JPS6124983Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a lens mount mechanism for a camera, and particularly to a lens mount mechanism for a camera that performs a bayonet type lens exchange.

In general interchangeable lens cameras, such as single-lens reflex cameras, almost no measures are taken to ensure dustproof and waterproof effects between the interchangeable lens and the lens mount section of the camera body. Especially when the interchangeable lens is heavy, such as a long focal length lens or a zoom lens, the weight of the lens creates a considerable gap between the interchangeable lens and the mount, which is a serious problem from a dust-proofing and waterproofing point of view. It is causing

On the other hand, underwater cameras with interchangeable lenses employ O-rings as a waterproof mechanism. That is, the waterproof effect is achieved by connecting the mount section and the interchangeable lens via an O-ring and compressing and clamping the O-ring between them. However, conventionally, installing O-rings is time-consuming and difficult to adjust.
O-rings have a unique drawback in that their lifespan shortens as the number of lens replacements increases.

This idea was made in view of the above circumstances,
The purpose is to provide a camera lens mount mechanism that can reliably achieve waterproof and dustproof effects with simple operation, and that does not deteriorate as the number of lens replacements increases. There is a particular thing.

A first embodiment of the camera lens mount mechanism according to the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates a camera body, and a lens mount mechanism 12 to which an interchangeable lens (not shown) is attached is provided at the center of the front surface of the camera body 10. This lens mount mechanism 12 is fixedly provided to the camera body 10 and has a support plate 14 that supports the bottom surface of the interchangeable lens. This support plate 14 is formed in a substantially annular shape, and a plurality of recesses 16, in this embodiment, three recesses 16 are provided in a part of the inner circumference of the support plate 14. These recesses 16 are formed to have the same size and are arranged at equal intervals along the circumferential direction.

Below this support plate 14, as shown in FIG. 2, a rotating plate 18 as a first member is rotatably attached to the support plate 14. This rotating plate 1
8 is formed in a substantially annular shape, and the center of the support plate 14 and the center of the rotary plate 18 are set to coincide with each other. Arc-shaped guide grooves 20 and 22 are formed on both the upper and lower surfaces of the rotary plate 18. The center of the arc of each guide groove 20, 22 coincides with the center of the rotating plate 18. The lower surface of the support plate 14 has a rotary plate 1
A guide pin 24 is attached to be inserted into a guide groove 20 formed on the upper surface of the 8. Also,
A guide pin 26 is attached to the camera body 10 to be inserted into a guide groove 20 formed on the lower surface of the rotating plate 18. The guide grooves 20 and 22 formed in the rotary plate 18 are connected to the guide pins 24 and 2.
6 and rotates around the central axis of the rotary plate 18 as the rotation axis.

A protruding piece 28 is provided on a part of the inner circumference of the rotating shaft 18.
The same number of recesses 16 as described above, three in this embodiment, are provided so as to protrude a predetermined length toward the center. These protruding pieces 28 are arranged at equal intervals along the circumferential direction. The circumferential size of each protruding piece 28 is the same and is set to be sufficiently smaller than the circumferential size of the recess 16.
The tip of each protrusion piece 28 is held at a predetermined position within each recess 16, for example, in a clockwise direction within each recess 16, in a state where no external force acts on it in the clockwise direction in the figure. That is, a spring 30 is provided between the rotating plate 18 and the camera body 10 to bias the rotating plate 18 counterclockwise in the figure. Further, a rotating plate 18 is provided at a predetermined position of the camera body 10.
A locking piece 32 is provided, with which the counterclockwise end surface of each projection piece 28 comes into contact. Rotating plate 1
8 is biased counterclockwise by a spring 30, but is kept in a predetermined position by abutting against a locking piece 32. A right-handed male screw is formed on the outer peripheral surface of the rotary plate 18 .

A moving plate 34 as a second member is provided on the outer periphery of the rotating plate 18 so as to be movable in the thrust direction. The moving plate 34 is formed in an annular shape.
A right-handed female thread is formed on the inner circumference of the plate. The male thread of the rotating plate 18 and the female thread of the moving plate 34 mesh with each other. A guide plate 36 that defines the outer periphery of the lens mount mechanism 12 is fixed integrally to the camera body 10 on the outer periphery of the moving plate 34. The upper surface of the guide plate 36 is flush with the upper surface of the support plate 14.
A plurality of guide grooves 38 extending in the axial direction are formed on the outer periphery of the guide plate 36. Guide pins 40 to be inserted into each guide groove 38 are attached to the inner periphery of the guide plate 36 and extend in the axial direction. Since the guide grooves 38 and guide pins 40 are thus provided extending in the axial direction, the rotational force of the rotating plate 18 acts as a thrust on the moving plate 34, and since the two are connected via a right-handed screw, the moving plate 34 moves upward in the figure as the rotating plate 18 rotates clockwise in the figure.

