JPH0593833A - Rotary extending mechanism - Google Patents

Abstract

(57) [Abstract] [Purpose] [Structure] Inner annular body and outer annular body that are screwed together via multiple-start male threads and multiple-start female threads ;
A rotary feed-out mechanism comprising: a gear formed to be inclined in the same direction as the multi-thread male screw ; and a pinion that meshes with the gear and relatively rotates the inner annular body with respect to the outer annular body. the outer periphery of the body, as well as plural rows forming the gear, during these plural rows of gears, to form a male screw at least Ichijo, said outer annular
A female screw that is screwed with the male screw is formed on the inner circumference of the body , and the pinion is engaged with at least one gear of the plurality of gears regardless of the feeding position of the inner annular body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary feeding mechanism that feeds one of a pair of annular bodies screwed together via a multiple thread (helicoid) while rotating it via a gear mechanism.

[0002]

2. Description of the Related Art For example, in a lens barrel, a movable (inner) annular body is screwed into a fixed (outer) annular body via a multiple thread screw, and the movable annular body is rotated to generate an optical beam. A large number of axially extending mechanisms are adopted. In the zoom compact camera, in order to drive the movable annular body with power, a gear is provided on the outer periphery of the movable annular body, and this gear is meshed with a pinion driven by a motor.

In this rotary feeding mechanism, it is necessary to provide both the multiple thread and the gear on the outer circumference of the movable annular body. Conventionally, in order to shorten the axial length of the movable annular body, this multi-thread screw and gear cut off a part of the thread of the multi-thread screw, and the cut portion is a gear inclined in the same direction as the multi-thread thread. Was provided. Thus, if the multiple thread and the gear are mixed in the same axial position, the axial length of the movable annular body can be shortened as compared with the case where both are provided in different axial positions.

However, it has been found that the following problems are encountered when trying to further increase the amount of feeding of the movable annular body in this rotary feeding mechanism. That is, in order to increase the feed amount, it is necessary to increase the number of teeth of the gear or increase the width of the gear and increase the axial length of the pinion meshing with the gear. However, increasing the number of gear teeth means that the gear extends obliquely in the direction of the multiple thread, that is, the axial length of the movable annular body increases. Further, if the width of the gear is increased, the ratio of the multiple threads to be formed in the circumferential direction is correspondingly decreased, and as a result, the movable annular body falls down.

In order to increase the zoom ratio in a zoom lens of a camera which is required to be miniaturized to the utmost limit, it is necessary to give a sufficient amount of extension without causing the movable annular body to fall down. I can't meet the demand.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotary feeding mechanism which can take a large amount of feeding of a movable annular body (inner annular body) and is less likely to fall down, based on the above-mentioned awareness of the problems of the rotary feeding mechanism. With the goal.

[0007]

SUMMARY OF THE INVENTION According to the present invention, an inner annular body and an outer annular body are screwed together via a multi-thread screw, and the gear is formed by inclining the outer circumference of the inner annular body in the same direction as the thread of the multi-thread screw. In the rotary feeding mechanism in which the gear is engaged with the pinion and the inner ring is rotated relative to the outer ring by the rotation of the pinion, a plurality of gears are formed on the outer periphery of the inner ring and At least one thread of the multi-thread screw is formed between the gears of the plurality of threads, while a plurality of escape grooves through which the gear of the plurality of threads passes are formed on the inner circumference of the outer annular body, A thread that meshes with the thread of the inner ring is formed between these clearance grooves, and the pinion is meshed with at least one gear of these multiple gears regardless of the feeding position of the inner ring. It is characterized by

According to this structure, a sufficient feed amount of the inner annular body can be ensured by the relationship between the plurality of gears and the pinion that meshes with any one of the plurality of gears. The inner threads of the inner annular body can be prevented from falling due to the threads of the multi-threaded screws which are also engaged with each other and which are also present between the clearance groove and the clearance groove.

