JPH01219810A - Zoom lens barrel - Google Patents

Abstract

PURPOSE:To eliminate play at the time of power varying operation by fitting an intermediate cylinder united with a power varying operation ring for the power varying operation in a fixed cylinder with sufficient fitting length. CONSTITUTION:When the power varying operation ring 2 is moved straight in the direction of the optical axis, the intermediate cylinder 6 also moves similarly, and is fitted in the projection part 1f of the fixed cylinder 1 with a cylindrical slide part 6a extending integrally at the inner peripheral part of the cylinder 6, and this slide part 6a has the coupling length enough to prevent the play between a power varying operation member 2 and the intermediate cylinder 6. A cam pin 8 is implanted in the slide part 6a and the cam pin 8 engages a straight groove 1e provided to the fixed cylinder 1 and a cam groove 10c provided to a cam ring 10 fitted onto the fixed cylinder. The power varying operation ring 2 and intermediate cylinder 6 are movable only in the optical axis direction and inhibited from moving in the rotating direction. Consequently, the secure power varying operation is enabled.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention has a variable power optical system and a focusing optical system that move together in the optical axis direction during a variable power operation, and also includes a variable power optical system and a focusing optical system that move together in the optical axis direction during a variable power operation. Regarding a zoom lens barrel equipped with an external operating member for moving the variable magnification optical system in the optical axis direction in a straight line, more specifically, an intermediate barrel and a fixed barrel that move in the optical axis direction integrally with the external operating member. Regarding the improvement of the structural relationship between

(Prior Art) Conventionally, in this type of zoom lens barrel, for example, the fifth
The structure shown in the figure is known (Japanese Patent Application No. 62
-298680).

In FIG. 5, the fixed barrel 51 holds the fixed lens group L3 at its inner peripheral portion 51g. The fixed barrel 51 is provided with a protrusion 51f extending in the optical axis direction. Furthermore, a first group sliding ring 57 and a second and fourth group holding ring 62 are fitted inside the protruding portion 51f. The 2.4 group holding ring 62 holds variable power lens groups L2 and Ls. An engaging protrusion 51b is provided at the object-side end of the fixed barrel 51, and is fitted into a rectilinear groove 52a provided in a variable magnification operation ring 52 disposed outside the fixed barrel 51. The variable power operation ring 52 moves straight in the optical axis direction due to the engagements 51b and 52a.

Since the variable power operation ring 52 is integrated with the intermediate cylinder 56 by screwing, the intermediate cylinder 56 also moves straight in the optical axis direction as a body. The subject-side inner peripheral portion 56d of the intermediate cylinder 56 is located outside the fixed cylinder protrusion 51f and the cam ring 60, and is connected to the first group sliding ring 57.
It fits into a protrusion 57b that protrudes further toward the body.

Further, a fine thread 56b is provided on the outer periphery of the inner peripheral portion 56d of the intermediate cylinder 56, and is screwed into a fine thread 53b provided on the inner periphery of the focusing adjustment ring 53 on the body side.
The J4 node ring 53 is rotatable with respect to the intermediate cylinder 56.

The first group holding ring 61 has a focusing lens group L inside it! is held. The first group holding ring 61 is provided with an engaging protrusion 61 a on the body side end of its outer periphery, and is fitted into a groove 53 a provided on the inner periphery of the focusing adjustment ring 53 . 1f! A helicoid screw 61b is provided on the inner circumference of the holding ring 61 on the body side, and is screwed into a helicoid screw 57a provided on the outer circumference of the first group sliding ring 57 on the subject side.

The first group holding ring 61 is rotatable with respect to the first group sliding cylinder 57. A bayonet portion 6Lc for attaching a hood is provided at the object-side end of the outer periphery of the first group holding ring 61.

A cam pin 58 is implanted in the cam ring 60, and a protrusion 56c protrudes from the intermediate cylinder 56 on the outside of the cam ring 60.
It fits into a cam groove 56a provided in the cam groove 56a. Cam pin 5
8 and the cam groove 56a, the movement of the variable power operation member 52, 56 in the optical axis direction is converted into rotation of the cam ring 6o about the optical axis.

A cam pin 63 is implanted in the sliding portion 57c of the first group sliding ring 57, and a cam groove 6 is provided in the straight groove 51c provided in the protruding portion 51f of the fixed barrel 51 and the cam ring 60 on the outside thereof.
It is inserted into 0b. By engaging the cam pin 63, the linear groove 51c, and the cam groove 60b in this manner, rotation of the cam ring 60 about the optical axis is converted into movement of the first group sliding ring 57 in the optical axis direction.