An annular packing member 42 is provided on the entire upper surface of the movable plate 34 so as to be replaceable. This packing member 42 is made of rubber to obtain a watertight effect. The outer peripheral surface of the packing member 42 is in slight sliding contact with the inner peripheral surface of the guide plate 36. The thickness of the upper surface of this packing member 42 is such that it is flush with the upper surfaces of the guide plate 36 and the support plate 14 in the state shown in FIG. It is set. On the other hand, the upper surface of this packing member 42 protrudes upward from the upper surfaces of the guide plate 36 and the support plate 14 as the moving plate 34 moves upward as the rotary plate 18 is rotated clockwise in the figure. do.

Lens mount mechanism 12 configured in this way
The interchangeable lenses that can be attached to the
As shown in the figure, a mounting plate 44 is fixed to the bottom surface. This mounting plate 44 has an annular mounting body 46.
and extends outward from the lower surface of the mounting body 46,
It has a lower piece portion 48 as a pushing member provided corresponding to each recess 16. This lower piece portion 48 acts as a bayonet pawl. The outer diameter of the attachment body 46 is defined so that the outer circumferential surface of the attachment body 46 comes into sliding contact with the inner circumference of the support plate 14 .
Each tongue piece 48 is formed into a fan shape, and its size along the circumferential direction is set sufficiently so that it can be inserted into each recess 16 while avoiding the projection piece 28. Further, the outer circumferential surface of the tongue portion 48 is located inside the inner circumferential surface of the recess 16. The clockwise end face of each tongue piece 48 can come into contact with the counterclockwise end face of the corresponding projection piece 28 . The upper surface of each tongue portion 48 is positioned so as to be able to come into sliding contact with the lower surface of the support plate 14. When the mounting plate 44 is rotated clockwise in the figure and the contacting protrusions 28 are rotated in the same direction against the biasing force of the spring 30, each tongue piece 48 enters below the support plate 14, The interchangeable lens is attached to the camera body 10 via the lens mount mechanism 12 by the upper surface of each tongue piece 48 slidingly contacting the lower surface of the support plate 14 .

Here, the upper surface of the packing member 42 of the lens mount mechanism 12 can be pressed against the peripheral edge of the rear end surface of the interchangeable lens 50, as shown in FIGS. 3 and 4, respectively.

Lens mount mechanism 1 configured as above
2, its operation will be explained below.

When attaching the interchangeable lens 50 to the camera body 10, first place each tongue portion 48 of the mounting plate 44 fixed to the bottom surface of the interchangeable lens 50 into the corresponding recess 16 of the support plate 14. Projection piece 28
Insert while avoiding. As a result, the tongue portion 48 passes through the recess 16 of the support plate 14 and is located below the support plate 14 when the bottom surface of the interchangeable lens 50 is supported by the top surface of the support plate 14. Next, the interchangeable lens 5
0 in the clockwise direction in FIG.
This is rotated clockwise in the figure against the biasing force of the spring 30. This rotation of the interchangeable lens 50 continues until the upper surface of the tongue portion 48 comes into sliding contact with the lower surface of the support plate 14. Therefore, the interchangeable lens 50
is securely attached to the camera body 10 by sandwiching the support plate 14 of the lens mount mechanism 12 between the bottom surface and the top surface of the tongue portion 48 from both sides.

On the other hand, the projection piece 28 due to rotation of the interchangeable lens 50
By rotating clockwise in the figure, the moving plate 34 connected to the rotating plate 18 via a right-handed screw is guided by the guide groove 38 and the guide pin 40 and moves upward in the figure. The packing member 42 provided on the moving plate 34 also moves upward in the figure and comes into pressure contact with the peripheral edge of the bottom surface of the interchangeable lens 50, so that the space between the packing member 42 and the interchangeable lens 50 becomes watertight. Also, due to this pressure contact, the packing member 42
expands in the radial direction due to its elasticity, and the outer peripheral surface of the packing member 42 comes into pressure contact with the inner peripheral surface of the guide member 36. Here, since the guide member 36 is integrally provided with the camera body 10, the packing member 42 and the camera body 10 are brought into contact with each other by pressure contact as described above.
There will be a watertight condition between the two.