[0009]

The present invention will be described below with reference to the illustrated embodiments.
First, with reference to FIGS. 3 to 5, an example of a zoom lens barrel provided with a rotary feeding mechanism, which is a target of the present invention, will be described.

Fixed lens barrel 11 integrated with the camera body
The helicoid ring (outer annular body) 12 is fixed to the female multi-threaded screw 12a of the helicoid ring 12, and the male multi-threaded screw 10a formed on the outer peripheral surface of the cam ring (inner annular body) 10 is screwed into the helicoid ring 12. ing. A female multi-thread screw 10b and an inner cam groove 10c are formed inside the cam ring 10, and the female multi-thread screw 10b has a front lens group barrel (male helicoid body) 13
Male multi-threaded screw 13a is screwed. A linear guide plate 14 is located at the rear end of the cam ring 10, and a radial projection 14a of the linear guide plate 14 is fitted in a linear guide groove 11a formed in the fixed lens barrel 11. A linear guide ring 15 is fixed to the linear guide plate 14, and the cam ring 10 is rotatable with respect to the linear guide ring 15.

A shutter holding frame 13b, to which a rear end portion of an annular shutter unit 16 is fixed, is fixed to the front lens barrel 13, and a helicoid ring 17 integrally provided on the inner peripheral portion of the shutter unit 16 has a shutter holding frame 13b. The front lens group frame 18 holding the front lens group is screwed. Shutter unit 1
The drive pin 16a is engaged with a driven pin 18a which is integrated with the front lens group frame 18. Drive pin 16a
As is well known, the lens is driven to rotate by an angle according to the distance measurement signal from the distance measuring device, and this rotation is transmitted to the front lens group frame 18 via the driven pin 18a, and the front lens group frame 18 (front lens group) is moved. While L1) rotates, it moves in the optical axis direction for focusing. Further, the shutter unit 16 is
The shutter blade 16b is opened and closed according to the brightness signal of the subject.

Rear lens group frame 1 supporting the rear lens group L2
9 has a cam pin 19a protruding in the radial direction, and this cam pin 19a is fitted in the above-mentioned cam groove 10c formed on the inner surface of the cam ring 10. The rear lens group frame 19 and the shutter holding frame 13b are connected to each other by the linear guide ring 15 described above.
The vehicle is guided straight by the straight guide surface formed on. FIG. 5 shows the rectilinear guide surface 15a of the rectilinear guide ring 15 and the rectilinear guide surface 19b of the rear lens group frame 19 which are engaged with each other.

The cam pin 19a of the rear lens group frame 19 has a recess 13 formed in the rear end surface of the front lens barrel 13 during assembly.
fit in b. This is because when the male multi-thread screw 13a on the outer circumference of the front lens barrel 13 is screwed into the female multi-thread screw 10b of the cam ring 10, the cam pin 19a is simultaneously moved to the inner cam groove 10c.
It is a structure to fit in. After assembly, the front group lens barrel 13 is rotated by the cam ring 10 so that the front group lens barrel 13 has multiple threads 10b, 13a
Accordingly, the rear lens group frame 19 independently moves in the optical axis direction according to the cam groove 10c.

That is, the zoom lens barrel having the above structure is
When the cam ring 10 is rotationally driven, the cam ring 10 itself moves in the optical axis direction according to the relationship between the male multi-thread screw 10a and the female multi-thread screw 12a. At the same time, female multi-start thread 10b and male multi-start thread 1
Due to the screwing relationship of 3a and the linear guide mechanism of the shutter holding frame 13b and the linear guide ring 15, the front group lens barrel 13 is provided.
The (front lens group L1) moves straight in the optical axis direction. When the cam ring 10 rotates, the relationship between the cam groove 10c on the inner surface of the cam ring 10 and the cam pin 19a provided on the rear lens group frame 19 and the rectilinear guide mechanism of the rear lens group frame 19 and the rectilinear guide ring 15 cause the rear group lens to move. The frame 19 (rear group lens L2) moves in the optical axis direction to perform zooming.

