JPH0943477A - Zoom lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the whole length of a screw-extending system zoom lens. SOLUTION: A screw rod 20 is fixed on the base part 13 of a fixed barrel 12, a driving bar 30 and guide bars 40 and 41 are engaged with the rod 20. A gear cylinder 24 which is engaged with the driving bar 30 and the guide bars 40 and 41 is installed inside the fixed barrel 12. The engaging part 88 of a 2nd moving group 80 is engaged with the male screw 38 of the driving bar 30. A cam plate 50 is rotatably and turnably supported by the guide bar 41. When the gear cylinder 24 is rotated by a zoom driving unit 26, the driving bar 30 and the guide bars 40 and 41 are screw-extended along the screw rod 20. The 2nd lens group 80 is stillmore screw-extended by the male screw 38 of the driving bar 30. The 1st lens group 60 is moved by the cam plate 50 in accordance with the movement of the 2nd lens group 80.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zoom lens barrel, and more particularly to a zoom lens barrel suitable for a zoom lens.

[0002]

2. Description of the Related Art In a zoom lens, the focal length is changed by moving a plurality of lens groups. As a method for moving the lens groups, there are a cam ring method using a cam ring and a feed screw method using a feed screw. is there.

In a cam ring type zoom lens, a cylindrical cam ring is arranged so as to surround the optical axis of the lens,
A plurality of lens groups in the zoom lens barrel can be moved in the optical axis direction by guiding a cam groove formed on the circumferential surface of the cam ring. When the cam ring rotates and the lens group moves, the entire lens length expands and contracts. Further, by using a lens barrel using a multi-stage cam, it is possible to shorten the total lens length when not in use.

However, when the cam ring system is applied to a power zoom lens or the like which requires a motor for driving a zoom and devices such as an electric circuit to be arranged in the zoom lens barrel, the devices are placed outside the cam ring. If they are arranged, the outer diameter of the lens becomes larger accordingly. Further, if the devices are arranged inside the cam ring, the cam ring itself becomes large, and eventually the lens outer diameter becomes large. Although it is conceivable to cut out the cam ring to arrange the devices, it is not practically easy because a plurality of cam grooves of the same shape are normally formed in the cam ring evenly in the circumferential direction.

On the other hand, in the feed screw type zoom lens, like the zoom lens 1 shown in FIG. 1, for example, two rotary shafts 2a and 2b and two guide rods 3a and 3b are provided around the optical axis. Will be placed. A male screw is formed on the outer peripheral surface of the first rotating shaft 2a, and the rear lens group 6 screwed onto the male screw is screw-fed in the optical axis direction by the rotation of the first rotating shaft 2a.
Engaging pins 5a (not shown) and 6a are provided on the front and rear lens groups 5 and 6, and the engaging pins 5a and 6a are rotatably supported by a pin 8c on the zoom lens barrel fixing portion 9. The two cam grooves 8a and 8b formed in the cam plate 8 are engaged with each other. When the rotation shaft 2a rotates and the rear lens group 6 is moved, the cam plate 8 rotates, and the front lens group 5 moves the rear lens group 6 by the relative distance determined by the cam grooves 8a and 8b. Moved to a position away from. The zoom lens 1 of FIG. 1 is a power zoom lens, and devices such as a motor 7a for driving the lens and a gear train 7b are arranged between the rotation shafts 2a and 2b and the guide shaft 3b. Therefore, the lens outer diameter does not become large as in the case of the cam ring system (for example, Japanese Patent Laid-Open No. 3-223803).

However, the two rotary shafts 2a and 2b and the two guide rods 3a and 3b are connected to the front wall 9a of the zoom lens barrel fixing portion 9.
Since it is arranged between the rear wall 9b and the rear wall 9b, the total lens length remains the fixed length determined by the zoom lens barrel fixing portion 9, and the total lens length cannot be shortened.

That is, in the zoom lens, if the multi-stage cam ring system is adopted, the total lens length can be shortened but the lens outer diameter becomes large. On the other hand, if the feed screw method is adopted, the outer diameter of the lens can be reduced, but the total lens length cannot be shortened.

[0008]

SUMMARY OF THE INVENTION Therefore, the technical problem to be solved by the present invention is to provide a zoom lens barrel capable of shortening the total lens length without increasing the lens outer diameter.

