JP2727535B2 - Camera shutter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera shutter, and more particularly, to a shutter structure for blocking incident light with a single shutter blade.

[0002]

2. Description of the Related Art In a shutter of a camera, the shutter is opened and closed by swinging a shutter blade after a stop (one of field stops) for limiting a light beam from a subject. FIG. 4 shows a configuration of a shutter unit in the simple camera. The lens 1 is fitted into the lens frame 3 at the tip of the first support unit 2, and is fixed by the lens holder 4. A first stop 5 is formed inside the first support portion 2 behind the lens 1, and a shutter (sector) blade 6 is disposed after the first stop 5. A second stop (for example, as an aperture stop) 7 is formed on the second support portion 8 at a subsequent stage. According to the above configuration, the shutter blade 6 opens and closes the shutter by a swinging operation in which the shutter blade 6 reciprocates up and down in the illustrated D range,
The shutter is opened and closed during the time when the shutter blade 6 swings a distance of 2D. And by opening and closing this shutter,
An exposure range 100 is formed on the film 8 disposed on the rear surface of the camera by the first stop 5, whereby exposure is performed.

[0003]

However, in the conventional shutter described above, the shutter blades 6 are arranged apart from the first diaphragm 5 depending on the arrangement of the respective members, and the swing range of the shutter blades 6 is determined. There was a problem that would become wide. That is, FIG. 5 shows the area of the incident light beam in each part, and the light beam area in which the shutter blade 6 blocks the light beam area 101 at the rear surface position of the first diaphragm 5 is shown at 102. Area. Therefore,
When the shutter blades 6 are operated on the rear surface of the first aperture 5, the range E shown in the figure may be swung, whereas in the conventional shutter blade 6, the range D must be swung. , The swing range becomes wider.

As described above, if the swing range of the shutter blade 6 is widened, not only does it take a long time to open and close the shutter, but also in the case of a single blade shutter, the exposure is performed at points P and Q shown in FIG. There is an inconvenience that a time difference occurs. In other words, the shutter blade 6 performs a swinging operation in which the shutter blade 6 moves from the upper right portion to the lower left portion in the figure and returns. Not done. Therefore, in the film 9, exposure unevenness occurs at locations corresponding to the upper left and lower right portions of the drawing. In the conventional arrangement, the shutter blade 6
May not be able to be arranged on the rear surface of the first diaphragm 5, without changing the mounting position of the shutter blade 6.
It is required to reduce the swing range of the shutter blade 6.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a camera shutter capable of opening and closing a shutter in a short time with a small swing range without changing a mounting position of a shutter blade. Is to do.

[0006]

In order to achieve the above object, the present invention is directed to a camera shutter in which shutter blades are arranged at a stage subsequent to a stop for incident light, in a direction from the part of the shutter blades to the stop. The shutter blade is provided with a protruding portion for projecting light and blocking an incident light beam immediately after the stop.

[0007]

According to the above construction, for example, the projection is formed close to the rear surface of the aperture at the end of the shutter blade in the swing direction, and only the projection is swung immediately after the aperture in the opening and closing operation of the shutter. It will move. Therefore, it is possible to block the light flux in the minimum area formed by the aperture by the projection while the shutter blade itself is arranged at the same position as in the related art.

[0008]

FIG. 1 shows the structure of a shutter of a camera (simple camera) according to an embodiment. In FIG. 1B, a lens 1 is formed on a first support portion 2 as in the prior art. It is held by the lens frame 3 and is fixed to the outer case 10 by a lens holder 4 which is integral with the outer case 10. A first stop (field stop) 5 is formed on the first support portion 2 after the lens 1, and a second stop (for example, as an aperture stop) 7 is provided on the second support portion 8 after the first stop 5. It is formed. A shutter (sector) blade 12 is provided between the first stop 5 and the second stop 7, and the shutter blade 12 is swingably mounted by a shaft 13 formed on the second support portion 8. Then, as shown in FIG. 1A, a projection 14 is formed at the upper left of the tip of the shutter blade 12, and
The projection 14 protrudes toward the first aperture 5 [FIG. (B)], is disposed close to the rear surface of the first aperture 5, and the length of the projection 14 in the longitudinal direction is the first. The aperture 5 is formed to be larger than the opening radius. Therefore, by swinging the shutter blade 12 in the direction of arrow 200,
The projection 14 can block an incident light beam immediately after the rear surface of the first diaphragm 5.

