JP2002202548A - Lens hood attaching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve operability for attaching a lens hood with a simple constitution. SOLUTION: Two bayonet pawls 12, a front side small diameter part 11a and a rear side large diameter part 11b are formed on the outer peripheral surface 11 on the leading end side of a lens barrel 10, and the level difference part 13 is formed at the same level as the front surface of the bayonet pawl 12. 1st and 2nd notched parts 22a and 22b for inserting two bayonet pawls 12 formed on the lens barrel 10 and 1st and 2nd bayonet grooves 23a and 23b communicating with the notched parts are arranged on the inner peripheral surface on the trailing end side of the lens hood 20, and also, a link-like contact part 24 coming into contact with the level difference part 13 formed on the lens barrel 10 is arranged all around the periphery of the lens hood 20. By providing the guiding parts all around the inside diameter part of the lens hood 20 and the outside diameter part of the lens barrel 10 in such a way, the operability for attaching the lens hood is drastically improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens hood mounting device for mounting a lens hood on a lens barrel having a plurality of bayonet claws on the outer peripheral surface on the distal end side.

[0002]

2. Description of the Related Art As a device for mounting a lens hood mounted on the front end of a lens barrel to shield harmful light rays from outside the angle of view of a lens, a plurality of lens hoods conventionally provided protruding from the outer peripheral surface of the front end of the lens barrel. There is known a device in which a bayonet groove on the lens hood side is fitted to and attached to the bayonet claw described above, but all have difficulty in operability and productivity. For example, the one disclosed in Japanese Patent Application Laid-Open No. Hei 6-130466 requires a large number of man-hours for workability and assembling adjustment, increases production cost, and energizes a click feeling portion for sensing a click feeling when a lens hood is attached. Since the member slides on the outer peripheral portion of the lens barrel, there is a possibility that the clicking feeling may be weakened by repeated use, or the appearance may be impaired due to scratches.

Further, the one disclosed in Japanese Unexamined Patent Publication No. 8-82830 has a problem that the number of parts is large, assembly adjustment is troublesome, and the cost is high.

In these conventional lens hood mounting devices, as shown in FIG. 11 showing a forward mounting state and FIG. 12 showing a reverse mounting state, a plurality of Of the lens hood 40 and the inner peripheral surface 41 of the lens hood 40.
Notch 4 into which the bayonet claw 32 can be inserted and which has flange-shaped bayonet receivers 42d and 42c at the rear.
2a, 42b and the bayonet claw 32 communicating therewith.
Are provided with a slidable bayonet groove 43. Tip outer peripheral surface 31 of lens barrel 30 excluding bayonet claw 32
Is a cylindrical surface, and a rear end side inner peripheral surface 41 of the lens hood 40
Is a cylindrical inner peripheral surface on which the distal outer peripheral surface 31 of the lens barrel 30 is loosely fitted.

In order to mount the lens hood 40 to the lens barrel 30 in such a configuration, a plurality of bayonet claws 32 on the lens barrel 30 side are attached to the lens hood 40 with their axes aligned. After being inserted from the axial direction into the notch 42a, the inside of the bayonet groove 43 is rotated by a predetermined angle in the circumferential direction to obtain the normal mounting state shown in FIG. Further, in order to store the lens hood 40 in the lens barrel 30 when not in use, as shown in FIG. After inserting the plurality of bayonet claws 32 on the cylinder 30 side into the plurality of notches 42b on the lens hood 40 side from the optical axis direction, the inside of the bayonet groove 43 is rotated by a predetermined angle in a circumferential direction opposite to that at the time of mounting. It was in the reverse mounting state.

[0006]

However, in such a conventional lens hood mounting apparatus, a bayonet claw and a notch are provided between the outer peripheral surface on the lens barrel side and the inner peripheral surface on the lens hood side. Positioning in the optical axis direction was performed by the rear bayonet receiver, so if the axis on the lens hood side and the axis on the lens barrel side were misaligned, or if the two axes were out of parallel, it would not be possible to mount the camera. There is a risk that the lens hood may be stably mounted obliquely, or a mounting angle error may occur in a lens hood requiring a mounting angle position such as a flower hood. In addition, there are also problems that the configuration is complicated, the number of parts is increased, the cost is increased, the clicking feeling is weakened by repeated use, and the appearance is impaired. The present invention has been made in view of the above points, and an object of the present invention is to provide a low-cost lens hood mounting device that can improve operability at the time of mounting with a simple configuration.