In the present invention, for example, the helicoid ring (outer annular body) 12 in the zoom lens barrel having the above-mentioned structure
The gist of the present invention is the engagement structure between the cam ring (inner annular body) 10 and the rotation drive mechanism of the cam ring 10. Cam ring 1
As shown in the development view of FIG. 1 and FIG. 5, the male 0 is formed with a male multi-thread screw 10a and a plurality of threads (three threads in this embodiment) 10d parallel to each other. ing. The gear 10d is composed of a spur gear whose teeth are parallel to the axis of the cam ring 10, is inclined in the same direction as the direction of the ridges of the male multi-thread screw 10a, and between the gears 10d,
A single thread 10a 'is formed on the male multi-thread screw 10a. In other words, the male multi-thread screw 10a is cut off at one part in the circumferential direction except for one thread 10a ', and the cut portion is provided with the gear 10d. In this embodiment, the multi-start screw 10a is a triple-start screw, and the gear 10d is provided at the cut-out portion of the double-start screw. The male multi-thread screw 10a, the thread 10a 'of one thread, and the formation length s of the gear 10d in the axial direction are the same.

On the other hand, as shown in FIG. 2, the helicoid ring 12 has, on its inner surface, the male multi-thread screw 10 of the cam ring 10.
a, a female multi-start thread 12a, and a single thread 12 corresponding to the single thread 10a 'and the triple gear 10d, respectively.
a'and an escape groove 12c are formed. That is, the screw thread 10a ′ and the screw thread 12a ′ mesh with each other, and the gear 10d has the male multi-thread screw 10a (the screw thread 10a).
When the cam ring 10 rotates in accordance with the meshing of the a ′) and the female multi-thread screw 12a (thread 12a ′), the cam ring 10 moves in the escape groove 12c without contact.

A cutout 12d is formed in the helicoid ring 12, and the pinion 20 located in the cutout 12d.
, Meshes with the gear 10d. This pinion 20
Has an axial length capable of meshing with the three gears 10d at the same time, but meshes only with the rearmost and frontmost gears 10d at the front moving end and the rear moving end of the cam ring 10, respectively. The pinion 20 is located at a fixed position in the cutout 12d, and is rotationally driven by the motor 21.

In FIG. 1, the two pinions 20 are drawn at different positions, but this is to show the meshing relationship between the pinion 20 and the gear 10d at the forward end and the backward end of the cam ring 10. Actually, the pinion 20 does not move, but the cam ring 10 moves in the optical axis direction.

Therefore, when the pinion 20 is rotationally driven by the motor 21 in the main rotation feeding mechanism having the above-described structure, the rotation is transmitted to the cam ring 10 via the gear 10d. Then, according to the engagement of the male multi-thread screw 10a (thread 10a ') and the female multi-thread screw 12a (thread 12a'), the cam ring 1
While 0 rotates forward and backward in the optical axis direction, zooming is performed.

When rotating the cam ring 10, the pinion 20 always meshes with one of the three gears 10d, and the thread 10a 'and the thread 12 are engaged.
The meshing of a'is maintained. Of course, the engagement between the male multi-thread screw 10a and the female multi-thread screw 12a is maintained, so that the helicoid ring 1
The cam ring 10 does not fall down with respect to 2.

By the way, FIGS. 6 and 7 show two comparative examples for obtaining the same feed amount of the cam ring 10 as in the embodiment of the present invention without forming the three gears 10d. FIG. 6 shows an example in which a gear 10d ′ having the same width as the gear 10d of the embodiment of the present invention is formed as one thread, and FIG. 7 shows a wide gear having the same axial length s as the gear 10d of the embodiment of the present invention. 10d ″ is formed. In the comparative example of FIG. 6, the installation length of the gear 10d ′ in the axial direction, that is, the cam ring 1 is shown.
0 becomes long, and in the comparative example of FIG. 7, the installation length of the male multi-thread screw 10a in the circumferential direction becomes short, and the cam ring 10 easily falls.