[0009]

According to the present invention, there is provided a zoom lens barrel having the following configuration.

That is, the zoom lens barrel basically comprises at least two lens groups and a feed mechanism for moving the support members supporting the lens groups back and forth in cooperation with each other. In the feed mechanism, at least a first outer peripheral screw is formed on each of the lens groups, a screw rod having one end fixed to the zoom lens barrel base and extending in the optical axis direction, and a first inner peripheral screw are formed. A sleeve having a threaded hole that is fitted into the threaded rod and screw-engaged with the threaded rod.
Each of them is provided with a rotation driving means for rotating the sleeve. A second outer peripheral thread is formed on the sleeve and a second inner peripheral thread is formed on the support member for at least one of the lens groups, and the second outer peripheral thread is threadedly engaged with the sleeve.

In the above-mentioned structure, the screw feed engagement by the outer peripheral screw and the inner peripheral screw widely includes those by a mechanism in which one is relatively rotated with respect to the other to move relative to each other in the axial direction. Widely includes not only a general screw mechanism using an internal thread and a female screw, but also a cam mechanism in which one is a cam groove or a cam mountain and the other is a protrusion or a recess that engages with the cam groove or the cam mountain. . Therefore, in addition to the external thread and the internal thread, the outer peripheral thread and the inner peripheral thread are provided on the cam groove or the cam crest formed on either the outer peripheral side or the inner peripheral side, and on the cam groove or the cam crest formed on the other side. Including protrusions or recesses that engage. For example, the case where the outer peripheral screw or the inner peripheral screw is a protrusion or a recess is also included.

In the above structure, when the sleeve is rotated by the rotation driving means, the sleeve is fitted in the screw rod and engages in the screw feed, and therefore moves in the axial direction while rotating relative to the screw rod. For one of the lens groups, the support member threadably engages the sleeve, so that the support member moves further in the axial direction relative to the sleeve as the sleeve rotates. That is, the support member for one lens group further moves in addition to the axial movement amount of the sleeve with respect to the screw rod, and the axial relative movement amount with respect to the sleeve due to the rotation of the sleeve.
Therefore, it is possible to expand and contract the entire lens length.
Further, if the rotation driving means and the like are arranged between the screw rods,
It is possible to prevent the lens outer diameter from increasing as in the cam ring type power zoom lens.

Therefore, the zoom lens barrel having the above structure can shorten the total lens length without increasing the lens outer diameter.

In the zoom lens, it is necessary to link at least two lens groups, and the present invention includes the following three modes.

That is, in a first aspect, the feed mechanism further includes a cam plate rotatably and rotatably supported by the sleeve for the other lens group.
The cam plate is formed with at least two cam grooves that engage with the support members that support the lens groups.

In the above-mentioned structure, each sleeve is axially moved by the rotation driving means while rotating along the screw rod. The support member for one of the lens groups is further moved in the axial direction relative to the sleeve by the rotation of the sleeve. The cam plate supported by the sleeve with respect to the other lens group does not rotate together with the sleeve even if the sleeve rotates, and generally holds its posture. However, the cam plate moves axially with the sleeve. The cam plate supported by the sleeve for the other lens group is rotated by the axial relative movement of the support member for the one lens group with respect to the sleeve. Since the support member for the other lens group engages with another cam groove of the cam plate, the rotation of the cam plate brings the position apart from the support member for one lens group by the distance between the cam grooves. That is, the support member for the other lens group is moved in the axial direction by the axial movement of the cam plate due to the axial movement of the sleeve and the rotation of the cam plate by the support member for the one lens group. That is, the support member for the first lens group and the support member for the second lens group are interlocked.

Therefore, the position of each lens group can be controlled with high precision with a small and simple structure.

As a second aspect, a second outer peripheral thread is formed on the sleeve and a second inner peripheral thread is formed on the support member with respect to the other lens group, and the sleeve and the screw feed. Engage. The feeding mechanism is provided with the rotary drive means for independently rotating the sleeves with respect to the lens groups, and further provided with interlocking control means for interlocking the drive by the rotary drive means.

In the above arrangement, for each lens group,
A support member, a sleeve, a screw rod, and a rotation drive unit are provided, and the position of the support member with respect to each lens group is independently driven by each rotation drive unit, and the position of the support member with respect to other lens groups is mutually independent. Irrelevant to. However, in order to interlock the position of the support member with respect to each lens group, the interlocking control means controls each rotation driving means.

