JPS61122616A - Lens holding device - Google Patents

Abstract

PURPOSE:To generate no distortion even if the use environment is varied, by providing extendedly a lens outer edge part in the optical axis direction, providing an engaging part to a lens frame side on its inside peripheral surface, providing projectingly the inside diameter side of the lens holding surface part of the mirror frame side, in the optical axis direction, and providing an engaging part to a lens engaging part on its outside peripheral surface. CONSTITUTION:An outer edge part 13 of a lens 11 is provided extendedly in the optical axis direction, also an engaging part 20 to a lens frame 12 side is provided on its inside peripheral surface, an inside diameter side of a lens holding surface part 18 of the lens frame 12 side is provided projectingly in the optical axis direction, and also on its outside peripheral surface, an engaging part 15 to the lens engaging part 20 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lens holding device that fixes and holds a lens at a predetermined position within a lens frame.

Conventionally, this kind of lens holding device is shown in Fig. 5 (
It was constructed as shown in FIGS. 6(a) and 6(b).

That is, in the technique shown in FIGS. 5(a) and 5(b), a female threaded portion 3 with a pitch equal to the edge thickness of the lens 2 to be fixed is screwed into the lens frame 1, and the female threaded portion 3 is threaded onto the female threaded portion 3. Screw in lens 2 (
By screwing in the lens 2, the lens 2 is fixedly held within a predetermined fitting 4 of the lens frame l. At the outer edge of the lens to be fixed, the cannibal holes 5, 5 are mutually arranged 18
There are two holes located at 0° offset positions.This crab hole is 5°5.
The lens 2 to be fixed can be screwed into the lens frame l by using the screw. Further, the lens 2 to be fixed is configured to overcome the deformed part 6 in the lens frame 1, to be housed in the fitting part 4, and to be fixedly held.

Further, the technique shown in FIGS. 6(a) and 6(b) configures the fixed lens 2 by providing a plurality of lens screw arms 8 on the outer circumference of the fixed lens body 7, and The fixed lens 2 can be fixed and held within the lens frame by being screwed into the lens frame having a corresponding threaded portion.

However, the conventional lens holding device described above has the following problems.

(1) When the lens is fixed, a large force acts on the lens surface in the radial direction, which may cause permanent distortion or cracks on the lens surface.

(2) In particular, in the case of the configurations shown in FIGS. 6(a) and (b), the lens shape is extremely complicated, and the presence of the lens screw arm 8 makes its manufacture extremely difficult. Ta.

(3) In each of the conventional structures described above, the lens 2 housed and held in the lens frame 1 is fitted in such a way that its expansion in the radial direction is restricted, so the environment in which the lens system is used is If the lens body changes (particularly at high temperatures), large distortions will occur in the lens body, which may cause permanent deformation of the lens body.

The present invention has been made in view of the problems of the prior art described above, and provides a lens holding device that prevents distortion from occurring in the lens body even when the environment in which the lens system is used changes significantly. The purpose is to

In the present invention, the outer edge of the lens is extended in the optical axis direction, and the inner circumferential surface thereof is provided with an engagement part with the lens frame side, and the inner diameter side of the lens holding surface on the lens frame side is provided to protrude in the optical axis direction. At the same time, the object of the present invention is achieved by providing an engaging portion with a lens engaging portion on the outer circumferential surface thereof.

F Hereinafter, embodiments of the present invention will be described in detail using fJS figures 1 to 4.

(First Embodiment) FIG. 1 shows a first embodiment of a lens holding device 9 according to the present invention, and since it is bilaterally symmetrical, the right half of the center line 10 is omitted.

Reference numeral 11 in the figure indicates a lens made of a plastic material that is fixedly held within a lens frame 12 made of an aluminum material or the like. Although it may be formed all around the outer edge portion 13 of the lens 11,
A configuration may be adopted in which a plurality of them are arranged with the circumferences equally or unevenly distributed.

Reference numeral 16 designates two cantilever holes for rotating the lens 11, which are provided at positions 180' out of phase with each other on the outer edge 13 of the lens 11.

The inner diameter side of the lens holding surface part 17 in the lens frame 12 is formed into an annular lens abutting part 18 that protrudes in the optical axis direction, and the tip of the lens abutting part 18 is orthogonal to the optical axis 10. It is formed on the lens contact surface 19. The outer peripheral surface of the lens abutting portion 18 is threaded with a female threaded portion 20 that can be screwed into the female threaded portion 15 on the lens II side. As shown in the figure, the space 22 formed between the threaded surface of the lens abutting part 18 and the inner circumferential surface 21 of the lens storage section allows the outer circumferential surface of the lens to be accommodated even when the lens 11 is fixedly held. It is set and shaped so that an appropriate interval is maintained between it and the inner circumferential surface 21 of the section.