The zoom lens barrel shown in FIGS. 3 to 5 is an example of a device to which the rotary feeding mechanism of the present invention can be applied. INDUSTRIAL APPLICABILITY The present invention can be widely applied to a rotary payout mechanism for another zoom lens barrel or a rotary payout mechanism other than the zoom lens barrel.

[0023]

As described above, according to the rotary feeding mechanism of the present invention, the feeding of the inner annular body which is rotationally driven through the gear formed on the outer peripheral surface by being screwed into the outer annular body through the multiple thread is carried out. A large amount can be taken and the fall can be prevented.

[Brief description of drawings]

FIG. 1 is a development view of an inner annular body (cam ring) showing an embodiment of a rotary feeding mechanism according to the present invention.

FIG. 2 is a cross-sectional view of a meshed state of the inner annular body and the outer annular body.

FIG. 3 is a cross-sectional view showing an example of a zoom lens barrel to which a rotary feeding mechanism according to the present invention can be applied.

4 is a cross-sectional view of a main part of the zoom lens barrel in FIG.

5 is an exploded perspective view of a main part of the zoom lens barrel of FIG.

FIG. 6 is a developed view corresponding to FIG. 1 and shown as a comparative example.

FIG. 7 is a development view corresponding to FIG. 1 and shown as another comparative example.

[Explanation of symbols]

 10 cam ring (inner ring) 10a male multi-thread screw 10a 'thread 10d gear 12 helicoid ring (outer ring) 12a female multi-thread 12a' thread 12c escape groove 12d notch 20 pinion

[Procedure amendment]

[Submission date] December 24, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Rotational feeding mechanism

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary feeding mechanism that feeds one of a pair of annular bodies screwed together via a multiple thread (helicoid) while rotating it via a gear mechanism.

[0002]

2. Description of the Related Art For example, in a lens barrel, a movable (inner) annular body is screwed into a fixed (outer) annular body via a multiple thread screw, and the movable annular body is rotated to generate an optical beam. A large number of axially extending mechanisms are adopted. In the zoom compact camera, a gear is provided on the outer periphery of the movable annular body in order to drive the movable annular body with power, and this gear is meshed with a pinion driven by a motor.

In this rotary feeding mechanism, it is necessary to provide both the multiple thread and the gear on the outer circumference of the movable annular body. Conventionally, in order to shorten the axial length of the movable annular body, this multi-thread screw and gear cut off a part of the thread of the multi-thread screw, and provided a gear inclined in the same direction as the thread on the cut part. Was formed. Thus, if the multiple thread and the gear are mixed in the same axial position, the axial length of the movable annular body can be shortened as compared with the case where both are provided in different axial positions.

However, it has been found that the following problems are encountered when trying to further increase the amount of feeding of the movable annular body in this rotary feeding mechanism. That is, in order to increase the feed amount, increase the number of teeth of the gear or increase the width of the gear,
It is necessary to increase the axial length of the pinion that meshes with this. However, increasing the number of teeth of the gear means that the gear extends obliquely in the direction of the multiple thread, that is, the axial length of the movable annular body increases. Further, if the width of the gear is increased, the ratio of the multi-threaded screw to be formed in the circumferential direction is reduced accordingly, and as a result, the movable annular body falls or rattles.

In order to increase the zoom ratio in a zoom lens of a camera which is required to be miniaturized to the utmost limit, it is necessary to give a sufficient amount of extension without causing the movable annular body to fall down. I can't meet the demand.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotary feeding mechanism which can take a large amount of feeding of a movable annular body (inner annular body) and is less likely to fall down, based on the above-mentioned awareness of the problems of the rotary feeding mechanism. With the goal.