A cam pin 59 is implanted in the sliding portion 62a of the second group holding ring 62, and is inserted into a straight groove 51d provided in the protruding portion 51f of the fixed barrel 51 and a cam groove 60a provided in the cam ring 60 on the outside thereof. It is embedded. The engagement of the cam pin 59, the linear groove 51d, and the cam groove 60& converts the rotation of the cam ring 60 around the optical axis into movement of the 2.4 group sliding ring 62 in the optical axis direction.

A pin 64 is implanted in the protrusion 51f of the fixed barrel 51, and is fitted into a circumferential groove 60c provided in the cam ring 60, thereby restricting movement of the cam ring 60 in the optical axis direction.

In the lens barrel configured as described above, the zooming operation is performed using the zooming operation member 52.56 or the focusing adjustment ring 5, which is integrated with the zooming operation member 52.56 in terms of movement in the optical axis direction during the zooming operation.
3 and move it in the optical axis direction.

This operation causes the intermediate cylinder 56 to move straight, so the cam ring 6
0 is restricted from moving in the optical axis direction by engagement with the pin 64 and the circumferential groove 60c, and rotates around the optical axis by engagement between the cam pin 58 and the cam groove 56a. When the cam ring 60 rotates around the optical axis, the first group sliding ring 57 moves straight due to the engagement of the cam pin 63, the straight groove 51c, and the cam groove 60b, and the first group sliding ring 57 and the optical axis during magnification changing operation move in a straight line. Regarding movement in the direction, the first group holding member 61, which is integral, also moves straight to move the focusing lens group Ll to a predetermined position.

Similarly, when the cam ring 60 rotates around the optical axis, due to the engagement of the cam bin 59, the linear groove 51d, and the cam groove 60a,
The 2.4 group holding ring 62 moves straight to the variable magnification lens group L2,
Move Ls to a predetermined position. During the magnification change operation, the moving speeds of the first group member Ll, 61.57 and the magnification change member 53, 56, 52 are not the same, and their relative positions approach each other, so an interval 3~intersection is provided between them. There is also a 1st group retaining ring 6
1 and the focusing adjustment ring 53 are engaged with each other by a groove 53a extending in the optical axis direction and an engaging protrusion 61a, and the zooming operation member 52.
56 in the optical axis direction, the first group holding ring 61 does not move together.

The focusing operation is performed by rotating the focusing adjustment ring 53 around the optical axis.

When the focus y4 joint ring 53 rotates, the cam groove 61a and the groove 53
The first group holding ring 61 rotates due to the engagement with
Since the group holding ring 61 is held by the helicoid screws 57a and 61b with respect to the first group sliding ring 57, it moves in the optical axis direction and moves the focusing lens group L+ to the focusing position.

(Problems to be Solved by the Invention) The conventional lens barrel described above has the following problems to be solved.

The variable magnification operation members 52 and 56 include a first group sliding ring 57 and an inner circumferential portion 56.
Although they are fitted at point d, since the fitting length is short, the variable magnification operation members 52 and 56 have a large play, and a good operating feeling cannot be obtained.

Further, during the zooming operation, the inner peripheral portion 56d slides on the protruding portion 57b of the first group sliding ring 57, but the zooming operation member 52.5
Due to the rattling of the lens 6, the two pressed against each other, increasing the force required to change the magnification, making it impossible to operate smoothly.

Further, the intermediate cylinder 56 is fixed to the focusing adjustment ring 53, and is provided with a notch 56e in order to reduce the rotation range around the optical axis of the transmission key 55 for transmitting driving force during automatic focusing. Furthermore, since a cam is provided on the protruding portion 56c on the inner circumference, the shape is complicated, machining is difficult, and it is difficult to ensure the accuracy of the cam.

Also, this intermediate cylinder 56 has many notches.

Its strength is weakened, and the outer peripheral portion 56f of the intermediate cylinder 56
If you hold firmly, the fine screw 56 provided near it will open.
b is deformed, the operation of the focusing adjustment ring 53 becomes defective, and the focusing operation is sometimes interrupted during automatic focusing.

