JPS63110411A - Lens barrel - Google Patents

Abstract

PURPOSE:To couple a helicoidal ring provided with plural different screw sections with another helicoidal ring, by providing plural helicoidal screws having different leads, etc., to one of the helicoidal ring to be coupled in such a way that they are superposed upon one plane. CONSTITUTION:Helicoidal screw 46 for a 1st lens barrel and helicoidal screw 47 for a 2nd lens barrel are provided in the helicoidal screw section 21 of an inner helicoidal ring 1 in a state where they are superposed. Therefore, when the screw 47 for a LB is a lead 24 and the screw 46 for the 1st lens barrel is another lead 8, the rotating angle of a gear ring 12 to the full forward movement of the 1st lens barrel approximates to that of the gear ring 12 to the full forward movement of the 2nd lens barrel. Therefore, one kind of inner helicoidal rings can be used commonly to the 1st and 2nd lens barrels.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a lens barrel, and more particularly, to a lens barrel that moves a lens forward and backward in the optical axis direction by fitting an inner helicoid ring and an outer helicoid ring. be.

[Conventional technology]

A typical lens barrel uses a helicoid screw to move the focus lens back and forth in the optical axis direction to adjust the focus. Conventional lens barrels have been manufactured with helicoid rings suitable for the amount of extension of the focus lens.

[Problem that the invention seeks to solve]

However, in conventional lens barrels, if the lens barrel is the same but there is an inner helicoid ring and an outer helicoid ring with different shapes such as lead, pitch, number of threads, thread cutting direction, etc. of the helicoid thread part of the helicoid ring, each It was necessary to manufacture the helicoid ring according to the lens barrel by molding, etc., and there was a cost problem as each mold was made.

In addition, because there are many similar parts, confusion in parts management may occur.

Therefore, an object of the present invention is to provide a lens barrel having a completely new helicoid ring in which one type of helicoid ring can be applied to a plurality of different lens barrels, in order to eliminate the drawbacks of the conventional techniques described above. be.

[Means and operations for solving the problems] In order to solve the above-mentioned problems, the present invention provides a lens barrel in which the lens moves forward and backward in the optical axis direction by fitting an inner helicoid ring and an outer helicoid ring. , so that one of the inner helicoid rings or the outer helicoid ring can guide a plurality of different helicoid rings as the other helicoid ring, the helicoid threads of the helicoid threads of the plurality of different helicoid rings, The helicoid rings are formed with chevron-shaped guide parts corresponding to the common part of each groove, and multiple helicoid rings with different leads, pinches, number of threads, thread cutting directions, etc. are selectively formed on one helicoid ring. It is something that can be fitted.

〔Example〕

The present invention will be explained below with reference to illustrated embodiments.

In the embodiment of the present invention, the present invention is applied to a helicoid threaded portion of a helicoid ring among a plurality of lenses.

1 to 6 show a first embodiment of the present invention. FIG. 1 is a sectional view of the first lens barrel LA.

A fixing ring 2 is fixed to a lens mount 1 that is detachably attached to a camera mount (not shown). An outer ring 3 is fixed to the outer periphery of the fixed ring 2. This outer ring 3
A zoom ring 4 is fitted to the rear end of the outer circumferential surface of the zoom ring 4 so as to be rotatable around the optical axis. The zoom ring 4 is restricted from moving in the optical axis direction by a stepped portion 5 of the outer ring 3 and a rear ring 6 fixed to the outer periphery of the lens mount 1. A rubber ring 7 is integrally provided on the outer periphery of the zoom ring 4 to prevent the photographer's finger from slipping during the zoom operation.

A cam ring 8 is fitted onto the outer peripheral surface of the fixed ring 2 so as to be rotatable around the optical axis. The cam ring 8 is restricted from moving in the optical axis direction by a C ring 9 fixed to the tip of the outer circumference of the fixed ring 2 and a collar 10 at the rear end of the outer circumference of the fixed ring 2.

The cam ring 8 is coupled to the zoom ring 4 by a zoom bin 11 so as to rotate together in the optical axis direction.

