JPH0895143A - Lens barrel - Google Patents

Abstract

(57) [Abstract] [Purpose] In a so-called collapsible type lens barrel in which the movable lens barrel can be extended from the fixed lens barrel or the camera body, by making the retractable length of the movable lens barrel longer, Aim for miniaturization. A first lens group, in which a movable lens barrel linear motor 11 of a movable lens barrel 7 is disposed in a fixed lens barrel 29, and which is located on an extension of the moving coil 10 moving direction in the movable lens barrel linear motor. A notch 8 is formed in a part of the rear lens 2c of the second lens 2 so that the front end portion of the movable lens barrel linear motor is located in the notch when the movable lens barrel is in the collapsed state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called collapsible lens barrel in which a movable lens barrel can be extended from a fixed lens barrel or a camera body. More specifically, it is an object of the present invention to provide a novel lens barrel that can be downsized by increasing the retractable length of the movable barrel.

[0002]

2. Description of the Related Art From the viewpoint of portability of a camera, there is a so-called collapsible lens barrel in which one lens barrel can be extended to the other fixed lens barrel or the camera body.

Such a collapsible lens barrel has driving means for moving the movable lens barrel, and examples of the driving means include a linear motor and a feed screw mechanism.

Such a linear motor and a feed screw mechanism are arranged long in the direction parallel to the optical axis in an outer peripheral portion of the internal space of the lens barrel that does not interfere with the image pickup of the lens system.

16 and 17 schematically show an example of a lens barrel in which the movable lens barrel is retracted with respect to the camera body.

Reference numeral a denotes a lens barrel, which is a fixed barrel b fixed to a camera body (not shown) and the fixed barrel b.
And a movable lens barrel c that can be extended with respect to
The movable barrel c is supported so as to be movable in the optical axis direction with respect to the fixed barrel b, and the movable barrel c is fixed to the fixed barrel b during photographing.
From the front to the front, the photographing is possible (see FIG. 16), and when the camera is not used, the movable lens barrel c is retracted into the fixed lens barrel b so that the photographing is impossible (see FIG. 17). Has become.

Reference numeral d denotes a first group lens arranged so as to cover the front opening of the movable lens barrel c. The first group lens d is composed of, for example, three lenses e, f and g. There is.

Reference numeral h denotes a second lens group as a movable lens of a variable power system, which is supported by a fixed lens barrel b so as to be movable in the optical axis direction, and the movable lens barrel c with respect to the fixed lens barrel b. In the extended state, the movable range of the second lens group h is formed. The other lens groups arranged in the lens barrel a are omitted, but the second lens group h is used.
To the rear of the, the third group lens as a fixed lens of the focusing system,
A fourth group lens or the like as a focusing movable lens is provided.

Reference numeral i denotes a linear motor for a movable lens barrel, which is disposed below the internal space of the fixed lens barrel b, and has a cylindrical outer yoke j having a slit (not shown) elongated in the axial direction.
And a rod-shaped inner yoke k formed of a material having good magnetic permeability, and a magnet l having an arc-shaped cross section attached to the inner peripheral surface of the outer yoke j and the inner yoke k slidably. It consists of a supported moving coil m and the like.

The outer yoke j and the inner yoke k are magnetically connected to each other by closing plates n.

The outer yoke j, the inner yoke k, and the magnet 1 are attached to the fixed lens barrel b, and the movable coil m is attached to the lower portion of the rear end of the movable lens barrel c.

Reference numeral o denotes a rotation stop shaft arranged in the upper part of the internal space of the fixed lens barrel b, and an engagement piece p attached to the rotation stop shaft o above the rear end of the movable lens barrel c. Are slidably engaged.

Since the movable coil m has a function as a sliding member having the inner yoke k as a guide shaft, it is formed to have a certain length in the axial direction.

When the movable coil m is energized, the movable coil m is slid with respect to the inner yoke k, the movable lens barrel c is moved in the optical axis direction, and the movable lens barrel c is moved with respect to the fixed lens barrel b. It is paid out or rolled in.

