JPH06265767A - Lens hood attaching structure - Google Patents

Abstract

PURPOSE:To attach a lens hood only in a state where the notch of the lens hood is at a specified position. CONSTITUTION:In this structure where the lens hood 50 is attached to a photographing lens 60 by respectively inserting plural projected line parts 51a to 51c formed on the peripheral surface of the base end of the lens hood 50 having the notch at its leading edge in plural recessed parts 61a to 61c formed on the peripheral surface of the leading edge of a photographing lens barrel 60; the position or the length of the projected line part and the recessed part in a peripheral direction are set so that the respective projected line parts 51a to 51c are inserted in the respective recessed parts 61a to 61c only when the notch of the lens hood 50 is on specified rotating phase with respect to the lens barrel 60.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for mounting a lens hood on a taking lens barrel.

[0002]

2. Description of the Related Art FIGS. 4A and 4B show a conventional example of a lens hood mounting structure of this type. FIG. 4A is a view of the lens hood as seen from the front end side, and FIG. 4B is a view showing the front end portion of a taking lens barrel. Is. As is well known, the lens hood 10 is for preventing unnecessary luminous flux from entering the photographing lens,
The base end portion is attached to the tip end portion of the taking lens barrel 20. On the inner peripheral surface of the base end portion of the lens hood 10, three protrusions 11a having the same shape are formed at equal angular intervals, while at the tip 21 of the lens barrel 20, three recesses having the same shape are formed. 21
a are formed at equal angular intervals, and the length of each recess 21a in the circumferential direction is longer than that of each ridge 11a. Further, in the lens barrel 20, the groove D is formed in the portion located between the recesses 21a.
(Also shown in FIG. 5) are formed, and the protrusions 11 a of the lens hood 10 can be inserted into these grooves D.

To attach the lens hood 10 to the lens barrel 20, first, the base end portion 11 of the hood 10 and the lens barrel 2 are attached.
0 front end portions 21 are opposed to each other, and
Insert into 1a. When the hood 10 is rotated in the direction A in the figure by a predetermined amount in this state, one end side of the protruding portion 11a is inserted into the groove D and the hood 1 is rotated as shown by a two-dot chain line in FIG.
0 is fixed to the lens barrel 20.

[0004]

By the way, when the hood 10 is attached to a wide-angle lens having a wide angle of view, especially when the hood 10 is
There is a risk that part of the hood 10 will be reflected in the corner.
Therefore, conventionally, notches (for example, 52 and 53 in FIG. 1) are provided at the tip of the hood 10, and the hood 10 is attached so that the notches come to the positions corresponding to the four corners of the screen. Prevents reflections.

However, in the above-mentioned conventional lens hood mounting structure, since all the three protrusions 11a and the recesses 21a have the same shape and are arranged at equal angular intervals, the respective protrusions are arranged. 11a to 11c can be inserted into any of the recesses 12a to 12c, and therefore the lens hood 1
0 can be attached to the lens barrel 20 in three rotation phases out of 360 degrees. In other words, the hood 10 can be attached even when the above-mentioned notches are not provided at the positions corresponding to the four corners of the screen, and thus there has been a risk that a part of the hood 10 would be photographed in the past.

An object of the present invention is to provide a lens hood mounting structure capable of mounting the lens hood only when the notch of the lens hood is in a predetermined position.

[0007]

1 and 2, which show an embodiment, the invention of claim 1 has a base end portion of a lens hood 50 having notches 52 and 53 at the front end portions. The plurality of protrusions 51a to 51c formed on the peripheral surface are
The present invention is applied to a structure in which the lens hood 50 is attached to the taking lens 60 by inserting the lens hood 50 into the plurality of recesses 61a to 61c formed on the peripheral surface of the tip of the taking lens barrel 60, respectively. The protrusions 51a to 51c are inserted into the recesses 61a to 61c only when the notches 52 and 53 of the lens hood 50 are in a predetermined rotation phase with respect to the taking lens barrel 60. The positions or lengths of the portions and the recesses in the circumferential direction are set to solve the above problems. In the invention of claim 2, contrary to the above, the ridge is provided on the lens barrel side and the recess is provided on the lens hood side.

[0008]

According to the above construction, each of the protrusions 51a to 51c forms the recess 6 only when the notches 52 and 53 of the lens hood 50 are in a predetermined rotation phase with respect to the taking lens barrel 60.
1a to 61c, the lens hood 50 can be attached to the taking lens barrel 60. In other words, the notches 52 and 53 of the lens hood 50 are formed in the taking lens barrel 6
The lens hood 50 cannot be mounted on the taking lens barrel 60 when it is not in a predetermined rotation phase with respect to zero.
As a result, it is possible to reliably prevent a part of the lens hood 50 from being reflected on the shooting screen.

Incidentally, in the section of means and action for solving the above-mentioned problems for explaining the constitution of the present invention, the drawings of the embodiments are used to make the present invention easy to understand. It is not limited to.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 1 is a view showing a lens hood mounting structure according to the present invention, FIG. 2 (a) is a view of the lens hood as seen from the front end side,
FIG. 2B is a diagram showing a base end portion of the lens hood and a front end portion of the taking lens barrel. As shown in FIG. 1, notches 52 and 53 are formed at the front end of the lens hood 50 so that part of the lens hood 50 does not appear in the photographing screen. Further, on the inner peripheral surface of the base end portion of the lens hood 50, three protrusions 5 are provided.
1a, 51b, 51c are formed, of which the ridge portion indicated by reference numeral 51c has a longer circumferential dimension than the other two.