Therefore, the positions of the respective lens groups can be freely set in association with each other.

As a third aspect, the feeding mechanism includes one of the rotary driving means. A second outer peripheral thread is formed on the sleeve and a second inner peripheral thread is formed on the support member with respect to the other lens group, and is engaged with the sleeve by screw feed. For at least one of the lens groups, one of the second outer peripheral thread of the sleeve and the second inner peripheral thread of the support member is a cam groove or cam crest, and the other is the cam groove or cam. Protrusions or depressions that engage the crests.

In the above structure, for each lens group,
The support member, the sleeve, the screw rod, and the rotation driving means are respectively provided, and the sleeve for each lens group is synchronously rotated by one rotation driving means. For each lens group, the second outer peripheral thread of the sleeve and the second inner peripheral thread of the support member are respectively formed with a cam groove or a cam crest and a protrusion or a recess that engages with the cam groove or the cam crest. The respective support members are cam-fed by the rotation of the sleeve. That is, the cam feed of the support member to each lens group can be interlocked with each other in response to the rotation of each sleeve by the rotation driving means.

Therefore, it is easy to interlock each lens group.

Preferably, for at least one of the lens groups, one of the first outer peripheral thread of the screw rod and the first inner peripheral thread of the sleeve is a cam groove or a cam crest, and the other is. A protrusion or a recess that engages with the cam groove or the cam crest.

Further, preferably, for at least one of the lens groups, one of the second outer peripheral screw of the sleeve and the second inner peripheral screw of the support member is a cam groove or a cam crest. The other is a protrusion or a recess that engages with the cam groove or the cam crest.

In each of the above-mentioned two configurations, the axial feed of the cam groove or the cam crest is arbitrarily changed with respect to the rotation, whereby the sleeve and / or the supporting member are appropriately proportioned to the rotation of the rotary drive means. It can move axially while changing. Therefore, it is possible to arbitrarily set the interval and position between the lens groups with respect to the rotation of the rotation driving means.

Preferably, each sleeve has external teeth on its outer circumference. The rotation driving means of the feeding mechanism includes a gear cylinder having inner teeth meshing with the outer teeth and provided outside the screw rod, and gear cylinder rotation driving means for rotating the gear cylinder.

In the above construction, by rotating the gear cylinder, each sleeve can be rotated in synchronization. Therefore, the lens groups can be easily interlocked.

Preferably, a plurality of the above-mentioned screw rods are provided so as to surround the lens frame, and a drive mechanism, for example, a drive motor of the above-mentioned rotary drive means is arranged between the adjacent above-mentioned screw rods.

Alternatively, a plurality of the above-mentioned screw rods are provided so as to surround the lens bead frame, and between the adjacent screw rods,
An electric circuit, for example, a drive motor control circuit for the rotation driving means is arranged.

In the above two configurations, the drive circuit or the electrical circuit can be arranged substantially inward of the screw rod in the radial direction. Therefore, the lens outer diameter can be made smaller than that of the cam ring type zoom lens barrel.

Preferably, the rotary drive means directly drives the sleeve with a drive motor. For example, the drive motor is fixed to the moving member of the zoom lens barrel, and the screw rod is cantilevered. A sleeve, which is directly connected to the output shaft of the drive motor, is screwed and engaged from the free end side of the screw rod.

In the above structure, the drive motor, which is the rotation driving means, is concentric with the screw rod and can be arranged so as not to extend outside the screw rod in the lens radial direction. Therefore, it is easy to reduce the lens outer diameter.

Preferably, the rotary drive means drives the sleeve with a drive motor via a reduction gear train.

In the above structure, the reduction gear train can reduce the movement amount of the sleeve with respect to the rotation angle of the drive motor, so that the lens drive control can be performed with high accuracy.