[0015]

However, as described above, in the conventional lens barrel a, when the movable lens barrel c is retracted, the rear lens g of the first lens group d and the second lens group d. There is a problem in that a space is created between h and h, and the collapsible length cannot be increased by that much.

That is, the linear motor i has its movable coil m.
Has a certain length in the optical axis direction, the movable lens barrel c
It is necessary to make the linear motor i longer than the retractable length of the fixed lens barrel a, and when such a linear motor i is arranged in the lens barrel a, it cannot be projected rearward from the rear end wall of the fixed lens barrel b. There is no choice but to project to the front of b.

Further, in order to prevent the lens barrel a from becoming large in the radial direction, it is necessary to dispose the linear motor i on the optical axis side as much as possible within the range not interfering with the lens system.

If the linear motor i is arranged so as to satisfy such a condition, the rear lens g of the first lens group d is positioned on the extension of the front of the linear motor i, and they do not interfere with each other. In order to do so, it is necessary to form a certain amount of space between the rear lens g of the first lens group d and the second lens group, and therefore the retractable length cannot be increased.

Further, such a problem occurs not only when the driving means for the movable lens barrel is a linear motor, but also when it is a feed screw mechanism.

[0020]

In order to solve the above-mentioned problems, the lens barrel of the present invention has a drive means for a movable lens barrel disposed inside the lens barrel, and a moving member of the drive means. A part of the lens system located on the extension of the moving direction is cut off so that the lens system and the driving means do not interfere with each other.

[0021]

Therefore, according to the lens barrel of the present invention, a part of the lens system located on the extension of the moving member in the driving direction in the driving means is cut off, so that the retractable length of the movable lens barrel is increased accordingly. Therefore, the lens barrel can be downsized, which contributes to downsizing of the entire camera.

[0022]

The details of the lens barrel of the present invention will be described below with reference to the respective embodiments shown in the accompanying drawings.

1 to 13 show a first embodiment in which the lens barrel of the present invention is applied to a lens barrel for a video camera. The first embodiment is one in which the present invention is applied to a driving means for a movable lens barrel using a linear motor.

Reference numeral 1 denotes a lens barrel of a video camera. The lens barrel 1 has a first lens group 2, a second lens group 3, an iris mechanism 4, a third lens group 5 and a fourth lens group 6 from the front. Are arranged in this order, and the first lens group 2 and the third lens group
The group lens 5 is a fixed lens, and the second group lens 3 and the fourth group lens 6 are movable lenses. The fixed lens means a lens that does not move in a shooting enabled state, and the movable lens means a lens that moves for shooting when shooting.

Reference numeral 7 denotes a cylindrical movable lens barrel which holds the first lens group 2 at the front end opening so as to close it. The movable lens barrel 7 is movable with respect to the fixed lens barrel as described later. It is supported and the movable lens barrel 7 is taken out from the fixed lens barrel (photographing state) (see FIG. 1), and the retracted state (collapsed state) is not possible to photograph (see FIG. 2). It

In FIG. 1, the diagonally downward left direction is the front side, the diagonally upward right direction is the rear side, the diagonally upward left direction is the right side, and the diagonally downward right direction is the left side. , The upward direction is the upper side, and the downward direction is the lower side. In the following description, when indicating the direction, it is based on this direction.

The first lens group 2 includes three lenses 2a and 2a.
b, 2c, the lens 2a is a negative meniscus lens, the lens 2b is a biconvex lens, the lens 2c is a positive meniscus lens, and the first lens group 2 is a positive lens as a whole. 2a and 2b are attached to each other and held by the front lens frame 7a of the movable lens barrel 7, and the lens 2c is held by a rear lens frame 7b positioned slightly behind the lens frame 7a.

A notch 8 formed by cutting a circle into an arc is formed in the lower left portion of the lens 2c on the rear side of the first lens group 2, and the notch 8 is formed by a movable lens barrel 7 as described later. This is to prevent the front end portion of the movable lens barrel linear motor, which will be described later, from interfering with the lens 2c when it is retracted into the fixed lens barrel (see FIG. 9).

