JPH073374Y2 - Lens barrel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a structure of an operating member in a lens barrel and a movable member interlocking with the operating member.

(Prior Art) As a lens barrel of this type, for example, as shown in FIG. 5, a fixed barrel 4, a moving frame 6, a cam barrel 3, and a fixed barrel 7.
There is a zoom lens barrel composed of the operation ring 2 and the like. The operation ring 2 moves the focusing lens L1 in the optical axis direction in cooperation with the movable member 21. The operation ring 2 and the movable member 21 are interlocked with each other by a long groove 2a formed in the optical axis direction inside the operation ring 2 and a key member 21a provided on the movable member 21.
And by. A holding member 5 that holds the focusing lens L1 is fixed to the movable member 21 with screws 21b. In this way, the lens group (by the key member 21a of the movable member 21 to which the focusing lens L1 is fixed and the long groove 2a formed in the operation ring (here, focusing ring) 2 which is interlocked with the movable member 21 ( Here, in order to drive the focusing lens L1), the movable member 21 and the operation ring 2 are linked together.

(Problems to be solved by the invention) Since the key member 21a is fixed to the movable member 21 with the screw 21c, when the movable member 21 is a metal, the key member 21a
Insert it through the through hole 2e provided in the operation ring 2 and use a tool to
There was a problem that it was difficult to assemble because it had to be fixed to the movable member 21 with c.

When the movable member 21 is plastic, the key member 21
In order to secure the tightening strength of the screw 21c that fixes a to the movable member 21, it is necessary to increase the thickness of the portion where the screw 21c stands to be considerably larger than that of metal, which causes a problem that the lens barrel becomes large in diameter. It was

An object of the present invention is to solve these problems and to provide a lens barrel which has a simple structure, is easy to assemble, and has a low component cost.

(Means for Solving Problems) According to the present invention, the operation ring is provided with two key grooves that are long in the optical axis direction, do not penetrate both ends, and are near the end surface of the operation ring at the groove end opposite to the camera body. The movable member is formed with a key member that engages with the key groove of the operation ring by plastic molding to prevent the movable member from elastically deforming and the key member deviating from the key groove. Thus, the fitting relationship between the operation ring, the movable member, and the lens barrel with which the movable member is fitted is set.

(Operation) In the present invention, the movable member and the key member are integrally molded by plastic molding, and the fitting relationship between the operation ring, the movable member and the lens barrel to which the movable member is fitted is set to a predetermined relationship. Therefore, the cost of the parts can be reduced, the parts can be easily assembled, and the movable member does not come off even if it is elastically formed.

(Embodiment) FIGS. 1 to 4 show an embodiment of the present invention. FIG. 1 is a partial sectional view of a lens barrel, FIG. 2 is a partially enlarged view of FIG. 1, and FIG. 4 and FIG. 4 are partially enlarged views of another embodiment different from FIG.

Since the lens barrel of the embodiment has substantially the same configuration as the zoom lens barrel shown in FIG. 5, similar parts are designated by the same reference numerals, and additional description and different configurations will be described.

In FIG. 1, the holding member 5 that holds the focusing lens L1 is screwed to the female helicoid screw portion 6a of the moving frame 6 by the helicoid screw portion 5a. The movable member 1 molded by a plastic material is fixed to the holding member 5 by a set screw 1b that is planted. The movable member 1 is formed by molding into a cylindrical shape similar to the operation ring 2, and the end of the movable member 1 engages with the key groove 2a of the operation ring 2.
Two 1a are formed. This keyway 2a has its end
2b is formed up to near the left end surface of the operating ring 2. The operation ring 2 is screwed with the screw 4a of the fixed barrel 4 by the screw 2c.
When the operation ring 2 is rotated, the rotation is transmitted to the movable member 1 via the key groove 2a and the key member 1a, the holding member 5 rotates, and the focusing lens L1 rotates while the helicoid screws 5a and 6a rotate. It is paid out in the axial direction.

In FIG. 2, the engagement amount between the key member 1a and the key groove 2a is B,
Further, assuming that the one-side gap amount between the movable member 1 and the operation ring 2 (the one-side gap amount around the optical axis) is A, the relationship of 2A> B is established. Due to such a relationship, when the movable member 1 and the operating ring 2 are assembled, the movable member 1 made of a plastic material is deformed in the radial direction, and the key member 1a is inserted into the key groove 2a of the operating ring 2. Can be incorporated.

On the other hand, after the movable member 1 and the operation ring 2 have been assembled, the cam cylinder 3 is fitted to the inner diameter side of the movable member 1. However, as shown in FIG. If C, then the relationship is 2C <B.

3 and 4 show sectional views of another embodiment. A key member 11a is integrally formed at two positions at the rear end of the movable member 11 formed of a plastic material, and the operation ring 12 has a portion where the key groove 12a of the operation ring 12 is formed. It is formed so as to slightly project to the inner diameter side. The key member 11a of the movable member 11 is engaged with the key groove 12a of the operation ring 12. The engagement amount between the key groove 12a of the operation ring 12 and the key member 11a of the movable member 11 is F, and the one-side clearance amount between the portion where the key groove 12a of the operation ring 12 is formed and the movable member 11 is G, Further, the amount of one side gap between the operation ring 12 and the movable member 11 is B. Then, the respective relationships are configured such that 2E> F and 2G <F.

With this construction, the key member 11a can be assembled in the same manner as the embodiment shown in FIGS. 1 and 2, and after the assembly as shown in FIG. It does not come off.

(Effect of the Invention) As described above, according to the present invention, the movable member and the key member are integrally molded by plastic molding, and the operation ring, the movable member and the lens barrel to which the movable member is fitted are fitted together. Since the relationship is set to a predetermined relationship, it is possible to reduce the component cost,
Moreover, it can be easily assembled, and does not come off from the operation ring even if the movable member is elastically deformed.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention. FIG. 1 is a partial sectional view of a lens barrel, FIG. 2 is a partially enlarged view of FIG. 1, and FIGS. Shows a partially enlarged view of another embodiment different from FIG. FIG. 5 shows a partial sectional view of a conventional lens barrel. (Description of symbols of main parts) 1 ... Movable member, 2 ... Operation ring, 1a ... Key member, 2a ... Key groove, 4 ... Fixed lens barrel, 5 ... Holding member

Claims (1)

[Scope of utility model registration request] 1. A lens barrel having an operation ring (2) that can be externally operated to extend a lens, and a movable member (1) that is movable in conjunction with the operation ring to extend the lens, The ring (2) is formed with two key grooves (2a) that are long in the optical axis direction and do not penetrate through both ends, and are located near the operation ring end face at the groove end opposite to the camera body. Includes a key member (1a) which is engaged with the key groove of the operation ring, is molded by plastic molding, and an inner cylinder (3) is fitted inside the key member (1a). 2A> B and 2C <B A: One-side clearance between the movable member and the operating ring so that the operating ring, the movable member and the inner cylinder fitted to the movable member are prevented from deviating from Amount B: Engagement amount of key member and key groove C: Gap amount on one side between movable member and inner cylinder A lens barrel characterized by being set to a predetermined relationship such that.