JPH063570A - Lens barrel - Google Patents

Abstract

PURPOSE:To provide a lens barrel where the deviation of the optical axis of each lens fixed in a lens holding part is prevented by sticking a diaphragm part in a lens barrel main body formed by successively working the inside diameters of plural lens holding parts by performing cutting work once. CONSTITUTION:The outer peripheral surface of the lens barrel main body 22 is chucked by the rotary chuck part of a lathe, and the main body 22 rotated by rotating the rotary chuck part. A cutting tool is inserted inside the main body 22 from the direction opposite to the rotary chuck part, and the edge of the cutting tool is arranged at the position of the lens holding part 30. By applying feed to the cutting tool in the diameter direction of the lens holding part 30 and the axial direction of the main body 22, the cutting work of the lens holding parts 30 and 32, a diaphragm fixing part 52, and the lens holding parts 26 and 24 is successively performed. After finishing the cutting work of the lens holding part 24 or 30 and the diaphragm fixing part 52, the main body 22 is removed from the rotary chuck part, and a diaphragm plate 50 is fixed in the fixing part 52.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrel, and more particularly to a lens barrel mount attached to a copying machine or the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, a lens barrel of this type has a plurality of lens holding portions 2, 3, 4, 5 inside a lens barrel body 1 formed in a cylindrical shape. It is formed along the longitudinal direction of the body 1. The lens holding portions 2, 3, 4, 5 are step-cut so that the inner diameter of the lens holding body 2 becomes smaller from both sides of the lens barrel body 1 toward the central portion. 3,
Lenses 6, 7, 8 and 9 are fixed to lenses 4 and 5 with their optical axes aligned.

Further, in the substantially central portion of the lens barrel body 1,
A diaphragm portion 11 having a fixed diaphragm hole 10 is arranged. The diaphragm 11 is machined when the lens holders 2, 3, 4, 5 are machined and is formed integrally with the lens barrel 1. By the way, in the cutting process of the lens holding parts 2, 3, 4, 5 and the diaphragm part 11, since the diaphragm part 11 is formed integrally with the lens barrel body 1, it is attempted to perform the machining in one cutting process. Then, the cutting bite is caught on the narrowed portion 11, so that the cutting work is performed twice.

That is, in the cutting method, for example, the outer peripheral surface of the lens barrel body 1 on the right side of the diaphragm 11 is chucked on the rotary chuck portion of the lathe, and the rotary chuck portion is rotated to rotate the lens barrel. Rotate the main body 1. Then, a cutting tool is inserted into the diaphragm 11 from the left side, and the tool is fed in the radial direction of the lens holding section and in the axial direction of the lens barrel main body, and the left side surface 11a of the diaphragm 11 is fed.
Then, the inner diameter portions of the lens holding portions 2 and 3 are sequentially cut.

Next, the lens barrel body 1 is detached from the rotary chuck portion, and the outer peripheral surface of the lens barrel body 1 on the left side of the diaphragm portion 11 is chucked to the rotary chuck portion to mount the lens barrel body 1. Then, the tool is rotated, and the cutting tool is inserted as described above, and the right side surface 11b of the diaphragm 11 and the inner diameters of the lens holding portions 4 and 5 are sequentially cut. In this way, the lens holding parts 2, 3, 4, 5 and the diaphragm part 11 are
It is formed in a single cutting process.

[0006]

However, in the conventional lens barrel, the lens holding portions 2, 3, 4, 5 and the diaphragm portion 1 are used.
Since 1 and 2 are processed in two cutting steps, the drawn portion 11
On the other hand, misalignment occurs between the lens holding portions 2 and 3 and the lens holding portions 2 and 3 due to chucking. This allows
There is a drawback that the optical axes of the lenses fixed to the lens holding portions 2 and 3 and the lens holding portions 4 and 5 are displaced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a lens barrel capable of processing a plurality of lens holding portions in a single cutting process to prevent deviation of the optical axis. To do.