According to the above configuration, by screwing the lens 11 through the female threaded part 15 on the lens side and the male threaded part 20 on the lens frame side,
The lens 11 is fixedly held on the lens frame 12. The screwing operation of the lens 11 can be performed using the cannulated hole 16. or.

In order to securely fix the lens 11, double screw portions 15 are provided.
．． Of course, an adhesive may be interposed between the two.

Even if the lens system (collectively the lens 11 and lens frame 12) fixed by the lens holding device 9 is used in a high-temperature environment, the lens 11 made of plastic material is better than the lens made of aluminum or other material. Since the linear expansion coefficient is larger than that of the frame side and the lens II is configured to be able to freely expand in the radial direction, the expansion of the lens 11 is not restricted. Even when used under low conditions, the lens does not produce any optical distortion and maintains stable lens performance.

Furthermore, when the above lens system is used at low temperatures, the play in the threaded portions 15 and 20 absorbs shrinkage and the coefficient of linear expansion decreases, so the lens 11
There is no internal distortion, and stable lens performance can be maintained.

Furthermore, even when the JIi adhesive is interposed between both threaded portions 15 and 20, there is no acting force that can affect the optical performance of the lens 11, and therefore, the lens system is not exposed to high temperatures at which it is planned to be used. Even when used in all low-temperature regions, stable lens performance can be maintained at all times, and reliability as a lens holding device can be improved.

(Excellent 2nd Embodiment) FIG. 2 shows a second embodiment of the present invention. The feature of this embodiment is that a so-called bayonet structure is used instead of the screw fitting in the first embodiment to The reason lies in the fact that it has been constructed. That is, the engaging portion on the lens outer edge 13 side is formed into a locking claw portion 24 having a U-shaped cross section and having an engaging #lI23 perpendicular to the optical axis direction, and the engaging portion on the other lens frame side is The engagement groove 2
3 and a guide rail part 25 that can guide the stopper part 2.
6 and is formed on a locking rail portion 27 formed by 6.

The thickness of the guide rail surface in the guide rail portion 25 may be uniform, but it may also be configured so that it becomes thicker as it approaches the stopper portion 26 so that the lens 11 is more securely fixed. Since the other configurations are the same as those of the first embodiment, the same members are given the same reference numerals and the explanation thereof will be omitted.

Note that the locking claw portion 24 and the locking rail portion 27 are as follows.

As shown in the figure, three pieces are installed at three equal intervals around the circumference, but it goes without saying that this is not limited to this.

According to the above configuration, the lens 11 is dropped until it abuts the lens contact surface 19 of the lens frame 12 without the locking claw portion 24 touching the locking rail portion 27, and the lens The lens 11 is rotated counterclockwise and stopped when it comes into contact with the stopper part 26.
can be securely fixed to the lens frame 12, and secure fixation can be achieved with a simpler operation.

Other functions and efficiency are the same as those of the first embodiment, so their explanation will be omitted.

(Third Embodiment) FIG. 3 shows a third embodiment of the present invention. The feature of the unembodied embodiment is that the lens 11 can be fixed to the lens frame 12 by simply pushing the lens II in the optical axis direction. This is because the engaging portions on the lens 11 side and the lens frame 12 side are configured in this manner. That is, the lens edge side engaging portion is formed into a serrated engaging portion 28.

The engaging part on the lens abutting part 18 side on the lens frame 12 side is formed into a sawtooth engaging part 29 that meshes with the engaging part 28. The rest of the structure is the same as in the first and second embodiments, so the same members will be given the same reference numerals and their explanation will be omitted.

According to the above configuration, by utilizing the elastic deformation of the special mention portion 14 in the radial direction, the lens 11 can be moved onto the lens frame 12 by simply pushing the lens 11 in the optical axis direction until it comes into contact with the lens contact surface 18. It can be held securely in place. Therefore, there is no need for a hook hole, and it is possible to fix and hold with a so-called one-touch operation. Other effects.

The effect is the same as that of the first embodiment, so the theory 1f
Omit +.