A rectangular notch 7c opening rearward is formed in the upper right portion of the rear end edge of the movable lens barrel 7, and the movable lens barrel 7 is retracted into the fixed lens barrel as will be described later. The drive motor, which will be described later, of the iris mechanism 4 does not interfere with the movable lens barrel 7 when it is turned on.

A lower protruding portion 9 protruding outward and further rearward is formed at a position diagonally lower left of the outer peripheral surface of the movable lens barrel 7 and corresponding to the notch 8 of the lens 2c. The lower projection 9 has a U-shaped cross section.

At the rear edge of the lower protrusion 9, the lower protrusion 9
A cylindrical moving coil 10 having an axial center extending in the front-rear direction is attached to the inside. The moving coil 10 constitutes a part of a movable lens barrel linear motor 11 for moving the movable lens barrel 7 in the front-rear direction with respect to the fixed lens barrel, as will be described later. The linear motor 11 for the movable lens barrel will be described later.

An upper projecting portion 12 projecting outward and further rearward is formed on the obliquely upper right portion of the outer peripheral surface of the movable lens barrel 7 and in the portion corresponding to the latter half thereof. The portion 12 also has a U-shaped cross section, and a locking piece 13 is provided at the rear end of the locking piece 13 so as to project inward, and the locking piece 13 has a U-shape opening inward. The notch 14 is formed.

Reference numeral 15 is a lens holder for the second lens group 3, and the lens holder 15 is sized so as to be housed in the movable lens barrel 7. The lens holder 15 is similar to the movable lens barrel 7. Movably supported with respect to the fixed lens barrel,
The movable lens barrel 7 is movable in a space 16 formed by being extended from a fixed lens barrel.

The second lens group 3 includes three lenses 3a and 3a.
b, 3c, the lens 3a is a negative meniscal lens, the lens 3b is a biconcave lens, the lens 3c is a positive meniscus lens, and the second lens group 3 is a negative lens as a whole. It is held at 15.

The second group lens 3 is moved in the front-rear direction by the movement of the lens holder 15, is a movable lens at the time of photographing, and is a zoom lens for zooming.

An L-shaped coil supporting arm 17 when viewed from the side is formed on the lower left portion of the outer peripheral edge of the lens holder 15 such that the long arm extends rearward. A cylindrical moving coil 18 having a center hole extending in the front-rear direction is attached to the outer end surface of the rear end portion. The moving coil 18 constitutes a part of a zoom lens linear motor 19 for moving the second lens group 3 in the front-rear direction, as will be described later. The zoom lens linear motor 19 will be described later.

An L-shaped locking piece supporting arm 20 is formed on the upper right side of the outer peripheral edge of the lens holder 15 so that its long arm extends rearward. A locking piece 21 is provided on the rear end of the one-sided support arm 20 so as to project outward, and a U-shaped notch 22 that opens outward is formed in the locking piece 21.

Reference numeral 23 denotes a ring-shaped lens holder whose outer diameter is slightly smaller than the inner diameter of the movable lens barrel 7.
The third group lens 5 is held.

Reference numeral 24 denotes a substantially cylindrical frame body integrally projecting from the outer peripheral edge of the lens holder 23 toward the front. The outer diameter of the frame body 24 is larger than the inner diameter of the movable lens barrel 7. It is formed to be slightly smaller and has an inner diameter slightly larger than the outer diameter of the lens holder 15, and the front end of the frame body 24 is open.

The third group lens 5 held by the lens holder 23 is composed of one biconvex lens and is a fixed lens of the focusing lenses.

Reference numeral 25 denotes a substantially rectangular lower notch which is opened to the lower left of the front end edge of the frame 24, and the lower notch 25 is formed at a position corresponding to the lower projection 9 of the movable lens barrel 7. The short arm of the coil supporting arm 17 does not interfere with the frame 24 when the lens holder 15 moves in the front-rear direction.

Reference numeral 26 denotes a substantially rectangular upper notch that is open to the upper right of the front edge of the frame 24. The upper notch 26 is formed at a position corresponding to the upper protrusion 12 of the movable lens barrel 7. The short arm of the locking piece support arm 20 does not interfere with the frame 24 when the lens holder 15 moves in the front-rear direction.