Further, a gear ring 12 is fitted into the inner circumferential surface of the outer ring 3 so as to be rotatable around the optical axis. Movement of this gear ring 12 in the optical axis direction is restricted by a stop ring 13 provided at the tip of the outer ring 3. A gear 14 is provided on the inner peripheral surface of the rear end of the gear ring 12.
is provided.

This gear 14 interlocks with a gear mechanism (not shown) inside the lens barrel, is provided on the camera body side, and is rotated by a coupler (not shown) driven by a drive mechanism. Also gear ring 1
A long groove 15 extending in the optical axis direction is formed in the front inner circumferential surface of the lens 2 .

Furthermore, an outer helicoid ring 16 having a large diameter at the front is fitted onto the inner circumferential surface of the fixed ring 2 so as to be rotatable around the optical axis at a small diameter section at the rear. This outer helicoid ring 1
A helicoid threaded portion 17 is provided on the inner peripheral surface of the front large diameter portion of 6.

Further, a roller 18 is installed on the outer peripheral surface of the outer helicoid ring 16, and the roller 18 fits into a cam groove provided in the cam ring 8 and a long groove provided in the fixed ring 2 and extending in the optical axis direction.

This roller 18 transmits the rotation of the cam ring 8 to the outer helicoid ring 16 as a back and forth motion.

The outer helicoid threaded portion 17 has a second lunion group A1.
A long groove 1 provided on an inner edge to hold the lens ring 19 together with the lens ring 19.
a drive ring 23 having a protrusion 22 that fits into the screw 24;
is integrated by.

This φ Further, a support ring 25 is provided at the front end of the drive ring 23. In other words, the inner helicoid ring 20. which holds the first lens group A1. The lens ring 19 can move forward and backward together with the drive ring 23 in the optical axis direction.

On the other hand, the inner circumferential surface of the outer helicoid ring 16 holds the second lens group A2 via the lens ring 26 and the fourth lens group A4 via the lens ring 27. The ring 2nd is fitted.

A roller 29 is attached to the second and fourth lens group moving ring 28.
The roller 29 is fixed to the cam groove provided in the cam ring 8 through an escape groove provided in the outer helicoid ring 16 so as not to interfere with the movement of the roller 29. It fits into a long groove provided in the ring 2 and extending in the optical axis direction.

The rotation of the cam ring 8 is controlled by the roller 29 in the second and fourth directions.
This is transmitted to the lens group moving ring 28 as a back and forth motion.

A third lens group moving ring 30 is fitted into the inner periphery of the second and fourth lens group moving rings 28 . The third lens group moving ring 30 holds the third lens group A3 via a lens ring 31. Further, a roller 32 is installed in the third lens group moving ring 30. This roller 32 is inserted into the cam groove provided in the cam ring 8 via the outer helicoid ring 16 and relief grooves provided in the second and fourth lens group moving rings 28 that do not interfere with the movement of the roller 32. It is fitted into a long groove provided in the fixed ring 2 and extending in the optical axis direction. This roller 32 transmits the rotation of the cam ring 8 to the third lens group moving ring 30 as a back and forth movement. Further, the third lens group moving ring 30 holds an aperture blade, a cornice, and a cornice stop.

Next, the operation of this first lens barrel LA will be explained.

When the zoom ring 4 is rotated around the optical axis, the zoom bin 1
1, the rotation is transmitted to the cam ring 8. When the cam ring 8 rotates, the roller 1B
, 29 and 32 move back and forth, and the movement of the outer helicoid ring 16 in the optical axis direction causes the second lens group A1 to move forward and backward.
By moving the fourth lens group moving ring 28 in the optical axis direction, the second lens group,
Fourth lens group A2. A4 and the third lens group A3 move back and forth in the optical axis direction as the third lens group moving ring 30 moves in the optical axis direction.

Next, during focusing, rotation is transmitted to the gear 14 of the gear ring 12 by a coupler (not shown). This rotation is transmitted from the long groove 15 of the gear ring 12 to the protrusion 22 of the drive ring 23, and this drive ring 23 rotates together with the inner helicoid ring 20 and moves back and forth due to the helicoid connection with the outer helicoid ring 16. Therefore, a focusing operation is performed.

