forth in claim 2, the first feed screw has a part in which a screw is not formed in a part thereof.
The present invention described in claim 4 is characterized in that the second feed screw is configured such that the rotational force is transmitted by an unthreaded portion of the first feed screw. Since the screwless portion of the feed screw has a two-way shape, the rotation interlock of the first feed screw and the second feed screw can be facilitated.

[0008] The present invention as set forth in claim 5 is characterized in that the fixed first
A second feed screw that is screwed with the first feed screw and that moves back and forth along the optical axis while rotating by receiving a driving force from a driving source; and rotating the second feed screw. A first moving cylinder which is held as possible and integrally moves back and forth along the optical axis, and which is screwed to the second feed screw and moves back and forth along the optical axis with respect to the first moving cylinder; And a second movable cylinder having a circular cross section orthogonal to the optical axis can realize a multi-stage retractable lens barrel without increasing the size of the movable cylinder. An excellent multi-stage retractable lens barrel can be realized.

According to a sixth aspect of the present invention, in the second feed screw, a cam groove for driving the optical member along the optical axis coexists with the screw, so that the movable cylinder is driven and photographed. It is possible to reliably drive the lens group in the optical axis direction. According to the seventh aspect of the present invention, the tip of the second feed screw functions as a drive member that closes and drives the barrier when retracted, so that the barrier drive mechanism can be manufactured at low cost and the cost of the camera can be reduced. . According to the eighth aspect of the present invention, since the first and second movable cylinders have a circular cross section orthogonal to the optical axis, the camera can be manufactured without being enlarged. According to the ninth aspect of the present invention, since the first and second movable cylinders have a substantially quadrangular cross section orthogonal to the optical axis, a camera with good space efficiency can be manufactured.

[0010]

1 to 3 show a first embodiment of the present invention.
It will be described based on. FIG. 1 is a sectional view of a main part of a camera as an optical apparatus according to the present invention, FIG. 2 is a perspective view of a main part of a first feed screw, and FIG. 3 is a perspective view of a main part of a second feed screw.
In the figure, reference numeral 1 denotes a camera body, and an exposure opening 1a is formed at the center thereof. Reference numeral 2 denotes a first feed screw. A gear portion 2a formed on the camera body 1 side is rotatably supported on a support shaft 1a of the camera body 1, and movement in the optical axis direction is restricted by a holding plate 3. The male screw 2d has a so-called two-sided shape in which flat portions 2b and 2c are formed on both sides over its entire length. The first feed screw 2 is rotationally driven by a driving gear 4 that rotates by receiving a driving force from a driving source (not shown).

Reference numeral 5 denotes a first movable cylinder which is held movably in the optical axis direction with respect to the camera body 1 and has a female screw 6a at its rear end which is screwed with the first feed screw 2. 6 are integrally formed or fixed. A second feed screw 7 is rotatably supported on the flange 6 while the movement of the second feed screw 7 in the optical axis direction with respect to the first movable cylinder 5 is regulated by a pressing member 8 similarly to the first feed screw 2. A fitting hole 7 a for receiving the rotational force from the first feed screw 2 is formed in the inner diameter portion of the second feed screw 7. The fitting hole 7a has a substantially square shape as shown in FIG. 3, and a pair of opposed two sides 7b and 7c are respectively formed with flat portions 2b and 2c forming a two-way shape of the first feed screw 2. Fitted slidably in the axial direction. At this time, the width of the remaining pair of opposite two sides 7d and 7e of the fitting hole 7a is set to be larger than the screw diameter of the first feed screw 2 so as not to interfere with the male screw portion 2d. I have. With this configuration, the second feed screw 7 is supported movably in the optical axis direction with respect to the first feed screw 2 only in the rotation direction when assembled.

Reference numeral 9 denotes a second movable cylinder for holding the first lens group 10, and a flange 11 having a female screw 11a at its rear end, which is screwed with a male screw 7f formed on the outer diameter of the second feed screw 7. Are integrally formed or fixed. 12
Is a decorative plate, which is fixed to the distal end of the second movable barrel 9 and serves as a lens barrel external part. The decorative plate 12 and the second moving cylinder 9
A well-known barrier 13 for protecting the entire photographing lens when retracted is provided between the lens and the inner diameter flange 9a formed on the front end side of the lens.
And a known driving member 14 for driving the same. Reference numeral 15 denotes an interlocking member, which is rotatably supported on the inner diameter flange 9a of the second movable cylinder 9 around a rotation shaft 15a and which comes into contact with the distal end of the second feed screw 7 during collapsing. By rotating counterclockwise, the known barrier driving member 14 is rotated around the optical axis to close the barrier.