[0036]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The zoom lens barrel of each embodiment of the present invention shown in FIGS. 2 to 12 will be described in detail below. FIG. 2 is an external perspective view of the zoom lens barrel according to the first embodiment of the present invention. FIG. 3 is a partially cutaway exploded perspective view of the zoom lens barrel of FIG. FIG. 4 is a sectional view taken along the line IV-I of FIG.
It is a top view of the cam plate seen along the V line. 5 to 7
FIG. 3 is a sectional view of the zoom lens barrel of FIG. 2. 5 shows the retracted state, FIG. 6 shows the wide end state, and FIG. 7 shows the tele end state. FIG. 8 is a schematic configuration diagram of the zoom lens barrel of the second embodiment. FIG. 9 is a schematic configuration diagram of the zoom lens barrel of the third embodiment. FIG. 10 is an exploded perspective view of the main part of the zoom lens barrel of FIG. FIG. 11 is a schematic sectional view showing the arrangement of the drive mechanism in the zoom lens barrel. FIG. 12 is a schematic cross-sectional view showing the arrangement of electrical circuits inside the zoom lens barrel.

First, the zoom lens barrel 1 according to the first embodiment.
0 will be described.

That is, the zoom lens barrel 10 is a power zoom lens, that is, an electric zoom lens. FIG.
As shown in, by operating the zoom operation button 16 provided on the outer peripheral surface of the zoom lens barrel 10, the entire length of the zoom lens barrel 10 can be expanded or contracted. That is, at the time of use, as shown in FIG.
The outer movable barrel 14 and the inner movable barrel 70 are extended from the fixed barrel 12, and when stored, the outer movable barrel 14 and the inner movable barrel 70 are separated from each other as shown in FIG. 2 (II).
It is in a retracted state, that is, it is retracted inside.

This zoom lens barrel 10 is shown in FIGS.
It is configured as shown in.

That is, the zoom lens barrel 10 includes the first moving group 60 including the first lens group 61 on the front side thereof.
The second moving group 80 including the second lens group 81 on the rear side,
Each has it.

The first moving group 60 includes an inner moving barrel 70 and a first lens support frame 62 housed inside the inner moving barrel 70.
And a focus drive unit 66.

The inner moving barrel 70 is provided with two guide portions 72, 76 projecting in the radial direction on the outer peripheral surface thereof. Also,
A transparent protective glass 78 is provided at the front end of the inner moving barrel 70. A helicoid screw 71 is provided on the inner peripheral surface of the inner moving barrel 70.
Are formed. The first lens support frame 62 has a helicoid screw 63 formed on the outer peripheral surface on the front side, and a focus gear 64 formed on the outer peripheral surface of the flange portion 65 on the rear side. The focus drive unit 66 includes a focus drive motor 67, a reduction gear train 68 that reduces the rotation of the focus drive motor 67, and an electrical circuit 69 (see FIG. 10).

The first lens support frame 62 includes an inner movable barrel 70.
The helicoid screw 71 on the inner peripheral surface of the inner moving barrel 70 and the helicoid screw 63 on the front outer peripheral surface of the first lens support frame 62 are screwed together. The output gear 68a of the reduction gear train 68 of the focus drive unit 66 meshes with the focus gear 64 on the rear outer peripheral surface of the first lens support frame 62. When the focus drive motor 67 of the focus drive unit 66 rotates, the first lens support frame 62
Moves relative to the inner moving barrel 70 and moves in the axial direction by the action of the helicoid screws 63 and 71. This allows focus adjustment.

The second moving group 80 includes a second lens support frame 82 which supports the second lens group 81 therein. On the outer peripheral surface of the second lens support frame 82, a guide roller 84 protruding outward in the radial direction, a guide portion 86, and an engaging portion 88 are provided. The second lens support frame 82 has a diaphragm unit 90 on the front side of the second lens group 81.

Inside the fixed barrel 12, a gear barrel 24, a zoom drive unit 26, three screw rods 20, a drive bar 30, two guide bars 40 and 41, and a cam plate 50 are provided. Further prepare.

The gear cylinder 24 is in sliding contact with the inner peripheral surface of the fixed cylinder 12 and is rotatable with respect to the fixed cylinder 12, but cannot move in the axial direction. Inner teeth 25 are formed on the inner peripheral surface of the gear cylinder 24. Zoom drive unit 26
Is a zoom drive motor 27, a reduction gear train 28 that reduces the rotation of the zoom drive motor 27, and an electric circuit 29 (see FIG.
The output gear 28a of the reduction gear train 28 meshes with the internal teeth 25 of the gear cylinder 24.

The three screw rods 20 are fixed to the base 13 of the fixed barrel 12 to which the lens mount 18 is fixed, are evenly arranged about the optical axis, and extend forward in the optical axis direction.
A male screw 22 is formed on the outer peripheral surface of the screw rod 20.