The movements of each of the lens groups A1 to A4 of the first lens barrel LA due to these operations are as shown in FIG. The state of the first lens barrel LA shown in FIG.
In the figure, the state is indicated by symbol T), and by rotating the zoom ring 4 (see FIG. 1) around the optical axis, it changes to the state on the wide-angle side (symbol W in FIG. 2).

Here, the focal length of the first lens barrel LA is the longest (
The amount of movement of each lens group A1 to A4 when changing from the telephoto state to the shortest distance (wide-angle state) is △At, △
A2. △A3. Assuming △A4, △A 1 = 24.5 Dragon △A2 (△A4) = 10.7 m ∆A3 = 6.6 (However, the direction of the subject along the optical axis from the position of each lens group on the telephoto side positive if it moves to ). Further, the amount ΔX that the 171st group A1 moves for focusing operation is ΔX=1.8 from the infinite distance position to the close distance position.

Next, FIG. 3 shows a sectional view of the second lens barrel LB.

This second lens barrel LB will be explained below. However, the same parts as the first lens barrel LA are given the same reference numerals, and detailed explanations are omitted.

A small diameter portion of an outer helicoid ring 16 is fitted into the inner circumference of the fixed ring 2 . A roller 33 is installed in the rear part of the outer helicoid ring 16, and the roller 33 is connected to the optical axis provided in the cam ring 34 via a long groove extending in the optical axis direction provided in the fixed ring 2. It fits into a groove that is at an angle to the

A second lens group moving ring 35 is fitted in the front of the inner circumference of the outer helicoid ring 16 . This second lens group moving ring 3
5 fixes the roller receiver 36. This roller receiver 36 is fitted into a groove provided in the outer helicoid ring 16 and having an angle oblique to the optical axis. A roller 38 is integrally fitted into this roller receiver 36 via a spring 37, and the tip end 39 of this roller 38 is in pressure contact with a cam groove 40 provided on the inner peripheral surface of the fixed ring 2. , are biased by springs 37. Moreover, this second lens group moving ring 35
A second lens group B2 is held via a lens ring 41.

A third lens group moving ring 42 is fitted into the rear inner surface of the outer helicoid ring 16 . A roller 43 is installed in the third lens group moving ring 42, and the roller 43 is inserted into the cam ring 34 through an escape groove provided in the outer helicoid ring.
It fits into a cam groove provided in the fixed ring 2 and a long groove extending in the optical axis direction provided in the fixed ring 2. Further, a third lens group B3 is connected to the third lens group moving ring 42 via a lens ring 44.
is retained.

A fourth lens ring 45 is provided on the inner circumferential surface of the rear end of the fixed ring 2 through a lens ring 45.
Lens group B4 is held.

Next, the operation of this second lens barrel LB will be explained.

When the zoom ring 4 is rotated around the optical axis, the zoom bin 1
1, the rotation is transmitted to the cam ring 34. When the cam ring 34 rotates, the outer helicoid ring 16 and the third lens group moving ring 42 are moved back and forth by the cam groove and roller. When the outer helicoid ring 16 moves back and forth, the second lens group moving ring 35 moves back and forth by the roller 3B and the cam groove 40.

Next, the rotation is transmitted to the gear 14 of the gear ring 12 by a coupler (not shown). This rotation is transmitted through the long groove 15 of the gear ring 12 to the protrusion 22 of the drive ring 23.
Since the lens rotates together with the inner helicoid ring 20 and moves back and forth due to the helicoid coupling with the outer helicoid ring 16, a focusing operation is performed.

The movements of each of the lens groups 31 to B4 of the second lens barrel LB configured as described above are as shown in FIG. The state of the second lens LB shown in FIG. 3 is on the wide-angle side (symbol W in FIG. 4). By rotating the zoom ring 4 (see FIG. 3), the zoom ring 4 (see FIG. 3) enters a telephoto side (- is indicated by the symbol T in FIG. 4), which is not shown in FIG.

Here, the focal length of the second lens barrel LB is the shortest (
The amount of movement of each lens group B1 to B4 when changing from wide-angle to longest (telephoto) is expressed as ΔBl, ΔB2. Δ
B3. Assuming ΔB4, ΔB 1 =25.411 ΔB2=4. In ΔB 3 =20.3 mm ΔB4 = Om (however, the case of moving toward the subject along the optical axis direction from each position on the wide-angle side is positive).

