JPH0882831A - Lens hood - Google Patents

Abstract

PURPOSE: To use a lens hood without reducing a light shielding effect even at the time of macro-photographing. CONSTITUTION: The lens hood is constituted of a slide hood 1 and a fixed hood 2 fitted thereto, a compression spring 4 energizing the lens hood 1 to slide it forward is connected to a lens cover 3 on a fixing side and a roller 6 is provided on the tip of a link bar 5 pivotally supported to turn and energized by the compression spring 7, in the fixed hood 2. The roller 6 is brought into press-contact with the inner periphery of the slide hood 1 and it is slid backward and fixed in this position, at the time of macro-photographing and when a knob 8 is slid forward at the time of returning the hood 1 to a standard state, the link bar 5 is turned clockwise with a link part 8a, the roller 6 is separated from the inner periphery of the slide hood 1 and it is returned to a home front position by the spring 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hood of a zoom lens for photographing.

[0002]

2. Description of the Related Art Usually, the hood of a TV lens is of a fixed type or is locked at a predetermined position even if it is slid, but when it is returned to the original position, it is unlocked and then manually slid and locked again. It is known to do things.

The length of the hood must be decided in consideration of the following points. (1) A light shielding effect that blocks unnecessary light rays. (2) Avoid rain when the lens is used outdoors when it is raining. (3) M. O. Macro photography to get closer than D (closest distance). Therefore, in order to satisfy points (1) and (2), make the hood as long as possible within the range that does not block the effective rays, and (3)
In order to fill the points, the length is designed to be shorter than the distance at the time of macro photography. However, in reality, it is difficult to satisfy all of these, and the hood is properly used depending on the intended use of the lens.

[0004]

However, in the above-mentioned conventional example, since the fixed hood is used, the following problems occur. (1) In the case of a hood that keeps a light-shielding effect and avoids rain, the hood becomes an obstacle, and the object cannot be brought close to the macro range so that the macro effect cannot be used to the maximum. (2) On the contrary, when it is desired to maximize the macro effect, the hood is removed before use, so that the light-shielding effect is almost negligible.

In view of the problems of the above-mentioned conventional example, the present invention as set forth in claims 1 and 2 slides when a load is applied to the hood in the optical axis direction, and returns to the normal position if the load is removed. It is a first object to provide a lens hood that does. A second object of the present invention is to provide a lens hood in which the hood is fixed at a sliding position and can be automatically returned to the original length by releasing the hood. And

[0006]

In order to achieve the above-mentioned first object, the invention described in claim 1 is a hood that slides parallel to the optical axis of a zoom lens for photographing, and in the optical axis direction at the tip of the hood. When the load is applied, it slides to become shorter, and the biasing member is provided to restore the original length when the load is removed. Further, in the invention as set forth in claim 2, it is preferable that the hood includes a fixed portion and a slide portion, and the urging means is a spring that connects the slide portion and the fixed portion side.

In order to achieve the above-mentioned second object, the invention as set forth in claim 3 is provided with a fixing means for fixing the hood in a sliding position and a releasing means for releasing the fixing by the fixing means. The hood is returned to its original length by releasing the fixing by means.

[0008]

When the lens hood having the above-described structure is mounted and, for example, macro shooting is performed, if the obstacle is obstructed, the slide part of the hood can be slid rearward to set the macro shooting position, and the shooting ends after the shooting. Then, the slide part of the hood returns to the original standard position for normal shooting. Further, when the fixing means is provided, the hood can be set at a desired slide position during macro photography, and the hood can be easily returned to the standard position by the releasing means after the photography is completed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A first embodiment of the present invention will be described below with reference to FIGS.
It will be described based on. FIG. 1 is a sectional view of the lens hood of the present embodiment at the time of normal photographing, FIG. 2 is a sectional view of the same at the time of macro photographing, and FIG. 3 is an enlarged view of part A of FIG. In the figure, 1
Is a slide hood, 2 is a fixed hood, the rear end side of which is supported by the lens cover 3, and the slide hood 1 is slidably fitted on the outer periphery thereof. Reference numeral 4 denotes a compression spring, both ends of which are attached to the slide hood 1 and the lens cover 3, respectively, and urges the slide hood 1 to push forward.