(Fourth Embodiment) FIGS. 4(a) and 4(b) show a fourth embodiment of the present invention.
Similar to the third embodiment, the feature of this embodiment is that the lens II and the engaging portion on the lens frame 12 side are configured so that the lens II can be fixed to the lens frame 12 with a single touch. At the point. That is, the lens contact portion 18 on the lens frame 12 side
The side engaging portion includes an elastic arm 30 of an appropriate width provided along the circumference, and a lock portion 31 protruding from the tip of the elastic arm 30.
1 elastic arm 3° has a proximal end 32
It is configured to be elastically deformable in the radial direction around the center. Reference numeral 33 indicates a recess for lifting the elastic arm 30A. Further, the engaging portion on the lens 11 side is formed in an engaging recess 34 that tightly fits into the locking portion 31. The lock portion 31 is set to always protrude outward from the outer peripheral surface of the lens contact portion 18, and when the lens 11 is pushed in, it is elastically deformed in the radial inward direction, and the lock portion 31 and the engagement recess 34 are elastically deformed. When engaged, the lens 11 protrudes outward again and is fixedly held on the lens frame 12.

According to the above configuration, the lens IL can be reliably fixed and held on the lens frame 12 with a one-touch operation of simply pushing the lens 11.

Other functions and effects are the same as those of the first embodiment, so their explanation will be omitted.

In addition, although two elastic arms 30 are arranged at symmetrical positions in the circumferential direction in the figure, it is needless to say that the present invention is not limited to this.

As described above, according to the present invention, it is possible to securely hold the lens with an easy fixing operation.

Assembly man-hours can be reduced. Further, since stress is not generated on the lens during assembly, there is no distortion during assembly and the lens performance can be maintained normally. Furthermore, even if the usage environment changes from high to low, the lens will not be distorted, so it is possible to always obtain a high-performance lens system.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional explanatory diagram of a first embodiment of the device according to the present invention;
FIG. 2 is a perspective explanatory view of a second embodiment of the device according to the present invention;
FIG. 3 is a sectional view explanatory diagram of the third embodiment of the device according to the present invention, and FIGS. 4(a) and (b) are the fourth embodiment of the device according to the present invention.
Explanatory diagram of the embodiment, No. 51) U (a), (b), FIGS. 6(a) and (b) are explanatory diagrams of the prior art. If... Lens I2... Lens frame 14 point extension parts 15, 20... Threaded parts (engaging parts) 18... Lens contact parts 23, 24. 27... Engaging parts 28, 29...Engaging part 30, 31.34...Engaging part Fig. 1 Fig. 2 Fig. 8 Fig. 6 Procedural amendment voluntarily written) 1. Indication of the case 1988 Patent Application No. 244071 2. Name of the invention Lens holding device 3, Relationship to the case of the person making the amendment Patent applicant Address: 2-43-2-4 Hatagaya, Shibuya-ku, Tokyo, Agent 6, ``Detailed description of the invention'' in the specification to be amended 7. Contents of correction (1) ``Brief explanation of the drawings, Part 7, Contents of correction (1) ``The outer edge 13J is corrected as ``The outer edge 13 of the lens 11'' written on page 5, line 17 of the specification. (2 ) The r present invention described on page 7, line 11 of the specification is corrected to be one embodiment. (3) The r# marking plate portion 14 described on page 1 O, line 13 of the specification is amended as " The extension part 141 is corrected. (4) "Distortion occurs" written in page 12, line 18 of the specification is corrected to "distortion occurs." (5) Specification, page 13, line 9 The '14-point extension part' written in is corrected to '14...extension part yo'.

Claims (5)

[Claims] (1) The outer edge of the lens to be fixed is extended in the optical axis direction, and an engaging part with the lens frame is provided on the inner peripheral surface, and the inner diameter side of the lens holding surface of the lens frame is annular in the optical axis direction. What is claimed is: 1. A lens holding device characterized in that the lens holding device is constructed by protruding from the lens abutting portion and providing an engaging portion on the outer circumferential surface thereof for engaging with a fixed lens side engaging portion. (2) The lens holding device according to claim 1, wherein the engaging portions on the lens side and the lens frame side are constituted by threaded portions. (3) The lens holding device according to claim 1, wherein the engaging portions on the lens side and the lens frame side have a bayonet structure. (4) The lens holding device according to claim 1, wherein the engaging portions on the lens side and the lens frame side are sawtooth-shaped engaging portions. (5) The engaging parts on the lens side and the lens frame side are composed of an elastic arm having a locking part and elastically deformable in the radial direction, and a recessed part that can freely engage with the locking part. A lens holding device according to claim 1.