JPH06175294A - Film unit with lens - Google Patents

Abstract

PURPOSE:To provide a film unit with a lens obtained by preventing the rear surface of a film from being scratched. CONSTITUTION:On the back cover 5 of a unit main body 2, a wall surface 15 covering a film roll chamber 10 from the back surface and a film supporting surface 16 supporting the film 12 extended to an exposure position from the back surface are formed. At a boundary part between the wall surface 15 and the supporting surface 16, three projected lines 18 and guide parts 30 are provided. The cross sections of the projected lines 18 in a film drawing direction semicircularly project and they are extended linealy in a direction perpendicular to the film drawing direction. The guide parts 30 are positioned on both sides distant from a film passing surface near the projected lines 18 and they become 0.05mm-0.2mm higher than the vertexes of the projected lines 18 in a film surface direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens-fitted film unit in which a film is previously built in a unit body having a photographing function.

[0002]

2. Description of the Related Art A film unit with a lens is a unit in which a simple photographing mechanism and a winding mechanism are incorporated and the film is stored in advance. It is widely used because it is easy to use and it is cheap. Yes (the product name is "Sharing Run Hi"). Such a lens-fitted film unit, as known from Japanese Patent Laid-Open No. 64-544, stores a cartridge in a cartridge chamber on the film take-up side and stores an unexposed film in a roll in a film roll chamber. However, each time I take a picture, the exposed film is wrapped around the film cartridge.

By the way, the work of storing the film in the unit main body is carried out in a dark room, but in order to simplify the work and reduce the number of parts, after loading a cartridge and a film roll, one rear cover is attached. By attaching the film, the film is housed in the unit body in a light-tight manner. For this reason, the rear cover is integrally formed with a film supporting surface in addition to the wall surface covering the back side of the cartridge chamber and the film roll chamber, and the film pulled out from the film roll chamber by the film supporting surface from the rear surface. It is supported and positioned at the exposure position.

[0004]

However, the film photographed by the conventional film unit with a lens has the following problem.
Sometimes the back surface, especially the back surface of the effective screen area, was scratched. If such a part is scratched, it may have an adverse effect on a printed photograph in an extreme case and may cause deterioration of the quality of the photograph.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a lens-fitted film unit in which scratches are not formed on the back surface of the film.

[0006]

In order to achieve the above object, the present invention is such that, when a film in a rolled state is drawn out to a film supporting surface, the extended part of the film is located on the back side in a cross section orthogonal to the film drawing direction. Focusing on the curling habit of deforming into a convex shape, and because such curling parts rub strongly against the rear cover, scratches are likely to occur, and the film is placed on a part of the rear cover near the film exit of the film roll chamber. 1 to several projections that are linear in a direction orthogonal to the drawing direction of the film and guide portions that support the film from the back side at the edge portions on both sides outside the exposure range of the film are provided. It is provided so as to project in the film direction from the apex of the linear projection.

[0007]

1 is an exploded view of a lens-fitted film unit according to the present invention, a unit main body 2 basically comprises a front cover 3, a main body portion 4, and a rear cover 5. The film winding dial 6,
In addition to the taking lens 7, shutter mechanism 8, etc., a cartridge room 9
And a film roll chamber 10 are provided, and a cartridge 11 and a film roll 12a are housed therein. By attaching the rear cover 5 to the back surface of the main body portion 4, the cartridge chamber 9 and the film roll chamber 10 are in a light-tight state. It should be noted that the illustration of the paper box used as the exterior cover is omitted in FIG.

As shown in the figure, the rear cover 5 is integrally formed with a film supporting surface 16 in addition to the wall surfaces 14 and 15 which cover the back surfaces of the cartridge chamber 9 and the film roll chamber 10, respectively. The film supporting surface 16 supports the film 12 pulled out from the film roll chamber 10 and spread at the exposure position from the back surface, and positions the film 12 at the exposure position. In addition, ribs 17 are provided above and below the wall surface 15, and in cooperation with ribs provided on the inner wall of the film roll chamber 10, the ribs 17 support the upper and lower side edges of the film roll 12a, and the inside of the effective screen of the film. I try not to scratch it.