[0007]

According to the present invention, in order to achieve the above object, the bayonet claw can be inserted into a lens barrel having a plurality of bayonet claws on an outer peripheral surface on a front end side and into an inner peripheral surface on a rear end side. In a lens hood mounting device for mounting a lens hood having a notch portion and a bayonet groove communicating with the notch portion, a step portion having a small-diameter tip end is provided on the outer peripheral surface on the distal end side of the lens barrel. A lens hood mounting device provided with an abutting portion which is capable of abutting on the step portion over the entire circumference on the inner peripheral surface on the rear end side of the lens hood.

In the above-described lens hood mounting device, a concave portion is click-coupled to one of the rear surface of the bayonet claw on the lens barrel side and the inner surface of the bayonet groove on the lens hood side, and the other is click-coupled corresponding to the concave portion. It is preferable to form each of the protrusions, and it is more preferable to provide the protrusions on a thin portion that can be elastically deformed. It is preferable that the number of bayonet claws on the lens barrel side be two or four. Further, the bayonet grooves on the lens hood side may be formed in parallel on two front and rear circumferences with the contact portion interposed therebetween. In the above-described lens hood mounting apparatus, the bayonet grooves are formed in directions opposite to each other on the circumference. Good to do.

The lens hood mounting device according to the present invention is constructed as described above, so that the step portion provided on the outer peripheral surface on the distal end side of the lens barrel over the entire circumference and the inner peripheral surface on the rear end side of the lens hood are provided. The abutment provided around the entire circumference serves as a guide when the lens hood is mounted. With an extremely simple configuration, it is not necessary to exactly match the axis of the lens barrel when mounting the lens hood, greatly improving operability. Can be improved.

[0010]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a partial cross-sectional view showing a forward mounting state of a lens hood and a lens barrel according to the present invention, FIG. 2 is a partial cross-sectional view showing a reverse mounting state thereof, and FIG. Front view showing a part, FIG.
FIG. 5 is a plan view of the lens hood as viewed from the direction indicated by the arrow X in FIG. 3, FIG. 5 is a partial rear view thereof, FIG. FIG. 8 is a side view showing a part thereof in cross section, FIG. 9 is a rear view thereof, FIG.
FIG. 10 is a side view of a main part viewed from the Z direction shown in FIG. 9.

First, the configuration on the lens barrel side in one embodiment of the present invention will be described with reference to FIGS. The lens barrel 10 having the optical axis A has an outer peripheral surface 11 on the distal end side.
A plurality of (two in the figure) bayonet claws 12, a front small diameter portion 11a and a rear large diameter portion 11b are provided over the entire circumference excluding these bayonet claws 12, and the step portion 1 is provided at the boundary thereof.
3 and one attachment index 14 is provided. The front surface of the step portion 13 and the front surface of the bayonet claw 12 are flush with each other, and the position is determined so that the mounting index 14 is directly above when the lens barrel 10 is mounted on a camera body (not shown). Further, a first stopper portion 12a and a second stopper portion 12b are formed at one end of each bayonet claw 12, and the first stopper portion 12a is formed.
a is applied to the positioning portion when the lens hood is used (when mounted in the forward direction), and the second stopper portion 12b is applied to the positioning portion when the lens hood is stored (when mounted in the reverse direction). And
Stopper portion 12 on the back of each bayonet claw 12
As shown in FIGS. 5 and 6, click recesses 12 c and 12 d having a cylindrical inner surface are provided near a and 12 b.

On the other hand, as shown in FIGS. 7 to 10, a lens hood 20 detachably mountable on the lens barrel 10 has a rear end side inner peripheral surface 21 extending over the entire circumference. Ring-shaped contact portion 2 that can contact the step 13 on the side
4 (FIG. 8), a first notch 22a (FIG. 9) into which the bayonet claw 12 of the lens barrel 10 can be inserted at a predetermined distance in the direction of the axis B across the contact portion 24. ), A second notch 22b (FIG. 7), and a first bayonet groove 23 in which the bayonet claw 12 is slidable in communication therewith.
a and the second bayonet groove 23b. Note that these first and second bayonet grooves 23a and 23b are formed in the circumferentially opposite directions from the first and second cutouts 22a and 22b, and the first and second bayonet claws 12 are provided at the ends thereof. First and second locking portions 23c (FIG. 9) and 23d (FIG. 7) that can abut against the stopper portions 12a and 12b, respectively, are provided.

