JP4608199B2 - Bayonet mount structure and bayonet adapter using the same - Google Patents

Description

The present invention relates to a bayonet mount structure, and more particularly, to a bayonet mount structure in which a plurality of claws are engaged with an accessory claw of a lens device or the like to fix the accessory.
The present invention also relates to a bayonet adapter for attaching an accessory to the front part of a lens of an optical device such as a camera or projector using a bayonet mount structure.

  Conventionally, a bayonet mount structure for attaching a lens device to a camera body or the like is known. In the bayonet mount structure, when the lens device is rotated in the circumferential direction by a predetermined angle with the nail of the lens device being inserted between the plurality of claws formed in the circumferential direction of the bayonet mount, the nail of the lens device is The lens device is fixed by being engaged with the claw of the mount and pressed by a leaf spring disposed on the back surface of the claw of the bayonet mount.

  With this bayonet mount structure, it is possible to attach and detach the lens device with good operability. However, in order to prevent the lens device from rotating in the reverse direction and dropping off from the bayonet mount for some reason, it is disclosed in Patent Document 1, for example. As described above, a structure including a lock mechanism having a lock claw and prohibiting the rotation of the lens device is employed. When removing the lens device, the lens device may be rotated by operating the lock release pin to retract the lock claw.

Registered Utility Model No. 3018756

However, the lock mechanism and the lock release mechanism are complicated, the number of parts is large, and there is a problem that the size is increased.
The present invention has been made to solve such problems, and has an object to provide a bayonet mount structure that can easily and firmly fix accessories such as a lens device while having a simple structure. To do.
Another object of the present invention is to provide a bayonet adapter using such a bayonet mount structure.

Bayonet mount structure according to the present invention, the bayonet mount structure for fixing the accessory of the lens device or the like, circumferentially arranged formed nail accessory together with having contact with the annular stage in the optical axis direction, the outer periphery mount by this screw cut is screwed into the screw cut mounting base and having a ring-shaped or cylindrical mount base screw cut is formed along the surface, the screw cut formed along the inner circumferential surface A bayonet ring in which a plurality of radially projecting claws that are rotatably held with respect to the base and engage with the claws of the accessory are arranged in the circumferential direction, and an optical axis back of one of the bayonet rings And a stopper that protrudes inward in the radial direction and is engaged with an end portion of the claw of the accessory. When the accessory's claws are inserted between the bayonet ring claws and are in contact with the mount base stage, the accessory claws are rotated between the bayonet ring claws and the mount base stage. The end of the accessory claw engages with the stopper, the bayonet ring rotates with the accessory relative to the mount base, and the accessory claw is tightened between the bayonet ring claw and the stage of the mount base.

In addition, it is preferable to provide the mount base with a restricting portion that restricts the rotation angle of the bayonet ring by engaging with the stopper.
Also, the plurality of bayonet ring claws and the accessory pawls are arranged unevenly or circumferentially in the circumferential direction so that the bayonet ring and the accessory can be attached to the accessory only at a specific rotational position. If it comprises so that a some nail | claw may be inserted between the some nail | claws of a bayonet ring, the rotation position of a bayonet mount structure and an accessory can be controlled.
Furthermore, a bayonet adapter according to the present invention has the above-described bayonet mount structure, and includes a cylindrical adapter body in which a mount base is detachably attached to an optical device.

  In the bayonet mount structure according to the present invention, the accessory claw can be turned into the bayonet simply by inserting the claw of the accessory between the claw of the bayonet ring and rotating the accessory in the circumferential direction in contact with the stage of the mount base. The nail end of the accessory enters the stage between the ring claw and the mount base, and the end of the accessory claw engages with the stopper, and the bayonet ring rotates with the accessory relative to the mount base so that the accessory claw rotates with the bayonet ring claw and the mount base. Therefore, it is possible to easily and firmly fix an accessory such as a lens apparatus with a simple structure.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 and 2 show a bayonet adapter employing a bayonet mount structure according to an embodiment of the present invention. The bayonet adapter includes an adapter main body 1 constituting a mount base of a bayonet mount structure, and a bayonet ring 2 attached to the front portion of the adapter main body 1. The adapter main body 1 has a substantially cylindrical shape, but a large-diameter portion 3 having a large diameter is formed at a front portion thereof, and a threaded opening 4 is formed along the outer peripheral surface of the large-diameter portion 3. On the other hand, the bayonet ring 2 has a peripheral wall portion 5 having a diameter capable of accommodating the enlarged diameter portion 3 of the adapter main body 1, and a screw corresponding to the threaded opening 4 of the adapter main body 1 along the inner peripheral surface of the peripheral wall portion 5. A cut 6 is formed. The bayonet ring 2 is rotatably held with respect to the adapter main body 1 by screwing the screw cut opening 6 of the bayonet ring 2 into the screw cut opening 4 of the adapter main body 1.

