JPS6084518A - Helicoid member for lens - Google Patents

Abstract

PURPOSE:To eliminate play in a thrust direction and a radial direction securely without the smallest strain by providing an elastic deforming part which deforms elastically in axial directions of a helicoid member. CONSTITUTION:The elastic deforming thread part 5 which deforms elastically in the axial directions of the helicoid member 1 when engaging the female screw of an outer cylinder is provided as a part of a screw thread 3. The thread part 5 consists of a hollow thread ridge type elastic deforming part 6 which has an angle a little bit larger than the included angle of the screw thread 3 and deforms elastically and a column part 7 which supports the deforming part 6, and the hollow part 8 of the deforming part 6 functions to absorb the deformation of the deforming part 6. The column part 7 is formed integrally with the screw thread 3 of the member 1 and the thread part 5 is therefore connected to the screw thread 3 only through the column part 7.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a helicoid member for a lens.

Prior Art 1 - The problem with helicoids in helicoid members such as lens barrels is how to eliminate the backlash, and many proposals have been made regarding this problem. For example, various proposals have been made as described in Japanese Patent Application Laid-open No. 56-9710, Japanese Utility Model Application No. 58-102861, and Japanese Patent Application Laid-open No. 58-118612.

The technique disclosed in JP-A-56-9710 changes the shape of the helicoid to give a bending action in the thrust direction to the threaded part, and changes the pitch or part of the lead to prevent interference with the threaded part. A means for eliminating backlash in the threaded portion is adopted.

However, since the above means forcibly eliminates play by causing deformation or interference with the threaded part, the threaded part becomes a solid state and the rotation of the lens barrel is prevented. The disadvantage is that the motion becomes significantly slower. Moreover.

It is difficult to adopt method 7 because errors in the processing of the shape deformation portion, pitch, or lead deformation portion directly affect the above-mentioned drawbacks.

The technique disclosed in Japanese Utility Model Application Publication No. 58-102861 involves notching the -s of the thread of the helicoid, inserting a threaded piece with the same pitch into the notch, and thrusting this threaded piece through a spring. By pressing in this direction, it is intended to eliminate pitch deviation and backlash in the thrust direction.

However, with the above means, not only the structure becomes complicated, but also the shape of the component parts themselves becomes complicated, and the number of processing steps and assembly steps increases, resulting in an increase in cost.

The technique disclosed in Japanese Unexamined Patent Publication No. 58-118612 provides a notch s in the thread of the helicoid, and in this notch there is a dorsal and ventral part that protrudes into the thread groove of the helicoid on the other side and engages with one side of the groove. The purpose is to eliminate backlash χ by inserting a eliminating member.

However, the above means is
Similar to the technique described in Japanese Patent No. 61, this technique has a complicated structure and has the drawback of high manufacturing and assembly costs. Furthermore, since positioning in the radial direction depends on the amount of screwing in of the tightening screw, it must be dealt with by adjusting the clearance of the recoid screw to the mating side, making alignment difficult and automatic assembly difficult. Furthermore, when the dorsoventral eliminating member is used at t1 locations, there is a drawback that backlash of the helicoid screw cannot be eliminated. Furthermore, when backlash of a helicoid screw is removed by installing dorsoventral elimination members at two or more locations, there is no place for the force to escape in the thrust direction, so the side surface of the groove of the helicoid screw on the other side is not a uniform surface. If the helicoid screw is not deformed or deformed, there is a problem in that interference occurs on the deformed surface, resulting in a so-called helicoid screw jamming phenomenon.

Purpose of the Invention The present invention has been made in view of the problems of the prior art described above, and its purpose is to make it possible to easily and reliably eliminate backlash in the thrust direction and radial direction in a helicoid screw. The object of the present invention is to provide a helicoid member for a lens.

Structure of the Invention The present invention provides a helicoid member for a lens in which a helicoid is threaded on the outer circumferential surface. By providing the modification s, the above object of the present invention is attempted to be achieved. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment FIG. 1 shows a helicoid member (lens barrel) 1 and its outer cylinder 2 according to the present invention. A helicoid thread 3 is threaded on the outer peripheral surface of the helicoid member 1, and the helicoid member 1 is attached to an outer cylinder 2 that shoulders a female threaded portion 4 which is threadedly engaged with the thread 3 through this thread 3. It has a structure that can be screwed freely.