FIG. 4b shows a state in which the hood 65 is attached to the bayonet portion 61c at the tip of the first group holding member 61. In this state, when the focus adjustment ring 53 is held and operated, the position of the finger is not on the focus adjustment ring 53. If the hood 6 is located at the tip G' (solid ellipse) instead of at the center G (dashed ellipse),
5, the distance between the 1st group member I, +, 57.61 and the variable magnification operation member 52.56 is too large for this lens barrel when the variable magnification operation is performed. 14 (shown in FIG. 5), but if you grip the focusing operation ring 53 and try to operate it in the optical axis direction during this magnification change operation, your finger will touch the tip G.

In this position, since the focus adjustment ring 53 and the hood 65 are held down at the same time, the distance 4 cannot be changed, and the magnification cannot be changed.

Furthermore, during focusing operations, if the focusing adjustment ring 53 is rotated in the direction in which the distance indicator 4 in FIG. .

Furthermore, the intermediate cylinder 56 is located above the movable member 57, which also has the drawback of large play.

Accordingly, an object of the present invention is to provide a zoom lens barrel that eliminates the backlash of the intermediate barrel 56 and allows easy and reliable zooming operations.

(Means for Solving the Problems) In order to achieve the above object, the zoom lens barrel of the present invention includes a variable power optical system (L2) that moves in the optical axis direction during a variable power operation.
, L4) and a focusing optical system (Ll),
A zoom lens barrel equipped with an external operation member (2) for moving the variable power optical system in the optical axis direction by moving straight in the optical axis direction during a variable power operation, comprising: a fixed barrel (1); A retaining ring (12) that holds the optical system; an intermediate cylinder (6) that is operatively connected to the retaining ring and moves straight in the optical axis direction integrally with the external operating member; and interlocking with the external operating member. and a sliding ring (7) for moving the focusing optical system, and the intermediate cylinder is fitted inside the fixed cylinder with a long fitting length,
The sliding ring and the holding ring are further fitted inside the intermediate cylinder.

(Function) According to the present invention configured as described above, since the intermediate cylinder is fitted inside the fixed cylinder with a sufficient fitting length, shaking of the variable power operation member can be prevented. Furthermore, since the sliding ring and the retaining ring are fitted inside the intermediate cylinder, the tilting of the optical system is reduced, and optical performance is maintained.

(Embodiment) An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. In the drawings, the same parts are indicated by the same reference numerals.

FIG. 1 is a longitudinal sectional view of a zoom lens barrel showing one embodiment of the present invention. One end of the fixed barrel l in the optical axis direction is a mount part la provided for attaching the lens barrel to a camera body (not shown). A holding frame 1h is provided on the inner circumference of the fixed barrel l, and holds the fixed lens group L3. The fixed barrel 1 further includes an annular protrusion 1f extending toward the subject in the optical axis direction, and a cam ring 10 is fitted on the radially outer side of the protrusion 1f.

The variable power operation ring 2 is disposed outside the fixed tube 1, and the intermediate tube 6 is integrally fixed to the variable power operation ring 2 by screws or the like.

Therefore, when the variable power operation ring 2 is moved straight in the optical axis direction, the intermediate tube 6 is also moved in the same way. The intermediate cylinder 6 has a cylindrical sliding part 6a that extends integrally at its inner circumference and fits inside the protruding part if of the fixed cylinder l, and this sliding part 6a is connected to the variable magnification operation member. A sufficient length is ensured as the fitting length to prevent the 2 and intermediate cylinders 6 from wobbling. Sliding part 6a
A cam pin 8 is installed in the cam pin 8.

The cam pin 8 engages with a straight groove le provided in the fixed barrel 1 and a cam groove 10c provided in a cam ring 10 that fits on the outside of the fixed barrel 1. Therefore, the intermediate cylinder 6 has the straight groove 1
e and the cam pin 8, so that the variable power operation members, that is, the variable power operation ring 2 and the intermediate tube 6, can only move in the optical axis direction, and cannot be moved in the rotational direction. are regulated. Furthermore, due to the engagement between the cam pin 8 and the cam groove 10c, the amount of movement of the variable power operation ring 2 and the intermediate cylinder 6 in the optical axis direction is converted into the amount of movement in the rotational direction of the cam ring 10 via the cam groove 10c. Ru.

A helicoid portion 6b is further provided on the outer circumferential side of the intermediate cylinder 6, and is screwed into a helicoid portion 3b provided on the inner circumference of the end of the focusing TR segment ring 3. Therefore, by screwing these two together, the focusing adjustment ring 3 is held in the intermediate cylinder 6.
A bayonet portion 3C is provided on the outer periphery of the object-side end of the focusing steel ring 3 for attaching an accessory such as a lens hood.

