JPS62265608A - Lens barrel - Google Patents

Abstract

PURPOSE:To reduce the weight of a lens barrel and to improve the durability and mass-productivity of the products by strengthening the structure of a female helicoid for the lens barrel. CONSTITUTION:The female helicoid 2 is constituted mainly of a cylindrical barrel part 2a and a fixing screw thread and a working helicoid screw thread are respectively formed on the outer periphery and inner periphery of the barrel part 2a. A flange part 2b to be a projection part to be fitted to a front body is formed on the outer periphery of the front end of the barrel part 2a. In addition, a ring-like rib 2c is formed integrally with the inner periphery of the rear end of the barrel part 2a. Thereby, the barrel part 2a is reinforced by the rib 2c in addition to the flange part 2b and its rigidity is strengthened. Therefore, the whole female helicoid 2 can be formed as a mold consisting of a synthetic resin material. Since the size D of the inner diameter of the rib 2c can be optionally set up, the rib 2c can be as an opening diaphragm of a lens.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lens barrel that houses a photographic lens used in an optical device such as a camera.

r 斤, 1tZnbohong) In the lens barrel that houses the photographic lens, a helicoid screw unit that is configured with a large lead amount using a multi-thread screw is generally used as a device to advance the lens to the in-focus position. .

A helicoid screw unit is a fixed female helicoid and a movable male helicoid screwed together, and usually by rotating the male helicoid, it gives movement in the optical axis direction to the photographic lens attached to the male helicoid. 5, but as is well known, its operation is accurate and reliable, and in addition, those operated by the biasing force of a spring based on automatic focus adjustment require a high degree of comfort and smoothness. There is.

Therefore, both the female helicoid and the male helicoid that make up the helicoid screw unit need to have sufficient rigidity so that they will not be distorted even by some external force, so the female helicoid has a relatively simple cylindrical shape with few steps. Since it is difficult to mold with a resin material, it is often formed by cutting a metal material.

[A point of focus while the invention solves the problem 5] However, the use of metal materials not only requires high material and processing costs and is not suitable for mass production, but also poses an obstacle in terms of reducing the weight of the product. In particular, there were many problems with helicoid screw units used in the lens barrels of small cameras.

As a result of solving and improving this point, the present invention realizes the molding of a male helicoid as well as a female helicoid with extremely high rigidity made of resin, thereby creating a lens barrel with a helicoid screw unit completely made of resin. It is intended for the purpose of providing.

[Means for solving problems]

The above object is achieved by a lens barrel characterized in that the female helicoid is made of resin and has a rib formed on the end opposite to the side that contacts the male helicoid.

〔Example〕

An embodiment of the invention is shown in FIGS. 1 and 2.

Figure 1 shows the structure of a lens barrel of a camera equipped with an automatic focus adjustment device, where l is a topodium 70 attached to the front of the camera body, and 2 is a female helicoid screwed onto the front body 1. , 3 is a male helicoid screwed into the female helicoid 2.

Together with the female helicoid 2, it constitutes a helicoid screw unit.

The inner diameter portion of the male helicoid 3 is processed into a lens frame, and a photographing lens 4 housed therein is held by a screw ring 5.

Further, the gap between the front body 1 and the female helicoid 3 is rotated by the focus adjustment operation.
The interlocking pin 7 engages with a drive ring 8 attached to the 7 flange portion of the male helicoid 3, and rotates the drive ring 8 as a unit.

As shown in FIG. 2, the female helicoid 2 has a cylindrical body 2a as its main body, and the body 2a has a screw thread for fixing on its outer circumferential surface, and an operating screw thread on its inner circumferential surface. A helicoidal screw thread is formed, and the front end is provided with a 7 flange portion 2b on the outer circumferential surface as an abutting portion for attachment to the front body 1. A ring-shaped rib 2C is integrally formed on the inner peripheral surface of the rear end of 2a.

Therefore, the trunk portion 2a has its front and rear ends connected to the two lunges 2.
In addition to b, it is further reinforced by the ribs 2C, and its rigidity is significantly strengthened.As a result, even if the female helicoid 2 is entirely molded from a synthetic resin material, the dimensions and true circularity of the body 2a are not affected. The degree is maintained accurately, and the attachment to the front body l or the cucoid 3 to the male
It has such strength that it will not deform even when subjected to stress associated with zero weight support.

Furthermore, since the inner diameter of the rib 2C can be freely set, it can also be used as an open aperture member that limits the light flux emitted from the photographic lens 4.
It is possible to provide an open aperture with extremely high positional accuracy for t.

Furthermore, the end of the female helicoid 2, that is, the rear surface of the rib 2C, is connected to the front body 1 as shown in FIG.
For example, the light amount adjusting member on the shutter board 9, which is incorporated from the lens magnification 1 to the shutter board 9, for example, the shutter blade 1.
The shutter blade 10 is opened and closed within the space formed between the rib 2C and the shutter substrate 9 with the shaft 10B as a fulcrum.

Therefore, the shutter board 9 does not require a dedicated holding member for holding the shutter blade IO and a spacer for maintaining a space between it and the shutter board 9, and its structure is significantly simplified. .

The charge ring 6 is given a predetermined rotation operation corresponding to the subject distance by the action of the automatic focus adjustment device, and at the same time, the rotation is also transmitted to the male helicoid 3 and the male helicoid is rotated by the action of the helicoid screw unit. 3
is moved eight times in the optical axis direction from the screwed position with the female helicoid 2. As a result, the photographic lens t is moved to the in-focus position for the subject, and then the shutter blade 10
Exposure is performed by

〔Effect of the invention〕

The present invention has realized the structural reinforcement of the female helicoid in the lens barrel, which has traditionally been considered the most problematic in terms of strength.As a result, the female helicoid can be made of resin, making it highly durable and mass-produced in 1 Ift. A lens barrel suitable for this purpose is now available.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a lens barrel according to the present invention. FIG. 2 is a sectional view of a female helicoid used in the lens barrel. l...Front body 2...Female helicoid 2a
...Body part 2b...Flange part 2c...
・Rib 3...Male helicoid 4...Photographing lens 5...Screw ring 9...Shutter board 10...Shutter blade Presenter Konishiroku Photo Industry Co., Ltd. Figure 1 Figure 2 Figure procedure amendment book Showa March 31, 1962 1. Indication of the case 1986 Patent A No. 110281 2. Name of the invention Lens barrel 3. Person making the amendment Relationship to the case Patent applicant address 1-26 Nishi-Shinjuku, Shinjuku-ku, Tokyo Number 2 Contact address: 1 Sakura I'r, Hino City, Tokyo 191 Konishiroku Photo Industry Co., Ltd. (Telephone: 0425-83-152
1) Patent Department 6,-1:--81,
＼-・１ 5. Subject of correction (1) Figure 2 of the drawing 6. Details of correction (1) Figure 2 of the drawing will be corrected as shown in the attached sheet. Figure 2

Claims (3)

[Claims] (1) A lens barrel characterized in that the female helicoid is made of resin and has a rib formed on the end opposite to the side that contacts the male helicoid. (2) The lens barrel according to claim 1, wherein the rib forms a fixed open aperture. (3) The lens barrel according to claim 1 or 2, wherein the female helicoid end formed by the rib serves as a holding member for a light amount adjusting member.