The wall surface 15 of the rear cover 5 and the film supporting surface 1
6, a part of the rear cover 5 that is close to the film outlet of the film roll chamber 10 extends in a direction orthogonal to the film drawing direction, as shown in detail in the section of the main part of FIG. In addition, three convex ridges 18 are integrally formed. The ridges 18 are the wall surface 15 and the film supporting surface 16.
Is provided in the vicinity of the step 19 between the and, and the cross-sectional shape in the film withdrawing direction is a semicircular shape with a radius of curvature of 2 mm. There is. The radius of curvature is preferably about 1 to 5 mm, the protrusion amount is about 0.1 to 0.5 mm, and the pitch interval is about 1 to 3 mm. Also,
Although the distance from the step 19 to the ridge 18 is 2 mm, it may be changed in the range of about 0 to 5 mm, and the number of the ridge 18 may be about 1 to 5.

In the vicinity of the ridges 18, guide portions 30 for supporting the film extended from the upper and lower ribs 17 of the wall surface 15 are provided at upper and lower positions separated from the film effective screen. The cross-sectional shape of the guide portion 30 in the film withdrawing direction is chamfered and is smoothly processed so as not to damage the film. Further, the height of the guide portion 30 is higher than the apex of the ridge 18 by D in the film surface direction. The value of D is preferably in the range of 0.05 to 0.2 mm.

As shown in FIG. 2 and FIG. 3 showing the AA cross section, the exposure frame 20 formed on the back surface of the main body portion 4 is located substantially opposite to the convex strip 18. Then, the film 12 pulled out from the film roll chamber 10 passes between the film guide rail 20a provided on the exposure frame 20 and the guide portion 30, and then passes between the film guide rail 20a and the ridge 18. The film is sent to the exposure position, and is positioned by the film support surface 16 and the film guide rail 20a at the exposure position.

The operation of the above configuration will be described. Although the film roll 12a is housed in a substantially cylindrical shape in the film roll chamber 10, when the film 12 is pulled out from the film roll chamber 10 and is attempted to be spread on the film supporting surface 16, as shown in FIG. Immediately after being pulled out from the film roll chamber 10, the film 12 exhibits a curl habit of bulging to the back side. This curl tendency is particularly strong at the boundary between the film roll 12a and the spread film 12, and therefore the pressing force dispersed on the ridge 18 is applied. Even with the distributed pressing force, this pressing force is enough to scratch the effective screen of the film.

However, as described above, the guide portion 3 extended from the rib 17 provided on the wall surface of the film roll chamber.
When 0 is formed and the height of the guide portion 30 is set higher than the apex of the ridge 18, the guide portion 30 is higher than the ridge 18, so that the pressing force itself applied to the ridge 18 is further reduced.
Even if the film 12 is pulled out as it is, no large scratches are formed on the back surface of the film 12. Further, since the ridges 18 pull out the film 12 while floating from the film supporting surface 16, dust is not trapped between the film 12 and the film supporting surface 16.

[0014]

As described above, according to the lens-fitted photo film unit of the present invention, a part of the rear cover that approaches the film exit of the film roll chamber has a film that bulges to the back side due to curl habit. Providing a protrusion to receive the back side, at the upper and lower positions outside the film effective screen,
By providing a guide portion that protrudes from the protrusion to the film surface side, the contact pressure between the film and the rear cover is dispersed, so that the back surface of the film does not rub strongly against the rear cover, and It is possible to prevent scratches from entering.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a lens-fitted film unit of the present invention.

FIG. 2 is a partial cross-sectional view showing a main part of the present invention.

3 is a cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

 2 unit body 4 body portion 5 rear cover 10 film roll chamber 12 film 15 wall surface 16 film support surface 17a bridge portion 18 convex strip 30 guide portion

Claims (1)

[Claims] 1. A lens-fitted film unit in which a back surface of a film roll chamber accommodating a roll-shaped film is covered with a rear cover, wherein a part of the rear cover which is close to a film outlet portion of the film roll chamber, A protrusion extending linearly in a direction orthogonal to the drawing direction of the film and guide portions for supporting the edge portions on both sides outside the effective screen area of the film from the back surface are provided, and the guide portion is the apex of the linear protrusion. A film unit with a lens, which is characterized in that it is further projected in the film surface direction.