Therefore, a watertight state is established between the interchangeable lens 50 and the camera body 10 via the packing member 42 of the lens mount mechanism 12.

That is, according to the first embodiment, the packing member 42 is moved in the direction of the interchangeable lens 50 using the rotation for attaching the interchangeable lens 50 to the camera body 10.
is brought into pressure contact with the bottom surface of the interchangeable lens 50, thereby creating a watertight state between the interchangeable lens 50 and the camera body 10.

In this way, no special operation is required to establish a watertight state, and the operation is easy because all that is required is the usual operation of loading an interchangeable lens. Further, since the packing member 42 does not come into sliding contact with the bottom surface of the interchangeable lens, but only comes into pressure contact with it, the packing member 42 does not deteriorate in relation to the number of times the interchangeable lens is attached and detached. Furthermore, since the packing member 42 only needs to be placed on the movable plate 34, the task of replacing the packing member 42 is greatly simplified.

In this first embodiment, as shown in FIGS. 3 and 4, the upper surface of the packing member 42 is configured to come into pressure contact with the lower surface of the interchangeable lens 50. However, the pressure contact point is not limited to such a configuration, and may be anywhere on the wall surface of the interchangeable lens. For example, as shown in FIGS. 5 and 6 as a second embodiment, the packing member 42 is connected to the A similar effect can be obtained by configuring the inner circumferential surface of the packing member 42 of the lens mount mechanism 12 to be pressed against the outer circumferential surface of the interchangeable lens 50 by moving in the axial direction as shown in FIG.

Next, referring to FIG. 7, a third embodiment of the camera lens mount mechanism according to this invention will be described. It should be noted that the same parts as in the first embodiment described above are given the same reference numerals and their explanation will be omitted. The third embodiment differs from the first embodiment in the mechanism for converting rotational force into axial thrust force.

That is, a rotary member 52 is rotatably provided, with each tongue portion 48 of a mounting plate 44 fixed to the bottom surface of a conversion lens (not shown) abutting one end thereof. Each rotating member 52 is a member corresponding to each rotating plate 18 of the first embodiment described above, and is formed in a round bar shape. This rotating member 52 is connected to the guide pin 24 provided on the lower surface of the support plate 14 and the camera body 1.
0, and is regulated to be located within a movement path extending along the rotational surface of the conversion lens. Further, the rotating member 52 is rotated so that the extension line of its central axis always passes through the rotation center of the mounting plate 44.
Its movement is regulated.

A slit 54 is formed in the inner peripheral surface of the moving member 34, into which the other end of the rotating member 52 is inserted.
The slit 54 is inclined downward as it goes clockwise in the figure. In the state shown in FIG. 7 in which the rotating member 52 is not receiving any external force, the other end of the rotating member 52 is located at the end of the slit 54 along the counterclockwise direction. In this state, the upper surface of the packing member 42 is attached to the guide plate 36.
It is on the same plane as the upper surface and the upper surface of the support plate 14.

On the other hand, when the conversion lens is rotated to attach to the camera body 10, the tongue portion 48 of the attachment plate 44 is rotated. According to this rotation, the tongue portion 48
The rotating member 52 that contacts the locking piece 32 rotates clockwise in the drawing from the position where it contacts the locking piece 32 against the biasing force of the spring 30 in the counterclockwise direction in the drawing. By this rotation of the rotating member 52 in the clockwise direction, the moving member 3
4 moves upward in the figure in accordance with the inclination of the slit 54 into which the other end of the rotating member 52 is inserted.
Therefore, the packing member 42 is pressed against the bottom surface of the interchangeable lens, and the interchangeable lens and the camera body 10 are brought into a watertight state, so that the same effect as in the embodiment described above can be obtained.

Furthermore, with reference to FIGS. 8 to 10, a fourth embodiment of the camera lens mount mechanism according to this invention will be described. Incidentally, the same parts as in the first embodiment described above are given the same reference numerals, and the explanation thereof will be omitted. The fourth embodiment differs from the first embodiment in the mechanism for converting rotational force into axial thrust force.