A portion of the thread 3 is provided with an elastically deformable threaded portion 5 that is configured to be elastically deformable in the axial direction of the helicoid member 1 when screwed into the female threaded portion 4 of the outer cylinder 2 . The elastically deformable screw $5 has a hollow screw thread-like elastically deformable portion 6 formed to be elastically deformable and has an angle slightly larger than the angle of the thread 3, and is used to support this elastically deformable portion 6. Strut part 1
The hollow portion 8 in the thread-like elastic deformation s6 is formed to function as a deformation absorbing groove when the elastic deformation portion 6 is deformed. The strut s7 is integrally formed with the thread 3 of the helicoid member 1, and therefore the elastically deformable threaded portion 5 is connected to the thread 3 only with the strut portion 1. That is, the thread-like elastic deformation portion 6 of the elastic deformation screw s5 is configured separately from the thread 3, and when screwed into the female thread s4 of the outer cylinder 2, the helicoid member 1
By deforming in the axial direction (thrust direction), rattling in the thrust direction and radial direction in the threaded portion can be prevented. The elastically deformable threaded portions 5 are arranged, for example, in three equal locations in the circumferential direction and in three equal locations in the axial direction, so that no bias occurs during screwing. In addition, in the above embodiment, the elastically deformable screw portion 5
is provided in a part of the thread 3 of the helicoid member 1, but the structure is not limited to this. Elastic deformation@6 and a hollow part 8 for absorbing deformation are arranged, and the thread 3 is formed by post-processing.
The configuration may be such that it is provided in a part or all of the area.

According to the helicoid member 1 for lenses having the #l configuration, when the helicoid member 1 is screwed into the outer cylinder 2, the thread-like elastic deformation s6 of the elastically deformable threaded portion 5 is caused in the thrust direction and the radial direction at the screwed portion. Since it is elastically deformed to absorb the play in the direction, it is possible to prevent play in the thrust direction and the radial direction from occurring in the threaded portion. As a result, the helicoid member (
When screwing in the lens barrel (1), the lens can be folded in and pulled out with high precision without causing eccentricity in the lens system.

6 and 1 show a second embodiment of the present invention. The feature of this embodiment is that the elastically deformable screw portion 5
The strut portion 1 and the thread-shaped elastic deformation s6 are constructed separately. That is, as shown in Fig. wE7, a retaining structure 9 for the support column 7 is provided on the inner surface of the thread-shaped elastic deformation section 6, and the elastic deformation section 6 and the support column 1 are bonded together via this retaining groove 9. They are integrally joined to each other by means of an agent (or means such as pressure bonding).

According to the above configuration, the elastically deformable portion 6 having an arbitrary shape is connected to the support portion 7.
There is an advantage that the elastic deformation part 6, which is most suitable for preventing backlash, can be attached. The other configurations and operations are the same as those of the first embodiment, so their explanation will be omitted.

FIGS. 8a and 8b show a third embodiment of the present invention. The feature of this embodiment is that the elastically deformable portion 6 of the elastically deformable threaded portion 5 is erected in the radial direction in a rabbit-ear shape as shown in Fig. In the process of screwing together, as shown in the figure, they are elastically deformed as if folded outwards and screwed together.

According to the above configuration, as shown in the figure, the restoring force of the elastically deformed portion 6 that is elastically deformed reliably prevents the looseness of the threaded portion of the helicoid member 1. Note that the other configurations and operations are the same as those of the first embodiment, so their explanation will be omitted.

Effects of the Invention As described above, according to the present invention, the elastic deformation of the elastically deformable threaded portion provided in a part or substantially all of the threaded portion of the helicoid member allows the helicoid member to be screwed together. It is possible to reasonably and reliably prevent backlash, prevent eccentricity of the lens system when the lens is folded in or pulled out, and ensure that the lens characteristics of the optical device are maintained.

[Brief explanation of the drawing]

1 to 4 are explanatory diagrams of the first embodiment of the present invention, and FIG.
Figures a and b are explanatory diagrams showing modifications of the main parts of the first embodiment, Figures 6 and 1 are perspective explanatory diagrams showing the second embodiment of the present invention, and Figures 8a and b are explanatory diagrams of the main parts of the first embodiment. It is an explanatory view showing a third example of the invention. 1... Helicoid member 3... Helicoid thread 5... Elastic deformation screw part 6... Elastic deformation part procedural amendment (voluntary) Commissioner of the Japan Patent Office Kazuo Wakasugi 1, Display of the case 1982 Patent Application No. 193254 2, Name of the invention Helicoid member for lenses 3, Relationship to the case of the person making the amendment Patent applicant address 2-43-2-4 Hatagaya, Shibuya-ku, Tokyo, Agent 6, Amendment Target drawing Plane 7, details of correction (1) Among the drawings, Figure 3 will be corrected as shown in the attached corrected drawing. 157

Claims (2)

[Claims] (1) In a helicoid member for a lens in which a helicoid is threaded on the outer circumferential surface, the helicoid is provided with an elastic deformation part that can be elastically deformed in the axial direction of the helicoid member when screwed into the threaded part. A helicoid member for lenses that contains t% mold. (2) The helicoid member for a lens according to claim 1, wherein the elastic deformation portion is formed by separating the -s of a screw in the helicoid on the outer peripheral surface of the helicoid member.