[0007]

SUMMARY OF THE INVENTION According to the present invention, an inner annular body and an outer annular body are screwed together via a multiple-thread male thread and a multiple-thread female thread; formed on the outer periphery of the inner annular body by inclining in the same direction as the above-mentioned multiple-thread male thread. And a pinion that meshes with the gear and rotates the inner annular body relative to the outer annular body; in the rotary feeding mechanism, a plurality of the gears are formed on the outer periphery of the inner annular body. At the same time, at least one male thread is formed between the plurality of gears, a female thread is formed on the inner circumference of the outer annular body to be screwed with the male thread, and the pinion is extended from the inner annular body. It is characterized in that it meshes with at least one gear of the plurality of gears regardless of the position.

According to this structure, a sufficient feed amount of the inner annular body can be ensured by the relationship between the plurality of gears and the pinion that meshes with any one of the plurality of gears. The inner threaded body can be prevented from collapsing by the interlocking multi-threaded screws that are also present between the clearance groove and the escape groove.

[0009]

The present invention will be described below with reference to the illustrated embodiments.
First, with reference to FIGS. 3 to 5, an example of a zoom lens barrel provided with a rotary feeding mechanism, which is a target of the present invention, will be described.

Fixed lens barrel 11 integrated with the camera body
The helicoid ring (outer annular member) 12 is fixed, the multi-strip female ne Flip 12a of the helicoid ring 12, multi-start external thread 10a is screwed formed on the outer peripheral surface of the cam ring (inner annular member) 10 ing. Inside the cam ring 10, have multi-start internal thread 10b and inner cam groove 10c is formed, the multi-strip female
The screw 10b has a front lens group barrel (male helicoid body) 13
The multi-thread male screw 13a is screwed. A linear guide plate 14 is located at the rear end of the cam ring 10, and a radial projection 14a of the linear guide plate 14 is fitted in a linear guide groove 11a formed in the fixed lens barrel 11. A linear guide ring 15 is fixed to the linear guide plate 14, and the cam ring 10 is rotatable with respect to the linear guide ring 15.

A shutter holding frame 13b, to which a rear end portion of an annular shutter unit 16 is fixed, is fixed to the front lens barrel 13, and a helicoid ring 17 integrally provided on an inner peripheral portion of the shutter unit 16 has a shutter holding frame 13b. The front lens group frame 18 holding the front lens group L1 is screwed. The shutter unit 16 has its drive pin 16a engaged with a driven pin 18a integrated with the front lens group frame 18. Drive pin 1
As is well known, 6a is rotationally driven by an angle according to the distance measurement signal from the distance measuring device, and this rotation is transmitted to the front lens group frame 18 via the driven pin 18a, and the front lens group frame 18
The (front lens group L1) moves in the optical axis direction while rotating, and focusing is performed. Further, the shutter unit 16 opens and closes the shutter blade 16b according to the brightness signal of the subject.

Rear lens group frame 1 supporting the rear lens group L2
9 has a cam pin 19a protruding in the radial direction, and this cam pin 19a is fitted in the above-mentioned cam groove 10c formed on the inner surface of the cam ring 10. The rear lens group frame 19 and the shutter holding frame 13b are connected to each other by the linear guide ring 15 described above.
The vehicle is guided straight by the straight guide surface formed on. FIG. 5 shows the rectilinear guide surface 15a of the rectilinear guide ring 15 and the rectilinear guide surface 19b of the rear lens group frame 19 which are engaged with each other.

The cam pin 19a of the rear lens group frame 19 has a recess 13 formed in the rear end surface of the front lens barrel 13 during assembly.
fit in b. This is a multiple thread on the outer circumference of the front lens barrel 13.
When the male screw 13a is screwed into the multiple thread female screw 10b of the cam ring 10, the cam pin 19a is simultaneously moved to the inner cam groove 10c.
It is a structure to fit in. After assembly, the front group lens barrel 13 is rotated by the cam ring 10 so that the front group lens barrel 13 has multiple threads 10b, 13a
Accordingly, the rear lens group frame 19 independently moves in the optical axis direction according to the cam groove 10c.