Drive bar 30 and guide bars 40, 41
Has a substantially cylindrical shape, and each has a threaded hole 47 formed therein, and an internal thread 44 is formed on the inner peripheral surface thereof so as to be screwed into the male thread 22 of the threaded rod 20. The drive bar 30 and the guide bars 40, 41 have flange portions 35, 45 on the rear side, and gears 36, 46 are formed on the outer peripheral surfaces of the flange portions 35, 45. This gear 36,46
Engages with the internal teeth 25 of the gear cylinder 24. The drive bar 30 has a screw 38 formed on the outer peripheral surface thereof on the front side of the flange portion 35, and the guide bars 40 and 41 have smooth surfaces 48 at those portions.

The guide portion 86 of the second lens support frame 82 is engaged with and slidably contacts one guide bar, that is, the smooth surface 48 of the first guide bar 40. The external thread 38 of the drive bar 30 is engaged with the engaging portion 88 of the second lens support frame 82. In addition, the smooth surface 4 of the guide bar 40, 41
8, the guide portions 72 and 76 of the inner moving cylinder 70 are engaged and
Make sliding contact. The front end of the first guide bar 40 and the front end of the drive bar 30 are rotatably supported by the front wall 14a of the outer moving cylinder 14.

The other guide bar, that is, the second guide bar 41, is a cam plate support portion fixed to the smooth surface 48 so as to be rotatable relative to the second guide bar 41 but not axially movable. 42. Cam plate support 4
A support pin 43 is provided so as to project from the outer peripheral surface of 2, and the cam plate 50 is rotatably and rotatably supported by the support pin 43. As shown in FIG. 4, the cam plate 50 has a substantially fan shape centered on the pin support portion 52 side, and the fan portion extends to the lens front side. The fan portion of the cam plate 50 has two cam grooves 54, 56 extending substantially in the oblique direction with the optical axis direction,
That is, the first cam groove 54 on the front side and the second cam groove 56 on the rear side
Are formed. The inner moving barrel 70 is provided in the first cam groove 54.
The guide roller 74 provided on the mounting portion of the first guide portion 72 is engaged and slidably contacted with the second cam groove 56, and the guide roller 84 provided on the second lens support frame 82 is engaged and slidably contacted with the second cam groove 56. It is like this.

When the zoom lens barrel 10 having the above-described structure is stored, the zoom lens barrel 10 is in a retracted state as shown in FIG. 5, and the drive bar 30 and the guide bars 40, 4 screwed onto the screw rod 20.
1 is located on the rearmost side, and the outer movable barrel 14, the inner movable barrel 70, the first lens support frame 62, and the second lens support frame 82 are located on the rearmost side.

On the other hand, in use, the entire lens length is extended by the following operation.

That is, during use, the zoom lens barrel 10 is first extended to the wide end to reach the wide end state shown in FIG. Then, by operating the zoom operation button 16, the zoom lens barrel 10 is further extended. When the zoom lens barrel 10 is most extended, the image shown in FIG.
The tele end state shown in FIG.

When the zoom lens barrel 10 is extended,
The zoom drive motor 27 rotates in the normal direction, and the gear cylinder 24 is rotated via the reduction gear train 28. Then, the drive bar 30 and the guide bars 40, 41 in which the gears 36, 46 mesh with the inner teeth 25 of the gear cylinder 24 are rotated. Since the drive bar 30 and the guide bars 40 and 41 are screwed into the screw rod 20, the drive bar 30 and the guide bars 40 and 41 move along the screw rod 20 toward the front of the lens as the lens rotates. The outer moving barrel 14 supported by the front end of the drive bar 30 and the front end of the first guide bar 40 also moves to the front of the lens. That is, the outer moving cylinder 14 is extended from the fixed cylinder 12.

At this time, since the drive bar 30 moves forward while rotating, the second lens support frame 82 in which the engaging portion 88 engages with the male screw 38 of the drive bar 30 is the drive bar 30.
Relative to moves to the front. That is, in addition to the movement of the drive bar 30 with respect to the screw rod 20, the second lens support frame 82 further moves forward by the amount that the drive bar 30 is rotated and screw-fed.