That is, a rotary member 56 is rotatably provided, with which each tongue portion 48 of a mounting plate 44 that is fixed to the bottom surface of an interchangeable lens (not shown) comes into contact. The rotating member 56 includes a support shaft 58, an engagement piece 60 that stands upright from the inner end of the support shaft 58, and an engagement piece 60 that stands upright from the outer end of the support shaft 58, and the engagement piece 60 is shown in FIG. The push-up piece 62 is inclined counterclockwise at a predetermined angle. Support shaft portion 5 of rotating member 56
8 is rotatably supported by a bearing 64. This rotation axis is set to coincide with the longitudinal axis of the support shaft portion 58. Further, the longitudinal axis of the support shaft portion 58 is set to pass through the rotation center of the mounting plate 44. The tongue portion 48 of the mounting plate 44 is capable of coming into contact with the engagement piece 60 of the rotating member 56.

An inner flange portion 66 is provided on the inner peripheral surface of the movable plate 34. A tip of a push-up piece 62 of the rotating member 56 can come into contact with the lower surface of the inner flange portion 66 . A spring 30 is wound around the support shaft 58 of the rotating member 56, one end of which is locked to a bearing 64, the other end is locked to the support shaft 58, and the spring 30 is
0 applies a biasing force to the rotating member 56 in a counterclockwise direction in the figure with the rotating shaft as the center. The locking piece 32 is provided so that the engaging piece 60 resists the urging force of the spring 30 and remains at a position orthogonal to the inner flange portion 66.

In the state shown in FIGS. 8 and 9 in which the rotating member 58 is not receiving any external force, the push-up piece 62 of the rotating member 58 is in light contact with the lower surface of the inner flange portion 66. In this state, the upper surface of the packing member 42 is on the same plane as the upper surfaces of the guide plate 36 and the support plate 14. On the other hand, the mounting plate 4 is rotated to attach the interchangeable lens to the camera body 10.
The tongue piece portion 48 of No. 4 rotates. Depending on this rotation,
Engagement piece 60 of rotating member 58 that tongue piece part 48 comes into contact with
rotates clockwise in the figure against the biasing force of the spring 30 in the counterclockwise direction in the figure. This rotating member 52
10, the push-up piece 62 pushes up the inner flange portion 66, and the moving member 34 moves upward. Therefore, the packing member 42 is pressed against the bottom surface of the interchangeable lens, and the interchangeable lens and the camera body 10 are brought into a watertight state, so that the same effect as in the embodiment described above can be obtained.

It goes without saying that the contact state between the packing member 42 and the interchangeable lens in the third and fourth embodiments may be the same as in the second embodiment.

Further, it goes without saying that in any of the above embodiments, a dustproof effect can be obtained due to the watertight state achieved.

As described in detail above, the camera lens mount mechanism according to the invention includes a first member that rotates in accordance with the rotation when an interchangeable lens is attached, and a ring-shaped member that rotates in accordance with the rotation of the first member. Therefore, a second member that is moved toward the interchangeable lens side along the thrust direction; It is characterized by comprising an annular packing member that presses against the wall surface of the interchangeable lens. Therefore, it is possible to provide a camera lens mount mechanism that reliably achieves waterproof and dustproof effects with simple operation, and in which the waterproof and dustproof effects do not change depending on the number of times the lens is replaced.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a camera equipped with a first embodiment of the lens mount mechanism according to this invention;
FIG. 3 is a top view of the camera with an interchangeable lens attached via the lens mount mechanism shown in FIG. 1; FIG. 4 is a schematic configuration diagram for explaining the operation of the lens mount mechanism shown in FIG. 1, and FIG.
FIG. 6 is a schematic configuration diagram for explaining the operation of the lens mount mechanism shown in FIG. 5, and FIG. FIG. 8 is a perspective view showing a portion of the fourth embodiment of the lens mount mechanism, and FIG. 9 and FIG. teeth,
FIG. 9 is a diagram showing different operating states of the lens mount mechanism shown in FIG. 8; 12... Lens mount mechanism, 18... Rotating plate (first member), 34... Moving plate (second member),
42...Packaging member, 50...Interchangeable lens.

Claims (1)

[Scope of Claim for Utility Model Registration] In a camera lens mount mechanism in which lenses are exchanged using a bayonet type, when an interchangeable lens is attached, it comes into contact with a pushing member integrally formed on the lens, and this pushing member a first member rotated by the member; an annular second member disposed near the outer periphery of the mount; and the second member is moved in the thrust direction by the rotation of the first member. a coupling mechanism for transmitting power between the two, and an annular coupling mechanism provided on the side surface of the second member on the side of the interchangeable lens and pressed against the wall surface of the interchangeable lens as the second member moves toward the interchangeable lens. A camera lens mount mechanism comprising: a packing member;