The first and second bayonet grooves 23
a and 23b, near the first and second locking portions 23c and 23d, respectively, the first and second thin portions 23e and 2 elastically deformable.
3f, these first and second thin portions 23e, 23
f, click projections 23g and 23h are formed, and when both forward and reverse are mounted on the lens barrel 10, the click recesses 12g and 23h are formed.
The positions of the click projections 23g and 23h are determined so that they can engage with c and 12d, respectively. Also, lens hood 2
A mounting index 25 is engraved on the rear portion of the outer peripheral surface of the lens 0 in correspondence with the mounting index 14 on the lens barrel 10 side. With such a configuration, the rear end side inner peripheral surface 21 of the lens hood 20 is
The lens hood 20 is attached to the outer peripheral surface 11 on the distal end side of the lens barrel 10.
It is a fitting part for attaching to the device, and by setting the appropriate sliding resistance by adjusting the diameter of both surfaces, a secure feeling of wearing is obtained.

Further, since the outer diameter portion of the bayonet claw 12 is very conspicuous when scratched, it is not desirable to provide a function as a sliding resistance or a fitting portion.
The clearance dimension is set for the second bayonet grooves 23a and 23b. Further, if the number of times of attaching and detaching the lens hood 20 increases, it is inevitable that the click mechanism will be damaged. Therefore, the rear surface of the bayonet claw 12 and the first and second bayonet grooves 23a, which are as invisible as possible. , 2
3b. It is to be noted that a step portion 13 is provided on the outer peripheral surface 11 on the distal end side of the lens barrel 10 over the entire circumference, and a contact portion 24 is provided on the inner peripheral surface 21 on the rear end side of the lens hood 20 correspondingly. Thereby, the mounting operability as a guide when mounting the lens hood 20 is remarkably improved.

Next, the operation of the lens hood attachment device having the above-described configuration will be described with reference to FIGS. When the lens hood is used, the mounting index 25 of the lens hood 20 is changed to the mounting index 14 of the lens barrel 10.
Is made to enter the lens barrel 10 from the optical axis A direction. At this time, after the bayonet claw 12 on the side of the lens barrel 10 is inserted into the first notch 22a of the lens hood 20, the contact portion 24 of the lens hood 20 is stepped over the entire circumference. The inner diameter of the abutting portion 24 is fitted to the front small-diameter portion 11 a of the outer peripheral surface 11 on the distal end side of the lens barrel 10, and the axis B on the lens hood 20 side and the light on the lens barrel 10 side Axis A automatically matches.

When the lens hood 20 is rotated clockwise as viewed from the front in this state, the bayonet claw 12 on the lens barrel 10 slides in the first bayonet groove 23a on the lens hood 20. First locking portion 2 provided at one end
3c comes into contact with the first stopper portion 12a of the bayonet claw 12, and its rotation stops. During the rotation of the lens hood 20, the first click projection 23g (FIG. 10) provided on the inner surface of the first bayonet groove 23a retreats against the elasticity of the first thin portion 23e, and the bayonet claw 12 The first click projection 23g is fitted into the click recess 12c of the bayonet claw 12 just before stopping to provide a clear click feeling. Can be

When the lens hood is not used, the lens hood 20 is turned in the opposite direction to the time of use, and its mounting index 25 is adjusted to the mounting index 14 of the lens barrel 10 so that the second
Bayonet claw 1 of lens barrel 10 in notch 22b
2, the contact portion 24 on the lens hood 20 side is brought into contact with the step portion 13 on the lens barrel 10 side. In this state, when the lens hood 20 is similarly rotated clockwise when viewed from the front, the bayonet claw 12 is moved to the second bayonet groove 23b.
Slides while giving an appropriate frictional resistance, and the second locking portion 23d at the end contacts the second stopper portion 12b provided at the end of the bayonet claw 12 to rotate the lens hood 20. It stops, but just before that, the second bayonet groove 23
The second click convex portion 23h protruding from the second thin portion 23f of FIG. 2b is fitted into the click concave portion 12d of the bayonet claw 12, and a clear click feeling is obtained.

In the above embodiment, the case where the lens barrel has two bayonet claws has been described.
The number of bayonet claws is not limited to two, but may be three or more. However, when the lens hood is not a round shape but a flower shape and has directionality, it is necessary to use two or four lens hoods. In addition, a click concave portion for click-connecting the lens hood to the lens barrel is provided on the lens barrel side, and a click convex portion is provided on the lens hood side. It is also possible to provide a click recess on the lens hood side.