[0008]

In order to achieve the above object, the present invention provides a cylindrical lens machined in steps so that the inner diameters of a plurality of lens holding portions become smaller from both sides toward the central portion. In a lens barrel having a diaphragm portion arranged substantially in the center thereof, the lens barrel main body formed by sequentially cutting the inner diameters of the plurality of lens holding portions is provided with the diaphragm portion. It is characterized by being fixed.

[0009]

The feature of the present invention is that the diaphragm portion is not formed integrally with the lens barrel body, but a separate diaphragm portion is provided, and this diaphragm portion is formed after the lens holding portion has been cut. It was fixed in place. Accordingly, the plurality of lens holding portions can be processed in one cutting process, and thus the misalignment of the lens holding portions can be prevented. Therefore, it is possible to prevent the deviation of the optical axis of each lens fixed to the lens holding portion.

Further, when the plurality of lens holding portions are cut, the mounting groove of the diaphragm portion is machined, and the diaphragm portion formed in the shape of an elastic member is fitted into the mounting groove. good. By forming the narrowed portion into a substantially octagonal shape, it can be easily fitted into the mounting groove.

[0011]

The preferred embodiments of the lens barrel according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a sectional view showing a first embodiment of a lens barrel 20 according to the present invention.
The lens barrel 20 includes a lens holder 2 having a circular peripheral surface inside a lens barrel body 22 formed in a tubular shape.
4, 26, 28 and 30 are formed along the longitudinal direction of the lens barrel body 22. These lens holding parts 24, 2
6, 28 and 30 are both end portions 22 of the lens barrel body 22.
It is stepped so that its inner diameter becomes smaller from the a, 22b side toward the central part. Further, lenses 32, 34, 36 and 38 having different sizes are arranged in the lens holding portions 24, 26, 28 and 30 so that their optical axes coincide with each other.

The lens 32 and the lens 34 are arranged with a predetermined gap by a spacer ring 40 and pressed and fixed by a ring screw 42 screwed from the end 22a of the lens barrel body 22. Similarly, the lens 36 and the lens 38 similarly have the spacer ring 44.
Are arranged with a predetermined gap by and are pressed and fixed by a ring screw 46 screwed from the end 22b of the lens barrel body 22.

On the other hand, a diaphragm plate 50 having a fixed diaphragm hole 48 is fixed to a substantially central portion inside the lens barrel body 22. The diaphragm plate 50 is formed in a donut shape and is fixed to a diaphragm fixing portion 52 having a circular peripheral surface formed by cutting the lens barrel body 22. Next, a method of processing the lens barrel 10 configured as described above will be described with reference to FIG.

First, the lens barrel main body 22 of the lens holding portions 24 to 30 before being cut is chucked to the rotary chuck portion 54 of a lathe (not shown), and the rotary chuck portion 54 is then chucked.
Is rotated to rotate the lens barrel body 22. next,
A cutting bite 56 is inserted into the lens barrel main body 22 from a direction opposite to that of the rotary chuck portion 54, and
The blade edge 58 of is placed at the position of the lens holding portion 30. Next, the bite 56 is attached to the lens holder 30 in the radial direction (upward in the figure) and in the axial direction of the lens barrel body 22 (left in the figure).
The lens holding portion 30 is cut by feeding.

Next, in order to cut the lens holding portion 28, the cutting tool 56 is lowered from the position of the lens holding portion 30 by a predetermined amount, and the lens holding portion 28 is cut by feeding in the left direction in the drawing. . In this way, the diaphragm fixing part 5
2. The lens holding portion 26 and the lens holding portion 24 are sequentially cut.

After the cutting of the lens holding portions 24 to 30 and the diaphragm fixing portion 52 is completed, the lens barrel main body 2
2 is removed from the rotary chuck portion 54, and the diaphragm plate 50 described above is fixed to the diaphragm fixing portion 52. That is, according to the lens barrel 20 of the present embodiment, the diaphragm portion 11 (see FIG. 5) is not formed integrally with the lens barrel body 1 (see FIG. 5), but the separate diaphragm plate 52 is used as the lens. After cutting the holding parts 24 to 30, the holding parts 24 to 30 are fixed to the lens barrel body 22.