Also, the amount △y that the 1121st group B1 moves for focusing operation
is Δy=5.5m between the infinite distance position and the closest distance position.

As detailed above, the first lens barrel LA.

In the second lens barrel LB, lens mount=13-mount 1. Fixed ring 2. Outer ring 3. Zoom ring 4. Back item 6, rubber ring 7, C ring 9. Zoom bin 11° gear ring 12.
Retaining ring 13. Outer helicoid ring 16. Inner helicoid ring 20
．． Drive ring 23. Screw 24. The 25° hood ring, other rollers, etc. can be used in common.

However, the first lens barrel LA and the second lens barrel L
B, each lun group AI from an infinite distance position to a close distance position.

Since the amount by which B1 is extended, ΔX and Δy are significantly different, the outer helicoid ring 16. If the vericoid screw parts 17 and 21 provided in the inner helicoid ring 20 are made into a common lead (temporarily the lead 24 matches the second lens barrel LB), the first lens barrel LA and the second lens barrel LA Lens barrel L
The rotation angle of the gear ring 12 for extending the respective lens groups AI and Bl from the infinite distance position of B to the close distance position is 27° in the case of the first lens barrel LA.

In the case of the second lens barrel LB, the angle is 82.5°, and the bank lash of the gear system of the coupler drive mechanism has an effect on the first lens barrel LA that is less than the effect on the second lens barrel LB. It will be about three times as large.

In order to eliminate this difference in influence, the shape of the inner helicoid ring 20 was changed as shown in FIGS. 5 and 6.

This will be explained in detail below using FIGS. 5 and 6.

FIG. 5 is a plan view of the helicoid threaded portion 21 provided on the outer peripheral surface of the inner helicoid ring 2o. FIG. 6 is a sectional view taken along the line AA in FIG. 5.

The helicoid threaded portion 21 of the inner helicoid ring 1 is provided with a helicoid thread 46 for the first lens barrel LA and a helicoid thread 47 for the second lens barrel LB in an overlapping manner. Here, assuming that the helicoid screw 47 for LB is the lead 24 and the helicoid screw 46 for LA is the lead 8, the rotation angle of the gear ring 12 with respect to the full extension of the first lens barrel LA is 1.8. +8 x 360 = 81', and the rotation angle of the gear ring 12 with respect to the full extension of the second lens barrel LB is 5.5 ÷ 24 x 360 = 82.5 degrees, and the bank lash of the gear is The effects on the lens barrel LA and the second lens barrel LB can be made almost the same.

With the above configuration, it is possible not only to use one type of inner helicoid ring in common in the first and second lens barrels LA and LB, but also to reduce the rotational resistance of the helicoid ring. becomes.

Next, a second embodiment of the present invention will be described using FIGS. 7 and 8.

In the second embodiment, the configuration other than the helicoid threaded portion 21 of the inner helicoid ring 20 of the first embodiment described above is completely the same, so a detailed explanation of the same parts will be omitted.

FIG. 7 shows a helicoid ring 2 in a second embodiment of the present invention.
0 is developed on a flat surface. Further, FIG. 8 is a cross-sectional view of the helicoid threaded portion 48 taken along the line B-B.

49 is a helicoid screw for the first lens barrel LA, and 50 is a helicoid screw for the second lens barrel LB. The guide portion 51 surrounded by the LA helicoid screw 49 and the LB helicoid screw 50 is obtained by removing the acute angle portion of the guide portion surrounded by the helicoid screws 46 and 47 of the first embodiment described above. . By adopting such a configuration, the same operation and effect as in the first embodiment described above can be obtained, and since there is no acute angle part, when the outer helicoid ring and the inner helicoid ring are fitted together, the helicoid screw It is possible to reduce the amount of catching between parts.

Next, a third embodiment of the present invention will be described using FIGS. 9 and 10.

Similar to the second embodiment described above, this third embodiment is completely the same as the first embodiment except for the helicoid threaded portion 21 of the inner helicoid ring 20, so a detailed explanation of the same parts will be omitted. .

FIG. 9 shows the helicoid ring 2 in the third embodiment of the present invention.
0 is developed on a flat surface. FIG. 10 also shows the helicoid threaded portion 52,
FIG. 3 is a partially enlarged perspective view.