The first group lens holding ring 11 has a first lens group Ll on its inner periphery.
is held. The mount portion la of this first group holding ring 11
An engaging protrusion 11a is provided on the outer peripheral portion of the focusing ring 3, and the engaging protrusion 11a fits into a groove 3a carved in the inner circumference of the focusing adjustment ring 3 and extending in the optical axis direction. There is. Further, a helicoid portion 11b is provided inside the engagement protrusion 11a, and this helicoid portion 11b connects the sliding portion 6a of the intermediate cylinder 6 and the first group sliding ring 7 fitted inside the sliding portion 6a. Helicoid part 7a provided on the outer periphery of one end closer to the object in the optical axis direction
It is screwed together. Therefore, the rotation of the focus adjustment ring 3 is transmitted to the first group holding ring 11 by the screwing or engagement with the helicoid parts 3b and 6b, the engagement protrusion 11a and the groove 3a, and the helicoid part 7a and llb. Because of the above configuration, when the variable power operation ring 2 and the intermediate tube 6 move in the optical axis direction,
The focusing operation ring 3 also moves together, but the 1st group holding ring 1
1 is not restrained by the movement of the focusing adjustment ring 3 in the optical axis direction, so this movement in the forward axis direction is not transmitted to the first group holding ring 11.

The first group sliding ring 7 is fitted inside the intermediate tube 6 with a length sufficient to prevent the first group lens L1 from falling. A cam pin 13 for zoom operation that protrudes outward in the radial direction is implanted in the sliding ring 7. The cam pin 13 penetrates the escape groove 6c provided in the sliding portion 6a of the intermediate cylinder 6, and engages with the straight movement 1i11c provided in the fixed cylinder l and the cam groove 10b provided in the cam ring 10. It is unable to rotate. Therefore, the cam pin 13 and the cam fJ10b
] This functions to convert the rotational motion of the cam ring IQ into linear motion of the first group sliding ring 7 in the optical axis direction.

The second and fourth group holding ring 12 is fitted inside the intermediate cylinder 6, and holds the second lens group L2 and the fourth lens group L4 on the inner peripheral portion thereof.

A zoom cam pin 9 is provided on the outer periphery of the second and fourth group holding ring 12.
The cam pin 9 passes through an escape groove 1d provided in the intermediate cylinder 6 and fits into a straight groove 1d provided in the fixed cylinder 1 and a cam groove 10a provided in the cam ring IO. It matches. Therefore, the second and fourth group holding rings 12 are rendered unrotatable by the engagement between the linear groove 1d and the cam pin 9, and the engagement between the cam pin 9 and the cam groove 10a prevents the rotation of the cam ring 10. This is converted into linear movement of the second and fourth group holding rings in the optical axis direction.

The cam ring lO is restricted from moving in the optical axis direction because the pin 14 implanted in the fixed cylinder 1 is fitted into the circumferential groove 10d provided in the cam ring lO.

Also, between the inner periphery of the fixed barrel l and the cam ring 10, there is a driving force transmission mechanism (not shown) that transmits the driving force from the camera body (not shown), so that the optical axis is only rotated. A rotation transmission ring 4 is provided which is held in this manner. This rotation transmission ring 4 is provided with a keyway 4a, and a transmission key 5 fixed to the focusing adjustment ring 3 with screws or the like is fitted into this keyway 4a, so that the rotation of the rotation transmission ring 4 can be rotated. is transmitted to the focusing adjustment ring 3. As a result, the focus adjustment ring 3 is rotatably held by the intermediate cylinder 6 via the helicoid parts 3b and 6b, and thus rotates.

(motion) The zoom lens barrel described above operates as follows.

During automatic focusing operation, the rotation of the rotation transmission ring 4 causes the focus adjustment ring 3 to rotate as described above, and the rotation of the focus adjustment ring 3 is controlled by the first group holding ring 11 by the engagement protrusion 11a and the groove 3a.
transmitted to.

As a result, the rotation of the first group holding ring 11 is restricted.
Since it is screwed into the group sliding ring 7 by a helicoid, it moves in the optical axis direction while rotating to a predetermined focusing position.

In addition, during manual focusing operation, the focusing adjustment ring 3 is held and rotated, and then, similarly to automatic focusing, the first group holding ring 11 is moved in the optical axis direction to perform the focusing operation. is completed.