  As shown in FIGS. 3 and 4, the diameter-enlarged portion 3 of the adapter main body 1 is formed with an annular and forward-facing stage 7 and protrudes from the periphery of the stage 7 toward the front of the adapter main body 1. A protruding wall 8 is formed. The protruding wall 8 is cut out over a predetermined angle θ (for example, 120 degrees), and forms a restricting portion that restricts the rotation angle of the bayonet ring 2. In addition, a threaded opening 9 is formed on the outer peripheral portion of the rear end of the adapter body 1 so as to be detachably attached to an optical device such as a camera or a projector.

  As shown in FIGS. 5 and 6, the bayonet ring 2 is formed with three claws 10 that protrude inward in the radial direction and arranged at intervals in the circumferential direction. Moreover, the stopper 11 is being fixed to the surrounding wall part 5 so that it may be located in the back part of the nail | claw 10 in the edge part of one of these claws 10. FIG. The stopper 11 is made of a bolt, for example, and is fixed by being screwed in from the outside of the peripheral wall portion 5 of the bayonet ring 2.

  With the stopper 11 not attached to the bayonet ring 2, as shown in FIGS. 1 and 2, the threaded opening 6 of the bayonet ring 2 is screwed into the threaded opening 4 of the adapter body 1, and then the peripheral wall portion 5 of the bayonet ring 2. A stopper 11 is attached to the outside from the outside. At this time, the stopper 11 is attached so that the tip thereof protrudes into the notch portion of the protruding wall 8 of the adapter body 1 and is positioned between the stage 7 of the adapter body 1 and the claw 10 of the bayonet ring 2. Since the protruding wall 8 of the adapter main body 1 is disposed immediately inside the peripheral wall portion 5 of the bayonet ring 2, if the protruding wall 8 is a notch portion, the tip of the stopper 11 extends from the peripheral wall portion 5 to the central axis of the adapter main body 1. Can project in the direction.

  Due to the presence of such a stopper 11, the bayonet ring 2 is rotatable with respect to the adapter body 1 only within a range where the stopper 11 is located at a notch portion of the protruding wall 8 of the adapter body 1. That is, the bayonet ring 2 can rotate only by a predetermined angle θ, and therefore, as long as the stopper 11 exists, the bayonet ring 2 does not fall off the adapter body 1 even if the bayonet ring 2 is rotated.

  FIG. 7 shows a state in which a conversion lens is attached as an accessory to the lens front portion of the optical device using this bayonet adapter. The bayonet adapter is attached to the optical device 12 by screwing the screw cut port 9 at the rear end of the adapter body 1 into the screw cut port 13 formed in the optical device 12 such as a camera or a projector. At this time, the lens group 14 of the optical device 12 is located in the adapter body 1, and the bayonet ring 2 is located on the front side of the lens group 14.

  In this state, the conversion lens 15 is attached to the bayonet adapter. As shown in FIG. 8, three claws 16 projecting radially outward are arranged at the rear end of the conversion lens 15 at intervals in the circumferential direction. When the claws 16 of the conversion lens 15 are inserted between the claws 10 of the bayonet ring 2, these claws 16 come into contact with the stage 7 of the adapter body 1. When the conversion lens 15 is rotated in the circumferential direction, for example, in the clockwise direction while maintaining this contact state, the claw 16 of the conversion lens 15 is connected to the claw 10 of the bayonet ring 2 and the adapter body 1 as shown in FIG. The end of one claw 16 of the conversion lens 15 engages with the stopper 11. The shaded portion in FIG. 9 shows the overlapping portion of both claws 10 and 16 at this time.

  When the conversion lens 15 is further rotated, the bayonet ring 2 rotates with respect to the adapter body 1 together with the conversion lens 15 because the claw 16 is engaged with the stopper 11. Thereby, due to the interaction between the threaded opening 4 of the bayonet ring 2 screwed together and the threaded opening 6 of the adapter body 1, the bayonet ring 2 moves in the axial direction toward the adapter body 1, and the bayonet The distance between the claw 10 of the ring 2 and the stage 7 of the adapter body 1 is gradually reduced. As a result, the three claws 16 of the conversion lens 15 are tightened between the claws 10 of the bayonet ring 2 and the stage 7 of the adapter main body 1, and the conversion lens 15 is fixed.

  When removing the conversion lens 15 from the bayonet adapter, the conversion lens 15 may be rotated in the reverse direction. At first, the bayonet ring 2 rotates together with the conversion lens 15 so that the distance between the claw 10 of the bayonet ring 2 and the stage 7 of the adapter body 1 gradually increases, and then only the conversion lens 15 rotates to rotate one of the three claws 16. One engages the stopper 11. At this time, since the claw 16 of the conversion lens 15 is already located between the claw 10 of the bayonet ring 2, the conversion lens 15 may be taken out as it is away from the bayonet adapter.

  As shown in FIG. 10, the two claws 10a of the three claws of the bayonet ring 2 are formed larger in the circumferential direction than the remaining one claw 10b, thereby forming a recess 17a between the two claws 10a. As shown in FIG. 11, one claw 16 a of the three claw 16 of the conversion lens 15 is formed to be smaller than the other crevice 17 b and corresponding to the crevices 17 a and 17 b of the bayonet ring 2. It can also be formed smaller than the two claws 16b. Here, the claw 16a of the conversion lens 15 can be inserted into the recess 17a of the bayonet ring 2, and the claw 16b of the conversion lens 15 can be inserted into the recess 17b of the bayonet ring 2, but it can be inserted into the small recess 17a. Shall not be possible.