That is, the zoom lens barrel having the above structure is
When the cam ring 10 is driven to rotate, the multi-thread male screw 10a and the multi- thread male thread 10a
The cam ring 10 itself moves in the optical axis direction according to the relationship of the female screw 12a. At the same time, multi-condition the female screw 10b and the multiple-start male thread 1
Due to the screwing relationship of 3a and the linear guide mechanism of the shutter holding frame 13b and the linear guide ring 15, the front group lens barrel 13 is provided.
The (front lens group L1) moves straight in the optical axis direction. When the cam ring 10 rotates, the relationship between the cam groove 10c on the inner surface of the cam ring 10 and the cam pin 19a provided on the rear lens group frame 19 and the rectilinear guide mechanism of the rear lens group frame 19 and the rectilinear guide ring 15 cause the rear group lens to move. The frame 19 (rear group lens L2) moves in the optical axis direction to perform zooming.

In the present invention, for example, the helicoid ring (outer annular body) 12 in the zoom lens barrel having the above-mentioned structure
The gist of the present invention is the engagement structure between the cam ring (inner annular body) 10 and the rotation drive mechanism of the cam ring 10. Cam ring 1
As shown in the developed view of FIG. 1 and FIG. 5, the 0 is provided with a multi-start male screw 10a and a plurality of (in this embodiment, three) gears 10d parallel to each other, which are located at the rear portion. There is. The gear 10d is composed of a spur gear whose teeth are parallel to the axis of the cam ring 10, is inclined in the same direction as the direction of the ridges of the multi- thread male screw 10a, and there are many gears between the gears 10d.
A single thread 10a ' of the male thread 10a is formed. In other words, in the multi- thread male screw 10a, one or a plurality of threads 10a 'are cut off in a part of the circumferential direction thereof.
A gear 10d is provided at this cutout portion. In this embodiment, the threads of the multi-thread male screw 10a are every other thread.
Article 3 is excision, gears 10d are provided on their cutting portion. These multi-thread male threads 10a and threads 10a '
The formation length s of the gear 10d in the axial direction is the same.

On the other hand, as shown in FIG. 2, the helicoid ring 12 has, on its inner surface, a multi-thread male screw 10 of the cam ring 10.
a, a single thread 10a ′ and a triple thread 10d respectively corresponding to a multi-thread female thread 12a and a single thread 12
a'and an escape groove 12c are formed. That is, threads 10a 'with the thread 12a' is interdigitate gear 10d is a multi-strip external thread 10a and the multiple-start internal thread 12
When the cam ring 10 rotates in accordance with the screwing of “a” and the thread 10a ′ and the valley 12a ′, the cam ring 10 moves in the clearance groove 12c without contact.

A cutout 12d is formed in the helicoid ring 12, and the pinion 20 located in the cutout 12d.
, Meshes with the gear 10d. This pinion 20
Has an axial length capable of meshing with the three gears 10d at the same time, but meshes only with the rearmost and frontmost gears 10d at the front moving end and the rear moving end of the cam ring 10, respectively. The pinion 20 is rotatably supported by a fixed portion (not shown), is positioned at a fixed position in the notch 12d, and is rotationally driven by a motor 21.

In FIG. 1, the two pinions 20 are drawn at different positions, but this is to show the meshing relationship between the pinion 20 and the gear 10d at the forward end and the backward end of the cam ring 10. Actually, the pinion 20 does not move, but the cam ring 10 moves in the optical axis direction.