Zooming, that is, a variable magnification operation, is performed by holding the variable magnification operation ring 2 and moving it in the optical axis direction.
Since the rotation of the intermediate cylinder 6, the cam pin 8, and the straight groove 1e is restricted, it moves straight in the optical axis direction. Furthermore, when the cam pin 8 moves straight, the cam pin 8 and the cam groove 1
The cam ring 10 engaged at 0c is connected to the pin 14 and the circumferential groove 1.
Since movement in the optical axis direction is restricted by 0d,
When the cam ring 10 rotates, the cam n
The cam pin 9 and cam pin 13 engaged with 10 a and the fob move along the directions regulated by their respective cam grooves, and the optical systems of the 1st and 2.4th groups are moved to positions corresponding to predetermined focal lengths. move it to.

FIG. 2 is a developed view showing the arrangement of each cam groove of the cam ring 10. FIG. FIG. 2 shows the state at the tele (infinity side) end.

When the variable power operation ring 2 is moved in the optical axis direction from the telephoto state to the wide (close-up side) state, the cam pin 8 installed in the variable power operation ring 2 moves into the cam groove 1e provided in the fixed barrel 1. Since rotation is restricted by , it moves straight in the direction of arrow B in FIG.

At this time, since the cam pin 8 is also engaged with the cam groove 10c, the cam ring 10 rotates in the direction of arrow A in FIG. 2 as the cam pin 8 moves straight. As already explained, −
Since the movement of the cam ring 10 in the optical axis direction is restricted by the pin 14 installed in the fixed cylinder 1, the cam ring 10 does not move in the optical axis direction but only rotates around the optical axis.

The pin 13 implanted in the first group sliding ring 7 is engaged with the cam groove 10b, so when the cam ring 10 rotates in the direction of arrow A, the rotation is restricted by the straight groove lc of the fixed cylinder 1. Initially,
Move in the direction of arrow C. When the cam ring 10 rotates further and the cam pin 13 passes the U-turn portion of the cam groove 10b, it moves in the direction of arrow B. At this time, the first group holding ring 11 and the first group lens Ll also move together with the first group sliding ring 7 first in the direction of arrow C and then in the direction of arrow B. Also,? And the bottle 9 installed in the fourth group holding ring 12 is
Since it is engaged with the cam groove 10a, the arrow A of the cam ring 10
Along with the rotation in the direction, the rotation is restricted by the straight groove ld of the fixed cylinder 1 and moves in the direction of the arrow C. Therefore, at this time 2
The second and fourth lens groups L2 and L4 held by the fourth group holding ring 12 also move together in the direction of arrow C.

By this movement of the second and fourth lens groups, a wide-angle state is achieved. Incidentally, as shown in FIG. 2, all the cam grooves are gathered into a single cam ring 10, which is convenient for ensuring mutual accuracy of the cam grooves.

FIG. 3 is a diagram in which the telephoto ends T are aligned and overlapped in accordance with the shapes of the center lines of the cam grooves fob and 10c in FIG. 2.

In FIG. 3, the cam groove 10b controls the movement of the first group related members, that is, the first group lens L+, the first group holding ring 11, and the first group sliding ring 7, and the cam groove 10c controls the movement of the first group related members, that is, the first group holding ring 11 and the first group sliding ring 7. It shows the movement of the double operating ring 2 and the intermediate cylinder 6. In FIG. 3, when moving from the telephoto end T to the wide end W, the relative positional relationship of the first group related members and the zooming related members is as shown in the figure. After the member moves faster than the related member of the first group and gradually accelerates, and the difference in the amount of movement between the two reaches the maximum amount ■,
Deceleration begins in section E, and at the end of section E, the difference in the amount of movement between the two becomes O, and the relative positional relationship returns to the same state as at the telephoto end. After that, when moving to section F, the movement of the first group related members becomes faster, and while accelerating, the wide end W
As shown in the figure above, the distance between the magnification change operation related members and the 1st group related members will decrease by ll at the maximum, so the distance between them must be at least equal to or greater than this difference lr. This amount must be the distance it between the end surface of the engaging protrusion 11a and the end surface of the helicoid portion 3b of the focusing adjustment ring 3 and the end surface of the first group sliding ring 7 and the intermediate cylinder 6 shown in FIG. Distance statement between the end face of ? It is. Therefore, it is set so that ll>sentence 2 and Hz>lr.

