JPH0727158B2 - Optical equipment - Google Patents

Description

The present invention relates to an optical device such as a camera, an interchangeable lens, and an extender having a mount.

[Prior Art] Conventionally, this type of bayonet mount is made by cutting a metal material, but a method of molding the bayonet mount with a plastic material is known as disclosed in Japanese Utility Model Publication No. 55-138628. Has been.

[Problems to be Solved by the Invention] However, although the mount made of plastic is proposed in Japanese Utility Model Laid-Open No. 55-138628, it was difficult to put it into practical use. The reason is mainly because the mechanical strength of the bayonet mount is insufficient.For example, when force is applied to the interchangeable lens, the mount will be deformed and the optical performance cannot be guaranteed, or in the worst case, There was a problem such as damage.

[Means for Solving the Problem] A structure in which a device is coupled with another device by rotating in one direction and is separated by rotating in the other direction, and a plurality of bayonet claws protruding in a radial direction are formed, and an optical device is formed. In an optical device having a mount fixed to the main body, and the mount is molded from plastic, the first invention is that the cylindrical portion extending from the mount in the optical axis direction is integrally molded at an outer diameter position, and the optical device main body is provided. The mounting of the mount with respect to is performed by screwing the cylindrical portion in a direction substantially orthogonal to the optical axis, and the screwing position is set within the phase of the bayonet claw of the mount. A second invention is that the first cylindrical portion extending from the mount in the optical axis direction is integrally molded at an outer diameter position to be fixed to the optical device main body at the position of the first cylindrical portion. It is characterized in that the second cylindrical portion extending in the direction is integrally molded at the inner diameter position, and the optical lens is directly held by the second cylindrical portion.

[Embodiment] FIG. 1 and FIG. 2 show a first embodiment of the present invention.
The figure is a cross-sectional view of an interchangeable lens barrel as optical equipment.
In the figure, 1 is a bayonet mount, 1a is a bayonet claw, 1b is a cylindrical part extending in the optical axis direction from the outer peripheral position of the bayonet mount 1, 1c is a mounting screw hole, and 1e is a bayonet claw 1a.
Undercut part, 2 is a fixed barrel of the interchangeable lens barrel main body, 2a is a screw with a small pitch, 3 is a rotating helicoid barrel,
Reference numeral 3a is a helicoid screw for lens extension, 4 is a focus adjusting operation ring, 5 is a middle cylinder for holding and extending the lens, 5a is a key groove provided in the optical axis direction of the middle cylinder 5, and 6 is a front lens barrel. , 7 is a front cylinder having a mounting portion for accessories such as a lens cap and a filter, 8 is a decorative cover on the front side of the lens, 9 is an iris diaphragm device, 10 is a decorative cover on the rear side of the lens, 11, 12, 13, 14 Is a screw, 15 is a key for guiding the inner cylinder 5 in the optical axis direction, and L ₁ , L ₂ , L ₃ , L ₄ , L ₅ , and L ₆ are optical lenses.

2 is a perspective view of the bayonet mount 1 shown in FIG. 1, 1 is a mount, 1a is a bayonet claw, 1b is a cylindrical portion, 1c is a mounting screw hole, 1d is a rotation stopper at the time of mounting the mount, Reference numeral 1e is an undercut portion of the bayonet claw 1a, 1f is a lock groove that also serves as a position preventing member when mounting the mount, and 11 is a screw.

FIG. 3 is a perspective view showing a conventional example of a bayonet mount, which is made by cutting a metal material, 21 is a bayonet mount, 21a is a bayonet claw, 21b is a lock groove for preventing disengagement at the time of mounting, 21c is a screw hole for attaching the bayonet mount 21 to the interchangeable lens body, 21d is a rotation stopper screw at the time of attachment, and 22 is a screw.

Fig. 4 is a view of the bayonet mount as viewed from the optical axis side of the bayonet claw. In the figure, the shaded portion 31d is the mounting reference surface that is the sliding surface of the camera side bayonet mount of the camera as another optical device. The range of three bayonet claws 1a is shown.

FIGS. 5 and 6 show the principle of the mold when the bayonet mount is made by plastic injection molding. FIG. 5 is a sectional view of the mount optical axis center, and FIG. 6 shows the moving direction of the slide core viewed from the optical axis direction. 41 is a fixed side template, 42 is a movable side template, 43 is a core, 44 is a slide core, 44a is a screw hole (formed in the same phase as the bayonet claw), 45 is an angular pin, 46 is a spool, 47 is a molded product (bayonet mount), 47a is a bayonet claw, and 47b is an undercut portion of the molded product. Movable side template 42, core 43 and slide core
By opening 44 in the direction of the arrow in the figure, the angular pin
By the action of 45, the slide core 44 opens in the direction of the arrow shown in FIG. 6, and the M ₀ mold is released from the undercut portion 47b portion of the molded product 47 shown in FIG. 5, and the molded product 47 can be taken out from the mold. become. As can be seen from the above, the structure formed by the slide core 44 is undercut in the opening direction of the slide core 44, such as the screw hole 21c of the conventional example shown in FIG. Cannot be made by injection molding, but will be made by machining after molding. Therefore, the advantages of making by the injection molding method are reduced.