Reference numeral 27 is a rectangular hole formed in the upper left portion of the rear end portion of the frame body 24, and is for disposing the drive motor 28 of the iris mechanism 4.

The iris mechanism 4 has a plurality of diaphragm blades in a central hole of a case body 4a which is flat in the front-rear direction and has a plurality of diaphragm blades, and the diaphragm blades are attached to one end of the case body 4a. The iris mechanism 4 has a drive motor 28 and a frame 24.
Of the rectangular hole 27, and
The case body 4a is attached to the lens holder 2 in the frame body 24.
It is arranged so as to be located at the front of No. 3.

The movable lens barrel 7, the lens holder 15 of the zoom lens 3, the lens holder 23, and the frame 24 are arranged so that the optical axes of the first lens group 2, the zoom lens 3, and the third lens group 5 coincide with each other. When arranged, when viewed from the front, the axis of the moving coil 10 of the movable lens barrel 7 and the axis of the moving coil 18 of the lens holder 15 of the zoom lens 3 are aligned, and the locking piece of the movable lens barrel 7 is aligned. The notch 14 of 13 and the notch 22 of the locking piece 21 of the lens holder 15 are arranged to overlap with each other with their opening directions opposite to each other.

Reference numeral 29 denotes a substantially cylindrical fixed lens barrel whose rear end is closed. A rectangular opening 29b is formed in the rear end wall 29a of the fixed lens barrel 29, and a low-pass is provided in the rectangular opening 29b. The filter 30 is attached, and is located inside the rear end wall 29a of the fixed lens barrel 29 and at the upper and lower positions with the opening 29b sandwiched between the filter 30 and the upper and lower portions inside the fixed lens barrel 29. Yokes 31, 31 formed by being bent in a substantially U-shape when viewed from the side are respectively arranged.

Of the yokes 31, 31, the pieces located on the axial center side are the inner yoke pieces 31a, 31a, and the pieces located outside thereof are the outer yoke pieces 31b, 31b, and the outer yoke pieces 31b, 31b. Magnets 32, 32 are attached to the surfaces of the inner yoke pieces 31a, 31a facing the inner yoke pieces 31a, 31a, whereby the inner yoke pieces 31a, 31a and the magnet 3 are attached.
A magnetic field is formed between 2 and 32.

Reference numerals 33 and 33 denote guide shafts for slidably supporting the fourth group lens 6 in the optical axis direction. The guide shafts 33 and 33 are left of the rear end wall 29a of the fixed lens barrel 29. It is provided so as to project forward from the diagonally upper corner and the diagonally lower right corner. The front end portions of the guide shafts 33, 33 have guide shaft support holes 23a formed in the lens holder 23 when the lens holder 23 is assembled to the fixed lens barrel 29.
It is designed to be supported by 23a.

Reference numeral 34 is a cylindrical yoke having a rear end face closed and a front end face opened, and is long in the front-back direction. The shaft center and the fixed barrel 29 are located at the lower left corner of the outer surface of the fixed barrel 29. The cylindrical yoke 34 is attached so that its axis is parallel to the axial center of the fixed barrel 2.
The front one-third portion of the fixed lens barrel 29 is attached to the front end of the fixed lens barrel 29 and is projected forward.

35, 35 are on the side surface of the cylindrical yoke 34,
The slits 35, 35 are formed so as to open obliquely downward to the left and obliquely upward to the right and extend parallel to the axis of the cylindrical yoke 34. It is formed from the center to the front end, and the front end is opened to the front end of the cylindrical yoke 34.

Reference numeral 36 denotes a round rod-shaped guide shaft formed of a material having good magnetic permeability, and is arranged in the cylindrical yoke 34 such that its center coincides with its axial center.

Reference numerals 38 and 38 denote magnets having an arc-shaped cross section, which are attached to the inner peripheral surface of the cylindrical yoke 34 so as to avoid the slits 35 and 35, whereby the magnets 38 and 38 are formed. A magnetic field is formed between the guide shaft 36 and the guide shaft 36.