As a result, the lens holding portions 24 to 30 can be processed in one cutting process without the cutting tool 56 being caught by the diaphragm plate 50 during cutting. Therefore, the misalignment of the lens holding portions 24 to 30 can be prevented, and the deviation of the optical axes of the lenses 32 to 38 fixed to the lens holding portions 24 to 30 can be prevented. FIG. 3 is a sectional view showing a second embodiment of the lens barrel 60 according to the present invention.
The same or similar members as those shown in are designated by the same reference numerals, and the description thereof will be omitted.

The lens barrel 22 shown in FIG. 3 is provided with a groove 6 for mounting the diaphragm piece 62 substantially at the center of the inside of the lens barrel main body 22 when cutting the lens holding portions 24 to 30 shown in FIG.
4 is cut by a cutting tool 56. The diaphragm piece 62 is formed of an elastic piece (mylar plate) of plastic or the like, and a predetermined diaphragm hole 66 is formed in the center thereof as shown in FIG. Further, the diaphragm piece 62 is
In order to facilitate fitting into the circular mounting groove 64, the circular plate is cut out in the upper, lower, left, and right sides to form a substantially octagonal peripheral portion. As a result, the throttle piece 62 can be fitted into the mounting groove 64 very easily as compared with the case of a simple circular plate.

The second embodiment is also similar to the first embodiment.
Since the lens holders 24 to 30 can be processed in a single cutting process without the bite 56 being caught by the aperture piece 62, the deviation of the optical axes of the lenses 32 to 38 can be prevented.

[0020]

As described above, according to the lens barrel of the present invention, after cutting the plurality of lens holding portions,
Since the diaphragm portion is fixed to a predetermined position of the lens barrel body, the plurality of lens holding portions can be processed in one cutting process. As a result, misalignment of the lens holding unit can be prevented, and thus misalignment of the optical axis of each lens fixed to the lens holding unit can be prevented.

Further, when the plurality of lens holding portions are cut, the mounting groove of the diaphragm portion is cut, and the diaphragm portion formed of an elastic member in the shape of a thin piece is fitted into the mounting groove. good. By forming the narrowed portion into a substantially octagonal shape, it can be easily fitted into the mounting groove.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of a lens barrel according to the present invention.

FIG. 2 is a sectional view showing a method for processing a lens barrel according to the present invention.

FIG. 3 is a sectional view showing a second embodiment of the lens barrel according to the present invention.

FIG. 4 is a front view showing an embodiment of a diaphragm piece applied to a lens barrel according to the present invention.

FIG. 5 is a sectional view showing an example of a conventional lens barrel.

[Explanation of symbols]

 20, 60 ... Lens barrel 22 ... Lens barrel main body 24, 26, 28, 30 ... Lens holding part 32, 34, 36, 38 ... Lens 50 ... Aperture plate 56 ... Bite 62 ... Aperture piece

Claims (3)

[Claims] 1. A cylindrical lens barrel machined in a stepped manner such that the inner diameters of a plurality of lens holding portions become smaller from both sides toward the central portion, and a diaphragm portion is arranged substantially at the central portion. In the lens barrel, the lens barrel comprises a lens barrel body formed by sequentially cutting the inner diameters of the plurality of lens holding portions, and the diaphragm unit being fixed to the lens barrel body. 2. A cylindrical lens barrel machined in steps so that the inner diameters of a plurality of lens holding portions become smaller from both sides toward the central portion, and a diaphragm portion is arranged substantially at the central portion. In the lens barrel, the lens barrel body formed by cutting the inner diameters of the plurality of lens holding portions and the mounting groove of the diaphragm portion is provided with a diaphragm portion formed in a thin piece by an elastic member. A lens barrel formed by fitting in a mounting groove of the diaphragm portion. 3. The lens barrel according to claim 2, wherein the diaphragm portion is formed in a substantially octagonal shape so that the diaphragm portion can be easily fitted into the mounting groove of the diaphragm portion.