FIG. 4a shows a state in which the attachment part 15b of the lens hood 15 is attached to the bayonet part 3C.
4a is a partial cross-sectional view of the tip of the lens barrel shown in the figure, and when performing an automatic focusing operation in FIG.
This is done by holding the focusing adjustment ring 3 which is integrated with the intermediate cylinder 6 by a helicoidal connection.
This is because if the ring joint is maintained, the zooming operation and focusing operation can be performed in one operation, similar to the known one-operation zooming mechanism. The position F of the operating finger at this time is indicated by an ellipse in Fig. 4a, but as is clear from the drawing,
Since the bayonet portion 3c is provided at the front end of the focusing adjustment ring 3, when the focusing adjustment ring 3 is held, the finger is placed at the position F.
, the finger F hits the inclined part 15a of the lens hood 15, so the finger F ends up holding both a part of the outer periphery of the focusing joint 3 and this inclined part 15a, and is used for focusing operations and zooming operations. In either case, it can be held securely and operability is improved.

On the other hand, conventionally, as already explained, for example, the fifth
As shown in FIG. 4b, which is a partial cross-sectional view of the lens barrel shown in the figure, a bayonet portion 61c is provided on the outer periphery of the first group lens holding ring 61 that moves during a focusing operation, so a lens hood is provided here. When the mounting part Q5b of 65 is attached, when the distance 4 decreases during the zooming operation, if the lens hood 61 and the focusing adjustment ring 53 are simultaneously pressed down with fingers, this distance 4 will be maintained. This will make it impossible to change the magnification.

In other words, there is no problem if the finger is at position G, but when it is at position G', the finger gets in the way and interferes with the zooming operation. Further, in this case, the finger may be caught in the interval cross section 4, making it difficult to perform the focusing operation itself. However, according to an embodiment of the present invention as described above, these problems are solved.

(Effects of the Invention) According to the zoom lens barrel of the present invention described above, the following effects can be obtained.

Since the intermediate cylinder, which is integrated with the variable power operation ring that performs the variable power operation, is fitted inside the fixed cylinder with a sufficiently long fitting length, there is no wobbling during the variable power operation.

Further, since the sliding ring and the holding ring are fitted inside the intermediate cylinder, the tilting of the optical system is reduced, and the optical property is secured.

Furthermore, since the intermediate cylinder is fitted inside the fixed cylinder, the shape of the intermediate cylinder is simple and processing becomes easy.

Since the hood attachment part is provided on the focus adjustment ring, operability is improved during focusing operations and zooming operations.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a zoom lens barrel showing an embodiment of the present invention, FIG. 2 is a developed view of the cam ring in FIG. 1 in the telephoto state, and FIG. 4b is a diagram showing the relative positional relationship between the two cam grooves shown in FIG. 2; FIG. 4a is a partial cross-sectional view showing the embodiment shown in FIG. 1 with a lens hood attached; FIG. This figure is a partial sectional view showing a state in which a lens hood is attached to the conventional zoom lens barrel shown in FIG. FIG. 5 is a longitudinal sectional view showing a conventional zoom lens barrel. [Explanation of symbols of main parts] l... ...Fixed tube 2... ...Magnifying operation ring 6... ...Intermediate tube 7... ... 1 group sliding ring 12 ... ... holding ring 2) vl D E Ft 3 mouth 4a mouth'' 64b

Claims (1)

[Scope of Claims] 1. It has a variable power optical system and a focusing optical system that move together in the optical axis direction during a variable power operation, and moves straight in the optical axis direction during a variable power operation to move the variable power optical system to the optical axis. A zoom lens barrel equipped with an external operating member for moving in the axial direction, comprising: a fixed barrel, a retaining ring that holds the variable magnification optical system, and a retaining ring operably connected to the retaining ring and the external operating member. It consists of an intermediate cylinder that integrally moves straight in the optical axis direction, and a sliding ring that moves in conjunction with the external operating member and moves the focusing optical system, and the intermediate cylinder has a fitting length with the fixed cylinder. A zoom lens barrel characterized in that the intermediate barrel is long and fitted inside the barrel, and the sliding ring and the holding ring are further fitted inside the intermediate barrel. 2. A focusing operation ring that can be externally operated for performing a focusing operation is operatively connected to the sliding ring, and the focusing operation ring is provided with a mounting portion for attaching a lens hood. The zoom lens barrel according to claim 1, characterized in that: