JPS6365414A - Lens frame fixing mechanism for lens barrel of lens frame - Google Patents

Abstract

PURPOSE:To prevent positional shift to be induced from an inner cylinder from positional to an outer cylinder due to the influence of vibration or the like by fixing the inner cylinder on the outer cylinder by a large area of an elastic fixing member formed in a gap between the inner and outer cylinders. CONSTITUTION:After filling the gap 7 between the inner and outer cylinders 2, 1 with silicone resin 3 mixed with a curing agent e.g., the silicone resin left as it is for several hours to cure and harden the silicone resin 3, so that the silicone resin 3 is tightly stuck to the outer periphery of the inner cylinder 2 and the inner periphery of the outer cylinder 1, and the inner cylinder 2 can be fixed on the outer cylinder 1 without play under position-adjusted status. A temporarily fixing screw 4 is left as it is under the screwed state into the outer cylinder 1 also after fixing the inner cylinder 2 on the outer cylinder 1 with the silicone resin 3 to auxiliary fix the inner cylinder 2 on the outer cylinder 1. Even if vibration or shock is applied to the lens barrel, the vibration or shock is absorbed by the elastic force of the silicone resin 3 to be an elastic fixing member and the positional shift between the inner and outer cylinders 2, 1 can be suppressed.

Description

[Detailed Description of the Invention] The present invention relates to a lens for a lens barrel of an optical instrument such as a camera, in which an inner barrel is fixed in an adjusted position within an outer barrel of the lens barrel. Regarding the frame fixing mechanism.

Conventional technology In general, lens systems for optical instruments such as cameras require high precision when adjusting the positions of each part after assembling the parts, and especially in high-performance lens systems, the final precision is within μm.
It is necessary to adjust the unit.

For this reason, various lens frame fixing mechanisms have been conventionally provided in which, after adjusting the position of each lens in such a lens system, each lens is fixed in the adjusted position with a cylindrical member forming a lens frame. For example, as shown in FIG. 4, the lens frame is configured with a first inner tube 31, a second inner tube 33, and an outer tube 30, and the first inner tube 31 having the lens group L1 is connected to one end of the outer tube 30. Then, after screwing the aperture 32 into the outer cylinder 30 and fixing the first inner cylinder 31 in the outer cylinder 30, the second inner cylinder 33 having the second lens group is inserted into the outer cylinder 30. Adjust the position by screwing it in, then tighten the several fixing screws 34.
．． ..., fixing the second inner cylinder 33 to the outer cylinder 30 at 34,
There is one in which each lens is fixed to the outer cylinder 30 in a position-adjusted state.

Problems to be Solved by the Invention However, in such a device, the second inner cylinder 33 is fixed with several fixing screws 34. ..., since it is fixed to the outer tube 30 with only 34, if vibration or impact is applied during transportation, the fixing screw 34 will loosen, and the position of the inner tube 33 with respect to the outer tube 30 will shift, causing the lens to deteriorate. There was a problem that the performance of the lens barrel deteriorated.

Therefore, an object of the present invention is to solve the above-mentioned problems, and to provide a lens frame fixing mechanism for a lens barrel in which the inner cylinder is unlikely to be misaligned with respect to the outer cylinder even when vibrations or shocks are applied. There is a particular thing.

Means for Solving the Problems In order to achieve the above object, the present invention is configured such that the inner cylinder is fixed with an elastic fixing member in a position adjusted state with respect to the outer cylinder. That is, the lens frame for fixing the lens is composed of an outer cylinder and an inner cylinder inserted into the outer cylinder, an annular gap of a certain size is formed between the outer cylinder and the inner cylinder, and the inner cylinder An elastic fixing member is interposed in at least a part of the gap to fix the to the outer cylinder, and the fixing member is in close contact with the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder, and the elastic fixing member is fixed to the outer cylinder. On the other hand, the inner cylinder was configured to be fixed in a position adjusted state.

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 3.

As shown in FIG. 1.2, the lens frame fixing mechanism of the lens barrel according to the present embodiment fixes the lens frame between the pair of lenses 5.6 and 5.6.
The inner cylinder 2 is inserted into the outer cylinder 1 through an opening at one end, and the position of the inner cylinder 2 with respect to the outer cylinder l is adjusted with an adjustment screw (not shown). 4 temporary screws 4. . . , 4 temporarily fix the inner tube 2 to the outer tube 1, and then pour the liquid silicone resin 3 as an elastic fixing member into the tube through the four through holes 1a, . . . , la of the outer tube l. The silicone resin 3 is poured into the gap 7 formed between the outer cylinder 1 and the inner cylinder 2 to be filled, and the silicone resin 3 is cured to fix the inner cylinder 2 to the outer cylinder 1.

The outer cylinder 1 has four screw holes 1b, . In addition, four silicone resin filling through holes 1a are provided on the peripheral wall surface.
, . . , 1a are formed at predetermined intervals.

The inner tube 2 adjustably fixes the pair of lenses 5°6 therein, and has both ends 2a and 2b concave in the radial direction than the axially central portion 2C on the outer circumferential surface of the inner tube 2. A gap 10.7 of a certain size can be formed between the inner circumferential surface of the

The elastic fixing member 3 is a cylindrical body, and the other end 2 of the inner cylinder 2
It covers the outer peripheral surface of the inner cylinder 2 and the inner peripheral surface of the outer cylinder 1, and is interposed in one of the gaps 7 formed between the two surfaces. The elastic fixing member 3 is liquid at room temperature so that it can be sufficiently filled into the gap 7 between the outer cylinder 1 and the inner cylinder 2, but it hardens if left for several hours after being filled, and when it hardens, it releases gas. It is preferable that there is no expansion or contraction. As an example of the elastic fixing member 3, silicone resin is preferably used, which fully satisfies the above-mentioned properties and also has sufficient pressure resistance after curing.

According to the above configuration, after inserting the inner cylinder 2 into the outer cylinder l,
The position of the inner tube 2 in the optical axis direction C and the direction perpendicular to the optical axis direction with respect to the outer tube L is adjusted by using a slight gap 9 corresponding to the play in the fit between the outer tube L and the inner tube 2. Adjust using adjustment screws (not shown). - After the adjustment, temporarily tighten the inner cylinder 2 with the screw 4. . . . Lightly fix it to the outer cylinder 1 with the position adjusted in step 4. Next, both cylinders 1.
A liquid silicone resin 3 is poured into the gap 7 between the two so as to cover the outer peripheral surface of the inner cylinder 2 in a cylindrical shape, and the silicone resin 3 mixed with a vulcanizing agent is poured into the inner cylinder 2 and the outer cylinder l. After filling the above-mentioned gap 7, the silicone resin 3 is left for several hours to vulcanize and harden, and the silicone resin 3 comes into close contact with the outer peripheral surface of the inner cylinder 2 and the inner peripheral surface of the outer cylinder l. To fix an inner cylinder 2 in an adjusted position relative to an outer cylinder 1 without wobbling. Note that even after the inner cylinder 2 is fixed to the outer cylinder l with the silicone resin 3, the temporary fixing screw 4 is left screwed into the outer cylinder 1 as it is, and the inner cylinder 2 is auxiliary attached to the outer cylinder l. Make it fixed.

According to the above embodiment, the temporary fixing screw 4. ....

4, the inner tube 2 is fixed to the outer tube L with the silicone resin 3, so even if vibrations or shocks are applied to the lens barrel during transportation, the silicone resin 3 acts as an elastic fixing member. By absorbing the elastic force to some extent, it is possible to effectively prevent misalignment between the inner cylinder 2 and the outer cylinder l. In addition, after adjusting the position of the inner cylinder 2 to the outer cylinder l, the gap 7 between the two cylinders 2j is filled with silicone resin 3 in a cylindrical shape and cured.
can be easily and accurately fixed to the outer cylinder 1 in a state where the position is adjusted.

Note that the present invention is not limited to the above embodiments,
It can be implemented in various other ways. For example, the silicone resin 3 is applied to the gap 7 between the inner cylinder 2 and the outer cylinder l so as to cover the entire outer peripheral surface of the inner cylinder 2. IO and the entire gap 9 may be filled. Moreover, the silicone resin does not need to be filled over the entire circumference of the inner cylinder 2 in the gap 7, but may be filled only in the vicinity of the through holes 1a, . . . , la. Further, as shown in FIG. 3, an annular protrusion 1c having an opening 1d smaller in diameter than the outer diameter of the inner cylinder 2 is integrally formed on the inner surface of the opening at one end of the outer cylinder l, while an annular protrusion 1c having an opening 1d having a diameter smaller than the outside diameter of the inner cylinder 2 is formed inside the opening at the other end. The screw washer 8 may be configured to be screwed in. In this embodiment, after inserting the inner cylinder 2 into the outer cylinder l and bringing the end surface of one end 2b of the inner cylinder 2 into contact with the protrusion 1c, a screw washer 8 is inserted into the opening at the other end of the outer cylinder 1. Lightly screw in the inner cylinder 2 and outer cylinder 1.
The inner cylinder 2 is held movably within the outer cylinder l by being held between the protrusion 1c and the screw washer 8. And in this state,
The position of the inner tube 2 is adjusted with respect to the outer tube 1 only in the direction perpendicular to the optical axis direction C by using a slight gap 9 corresponding to the play in the fit between the inner tube 1 and the outer tube 1. After adjusting the position, as in the above embodiment, liquid silicone resin 3 is poured into the gap 7 between the two cylinders 1°2 through the through holes la, ..., la of the outer cylinder l.
Pour it into the inner cylinder, leave it for several hours to harden it, and make the inner cylinder 2.
is fixed to the outer cylinder 1 in an adjusted position without wobbling relative to the outer cylinder 1. In addition, in this example,
When attaching the lens barrel to the main body of the device in which it is used, the optical axis direction C is adjusted.

Effects of the Invention According to the above configuration, the inner cylinder is attached to the outer cylinder not in a small area like the end face of a screw, but in the large area of the elastic fixing member interposed in the gap formed between the inner cylinder and the outer cylinder. This will fix the inner cylinder to the outer cylinder. Therefore, the resistance force against vibrations or shocks applied from the outside during transportation increases, and the vibrations and shocks can be absorbed to some extent by the elastic force of the elastic fixing member, and as a result, the effects of vibrations, etc. The rising inner cylinder is less likely to be misaligned with respect to the outer cylinder, and the inner cylinder can be reliably fixed at the adjusted position with respect to the outer cylinder. Furthermore, since the inner and outer cylinders are not fixed with fixing screws, even if the lens barrel is used for a long period of time, the loosening of the fixing screws may cause the outer and inner tubes to become misaligned. Nor. In addition, the position of the inner cylinder can be adjusted by adjusting the position of the inner cylinder with respect to the outer cylinder and, for example, lightly inserting the inner cylinder into the outer cylinder with a temporary set screw or the like and fixing both cylinders with an elastic fixing member. In other words, the lens in the inner tube can be accurately and reliably fixed to the outer tube without being distorted. In other words, when fixing the inner cylinder to the outer cylinder strongly with fixing screws as in the past, the pressure of the fixing screws could cause distortion of the lens surface inside the inner cylinder, but fixing with an elastic fixing member In this case, the elastic fixing member does not forcefully come into contact with the inner cylinder, and the lens system is not adversely affected.

[Brief explanation of drawings]

1.2 are a vertical sectional view and a rear view of a lens barrel equipped with a lens frame fixing mechanism according to an embodiment of the present invention, and 3.
The figure is a longitudinal sectional view of a lens barrel according to another embodiment, and FIG. 4 is a longitudinal sectional view of a lens barrel equipped with a conventional lens frame fixing mechanism. l...outer cylinder, la...through hole, Ib...screw hole,
lc...protrusion, ld...opening, 2...inner cylinder, 2
a, 2b... end, 2c... protrusion, 3... silicone resin (elastic fixing member), 4... row 1 female screw, 5
6...Resozoo 710..."6 Dark...Screw washer, 9...Gap. Patent applicant: Minolta Camera Co., Ltd. Agent Patent attorney: Seihaku Ao and 2 others Fig. 3 Fig. 4 Q 0 ″ -1 Dimensions

Claims (2)

[Claims] (1) Attach the lens frame that fixes the lenses (5, 6) to the outer tube (1).
) and an inner cylinder (2) inserted into the outer cylinder (1), forming an annular gap (7) of a certain size between the outer cylinder (1) and the inner cylinder (2). An elastic fixing member (3) for fixing the inner cylinder (2) to the outer cylinder (1) is interposed in at least a part of the gap (7), and the fixing member (3) is interposed in at least a part of the gap (7).
) is in close contact with the outer peripheral surface of the inner cylinder (2) and the inner peripheral surface of the outer cylinder (1) to fix the inner cylinder (2) in a position-adjusted state with respect to the outer cylinder (1). A lens frame fixing mechanism for a lens barrel. (2) The lens frame fixing mechanism for a lens barrel according to claim 1, wherein the elastic fixing member (3) is made of silicone resin.