Reference numeral 37 is a disk-shaped closing plate having a central hole 37a formed of a material having a good magnetic permeability. The closing plate 37 covers the front end opening of the cylindrical yoke 34 and forms a central hole 37a. The guide shaft 36 is arranged so that the tip end thereof is press-fitted, whereby the cylindrical yoke 34 and the guide shaft 36 are magnetically coupled to each other, and when a magnetic path is formed as described later, A magnetic path passing through the rear end wall of the cylindrical yoke 34 and a magnetic path passing through the closing plate 37 are formed from the magnets 38, 38 through the cylindrical yoke 34.

Further, the obstruction plate 37 has a fan-shaped notch 37a at an obliquely upper right portion thereof at a position corresponding to the slit 35 formed on the fixed lens barrel 29 side of the slits 35, 35 of the cylindrical yoke 34. Has been formed, which allows
Coil support arm 17 of lens holder 15 of zoom lens 3
It does not prevent the movement of the.

When the moving coil 18 of the lens holder 15 and the moving coil 10 of the movable lens barrel 7 are positioned on the guide shaft 36 so as to be fitted to each other, the magnets 38 and 38-cylindrical yoke 34- (closing plate). 37)-
A magnetic path of the guide shaft 36 and the magnets 38, 38 is formed to configure the linear motor 11 for the movable lens barrel and the linear motor 19 for the zoom lens.

Reference numeral 39 denotes a cylindrical upper projection which is integrally formed on the upper right portion of the fixed lens barrel 29 so as to project outward, and the axial center of the upper projection 39 extends in the front-rear direction. The fixed lens barrel 29 is formed over substantially the entire length.

Further, on the diagonally right upper part of the upper projecting portion 39,
The cylindrical yoke 34 is opened so as to be obliquely upward to the right.
A slit 39a is formed so as to extend parallel to the axis of the movable lens barrel 7. The slit 39a is formed at a position corresponding to the locking piece 13 of the upper protruding portion 12 of the movable lens barrel 7, and the movable lens barrel 7 moves forward and backward. When the locking piece 13 is moved in the direction,
It does not interfere with the above-mentioned upper projection portion 39 of 9.

Reference numeral 40 denotes a detent shaft arranged so as to be positioned substantially at the axial center of the upper projecting portion 39, which is provided so as to project forward from the rear end wall of the upper projecting portion 39 and has its front end. The cylindrical yoke 34 projects forward from the front end of the fixed lens barrel 29, and
Is formed to have substantially the same length.

The lens holder 1 is attached to the rotation stop shaft 40.
Notch 22 of locking piece 21 of No. 5 and locking piece 13 of movable lens barrel 7
The notches 14 are slidably engaged with each other, whereby
The lens holder 15 and the movable lens barrel 7 are prevented from rotating around the guide shaft 36.

Reference numeral 41 denotes a substantially cylindrical lens holding member for the fourth lens group 6, and the left diagonally upper portion and the right diagonal lower portion thereof respectively have supported pieces 42, 4 protruding outward.
2

The fourth lens group 6 includes two lenses 6a and 6b.
The lens 6a is a negative meniscus lens, the lens 6b is a biconvex lens, and the fourth lens group 6 is a positive lens as a whole, and is held by the lens holding member 41.

The fourth group lens 6 is moved in the front-rear direction by the movement of the lens holding member 41, is a movable lens at the time of photographing, and is mainly a focusing lens for focusing. The focus lens 6 also complements the variable power lens.

Reference numerals 43 and 43 are guide holes formed in the supported pieces 42 and 42 of the lens holding member 41, which are provided at positions facing the guide shafts 33 and 33, respectively, and one of the guide holes is provided. Reference numeral 43 is substantially the same size as or slightly larger than the guide shaft 33, and the other guide hole 43 has a cross-sectional shape of a long hole and its minor diameter is substantially the same size or slightly larger than the guide shaft 33. There is.

Reference numeral 44 denotes a rectangular cylindrical coil bobbin integrally formed with the supported pieces 42, 42 so as to surround the lens holding member 41, and has a sectional shape slightly smaller than that of the fixed lens barrel 29. And the coil bobbin 44
A movable coil 45 is wound around the outer periphery of the.