In this way, the conversion lens 15 can be attached only at the rotational position where the claw 16a of the conversion lens 15 corresponds to the concave portion 17a of the bayonet ring 2, and the conversion lens 15 can always be mounted at an easy-to-use rotational position. It becomes.
In addition, it is preferable that the rotation positions of the conversion lens 15 and the bayonet ring 2 are adjusted by attaching indices to the outer portions of the conversion lens 15 and the bayonet ring 2. Further, an index is also attached to the outer part of the adapter body 1 to indicate that the conversion lens 15 can be attached when the conversion lens 15, the bayonet ring 2, and the adapter body 1 are indexed together. May be.
Instead of forming the nails of the bayonet ring 2 and the nails of the conversion lens 15 in an uneven size as described above, the three nails of the bayonet ring 2 and the three nails of the conversion lens 15 are made uneven in the circumferential direction. Even if it is arranged, similarly, the conversion lens 15 can be attached only at a specific rotational position.

In the embodiment described above, the three claws 10 and 16 are formed on the bayonet ring 2 and the conversion lens 15, respectively. However, the number of claws is not limited to this and can be set as appropriate.
In the above embodiment, the conversion lens 15 is attached to the front portion of the optical device 12 using the bayonet adapter. However, other accessories such as a filter and a hood can be attached instead of the conversion lens 15. . Furthermore, if a mount base portion such as the adapter main body 1 is formed in the front portion of the camera body or the like, and the bayonet ring 2 is combined with the mount base portion to constitute a bayonet mount structure, accessories such as a lens device can be easily attached and detached. Is possible.

It is a partially broken side view which shows the bayonet adapter which employ | adopted the bayonet mount structure which concerns on embodiment of this invention. It is a front view of the bayonet adapter of FIG. It is a partially broken side view which shows the adapter main body used for the bayonet adapter of FIG. It is a front view which shows the adapter main body of FIG. It is a partially broken side view which shows the bayonet ring used for the bayonet adapter of FIG. It is a front view which shows the bayonet ring of FIG. It is a partially broken side view which shows the state which mounted | wore the optical apparatus with the conversion lens using the bayonet adapter of FIG. FIG. 8 is an end view showing the optical apparatus of FIG. 7. It is a front view which shows roughly the overlapping state of the nail | claw of the optical apparatus of FIG. 7, and the nail | claw of a bayonet ring. It is a front view which shows the bayonet ring used for the bayonet adapter which concerns on other embodiment. It is an end view which shows the optical instrument applied to the bayonet ring of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Adapter main body, 2 Bayonet ring, 3 Diameter expansion part, 4, 6, 9, 13 Screw opening, 5 Perimeter wall part, 7 Stage, 8 Projection wall, 10, 16, 16a, 16b Claw, 11 Stopper, 12 Optical apparatus, 14 lens group, 15 conversion lens, 10a, 10b, 10c interval.

Claims (4)

In the bayonet mount structure for fixing accessories such as lens devices,
Along with a plurality of pawls which are arranged and formed in the circumferential direction of the accessory has a contacting annular stage in the optical axis direction, a ring-shaped or cylindrical mount base screw cut is formed along the outer peripheral surface,
A diameter that has a threaded opening formed along the inner peripheral surface and that is rotatably held with respect to the mount base and engages with a claw of the accessory by screwing the threaded opening into the threaded opening of the mount base. A bayonet ring in which a plurality of claws protruding inward in the direction are arranged in the circumferential direction;
And a stopper for engaging the end of the bayonet ring one nail is fixed to protrude in the optical axis direction back to the radially inward and nail accessories, nail accessories during nail the bayonet ring When the accessory is rotated in the circumferential direction in a state where the accessory is in contact with the stage of the mount base, the accessory claw enters between the bayonet ring claw and the mount base stage, and the end of the accessory claw And the bayonet ring rotates with respect to the mount base together with the accessory, and the claw of the accessory is tightened between the claw of the bayonet ring and the stage of the mount base. Bayonet mount structure.   2. The bayonet mount structure according to claim 1, wherein the mount base has a restricting portion that restricts a rotation angle of the bayonet ring by engaging with the stopper. 3. The plurality of nails of the bayonet ring and the plurality of claws of the accessory are formed unevenly in the circumferential position or size, and the plurality of nails of the accessory are only in a specific rotational position with respect to each other. The bayonet mount structure according to claim 1 or 2, wherein the bayonet mount structure is inserted between a plurality of claws of the bayonet ring. A bayonet adapter for attaching accessories to the lens front of an optical device,
A bayonet adapter comprising the bayonet mount structure according to any one of claims 1 to 3, wherein the mount base is a cylindrical adapter body that is detachably attached to an optical device.

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