FIG. 2 is an exploded perspective view of a shutter portion of the embodiment. As shown, the shutter blade 12 is provided with a first support portion 2 and a second support portion 8 by a shaft 13.
Attached between. A shutter lever (not shown) is engaged with a release lever (not shown) above the shutter blade 12.
2 is provided with an action lever 16 for swinging. Then, a photographing button 17 is arranged on the upper part of the housing 2a, and by pressing the photographing button 17, the release lever can be operated.

According to the above arrangement, by pressing the photographing button 17 shown in FIG. 2, the operating lever 16 of the shutter blade 12 which is engaged with the release lever is moved, and the shutter blade 12 is moved in the direction shown by the arrow in FIG. 200. Then, the projection 14 of the shutter blade 12 swings on the rear surface of the first aperture 5, thereby causing the light beam incident from the first aperture 5 to be immediately thereafter, that is, the minimum beam formed by the first aperture 5. The luminous flux in the area can be blocked.

FIG. 3 shows a state in which the shutter is opened and closed by the projection 14 of the shutter blade 12, and as shown, the exposure range 10 is the same as in the conventional case (FIG. 4).
With respect to 0, the projection 14 swings in the range indicated by E in the drawing, and the opening and closing of the shutter ends in the time of swinging 2E. When the embodiment of FIG. 3 is compared with the case of FIG. 4 of the related art, it is understood that the swing range is extremely small, and the shutter operation can be executed in a short time.

In the above embodiment, the case where the projection 14 of the shutter blade 12 blocks the light beam immediately after the first stop 5 has been described. However, when the shutter blade 12 is provided at the subsequent stage of the second stop 7, A projection can be formed so as to block the light beam immediately after the second stop 7.

In the above embodiment, the case where the shutter is opened and closed with one blade has been described. However, when it is necessary to dispose the shutter blade away from the diaphragm due to restrictions on the configuration and arrangement, two blades are required. The present invention can be similarly applied to the present invention.

[0014]

As described above, according to the present invention,
A part of the shutter blade is projected in the direction of the aperture, and a projection for blocking the incident light beam is provided immediately after the aperture, so that the shutter blade is arranged at a position away from the aperture. Also, the opening and closing operation of the shutter can be performed immediately after the rear surface of the aperture by the projection, and therefore, the swing range of the shutter blade can be reduced. As a result, there is an advantage that the shutter can be opened and closed in a short time, and that exposure unevenness on the film does not occur.

[Brief description of the drawings]

FIG. 1 is a view showing a structure of a camera shutter according to an embodiment of the present invention, wherein FIG. 1 (a) is a front view and FIG. 1 (b) is a top sectional view.

FIG. 2 is an exploded perspective view of a shutter portion of the embodiment.

FIG. 3 is a block diagram of the exposure range and the protrusion (swing) in the embodiment.
It is a side sectional view showing a range.

FIG. 4 is a side cross-sectional view showing a configuration of a conventional shutter portion and an exposure range and a blocking range thereof.

FIG. 5 is an explanatory diagram showing a state in which a light beam is blocked when a shutter is opened and closed in the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Lens, 2 ... 1st support part, 3 ... Lens frame, 5 ... 1st stop, 6, 12 ... Shutter blade, 7 ... 2nd stop, 8 ... 2nd support part, 14 ... Projection part.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Junichi Takashiro 1-324 Uetakecho, Omiya City, Saitama Prefecture Inside Fuji Photographic Equipment Co., Ltd. (72) Inventor Seiji Asano 1-324 Uetakecho, Omiya City, Saitama Prefecture Fuji Photo Optical Machine Co., Ltd.

Claims (1)

(57) [Claims] 1. A camera shutter in which shutter blades are disposed at a stage subsequent to a stop for incident light, wherein a projection protrudes from a part of the shutter blades toward the stop, and a projection that blocks an incident light beam immediately after the stop. A camera shutter provided on a shutter blade.