JPH0731295B2 - Lens barrel - Google Patents

Description

TECHNICAL FIELD The present invention relates to a lens barrel that can be attached to and detached from a main body, and more particularly to an interchangeable lens barrel that has a mount for attachment to and detachment from the main body formed of plastic.

[Prior Art] Conventionally, there is known an interchangeable lens barrel that holds a moving lens by a guide rod and guides the movement.

Regarding the method of holding the guide rod, see
As described in Japanese Patent Publication No. 1989-331, a disc-shaped base plate is fixed to both ends of a cylindrical fixed cylinder, and the base plate holds a guide rod. Further, as described in JP-B-58-23603 and the like, one end of the rod is directly held by a cylindrical fixed cylinder, and the other end is held by a main plate fixed to the fixed cylinder.

[Problems to be Solved by the Invention] However, in the conventional interchangeable lens barrel, a number of members are interposed between a mount for attaching to and detaching from the camera body and a member or cam that supports the guide rod. There is a problem that the positional accuracy of the moving lens with respect to the camera body cannot be improved when the lens barrel is attached to the camera body.

[Means for Solving the Problems] In order to reduce the above problems, the first invention of the present application is to attach and detach a guide member extending in the optical axis direction to guide movement of a lens in the optical axis direction, and a main body. In the lens barrel having a mount for, a support portion integrally formed with the mount is provided, and the guide member is supported by the support portion.

Further, the second invention of the present application is a lens barrel having a plate cam for moving the lens in the optical axis direction and a mount for attaching to and detaching from the main body, and having a support portion integrally formed with the mount. The plate cam is supported by the supporting portion.

Embodiments FIGS. 1 to 4 show a first embodiment of the present invention. FIG. 1 is a sectional view including an optical axis of an interchangeable lens barrel including a bayonet mount, and FIG. FIG. 4 is a perspective view from the front of the main part of the interchangeable lens barrel shown in FIG. 1, and FIG. 4 is a perspective view from the rear. FIG. 2 is a perspective view of the cam plate shown in FIG.

1 to 4, 1 is a bayonet mount made by plastic injection molding, and 1a is integrally molded at the time of the mount molding, and is a support member extending in the optical axis direction (support portion of the plate cam). ), 1b are rod press-fitting bosses (guide rod support portions), which are integrally molded when the mount is molded, and the bosses are provided with press-fitting holes. 1c is a positioning protrusion, which is formed at the tip of the support member 1a. A guide rod holding plate 2 has a hole 2a for supporting the other end of the guide rod 3. Reference numeral 3 is a guide rod, one end of which is press-fitted and supported by the press-fitting boss 1b, and the other end of which is supported by being inserted into the hole 2a of the plate 2. 4 is a cam plate (plate cam), 4a is a rotation center hole of the cam plate, 4b and 4c are cam grooves, 5 is a rotary shaft screw of the cam plate 4, 6 is a front lens group moving frame, and 6a is the moving frame 6 Sleeve portion, 6b is a cam pin integrated with the moving frame 6, 7 is a rear lens group frame, and 7a is the lens frame 7
And 7b are cam pins integrated with the lens frame 7, 8 is a front group lens holding frame, 9 is an outer cylinder, 10 is protective glass, and 11 and 12 are screws. L1 is a front lens group, and L2 is a rear lens group.

Next, in the above structure, one end of the guide rod 3 is tightly pressed into the hole of the boss 1b of the bayonet mount 1 so as not to easily come off. Bayonet mount 1
A hole into which the positioning protrusion 1c is inserted at the end of the support member 1a
The plate 2 positioned at the correct position due to the relationship with 2b is fixed by the screw 11. Also, the guide rod 3
The other end is inserted into and supported by the hole 2a of the plate 2.
The center hole 4a of the cam plate 4 is inserted and supported by a screw 5 fixed to the support member 1a, and the cam plate 4 is rotatable around the screw 5.

