JPH0132031Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a lens hood, and particularly to a lens hood suitable for outdoor use.

The original purpose of a lens hood is to block harmful rays that are unnecessary for imaging. Therefore, the lens hood may be extended in front of the most advanced lens of the lens barrel to the extent that the effective screen does not decrease, or a mask that is approximately similar to the effective screen may be provided at the tip of the lens hood. There is. The first figure shows a side view including a partial cross section of a conventional lens barrel with a lens hood.
In the figure, harmful light rays coming from the front diagonally downward arrow direction 2 of the lens 1 are blocked by the lower wall 3a of the lens hood 3, but dust tends to accumulate on the inner surface of the lower wall 3a. Especially when used outdoors in the rain,
Raindrops containing dust from the four directions of the arrows fall on the lower wall 3a.
There was a defect in which the particles accumulated on the inner surface of the lens or bounced off and adhered to the surface of the lens 1 of the lens barrel 5, thereby hindering the best possible imaging. Although there is a conventional example in which a hole is provided in the lower wall 3a as a measure against raindrops accumulating and dust accumulating on the inner surface of the lower wall 3a, in order to prevent harmful rays from entering from diagonally downward in front of the lens 1, However, there are restrictions on the position and size of the hole, so it is not an effective countermeasure, and even more so when the lower wall 3
Conventionally, no measures have been taken to simultaneously solve the problem of raindrops bouncing off the inner surface of the a.

SUMMARY OF THE INVENTION The present invention aims to overcome the above-mentioned deficiencies and to prevent the lens hood from blocking harmful rays and preventing the surface of the lens from becoming contaminated due to raindrop accumulation, dust accumulation, and raindrop bounce within the lens hood.

That is, the present invention is configured such that a plurality of fins and a plurality of holes are alternately arranged in a part of a cylindrical body.

Hereinafter, the present invention will be described by way of examples with reference to the drawings.

In FIG. 2, which is a side view including a partial cross section of the embodiment of the present invention, a lens 12 is installed in the lens barrel 11 on the right side.
is attached, and there is a lens hood 13 attached to the lens barrel 11 on the left side. Further, FIG. 3 is a front view from A in FIG. 2, and FIG. 4 is a bottom view from B in FIG. A plurality of fins 15 are held at both ends by lower frames 13b and 13c on both sides of the lens hood 13, parallel to the fins 15 and forming an acute angle θ toward the bottom surface 14 of the lens hood 13 and the front mask 13a. The present invention is constructed by arranging holes 16 in parallel and alternately with a plurality of fins 15. Note that fins may be arranged in parallel on one plane so as to divide one large opening.

Next, to explain its effect, the mask 13
Dust that enters from the hole 16 falls downward to the outside, and harmful rays from the diagonally downward direction of the arrow 17 in front of the lens 12 are blocked by the fin 15 and the lens hood 13
In addition, even if raindrops from the direction of arrow 18 enter the lens hood 13 when used outdoors in the rain, some of them fall directly downward from the holes 16 and some of them bounce off the fins 15. It falls from the hole 16 downward to the outside.

As explained above, according to the present invention, effects such as shielding of harmful rays, prevention of dust accumulation in the lens hood 13, and ease of cleaning are achieved. Furthermore, even when used outdoors in the rain, the lens 12 surface is prevented from becoming contaminated due to raindrops accumulating in the lens hood 13 and raindrops bouncing back.

[Brief explanation of the drawing]

FIG. 1 is a side view with a partial cross section of a conventional lens barrel with a lens hood, FIG. 2 is a side view with a partial cross section of an embodiment of the present invention, and FIG. 3 is a side view of a conventional lens barrel with a lens hood. A front view as viewed from A, and FIG. 4 are a bottom view as viewed from B in FIG. 2. 12... Lens, 13... Lens hood, 13
a... Lens hood front mask, 14... Lens hood bottom, 15... Fin, 16... Hole.

Claims (1)

[Scope of utility model registration request] A lens hood characterized in that a plurality of forward-slanted fins and a plurality of holes are alternately arranged in the lower part of a cylindrical body located on the object side of an objective lens.