The relative distance between the second lens support frame 82 and the inner moving barrel 70 is adjusted by the cam plate 50. That is, since the cam plate 50 is supported by the support pins 43 of the cam plate support portion 42 of the second guide bar 41, it moves together with the second guide bar 41. The drive bar 30 and the guide bars 40 and 41 have the same movement amount due to the rotation of the gear cylinder 24, but the second lens support frame 82 in which the guide roller 84 engages and slides in the second cam groove 56 of the cam plate 50 is As described above, the male screw 38 of the drive bar 30 moves relative to the second guide bar 41 by the amount of relative movement. Therefore, the guide roller 84 of the second lens support frame 82 rotates the cam plate 50 around the support pin 43 along the second cam groove 56, whereby the guide roller 74 causes the first roller of the cam plate 50 to move. The inner moving cylinder 70 that engages and slides in the groove 54 is the second
It is moved relative to the lens support frame 82. As a result, the relative distance between the first lens group 61 supported by the first lens support frame 62 housed inside the inner moving barrel 70 and the second lens group 80 supported by the second lens support frame 82 becomes smaller. change. The inner moving barrel 70 whose relative distance to the second lens support frame 82 screw-fed by the drive bar 30 is determined by the cam plate 50 is an outer moving barrel that moves integrally with the first guide bar 40 and the drive bar 30. Compared with 14, the movement amount becomes larger by the relative movement amount of the second lens support portion 82 with respect to the drive bar 30. Therefore, the inner moving barrel 70 comes to project from the outer moving barrel 14.

When the zoom lens barrel 10 is further extended from the wide end to the tele end, the outer movable barrel 14 and the inner movable barrel 70 are similarly extended. In the tele end state, as shown in FIG. 7, the guide bars 40 and 41 and the drive bar 30 move to the frontmost with respect to the screw rod 20, and the inner moving barrel 70 moves to the frontmost with respect to the drive bar 30. Moving. Therefore, the total length of the zoom lens barrel is maximized. On the other hand, when the zoom lens barrel 10 is retracted, the operation reverse to the above is performed.

Next, the zoom lens barrel 1 according to the second embodiment.
0 will be described. As shown in the schematic configuration diagram of FIG.
The zoom lens barrel 10 has a drive bar 32 configured similarly to the drive bar 30 for the first moving group 60 including the first lens group 61 and the second moving group 80 including the second lens group 81. And the drive bar 32 includes a first moving group 6
0 for screw feed engagement as well. A rotary drive drive 33 for rotating the drive bars 30, 32 for each moving group 60, 80,
For example, a reduction gear train and a drive motor are separately provided, and an interlocking control unit 34 that interlocks the drive by each rotation drive unit 33 is further provided. The respective moving groups 60, 80 are independently moved by the respective rotation driving means 33, but the interlocking control means 34 interlocks the positions of the respective moving groups 60, 80, that is, the respective lens groups 61, 81.

Next, the zoom lens barrel 1 according to the third embodiment.
0 will be described. As shown in the schematic configuration diagram of FIG.
This is the same as the second embodiment in that the drive bars 30 and 32 are provided for each of the moving groups 60 and 80, but the rotary drive means 3
3 has only one. As shown in FIG. 10, a cam groove 39 of an appropriate shape is formed on the outer peripheral surface of the front side of each drive bar 30, 32, and each moving group 60, 80 engages with it. The movement groups 60 and 80 are restricted in rotation and are movable only in the axial direction. Therefore, when the rotation driving means 33 simultaneously rotates the drive bars 30 and 32, the respective moving groups 60 and 80 are
They move axially along the cam grooves 39 of the drive bars 30, 32 with which they engage. Therefore, each lens group 6
1, 81 are interlocked and move to an appropriate position.

The feed screw type zoom lens barrel 10 of each of the above aspects can be shortened to about half the maximum length when stored. Since there is more space inside the zoom lens barrel 10 than in the cam ring type zoom lens barrel, the screw rod 20, the drive bar 30, and the guide bar 4 are provided.
Devices can be arranged so as not to interfere with 0, 41 and the like. For example, as shown in FIG. 11, the zoom drive unit 26, the focus drive unit 66, and the aperture drive unit 92 can be arranged, and as shown in FIG. 12, the zoom drive unit 26 and the focus drive unit 66 can be arranged. Each electrical circuit 2 with the diaphragm drive unit 92
9,69,94 can be arranged.