The front group moving frame 6 which holds the front group lens holding frame 8 with a helicoid screw at the inner diameter is used as a guide rod 3 by a sleeve 6a.
It is supported so as to be movable in the optical axis direction. Rear lens frame 7
Also, the sleeve 7a is held by the guide rod 3 so as to be movable in the optical axis direction. Front lens group holding frame 8 and rear lens group frame 7
The cam pins 6b and 7b projecting from the cams are fitted into the cam grooves 4b and 4c of the cam plate 4 without play, and the cam frames 4 and 7 can move the lens frames 8 and 7 in the optical axis direction as the cam plate 4 rotates. it can.

[Other Embodiments] FIG. 5 shows another embodiment in which 11 is a bayonet mount and 11a.
Is a support member, 11b is a rod press-fitting boss, and 12 is a guide rod.

In this embodiment, as in the case of the first embodiment, the guide rod 12 is press-fitted and supported by the bayonet mount 11 formed by plastic, but if the guide rod is short, the first rod is mounted.
The plate 2 shown in the embodiment is abolished to further reduce the size and reduce the cost.

As described above, in the above-described embodiment, the bayonet mount of the interchangeable lens is molded by plastic and one end of the guide rod that is the guide member of the moving lens is press-fitted into the bayonet mount to ensure the distance between the guide rods. In the first embodiment, the other end of the guide rod is supported by the plate, so that the distance between the rods on the plate side (the other end) is accurately determined. As described above, the plurality of guide rods can maintain the parallel state. Further, by being guided by a positioning projection provided at the end of the supporting member of the bayonet mount and fixing the plate in the correct position, twisting of the plurality of guide rods is prevented, and the guide rods are made parallel to the optical axis. Be corrected. As a result of the above, it is possible to eliminate the previously required cylindrical fixed tube, and by directly pressing the guide rod into the bayonet mount, which is the reference to be attached to the camera body, without interposing other members. , It has become possible to increase the support accuracy of the movable lens group as compared with the conventional one. Further, since the cylindrical fixed cylinder is not necessary, an inexpensive cam plate can be used instead of the conventional cylindrical cam cylinder, and the effect of downsizing and cost reduction is great.

EFFECTS OF THE INVENTION According to the present invention, a support member for supporting a guide member such as a guide rod for guiding the movement of a lens in the optical axis direction or a plate cam for moving the lens is mounted on the main body for attachment / detachment. It is possible to provide a lens barrel that is integrally molded with the camera body and that improves the positional accuracy of the moving lens with respect to the camera body.

[Brief description of drawings]

 1 is a sectional view of the interchangeable lens barrel of the first embodiment, FIG. 2 is a perspective view of only the cam plate of FIG. 1, and FIG. 3 is a front perspective view of only the main part of FIG. FIG. 4 is a rear perspective view of only the main part of FIG. 1, and FIG. 5 is a perspective view showing the main part of the second embodiment. 1 is a bayonet mount 1a is a support member 1b is a rod press-fitting boss 3 is a guide rod 4 is a cam plate 4b, 4c is a cam groove 6 is a front lens group moving frame 7 is a rear lens group frame 6b, 7b is a cam pin 8 is a front group Lens holding frame

Claims (6)

[Claims] 1. A lens barrel having a guide member extending in the optical axis direction for guiding the movement of the lens in the optical axis direction and a mount for attaching to and detaching from the main body, the lens barrel being integrally molded with the mount. A lens barrel, comprising: a support portion, the support portion supporting the guide member. 2. The lens barrel according to claim 1, wherein the mount and the support portion are integrally molded of plastic. 3. A lens barrel having a plate cam for moving the lens in the optical axis direction and a mount for attaching to and detaching from the main body, the lens barrel having a supporting portion integrally formed with the mount, A lens barrel, wherein the plate cam is supported by a portion. 4. The lens barrel according to claim 3, wherein the mount and the supporting portion are integrally molded of plastic. 5. A guide member extending in the optical axis direction for guiding the movement of the lens in the optical axis direction, and a second support portion integrally formed with the mount, Two
The lens barrel according to claim (3), characterized in that the guide member is supported by a support portion of the lens barrel. 6. The lens barrel according to claim 5, wherein the mount and the supporting portions are integrally molded of plastic.