Reference numeral 5 denotes a link rod, one end of which is rotatably supported by a shaft 5a in a recess 2a provided at the outer peripheral front portion of the fixed hood 2, and a roller 6 is supported at the other end, and a compression spring. The roller 6 is urged to rotate outward and the roller 6 is brought into contact with the inner surface of the slide hood 1 to apply a load. And
The shaft 5a of the link rod 5 has a protrusion 5b protruding inward on the fixed hood 2, and the roller 6 is wound with rubber to obtain a frictional force. Reference numeral 8 denotes a knob, which is slidable in the optical axis direction within a hole 2b provided at the rear portion of the outer periphery of the fixed hood 2, and has a link portion 8a along the inner surface of the fixed hood 2 at its inner end side. The tip of the portion 8a is in contact with the protrusion 5b of the shaft 5a, and pushes it forward to rotate the link rod 5 inward. Reference numeral 9 denotes a ball plunger, which is attached to the rear side of the slide hood 1 and is provided with a positioning groove 2 provided at the front part of the outer periphery of the fixed hood 2.
The tip is engaged with c to keep the standard hood length. 10 is a lens cover 3 located in the fixed hood 2.
It is a focus lens group. In addition, M is a subject and N is an obstacle.

In the present embodiment having the above-described structure, assuming that the hood length of the slide hood 1 for obtaining the light-shielding effect necessary for the lens during normal photographing is L1 as shown in FIG. When a subject M is desired to be macro-photographed in the photographing situation as shown in, the tip of the slide hood 1 comes into contact with the obstacle N when the lens is brought closer. When the lens is brought closer than this, the slide hood 1 is pushed by the obstacle N and slides along the roller 6 which is tensioned by the spring 7 in the direction a perpendicular to the optical axis. At this time, the spring 4 is compressed in the b direction (rearward direction) in the drawing, so a force F1 that tries to return to the c direction (frontward direction) acts, but the spring 7 pushes it in the a direction (direction orthogonal to the optical axis). By increasing the frictional force F2 that causes the slide hood 1 to stop, the slide hood 1 stops.
At this time, the hood length of the slide hood 1 for obtaining the light blocking effect required for the lens is L2.

Next, when ending the macro photography and returning the length of the hood to its original position, when the knob 8 is slid in the direction d (forward direction) in the drawing, the link rod 5 is moved around the shaft 5a as shown in the drawing e.
It rotates in the direction (clockwise) and the roller 6 slides on the hood 1.
Get away from. Then, the slide hood 1 slides in the c direction (forward direction) by the spring force F2 of the spring 4, and the tip of the ball plunger 9 of the slide hood 1 engages with the positioning groove 2c of the fixed hood 2 and stops. This allows
There is an effect that macro photography is possible with a hood having a sufficient light-shielding effect attached.

4 and 5 show a second embodiment of the present invention. For simplification of description, the same parts as those in the first embodiment are designated by the same reference numerals, and only different points will be described. FIG. 4 is a sectional view of the present embodiment at the time of macro photography, and FIG. 5 is an enlarged view of part B of FIG. In this embodiment, a plurality of tooth grooves 1a are provided on the inner circumference of the slide hood 1 in the optical axis direction, and instead of the link rod 5 having the rollers 6 of the first embodiment, the tooth grooves 1a can be engaged. Insert the hook bar 11 into the recess 2 of the fixed hood 2.
One end of the shaft 11a is rotatably supported by the shaft 11a.
11 is provided on the fixed hood 2 and protrudes toward the inner surface side.
The tip of the link portion 8a of the knob 8 is in contact with b. The shape of the tooth groove 1a is a one-way moving type that locks the slide hood 1 in the forward direction only. The other structure is similar to that of the first embodiment.

In the present embodiment having the above-described structure, when the subject M is macro-photographed, the slide hood 1 is pushed by the obstacle N and slides backward, and the slide hood 1 has teeth on the inner circumference thereof at a desired macro-photographing position. The hook rod 11 is locked by being engaged with one of the grooves 1a by the urging force F2 of the spring 7.
On the other hand, when ending the macro photography and returning the slide hood 1 to the original position, when the knob 8 is slid in the direction d (forward direction) in the drawing, the hook bar 11 is disengaged from the tooth groove 1a, and the slide hood 1 moves to the spring 4. The urging force F2 slides in the direction c (front direction) in the drawing, and the tip of the ball plunger 9 engages with the positioning groove 2c of the fixed hood 2 and stops at the normal photographing position. In this way, the same effect as that of the first embodiment can be obtained.