The external dimension in the vertical direction of the coil bobbin 44 around which the movable coil 45 is wound is smaller than the distance between the magnets 38 and 38 attached to the two yokes 31, 31 of the fixed lens barrel 29. The inner dimension of the coil bobbin 44 in the vertical direction is formed larger than the distance between the surfaces of the inner yoke pieces 31a, 31a facing the magnets 38, 38.

Then, the above-configured members are assembled in the following manner to form the lens barrel 1.

First, the guide shafts 33, 33 of the fixed lens barrel 29.
The guide holes 43, 43 of the lens holding member 41 of the focus lens 6 are externally fitted to the lens holding member 41, and the lens holding member 41 is slidably supported by the fixed lens barrel 29.

At this time, when the lens holding member 41 is supported by the guide shafts 33, 33, the coil bobbin 44 and the movable coil 45 have upper and lower pieces respectively of the yokes 31, 31 of the fixed lens barrel 29. Are separately located in the magnetic field of and are not in contact with them.
Magnetic paths of magnets 32 and 32-outer yoke pieces 31b and 31b-inner yoke pieces 31a and 31a-magnets 32 and 32 are formed.

Therefore, when the movable coil 45 is energized, the movable coil 45 receives a moving force in the front-rear direction, so that the lens holding member 41 is guided by the guide shafts 33, 33 and moved in the front-rear direction. As a result, the focus lens 6 is moved in the front-back direction, that is, the optical axis direction of the lens system, and focusing is performed.

The lens holder 23 to which the third group lens 5 is attached covers the front opening of the fixed lens barrel 29, and the optical axes of the third group lens 5 and the focus lens 6 are the same. Are arranged so that they match.

Lens holder 1 holding zoom lens 3
5, the moving coil 18 has the above-mentioned cylindrical yoke 3
4 is loosely fitted inside and is slidably fitted onto the guide shaft 36, and the notch 22 of the engaging piece 21 is slidably engaged with the rotation stopping shaft 40 of the fixed lens barrel 29. Are combined. In this state, the optical axis of the zoom lens 3 is the third
The optical axes of the group lens 5 and the focus lens 6 coincide with each other, and the lens holder 15 is slidably supported in the optical axis direction.

As a result, the moving coil 18 is positioned within the magnetic field formed between the guide shaft 36 and the magnet 38 to form the linear motor 19 for the zoom lens,
The lens holder 15 does not rotate in the circumferential direction of the guide shaft 36 due to the engagement of the notch 22 and the rotation stop shaft 40, and the optical axis of the zoom lens 3 is the optical axis of the third group lens 5 and the focus lens 6. There is no deviation from it.

When the moving coil 18 is energized, the moving coil 18 receives a moving force in the front-rear direction, so that the lens holder 15 is guided by the guide shaft 36 and moved in the front-rear direction. The zoom lens 3 is moved in the front-back direction, that is, in the optical axis direction of the lens system to perform zooming.

In the movable lens barrel 7, after the lens holder 15 is supported by the fixed lens barrel 29, the moving coil 10 is loosely fitted in the cylindrical yoke 34 and slidable on the guide shaft 36. And the engaging piece 13
The notch 14 is slidably engaged with the rotation stop shaft 40 of the fixed lens barrel 29. In this state, the first movable lens barrel 7
The optical axis of the group lens 2 coincides with the optical axes of the zoom lens 3, the third group lens 5 and the focus lens 6, and the movable lens barrel 7 is slidably supported in the optical axis direction.

As a result, the moving coil 10 is positioned in the magnetic field formed between the guide shaft 36 and the magnet 38 to form the movable lens barrel linear motor 11, and
The movable lens barrel 7 does not rotate in the circumferential direction of the guide shaft 36 due to the engagement between the notch 14 and the rotation stop shaft 40, and the optical axis of the first group lens 2 is the zoom lens 3, the third group lens 5 and the focus. It does not deviate from the optical axis of the lens 6.