Therefore, if the zoom lens barrel 10 of each of the above embodiments is constructed, the total lens length can be shortened without increasing the lens outer diameter.

The present invention is not limited to the above embodiment, but can be implemented in various other modes. For example, a plurality of screw feed mechanisms and the like may be combined for multi-stage feeding. Further, although the power zoom has been described, the present invention may be applied to a manual zoom lens and a single focus lens not limited to the zoom lens. Furthermore, the present invention is not limited to a single lens, and can be applied to, for example, a zoom lens barrel of a retractable compact camera.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a conventional zoom lens barrel.

FIG. 2 is an external perspective view of a zoom lens barrel according to an embodiment of the present invention.

3 is a partially cutaway exploded perspective view of the zoom lens barrel of FIG. 2. FIG.

FIG. 4 is a plan view of the cam plate taken along line IV-IV in FIG.

5 is a cross-sectional view of the zoom lens barrel of FIG. This shows the retracted state.

FIG. 6 is a sectional view similar to FIG. 4; Indicates the wide end state.

7 is a sectional view similar to FIG. The tele end state is shown.

FIG. 8 is a schematic configuration diagram of a zoom lens barrel according to a second embodiment.

FIG. 9 is a schematic configuration diagram of a zoom lens barrel according to a second embodiment.

FIG. 10 is a partially cutaway perspective view of the zoom lens barrel of FIG. 9.

FIG. 11 is a schematic cross-sectional view showing the arrangement of the drive mechanism in the zoom lens barrel.

FIG. 12 is a schematic cross-sectional view showing the arrangement of electrical circuits in the zoom lens barrel.

[Explanation of symbols]

10 zoom lens barrel 12 fixed barrel 13 base portion 14 outer moving barrel 14a front wall 16 zoom operation button 18 lens mount 20 screw rod (feed mechanism) 20a tip 22 male screw (first outer peripheral screw) 24 gear barrel (feed mechanism, Rotational drive means) 25 Internal teeth 26 Zoom drive unit (feed mechanism, rotation drive means,
Gear cylinder rotation drive means, drive mechanism) 27 Zoom drive motor (drive motor) 28 Reduction gear train 28a Output gear 29 Electrical circuit 30 Drive bar (feed mechanism, sleeve) 32 Drive bar (feed mechanism, sleeve) 33 Rotation drive mechanism ( Feed mechanism) 34 Interlocking control means (feed mechanism) 35 Flange portion 36 Gear (external tooth) 38 Male screw (second outer peripheral screw) 39 Guide groove (second outer peripheral screw) 40 First guide bar 41 Second guide bar (feed Mechanism, sleeve) 42 cam plate support 43 support pin 44 female screw (first inner peripheral screw) 45 flange 46 gear (outer tooth) 47 screw hole 48 smooth surface 50 cam plate (feed mechanism) 52 pin support 54 1 cam groove (cam groove) 56 2nd cam groove (cam groove) 60 1st movement group 61 1st lens group (lens group) 62 1st lens support frame (support member, lens ball frame) 63 helicoid screw 64 Focuser Gear 65 Flange portion 66 Focus drive unit (drive mechanism) 67 Focus drive motor 68 Reduction gear train 68a Output gear 69 Electrical circuit 70 Inner moving cylinder (support member) 71 Helicoid screw 72 First guide portion 74 Guide roller 76 Second guide portion 78 Protective Glass 80 Second Moving Group 81 Second Lens Group (Lens Group) 82 Second Lens Support Frame (Supporting Member, Lens Frame) 84 Guide Roller 86 Guide Part 88 Engaging Part (Second Inner Circumferential Screw) 90 Aperture Unit 92 Aperture drive unit (drive mechanism) 94 Electrical circuit

Claims (11)