In FIGS. 9 and 10, 53 is the first lens barrel LA
54 is a helicoid screw for the second lens barrel LB. The guide portion 55 surrounded by the LA helicoid screw 53 and the LB helicoid screw 54 has a substantially truncated conical shape as shown in FIG. By adopting such a shape, the same functions and effects as those of the second embodiment described above can be obtained, and since there are fewer corner parts, it is very easy to cut out the mold during molding. Furthermore, it becomes easier to process the mold.

Next, a fourth embodiment of the present invention will be described using FIGS. 11 and 12.

This fourth embodiment is similar to the second embodiment described above. Similar to the third embodiment, the structure of the inner helicoid ring 20 other than the helicoid threaded portion 21 is completely the same as the first embodiment, so detailed explanation of the same parts will be omitted.

FIG. 11 is a partially enlarged view of the helicoid threaded portion 56 of the inner helicoid ring 20 according to the fourth embodiment of the present invention, developed on a plane.

Further, FIG. 12 is a partially enlarged perspective view of the helicoid threaded portion 56.

Three types of helicoids 57 in FIGS. 11 and 12.
58 and 59 have different leads, pitches, etc. In this way, three types of helicoid 57.5
The guide portion 6o surrounded by 8.59 has a shape as shown in the partially enlarged perspective view of FIG.

By forming such a shape, the above-mentioned first to third
Not only two different types of helicoid rings as described in the embodiment, but also three different types of helicoid rings can be screwed onto one inner helicoid ring. Unpaid, guide part 6o
The shape of the second embodiment is the same as that of the first embodiment. Even if the shape is changed in the same manner as in the third embodiment, the same actions and effects as those of the second and third embodiments with respect to the first embodiment can be obtained. Obtainable.

〔Effect of the invention〕

As described in detail above, according to the present invention, one of the helicoid rings that fit into each other has a lead, a pinch,
By providing multiple helicoid screws with different numbers of threads, thread cutting directions, etc. so that they overlap on one surface, a single helicoid ring can have multiple leads, pitches, etc.
By making it possible to selectively fit helicoid rings having helicoid threads with different numbers of threads, thread cutting directions, etc., (1) When manufacturing helicoid rings by molding, etc.,
Since the number of molds can be reduced, the cost of mold creation can be reduced.

(11) Since the number of similar parts is reduced, parts management can be streamlined.

(iii) Since the helicoid threaded portion of one helicoid ring has an intermittent shape, rotational resistance when the helicoid ring is fitted is reduced.

Remarkable effects such as

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a first lens barrel LA in a first embodiment of the present invention, and FIG. 2 is a first lens group A of the first lens barrel LA.
FIG. 3 is a cross-sectional view of the second lens barrel LB in the first embodiment of the present invention. Figure 4 shows the first group lens B of the second lens barrel LB.
FIG. 5 is a plan development view of the helicoid threaded portion of the inner helicoid ring in the first embodiment; FIG. is a cross-sectional view taken along the line A-A in FIG. 5, FIG. 7 is a plan development view of the helicoid threaded portion of the inner helicoid ring in the second embodiment of the present invention, and FIG. 8 is a cross-sectional view taken along line B in FIG. 9 is a plan development view of the helicoid threaded portion of the inner helicoid ring in the third embodiment of the present invention, FIG. 10 is a partially enlarged perspective view of FIG. 9, and FIG. 11 is the present invention FIG. 12 is a partially enlarged perspective view of FIG. 11. LA-----first lens barrel, LB-----second lens barrel, 16---outer helicoid ring, 20--inner helicoid ring, 21a---guide Part l
'-2

Claims (1)

[Claims] In a lens barrel that moves the lens forward and backward in the optical axis direction by fitting an inner helicoid ring and an outer helicoid ring, one of the inner helicoid ring and the outer helicoid ring is connected to the other helicoid ring. In order to be able to guide a plurality of different helicoid rings as rings, the helicoid threaded portion is formed with a chevron-shaped guide portion corresponding to the common portion of the grooves of the helicoid threaded portions of the plurality of different helicoid rings. Characteristic lens barrel.