In addition, in the above-mentioned embodiment, Y.
The maximum outside diameter of 10a (the height from the axis to the peak) is D
1, Multi-threaded male screw 10a (toe height from valley bottom to peak)
D) from the cylindrical surface connecting the peaks of the multi-thread male screw 10a
The toothbrush up to the tip of the gear 10d is d2, Of the escape groove 12c
Bottom thickness Let t be the helicoid 12 wall thickness T1
Is T1 = d1 + d2 + t Becomes

Therefore, when the pinion 20 is rotationally driven by the motor 21 in the main rotation feeding mechanism having the above-described structure, the rotation is transmitted to the cam ring 10 via the gear 10d. Then, according to the engagement of the multi- thread male screw 10a (thread 10a ') and the multi- thread female screw 12a (thread 12a'), the cam ring 1
While 0 rotates forward and backward in the optical axis direction, zooming is performed.

When rotating the cam ring 10, the pinion 20 always meshes with any of the three gears 10d, and the thread 10a 'and the thread 12 are engaged.
The meshing of a'is maintained. Of course, multi-thread male screw 10a and multi- thread
Since the meshing of the female screw 12a is also maintained, the helicoid ring 1
The cam ring 10 does not fall down with respect to 2.

By the way, FIGS. 6 and 7 show two comparative examples for obtaining the same feed amount of the cam ring 10 as in the embodiment of the present invention without forming the three gears 10d. FIG. 6 shows an example in which a gear 10d ′ having the same width as the gear 10d of the embodiment of the present invention is formed as one thread, and FIG. 7 shows a wide gear having the same axial length s as the gear 10d of the embodiment of the present invention. 10d ″ is formed. In the comparative example of FIG. 6, the installation length of the gear 10d ′ in the axial direction, that is, the cam ring 1 is shown.
0 becomes long, and in the comparative example of FIG. 7, the installation length of the multi-thread male screw 10a in the circumferential direction becomes short, and the cam ring 10 easily falls.

The zoom lens barrel shown in FIGS. 3 to 5 is an example of a device to which the rotary feeding mechanism of the present invention can be applied. INDUSTRIAL APPLICABILITY The present invention can be widely applied to a rotary payout mechanism for another zoom lens barrel or a rotary payout mechanism other than the zoom lens barrel.

[0024]

As described above, according to the rotary feeding mechanism of the present invention, the feeding of the inner annular body which is rotationally driven through the gear formed on the outer peripheral surface by being screwed into the outer annular body through the multiple thread is carried out. A large amount can be taken and the fall can be prevented.

[Brief description of drawings]

FIG. 1 is a development view of an inner annular body (cam ring) showing an embodiment of a rotary feeding mechanism according to the present invention.

FIG. 2 is a cross-sectional view of a meshed state of the inner annular body and the outer annular body.

FIG. 3 is a cross-sectional view showing an example of a zoom lens barrel to which a rotary feeding mechanism according to the present invention can be applied.

4 is a cross-sectional view of a main part of the zoom lens barrel in FIG.

5 is an exploded perspective view of a main part of the zoom lens barrel of FIG.

FIG. 6 is a developed view corresponding to FIG. 1 and shown as a comparative example.

FIG. 7 is a development view corresponding to FIG. 1 and shown as another comparative example.

[Explanation of Codes] 10 cam ring (inner ring) 10a multiple thread male thread 10a 'screw thread 10d gear 12 helicoid ring (outer ring body) 12a multiple thread female 12a' thread 12c escape groove 12d notch 20 pinion

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

Claims (1)

[Claims] 1. An inner annular body and an outer annular body which are screwed together via a multi-start screw; a gear formed on the outer periphery of the inner annular member so as to be inclined in the same direction as the thread of the multi-start screw; and In a rotary feeding mechanism including a pinion that meshes with the gear and rotates the inner annular body relative to the outer annular body, a plurality of the gears are formed on the outer periphery of the inner annular body, and the plurality of gears are formed. , At least one thread of a multi-thread screw is formed, and a plurality of escape grooves through which the gear passes are formed on the inner circumference of the outer annular body, and between the escape grooves, Forming a screw thread that meshes with the screw thread of the inner annular body, and, regardless of the feeding position of the inner annular body, the pinion,
A rotary feeding mechanism characterized by meshing with at least one gear of the plurality of gears.