JP3025376B2 - Flare prevention frame for film unit with lens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flare preventing frame for a film unit with a lens which has a simple photographing mechanism and has a built-in film.

[0002]

2. Description of the Related Art A film unit with a lens that eliminates the need for a cumbersome film loading operation, such as "Sharan Run Hi" (trade name), is manufactured and sold so that a photograph can be taken immediately after purchase. It's being used. This film unit with a lens has a built-in unexposed film in advance in a unit body incorporating a simple photographing mechanism.After performing the film winding operation in the same way as a general camera operation, the shutter button is pressed. Then, the shutter blades open and close, and the subject image is exposed on the film set in the aperture. The taking lens is provided on a lens substrate having an aperture opening, and a flare prevention frame is provided between the lens substrate and the aperture.
The flare prevention frame has an opening substantially similar to the aperture, and cuts a light flux of the subject light incident from the aperture opening toward the outside of the shooting screen to reduce flare.

[0003]

However, the above-mentioned film unit with a lens cannot sufficiently prevent flare when photographing under the fine weather, despite the provision of the above-mentioned flare prevention frame. Tended to decrease.

The present invention has been made in consideration of the above problems, and has as its object to provide a flare preventing frame for a lens-fitted film unit in which the above-described flare preventing frame is improved to prevent the occurrence of flare as described above. And

[0005]

Since it has been found that the above-mentioned flare is caused by the straight edge of the opening of the prevention frame, the flare prevention frame of the present invention achieves the above object. For this purpose, at least the edge on the short side of the opening is formed in a curved shape that is convex inward.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a unit main body 10 of a film unit with a lens has a front cover 12 and a rear cover 13 attached to a main body 11 incorporating a simple photographing mechanism. A patrone room 1 for accommodating a patrone body 15 of the photo film patrone 14 is provided in the main body 11.
6 and a film roll chamber 18 for storing the unexposed film 17 drawn from the cartridge body 15 in a roll form.
Are formed. A dark box 19 is provided between the patrone chamber 16 and the film roll chamber 18, and an aperture 20 for defining a photographing screen is formed. A cover 13a is formed on the rear cover 13 so as to be rotatable. By opening the cover 13a, the photographed film cartridge 14 which has been photographed can be taken out from the cartridge chamber 16. Although not shown, the lens-fitted film unit is used with the unit main body 10 covered with a package such as a paper box.

Inside the dark box 19, there is provided a flare prevention frame 22 for cutting a light beam going outside the photographing screen and for preventing flare. As shown in FIG. 2, the opening 21 has a short side edge 21a, 21b in the shape of a circular arc convex inward, and a long side edge 21c, 21d has a straight line shape. Here, when the edges 21a and 21b are linear, for example, when strong light such as sunlight shines on the edge 21a, the light reflected by the edge 21a reinforces each other to generate a strong flare at the center of the shooting screen. The reflected light is dispersed because the edges 21a and 21b are arc-shaped convex inward, and the amount of flare is reduced. In addition, the tangent line 2 of the edges 21a and 21b
The rectangle formed by 3a, 23b and edges 21c, 21d is substantially similar to the aperture 20,
The shooting screen is not shaken by a and 21b.

[0008] At the short side of the anti-flare frame 22, mounting holes 22a and 22b are formed. As shown in Fig. 3, after these are fitted into the mounting pins 19a and 19b in the dark box portion 19, the mounting is performed. By melting the tips of the pins 19a and 19b, the flare prevention frame 22 is mounted in the dark box portion 19. Further, the cross-sectional shapes of the edges 21a to 21d are formed, for example, in a shape pointed at 90 °.

In FIG. 3, an exposure opening 19c is formed at the front of the dark box 19, and shutter blades 24 for opening and closing the exposure opening 19c are rotatably mounted on the front of the dark box 19, and a lens is provided in front of the shutter. A substrate 25 is provided. An aperture 25a is formed in the lens substrate 25 at a position corresponding to the aperture 21.
6 is attached. Reference numerals 27, 28, 29
Is a support member that defines the mounting position of the flare prevention frame 22 in the optical axis direction, and is integrally formed on the inner wall of the dark box portion 19. Although not shown, a support member similar to the support members 27, 28, 29 is formed at a position facing the support members 27, 28, 29. Also, at the tip of the support member 28,
The mounting pin 19a is formed integrally.

When the user who has purchased the film unit with the lens constructed as described above operates the winding knob 29 until it stops, the first photographing frame becomes the aperture 2.
Set to 0 and shutter charge is performed. Aim the photographing lens 26 at a desired subject and turn the front cover 1
When a shutter button integrally formed with the shutter button 2 is pressed, the shutter blade 24 opens and closes the exposure opening 19c. The subject light passing through the taking lens 26, the aperture opening 25a and the exposure opening 19c is applied to the film 17 set on the aperture 20.
The light flux going out of the shooting screen is cut by the flare prevention frame 22. At this time, a part of the subject light is reflected by the edges 21a to 21d of the opening 21, but this reflected light is radiated by the arc-shaped edges 21a and 21b and does not reinforce each other, and the edges 21a to 21d are not strengthened. Since the tip of 21d is sharp and has a small reflection area, the amount of flare is extremely reduced, and the contrast of the photographed image is not reduced. Therefore,
A clear image is formed on the surface of the film 17 set on the aperture 20.

When the operation of the winding knob 29 and the pressing of the shutter button are alternately repeated, and all the frames of the film 17 have been photographed, the user operates the winding knob 29 continuously to expose the exposed inside of the patrone main body 15. The entire film 17 is stored. Thereafter, the film unit with the lens is submitted as it is to a developing dealer and sent to a developing laboratory. Here, a part of the paper box is peeled off, the lid 13a of the patrone chamber 16 is opened, and the exposed photo film patrone 14 is taken out of the unit main body 10. The photo film cartridge 14 is set in an automatic processor and developed and printed, and clear negative and print photographs without flare are given to the user.

In the embodiment described above, the short side edges 21a and 21b of the exposure opening 21 are formed in a gentle arc shape, but the long side edges 21c and 21d may be formed in a similar arc shape. Good. Further, the shape of the edge is not limited to the arc shape, and may be, for example, an elliptical shape as long as it is a convex curved shape.

[0013]

As described above, according to the flare preventing frame of the film unit with the lens according to the present invention, the opening is reduced at least.
Also, since the short side edge has a curved shape that is convex inward, the occurrence of flare can be prevented and a clear printed photograph can be obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a unit main body of a film unit with a lens.

FIG. 2 is an explanatory diagram showing an enlarged flare prevention frame.

FIG. 3 is a sectional view of a dark box portion showing a flare prevention frame from the side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Unit main body 11 Main body part 17 Film 19 Dark box part 21 Opening 21a-21d Edge 22 Flare prevention frame 24 Shutter blade 25a Aperture opening 26 Photographing lens

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-210207 (JP, A) (58) Fields studied (Int. Cl. ⁷ , DB name) G03C 3/00 G03B 17/04

Claims (1)

(57) [Claims] 1. A film unit with a lens comprising: a unit body incorporating a photographing mechanism such as a photographing lens, an aperture, and a shutter; an unexposed film pre-loaded in the unit; and an aperture for defining a photographing screen of the film. of
In flare preventing frame, disposed between the diaphragm and the aperture, which has a substantially similar shape aperture and aperture, the aperture small
A flare prevention frame for a film unit with a lens, characterized in that at least a short side edge is formed in a curved shape that is convex inward.