When the moving coil 10 is energized, the moving coil 10 receives a moving force in the front-rear direction, so that the movable lens barrel 7 is guided by the guide shaft 36 and moved in the front-rear direction. The movable lens barrel 7 is moved between a state where the movable lens barrel 7 is located on the fixed lens barrel 29 side (collapsed state) and a photographable state (photographing state) that is extended forward from this state.

When the movable lens barrel 7 is retracted with respect to the fixed lens barrel 29 and is retracted, the zoom lens 3
Is located at the position closest to the fixed lens barrel 29 in its movable range, and is prevented from moving forward.

Further, in this state, the front end of the movable lens barrel linear motor 11, that is, the front end of the cylindrical yoke 34, the magnets 38, 38 and the guide shaft 38, and the closing plate 37 are the first group lens. Since they are located in the cutouts 8 of the lens 2c on the rear side of the lens 2, they do not interfere with each other. Therefore, the retractable amount can be increased as compared with the case where the cutouts 8 were not provided.

On the other hand, when the movable lens barrel 7 is extended forward from the fixed lens barrel 29 to be in the photographing state, a space 16 is formed between the movable lens barrel 7 and the fixed lens barrel 29, and the space 16 is formed in the space 16. At, the zoom lens 3 becomes movable.

Further, in this state, the rear edge of the movable lens barrel 7 is located in front of the lens holder 23 of the third lens group 5, but the lens holder 23 has a frame projecting forward. Since the body 24 is integrally formed, the frame body 24
Is kept in a state where the rear end of the movable lens barrel 7 is externally fitted,
Therefore, it is possible to prevent dust and the like from entering from the portion.

Then, after the movable lens barrel 7 is brought into the photographing state, a driving current is supplied to the moving coil 18 of the zoom lens linear motor 19 to move the zoom lens 3 for proper zooming. A drive current is supplied to the movable coil 45 to move the focus lens 6 for appropriate focusing.

14 and 15 show a second embodiment 1A in which the lens barrel of the present invention is applied to a lens barrel for a video camera.
Is shown. The second embodiment is one in which the present invention is applied to the one using the feed screw mechanism as the driving means for the movable lens barrel.

The second embodiment 1A differs from the first embodiment 1 only in the drive means for the movable lens barrel, and therefore only the essential parts are shown in the drawings, and the description thereof is given above. Only different points will be described, and other parts will be omitted by giving the same reference numerals to the same parts in the first embodiment in the drawings.

Reference numeral 46 denotes a feed screw mechanism as a driving means for moving the movable lens barrel 7, and the feed screw mechanism 46.
Is a drive motor 47 attached to the lower left portion of the fixed lens barrel 29, a feed screw 48 formed integrally with the output shaft of the drive motor 47, and the feed screw 48 and the movable portion. A feed nut 4 integrally formed at the rear end of the lens barrel 7.
It consists of 9 mag.

Numeral 50 is a cylindrical lower protruding portion integrally formed on the lower left portion of the fixed lens barrel 29 so as to protrude outward. The lower protruding portion 50 has its axial center extending in the front-rear direction. The fixed lens barrel 29 is formed over substantially the entire length.

The drive motor 47 is disposed at the rear end of the lower projection 50 of the fixed lens barrel 29, and the tip of the feed screw 48 formed integrally with the output shaft of the drive motor 47 has the third lens group. The frame body 2 formed integrally with the lens holder 23 of No. 5
It is supported by a shaft support plate 51 projecting outward from the front edge of No. 4 at right angles to the optical axis.

The feed nut 49 of the movable lens barrel 7 is
Is integrally formed with a support piece 52 that is integrally formed inwardly at the rear end of the lower protrusion 9.

The feed nut 49 has a support piece 52 and a slit 50 formed in the lower protruding portion 50 of the fixed lens barrel 29.
It is positioned in the lower protruding portion 50 by passing through a and is screwed to the feed screw 48.

Therefore, the feed screw 48 is rotated by the rotation of the drive motor 47, and the feed nut 49 is moved in the axial direction according to the direction of the rotation, whereby the movable lens barrel 7 is moved to the fixed lens barrel 29. It is designed to be rolled out or rolled in.