FIG. 6 shows a third embodiment of the present invention. In this embodiment, the link rod 5 having the roller 6 in the first embodiment and the knob 8 having the link portion 8a for rotating the same are put in a simple structure.
The other structure is similar to that of the first embodiment. In the present embodiment having the above-mentioned configuration, in the shooting situation as shown in FIG. 3 in the first embodiment, when the subject M is desired to be macro-shot, the tip of the slide hood 1 is brought into the obstacle N when the lens is moved closer. Contact. When the lens is further brought closer than this, the slide hood 1 is pushed by the obstacle N and slides in the b direction (rearward direction) against the urging force of the spring 4. Next, when the macro photography is finished and the subject is separated, the slide hood 1 slides in the c direction (forward direction) by the urging force of the spring 4, and the tip of the ball plunger 9 comes into the positioning groove 2c of the fixed hood 2. Engage to return to the normal shooting position.

[0016]

Correspondence between Invention and Embodiment In the above embodiments, the slide hood 1 corresponds to the slide portion of the hood of the present invention, the fixed hood 2 corresponds to the fixed portion of the hood of the present invention, and the compression spring 4 corresponds to the present invention. The link rod 5 having the roller 6 biased by the compression spring 7 or the hook rod 11 biased by the compression spring 7 corresponds to the fixing means of the present invention and corresponds to the biasing means, and the knob having the link portion 8a. 8 corresponds to the releasing means of the present invention. The above is the correspondence relationship between each configuration of the embodiments and each configuration of the present invention, but the present invention is not limited to the configurations of these embodiments, and the functions shown in the claims or the functions of the configurations of the embodiments It goes without saying that any structure may be used as long as the above can be achieved.

[0017]

As described above, according to the present invention as set forth in claims 1 and 2, in the hood that slides parallel to the optical axis of the photographing zoom lens, a load is applied to the tip of the hood in the optical axis direction. It is possible to improve operability while maximizing the performance of the hood during macro shooting and normal shooting by providing a biasing means with a spring that returns to the original length when the load is removed. . Further, according to the present invention as set forth in claim 3, by providing the fixing means for fixing the hood at the sliding position and the releasing means for releasing the fixing by the fixing means, the hood is surely locked at the necessary macro position. When returning to the normal shooting, the operability can be improved because it can be easily returned to the original position and fixed.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a lens hood of a first embodiment according to the present invention during normal shooting.

FIG. 2 is an enlarged view of part A in FIG.

FIG. 3 is a vertical cross-sectional view of the lens hood during macro photography.

FIG. 4 is a vertical cross-sectional view of the lens hood of the second embodiment of the present invention during macro photography.

5 is an enlarged view of part B in FIG.

FIG. 6 is a vertical sectional view of a lens hood according to a third embodiment of the present invention during normal shooting.

[Explanation of symbols]

1 ... Slide hood, 1a ... Tooth groove, 2 ... Fixed hood, 2c ... Positioning groove, 3 ... Lens cover, 4 ...
Compression spring, 5 ... Link bar, 6 ... Roller, 7 ... Compression spring, 8 ... Knob, 9 ... Ball plunger, 10 ...
・ Focus lens group, 11 ・ ・ Hooking rod, M ・ ・ Subject, N ・ ・ Obstacles.

Claims (3)

[Claims] 1. In a hood that slides parallel to the optical axis of a zoom lens for photographing, when a load is applied to the tip of the hood in the direction of the optical axis, the length of the hood slides and shortens, and the original length is restored when the load is removed. A lens hood provided with a biasing means. 2. The lens hood according to claim 1, wherein the hood comprises a fixed portion and a slide portion, and the urging means is a spring connecting the slide portion and the fixed portion side. 3. The lens hood according to claim 1, further comprising a fixing means for fixing the hood in a sliding position, and a releasing means for releasing the fixing by the fixing means.