On the other hand, three concave portions 61a, 61b, 61c are formed on the outer peripheral surface of the front end portion of the lens barrel 60, and the length of the two concave portions 61a, 61b in the circumferential direction is a ridge portion. 51a, 51b longer than the ridge 61
It is made shorter than c. Therefore, the protrusions 51a and 51b can be inserted into the recesses 61a and 61b, but the protrusion 51c can be inserted.
Cannot be inserted. Further, the recess 61c is longer than the protrusion 51c, so that the protrusion 51c can be inserted into the recess 61c. The distance between the protrusions and the distance between the recesses are such that the protrusions 51a to 51c simultaneously form the recesses 61a to 61.
It is set in advance so that each can be inserted into c. Grooves D are formed in a portion between the recesses 61a to 61c from the one end side to the intermediate portion as in the conventional case, and the protrusions 51a to 51c of the lens hood 50 can be inserted into these grooves D.

In mounting the lens hood 50 on the lens barrel 60, first, as shown in FIG. 1, the base end of the hood and the tip of the lens barrel are opposed to each other, and the hood 50 is moved in the B direction to project the ridge. 51a-51c are inserted in the recessed parts 61a-61c, respectively. Here, since the lengths and intervals of the protrusions 51a to 51c and the recesses 61a to 61c are set as described above, the protrusions 51a, the recesses 61a, and the protrusions 51a.
b and the recess 61b, and the protrusions 51a to 51c at the same time only in the combinations of the protrusion 51c and the recess 61c.
It cannot be inserted into c. After that, lens hood 5
When 0 is rotated in the direction A in the drawing, each of the ridges 51a to 51a
c is inserted into the groove D, and the hood 50 is attached to the lens barrel 60.
Fixed to. Next, when the lens barrel 60 is attached to the camera body, the notches 52 and 53 of the lens hood 50 are
It is located at a position corresponding to the four corners of the shooting screen.

As described above, in this embodiment, each ridge 51 is formed.
a-51c can be inserted into each of the recesses 61a-61c at the same time in one phase of 360 degrees, that is, when the notches 52 and 53 of the lens hood 50 have a predetermined rotational phase with respect to the lens barrel 60. Limited to The predetermined rotation phase is a phase in which the notches 52 and 53 come to the positions corresponding to the four corners of the photographing screen when the lens hood 50 is fixed to the lens barrel 60, and therefore, the lens hood 5
It is possible to reliably prevent a part of the image from being captured in the shooting screen when shooting with 0.

The tip of the taking lens barrel 60 does not rotate during zooming or focusing, and therefore the positions of the notches 52 and 53 of the hood 50 are not changed. Needless to say, even if the lens barrel 60 is first attached to the camera body and then the hood 50 is attached to the lens barrel 60, the positions of the notches 52 and 53 are the same as described above.

In the above, in the combination of the protrusion of the lens hood and the recess of the lens barrel, the length of one set is longer than that of the other two sets, but the lengths of all three sets may be different. Good. Further, as shown in FIG. 3A, for example, the length of each combination is the same for all three sets, and the same effect can be obtained by changing only the length of the interval. Further, as shown in FIGS. 3B and 3C, two sets may be combined, or four or more sets may be combined. Although only the protruding portion of the lens hood is shown in FIG. 3, the concave portion of the lens barrel is also formed accordingly.

In the above, the example in which the projection is provided on the inner peripheral surface of the lens hood and the recess is provided on the outer peripheral surface of the lens barrel has been shown. However, the projection is provided on the outer peripheral surface of the lens hood. A recess may be provided on the inner peripheral surface of the lens barrel. Furthermore, while providing a recess on the lens hood side,
The present invention can be applied to a lens barrel provided with a ridge portion.

[0017]

According to the present invention, the lens hood is devised by devising the circumferential position or length of each of the ridges of the lens hood (shooting lens barrel) and the recesses of the shooting lens barrel (lens hood). Since the hood can be attached to the lens barrel only when the notch on the lens barrel is in the specified rotation phase with respect to the shooting lens barrel, part of the hood will not be attached when the lens hood is attached and shooting is performed. It can be surely prevented from being reflected on the screen.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a lens hood mounting structure according to the present invention.

FIG. 2A is a view of the lens hood as seen from the tip side,
FIG. 3B is a view showing the tip of the taking lens barrel.

FIG. 3 is a diagram showing a modified example of a lens hood base end portion.

4A and 4B are views showing a conventional lens hood mounting structure, in which FIG. 4A is a view of the lens hood as seen from the front end side, and FIG. 4B is a view showing the front end portion of the lens barrel.

FIG. 5 is a sectional view taken along line VV of FIG.

[Explanation of symbols]

 50 lens hood 51a, 51b, 51c ridges 52, 53 notch 60 photographic lens barrel 61a, 61b, 61c recess D groove

Claims (2)

[Claims] 1. A plurality of ridges formed on a peripheral surface of a base end of a lens hood having a notch at a front end are respectively inserted into a plurality of recesses formed on a peripheral surface of the front end of a photographing lens barrel. In the structure for attaching the lens hood to the taking lens by doing so, each of the protrusions is inserted into each recess only when the notch of the lens hood is in a predetermined rotation phase with respect to the taking lens barrel. A lens hood mounting structure characterized in that circumferential positions or lengths of the protrusions and the recesses are set. 2. A plurality of ridges formed on the peripheral surface of the front end of the taking lens barrel are inserted into a plurality of recesses formed on the peripheral surface of the base end of a lens hood having a notch at the front end. In the structure for attaching the lens hood to the taking lens by doing so, each projection is inserted into each recess only when the notch of the lens hood is in a predetermined rotation phase with respect to the taking lens barrel. A lens hood mounting structure characterized in that circumferential positions or lengths of the protrusions and the recesses are set.