[0019]

As described above, according to the present invention, the following effects can be obtained. According to the lens hood mounting device of the first aspect, a step portion having a small diameter at the distal end is provided on the outer peripheral surface on the distal end side of the lens barrel, and is provided on the entire inner peripheral surface on the rear end side of the lens hood. Since the contact portion that can contact the stepped portion is provided over the entire surface, it serves as a guide when the lens hood is mounted when the lens hood is mounted, and even if its axis does not exactly coincide with the optical axis of the lens barrel, it is oblique. There is no danger of being mounted on the device, and operability during mounting can be greatly improved.

According to the lens hood mounting apparatus of the second aspect, a concave portion is connected to one of the rear surface of the bayonet claw of the lens barrel and the inner surface of the bayonet groove of the lens hood, and the other is connected to the concave portion. Since the convex portions are formed, even if scratches occur due to repeated use, they are less noticeable, and the degree of freedom in design is improved.

According to the lens hood mounting apparatus of the third aspect, since the above-mentioned convex portion is provided on the thin portion which can be elastically deformed, the feeling of mounting becomes good, and the temporal change of torque when the lens hood is mounted and slid. At the same time,
Scratches given to the mating member can also be reduced.

According to the lens hood mounting device of the fourth aspect, the number of bayonet claws on the lens barrel side is two or four.
Since the lens hood is in a flower shape and the mounting angle position is important, it can be easily attached.

According to the lens hood mounting apparatus according to the fifth aspect, when the lens hood is not used, the lens hood can be turned upside down and put on the lens barrel, so that portability is improved and inconvenience such as loss is eliminated. Will be possible.

According to the lens hood mounting device of the present invention, the bayonet grooves on the lens hood side are formed in directions opposite to each other in the circumferential direction. In some cases, the mounting direction can be made the same when mounting in the opposite direction.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing a state in which a lens hood is mounted in a forward direction according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a main part showing a state where the lens hood is mounted in the reverse direction.

FIG. 3 is a front view showing the tip of the lens barrel.

FIG. 4 is a plan view of the same seen from the X direction shown in FIG. 3;

FIG. 5 is a partial rear view of the lens barrel.

FIG. 6 is a side view of a main part, similarly viewed from the Y direction shown in FIG.

FIG. 7 is a front view showing the lens hood.

FIG. 8 is a side view showing a part of the same in cross section.

FIG. 9 is a rear view of the same.

FIG. 10 is a side view of the main part, similarly viewed from the Z direction shown in FIG.

FIG. 11 is a sectional view of a main part showing a conventional lens hood mounted in a forward direction.

FIG. 12 is a sectional view of a main part showing a conventional lens hood mounted in a reverse direction.

[Explanation of symbols]

 10: Lens barrel 11: Front end outer peripheral surface 12: Bayonet claw 13: Stepped portion 14: Mounting index (lens barrel side) 20: Lens hood 21: Rear end side inner peripheral surface 22a: First cutout portion 22b : 2nd notch 23a: 1st bayonet groove 23b: 2nd bayonet groove 24: contact part 25: mounting index (lens hood side)

Claims (6)

[Claims] 1. A lens barrel having a plurality of bayonet claws on an outer peripheral surface on a distal end side, a notch portion into which the bayonet claw can be inserted and a bayonet groove communicating with the notch portion on an inner peripheral surface on a rear end side. In a lens hood mounting device for mounting a lens hood, a step portion having a small diameter at the front end is provided on the outer peripheral surface on the distal end side of the lens barrel, and on the inner peripheral surface on the rear end side of the lens hood, A lens hood mounting device, comprising: a contact portion capable of contacting the step portion over the entire circumference. 2. A concave portion is formed on one of a rear surface of a bayonet claw on a lens barrel side and an inner surface of a bayonet groove on a lens hood side, and a convex portion for click-coupling corresponding to the concave portion is formed on the other. The lens hood attachment device according to claim 1, wherein: 3. The lens hood attachment device according to claim 2, wherein said convex portion is provided on a thin portion which can be elastically deformed. 4. A plurality of bayonet claws on the lens barrel side
The lens hood attachment device according to any one of claims 1 to 3, wherein the number is four or four. 5. The lens hood mounting device according to claim 1, wherein the bayonet groove on the lens hood side is formed in parallel on two front and rear circumferences across the contact portion. 6. The lens hood mounting device according to claim 5, wherein the bayonet grooves on the lens hood side are formed in circumferentially opposite directions.