Reference numeral 16 denotes a second lens group, which is a lens holding member 1;
7, a known cam pin 17a is fixed to the lens holding member 17, and the cam pin 17a engages with a cam groove 7g formed in an outer diameter portion of the second feed screw 7, thereby the lens The holding member 17 can be moved in the optical axis direction with respect to the second moving cylinder 9 by a known means.

In this embodiment having the above structure, when the drive gear 4 rotates by receiving the driving force from the drive source (not shown) as described above, the first feed screw 2 also starts to rotate. And
By the rotation of the first feed screw 2, the first feed screw 2 and the first
The moving cylinder 5 is extended from the camera body 1 in the optical axis direction according to the screw lead of the male screw portion 2d. When the first moving cylinder 5 is extended along the optical axis direction, the second feed screw 7 is slidable with respect to the first feed screw 2 in the optical axis direction. 5 and is unified. However, at this time, since the phase of the second feed screw 7 in the rotation direction is regulated by the first feed screw 2, the first moving cylinder 5 rotates while rotating integrally with the first feed screw 2. Along with the optical axis.

Further, the male screw 7f of the second feed screw 7
Is screwed with the female screw 11 a of the flange 11, so that the second moving cylinder 9 integral with the flange 11 is rotated with respect to the first moving cylinder 5 by rotation of the second feed screw 7 in the optical axis direction. It is further paid out. At this time, the second moving cylinder 9
The position of the first lens group 10 in the optical axis direction is defined by the composite lead of the screw lead of the first feed screw 2 and the screw lead of the second feed screw 7, which is the first lens group 1.
The composite lead is determined so as to match the amount of extension by 0 during zooming.

As described above, when the first lens group 10 is extended, the second lens group 16 defines the position of the cam pin 17a in the optical axis direction by the cam groove 7g of the second feed screw 7. Therefore, the second lens group 16 is also extended to a predetermined position, and a zooming operation for changing a photographing magnification is performed.

In the above configuration, the cross section of the lens barrel orthogonal to the optical axis has not been described. However, the present invention can be applied to various cross sections such as a circle and a substantially tetrahedron as described above. Further, a plurality of feed screw mechanisms may be arranged to implement balance, and the first moving cylinder 5 is connected to the camera body 1 and the second moving cylinder 9 is connected to the first moving cylinder 5 by a known guide. A configuration such as a bar and a bush may be used so as to be movable in the optical axis direction.

FIG. 4 shows a second embodiment of the present invention. For the sake of simplicity, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In the present embodiment, one end of the first feed screw 21 is fixed to the camera body 1, and a male screw 21 a formed on the outer diameter of the first feed screw 21 is formed on the inner diameter of the second feed screw 22. The second feed screw 22 is screwed with the female screw 22a.
A male screw 22b formed on the outer diameter of the flange 11 is screwed with a female screw 11a of the flange 11 fixed to the rear end of the second movable cylinder 9. The second feed screw 22 is rotatably held by a flange 23 having a rear end portion fixed to the rear end surface of the first moving cylinder 5 and the holding member 8, and has an opening formed in the first moving cylinder 5. 5a having a gear portion 22c exposed from
The gear portion 22c meshes with a drive gear 24 rotatably supported by the camera body 1. The cam pin 17a fixed to the lens holding member 17 is engaged with a cam groove 22c formed on the outer diameter of the second feeder 22. Other configurations are the same as those of the first embodiment.

In this embodiment having the above structure, when the driving gear 24 rotates by receiving a driving force from a driving source (not shown), the second feed screw 22 also starts rotating via the gear portion 22c. When the second feed screw 22 rotates, the first
The second feed screw 22 itself moves back and forth along the optical axis by screwing with the feed screw 21, and as a result, the first moving cylinder 5 also moves back and forth along the optical axis. At this time, the second movable cylinder 9 further moves back and forth along the optical axis with respect to the first movable cylinder 5 by the screwing of the male screw 22b of the second feed screw 22 and the female screw 11a of the flange 11. Other operations are the same as in the first embodiment.

In the above construction, as in the first embodiment, the cross-sectional shape orthogonal to the optical axis of the lens barrel was not described. It is also adaptable to the shape. Further, a plurality of feed screw mechanisms may be arranged to implement balance, and the first moving cylinder 5 is connected to the camera body 1 and the second moving cylinder 9 is connected to the first moving cylinder 5 by a known guide. It goes without saying that the support such as a bar and a bush may be movably supported in the optical axis direction.