[Claims] 1. At least two lens groups (61, 81)
And each support member (6) for supporting each lens group (61, 81)
Feeding mechanism (2, 70; 82) for moving forward and backward in cooperation with each other (2
0,24,26,30,32,33,34,41,50) in the zoom lens barrel (10), the feed mechanism (20,24,26,30,32,33,34,4)
1, 50), at least a first outer peripheral screw (22) is formed for each of the lens groups (61, 81), one end of which is fixed to the zoom lens barrel base (13) and extends in the optical axis direction. And a sleeve (30, 32, 41) that has a screw rod (20) and a screw hole (47) in which a first inner peripheral screw (44) is formed and that is screwed into the screw rod (20) for screwing engagement. ) And rotation driving means (24, 26, 33) for rotating the sleeves (30, 32, 41) respectively, and at least one of the lens groups (81) has the sleeve (30 , 32) is formed with a second outer peripheral screw (38, 39), and the support member (82) is formed with a second inner peripheral screw (88) for screw-feeding engagement with the sleeve (30, 32). This is a zoom lens barrel. 2. The feed mechanism (20, 24, 26, 30, 3)
2, 33, 34, 41, 50) is the other lens group (6
The cam plate (50) rotatably and rotatably supported by the sleeve (41) with respect to (1) is further provided.
(50) is characterized in that at least two cam grooves (54, 56) with which the support members (62, 70; 82) for supporting the respective lens groups (61, 81) are respectively engaged are formed. The zoom lens barrel according to claim 1. 3. The sleeve (32) having a second outer peripheral thread formed on the sleeve (32) and the support member having a second inner peripheral thread formed on the other lens group (61).
And screw feed engagement with the feed mechanism (20, 24, 26, 30, 32, 33, 34, 4
1, 50) are provided with the rotation driving means (33) for independently rotating the sleeves (30, 32) with respect to the lens groups (61, 81), respectively. Three
The zoom lens barrel according to claim 1, further comprising an interlocking control means (34) for interlocking the drive by 3). 4. The feed mechanism (20, 24, 26, 30, 3)
2, 33, 34, 41, 50) is one of the rotary drive means.
(33), the sleeve (3) is attached to the other lens group (61).
A second outer peripheral thread is formed on 2), a second inner peripheral thread is formed on the supporting member, and is threadedly engaged with the sleeve (32), and at least one of the lens groups (61, 81) is hand,
One of the second outer peripheral thread (39) of the sleeve (30, 32) and the second inner peripheral thread (88) of the support member (82) is a cam groove or a cam crest, and the other is The zoom lens barrel according to claim 1, wherein the zoom lens barrel is a protrusion or a recess that engages with a cam groove or a cam crest. 5. At least one of the lens groups (61, 8)
In contrast to 1), one of the first outer peripheral screw (22) of the screw rod (20) and the first inner peripheral screw (44) of the sleeve (30, 32, 41) has a cam groove or a cam. Is a mountain,
5. The zoom lens barrel according to claim 1, wherein the other is a protrusion or a recess that engages with the cam groove or the cam crest. 6. At least one of the lens groups (61, 8)
1) to the second outer peripheral thread of the sleeve (30)
(38) and the second inner peripheral screw (88) of the support member (82)
4. The zoom lens barrel according to claim 1, 2 or 3, wherein one of the two is a cam groove or a cam lobe, and the other is a protrusion or a recess that engages with the cam groove or the cam lobe. . 7. Each of said sleeves (30, 32, 41) has external teeth (36, 46) on its outer circumference, and said feed mechanism (20, 24, 26, 30, 32, 33, 34, 4).
The rotational driving means (24, 26) of the external teeth (36,
46) having internal teeth (25) meshing with said screw rod
A gear cylinder (24) provided outside the (20) and the gear cylinder
The zoom lens barrel according to claim 1, 2 or 4, further comprising a gear cylinder rotation driving means (26) for rotating the (24). 8. A plurality of the screw rods (20) are provided so as to surround the lens ball frame (62, 82), and a drive mechanism (26, 66, 92) is provided between the screw rods (20) adjacent to each other. The zoom lens barrel according to claim 1, 2, 3 or 4, wherein the zoom lens barrel is arranged. 9. A plurality of the screw rods (20) are provided so as to surround the lens ball frame (62, 82), and an electrical circuit (29, 69, 94) is provided between the screw rods (20) adjacent to each other. The zoom lens barrel according to claim 1, 2, 3 or 4, wherein the zoom lens barrel is arranged. 10. The zoom lens barrel according to claim 1, 2 or 3, wherein the rotation driving means (24, 26) directly drives the sleeve (30, 41) by a drive motor. 11. The rotary drive means (24, 26) drives the sleeve (30, 41) by a drive motor (27) via a reduction gear train (28). The zoom lens barrel according to item 2, 3, or 4.