When the movable barrel 7 is retracted (see FIG. 14), the shaft support piece 51 for supporting the tip of the feed screw 48 is inside the notch 8 of the lens 2c on the rear side of the first lens group 2. Since they are located at the position, they do not interfere with each other, so that the retractable amount can be increased as compared with the case where the notch 8 is not provided.

[0091]

As is apparent from the above description, in the lens barrel of the present invention, the movable lens barrel is arranged so as to be able to be extended in the optical axis direction with respect to the fixed lens barrel or the camera body, and the movable mirror is provided. A retractable lens barrel capable of photographing in a state where the barrel is extended, in which a driving means of a movable lens barrel is disposed in the lens barrel, and an extension of a moving member of the driving means in a moving direction. It is characterized in that a part of the lens system positioned at is cut off so that the lens system and the driving means do not interfere with each other.

Therefore, according to the lens barrel of the present invention, a part of the lens system positioned on the extension of the moving member in the moving direction of the driving means is cut off, so that the retractable length of the movable lens barrel is increased accordingly. Therefore, the lens barrel can be downsized, which contributes to downsizing of the entire camera.

Although the lens barrel of the present invention is applied to the lens barrel of a video camera in the above embodiment, the present invention is not limited to this and may be applied to a so-called still camera lens barrel. In addition, the retractable lens barrel in which the movable lens barrel can be extended with respect to the fixed lens barrel has been described, but the present invention is a retractable lens barrel in which the movable lens barrel can be extended with respect to the camera body. It can also be applied.

Furthermore, the specific shapes and structures shown in the above embodiments are merely examples of the implementation of the present invention, and the technical scope of the present invention is limited by these. Should not be interpreted.

[Brief description of drawings]

1 to 13 show a first embodiment in which the lens barrel of the present invention is applied to a collapsible lens barrel of a video camera, and this figure is a perspective view showing a photographing state.

FIG. 2 is a perspective view showing a collapsed state.

FIG. 3 is an exploded perspective view.

FIG. 4 is a front view.

5 is a cross-sectional view taken along the line VV of FIG. 4, showing a collapsed state.

6 is a cross-sectional view taken along line VI-VI in FIG. 4, showing a telephoto end in a shooting state.

7 is a cross-sectional view taken along the line VII-VII of FIG. 4, showing the wide end in the shooting state.

8 is a cross-sectional view taken along the line VIII-VIII of FIG.
It shows a tele end in a shooting state.

9 is a sectional view taken along line IX-IX in FIG.

10 is a cross-sectional view taken along line XX of FIG.

11 is a cross-sectional view taken along the line XI-XI of FIG.

12 is a sectional view taken along line XII-XII in FIG.

13 is a sectional view taken along line XIII-XIII in FIG.

14 shows a second embodiment of the lens barrel of the present invention together with FIG. 15, and this figure is a cross-sectional view showing a collapsed state.

FIG. 15 is a cross-sectional view showing a shooting state.

FIG. 16 schematically shows an example of a conventional lens barrel together with FIG. 17, and this figure is a cross-sectional view showing a photographing state.

FIG. 17 is a cross-sectional view showing a collapsed state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lens barrel 2 Lens system 2c Lens (part of lens system) 7 Movable lens barrel (first lens group) 10 Moving coil (moving member) 11 Linear motor (driving means) for movable lens barrel 29 Fixed lens barrel 1A lens Lens barrel 46 Lead screw mechanism

Claims (3)

[Claims] 1. A collapsible lens barrel in which a movable lens barrel is arranged so as to be able to be extended in the optical axis direction with respect to a fixed lens barrel or a camera body, and which is capable of taking an image when the movable lens barrel is extended. The driving means for the movable lens barrel is disposed in the lens barrel, and a part of the lens system located on an extension of the driving means in the moving direction of the moving member is cut off to remove the lens system and the lens system. A lens barrel characterized in that it does not interfere with driving means. 2. The lens barrel according to claim 1, wherein the driving means is a linear motor. 3. The lens barrel according to claim 1, wherein the driving means is a feed screw mechanism.