In the above-described first embodiment, when the bayonet mount 1 is molded, the cylindrical portion 1b extending in the optical axis direction is also integrally molded, so that the conventional metal mount shown in FIG. Significantly improved flexural rigidity,
It was possible to commercialize the product. Further, when the bayonet mount 1 is fixed to the main body of the equipment, the screw hole 1c in the radial direction is formed in the cylindrical portion 1b and the screw 11 is used to fix the screw, which complicates the molding method of the bayonet mount 1. It is possible to form the screw hole 1c without any need. Furthermore, by positioning this screw hole 1c within the phase of the bayonet claw 1a (within the angle range around the optical axis of the bayonet claw 1a), the deformation of the bayonet claw which causes a particular problem of bending can be suppressed as much as possible. Further, since the cylindrical portion 1b is formed substantially at the outer peripheral portion of the bayonet mount 1, the strength of the mount surface 1m can be increased, and the positional accuracy of the mount surface 1m, which is the optical reference surface, can be improved. It was

Next, a second embodiment will be described with reference to FIG.

In the second embodiment, when molding the bayonet mount 1 with plastic, the flange portion 1g, the lens frame portion 1h and the second portion
The tubular portion 1i of is integrally molded.

The flange portion 1g and the lens frame portion 1h are the fixed lens holding lens barrel 24 also serving as the conventional mount decoration cover shown in FIG.
The optical lens L7 is directly fixed to the lens frame portion 1h.

It should be noted that the second tubular portion 1i is, firstly, the bayonet mount 1
Helps to further increase the mechanical strength of, and secondly serves as a light shielding tube.

[Advantages of the Invention] When the mount of the optical device is molded from the plastic material as described above, a cylindrical portion extending in the mount optical axis direction is integrally provided in order to compensate for the lack of strength, which is a weak point of the plastic. This increased the rigidity of the mount and made it possible for practical use.

In addition, the screws that fix the mount are screwed in the radial direction at the above-mentioned cylindrical portion position, and the screwing position is adjusted within the phase of the bayonet claws, which complicates the mold structure during mount molding. It is possible to manufacture at low cost, and even if external force is applied, the cylindrical part is firmly fixed to the optical device main body within the phase where the bayonet claw is located, so deflection at the position of the bayonet claw is as much as possible. You can hold it down.

Further, by forming the first cylindrical portion at the outer diameter position of the mount and forming the second cylindrical portion at the inner diameter position, the flexure due to the external force can be suppressed by both the cylindrical portions, and further the second cylindrical portion can be pressed. By directly holding the optical lens by the section, it is possible to provide an optical apparatus that can further improve the strength against bending and reduce the number of parts.

Further, by holding the optical lens by using the cylindrical portion for improving the strength of the mount, it is possible to provide an optical device capable of greatly reducing the number of parts.

[Brief description of drawings]

FIG. 1 is a sectional view of an interchangeable lens as a first embodiment of the present invention. FIG. 2 is a perspective view of only the bayonet mount of FIG. FIG. 3 is a perspective view of a bayonet mount formed by processing a conventional metal. FIG. 4 is a front view of the bayonet mount as the embodiment of FIG. 2 as seen from the bayonet claw side. 5 and 6 are explanatory views showing the principle of the injection molding die. 7th
The figure is a cross-sectional view of an interchangeable lens as a second embodiment of the present invention.
FIG. 8 is a perspective view of the periphery of a bayonet mount formed by processing a conventional metal. 1 …… bayonet mount, 1a …… bayonet claws, 1b ・ 1i
…… Cylindrical part, 1c …… Mounting screw hole, 2 …… Fixed cylinder, L7 …… Optical lens, 11 …… Screw

Claims (2)

[Claims] 1. A structure in which a device is coupled with another device by rotating in one direction and is separated by rotating in the other direction, and a plurality of bayonet claws protruding in a radial direction are formed and fixed to an optical device body. In an optical device in which the mount is molded from plastic, a cylindrical portion extending from the mount in the optical axis direction is integrally molded at an outer diameter position, and the mount is fixed to the optical device main body by the cylindrical portion. Is performed by screwing in a direction substantially orthogonal to the optical axis, and the screwing position is set within the phase of the bayonet claw of the mount. 2. A structure in which a device is connected to another device by rotating in one direction and is separated by rotating in the other direction, and a plurality of bayonet claws protruding in a radial direction are formed and fixed to an optical device body. In an optical device having a mount formed of plastic, the first cylindrical portion extending from the mount in the optical axis direction is integrally formed at an outer diameter position, and the first cylindrical portion is formed at the position of the first cylindrical portion. An optical device characterized by being fixed to an optical device body, integrally forming a second cylindrical portion extending in the optical axis direction at an inner diameter position, and directly holding an optical lens by the second cylindrical portion.