[0021]

As described above, the lens barrel of the optical apparatus according to the first aspect of the present invention has a first feed screw having a screw at an outer diameter portion and rotatably held therein, and A first moving cylinder screwed with the first feed screw and moving in the optical axis direction; and a first moving cylinder rotatably held by the first moving cylinder and rotating by receiving a rotational force of the first feed screw. 2 and a second moving cylinder that is screwed with the second feeding screw and moves in the optical axis direction with respect to the first moving cylinder.
A multi-stage collapsible lens barrel can be formed without increasing the size of a movable cylinder having a circular cross section orthogonal to the optical axis, and a multi-stage collapsible lens barrel with excellent space efficiency can be formed with a substantially square lens barrel.
According to a second aspect of the present invention, there is provided the present invention as set forth in claim 3, wherein the first feed screw has a part where no screw is formed. Since the rotational force is transmitted by the unthreaded portion of the first feed screw, the present invention as set forth in claim 4 provides that the unthreaded portion of the first feed screw has a two-sided shape. By doing so, the rotation interlock of the first feed screw and the second feed screw can be facilitated.

According to a fifth aspect of the present invention, there is provided the fixed first
A second feed screw that is screwed with the first feed screw and that moves back and forth along the optical axis while rotating by receiving a driving force from a driving source; and rotating the second feed screw. A first moving cylinder which is held as possible and integrally moves back and forth along the optical axis, and which is screwed to the second feed screw and moves back and forth along the optical axis with respect to the first moving cylinder; And a second movable cylinder having a circular cross section orthogonal to the optical axis can realize a multi-stage retractable lens barrel without increasing the size of the movable cylinder. An excellent multi-stage retractable lens barrel can be realized.

According to a sixth aspect of the present invention, in the second feed screw, a cam groove for driving the optical member along the optical axis coexists with the screw, so that the movable cylinder is driven and photographed. It is possible to reliably drive the lens group in the optical axis direction. According to the present invention, the tip of the second feed screw functions as a drive member that closes and drives the barrier when retracted, so that the barrier drive mechanism can be manufactured at low cost and the cost of the camera can be reduced. . According to the eighth aspect of the present invention, since the first and second movable cylinders have a circular cross section orthogonal to the optical axis, the camera can be manufactured without being enlarged. According to the ninth aspect of the present invention, since the first and second movable cylinders have a substantially quadrangular cross section orthogonal to the optical axis, a camera with good space efficiency can be manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a camera as an optical apparatus according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a main part of the first feed screw.

FIG. 3 is a perspective view of a main part of the second feed screw.

FIG. 4 is a sectional view of a main part of a camera as an optical apparatus according to a second embodiment of the present invention.

[Explanation of symbols]

1. Camera body, 2, 21 First feed screw, 3, 8
..Pressing member, 4,24..drive gear, 5..first moving cylinder, 6,11,23..flange, 7,22..second feed screw, 9, .. second moving cylinder, 10 ..・ First lens group, 1
3 barrier, 14 barrier driving member, 15 interlocking member, 16 second lens group, 17 lens holding member, 17a cam pin.

Claims (9)

[Claims] 1. A first feed screw having a screw at an outer diameter portion and rotatably held, and a first moving cylinder screwed with the first feed screw and moved in an optical axis direction. A second feed screw rotatably held by the first movable barrel and rotating by receiving the rotational force of the first feed screw, and a second feed screw engaged with the second feed screw and A lens barrel for an optical device, comprising: a second movable barrel that moves in the optical axis direction with respect to the movable barrel. 2. The first feed screw according to claim 1, wherein the first feed screw has a part where no screw is formed.
A lens barrel of the optical device described in the above. 3. The lens barrel of an optical device according to claim 2, wherein the second feed screw transmits a rotational force by a part of the first feed screw where the screw is not formed. 4. The threadless portion of the first lead screw comprises:
4. The lens barrel of an optical device according to claim 2, wherein the lens barrel has a two-way shape. 5. A fixed first feed screw, and a second feed screw that is screwed with the first feed screw and moves back and forth along the optical axis while rotating while receiving a driving force from a drive source. And the second
A first moving cylinder which rotatably holds the feed screw of the first moving cylinder and moves integrally back and forth along the optical axis; and an optical axis which is screwed with the second feed screw and is movable with respect to the first moving cylinder. And a second movable cylinder that moves back and forth along the axis. 6. The second feed screw according to claim 1, wherein a cam groove for driving the optical member along the optical axis coexists with the screw. A lens barrel of the optical device described in the above. 7. The mirror of an optical device according to claim 1, wherein the tip of the second feed screw functions as a driving member for closing and driving the barrier when retracted. Tube. 8. The optical system according to claim 1, wherein said first and second movable cylinders have a circular cross section orthogonal to the optical axis.
8. The lens barrel of the optical device according to 5, 6, or 7. 9. The apparatus according to claim 1, wherein said first and second movable cylinders have a substantially quadrangular cross section orthogonal to the optical axis.
9. The lens barrel of the optical device according to 3, 4, 5, 6, or 7.