JPH08304966A - Film unit with lens - Google Patents

Abstract

PURPOSE: To constitute a hinge part so that roundness of an angle may be large without lowering strength. CONSTITUTION: The hinge part 41 is constituted of a groove 46 formed on the front side wall surface 44 of a back cover 38, and a groove 47 formed on the back surface side wall surface 45. The grooves 46 and 47 are parallel with each other and the center positions P and Q of the grooves are shifted in a width direction by a distance D. The groove 46 on the front side has a flat base having specified width, and both edge parts are constituted of gentle curved surfaces. By bending the hinge part 41, the groove 46 is deformed to be extended with the center position P as center, and the groove 47 is deformed to be contracted with the center position Q as center. Since the hinge part 41 has two deformation centers, the load applied to the hinge part 41 is dispersed and the roundness γ-R of the angle becomes larger than the hinge part having one deformation center.

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, and more particularly, to a structure of a hinge portion for rotatably connecting a lid member provided on a rear cover of a lens-fitted film unit.

[0002]

2. Description of the Related Art A lens-fitted film unit in which a photographic film is preliminarily loaded in a unit main body having a simple exposure mechanism at a manufacturing stage, for example, "Shakenrun. Such a film unit with a lens is submitted to a DPE dealer as it is after the photographing is completed. At a DPE dealer, the lid member of the cartridge storage chamber of the lens-fitted film unit is opened, and the cartridge is taken out of the lid member for development processing. The lid member of the cartridge storage chamber is formed integrally with the rear cover via a hinge portion which is made thin by bending the material to be thin.

A structure of such a hinge portion is shown in FIG.
As shown in (A), it is common practice to form the groove 12 on the inner wall surface 10a of the hinge portion 10 to reduce the thickness of the hinge portion 10 so that the hinge portion 10 can be easily bent. The roundness αR of the corner 10b formed by bending the hinge portion 10 at a right angle as shown in (B) is, for example, about 0.5R.

However, there is a demand to make the body line of the lens-fitted film unit smoother. Therefore, as shown in FIG. 5A, on the outer wall surface 10c corresponding to the position of the groove 12 of the hinge portion 10,
It was considered that a groove 13 having a wedge-shaped cross-sectional shape with both edges formed into an arc shape was formed. As a result, the corner 10b has a larger roundness βR than the roundness αR, as shown in (B).

[0005]

However, when the wedge-shaped groove 13 as described above is formed in the hinge portion 10, the groove 1 is formed.
3 causes the hinge portion 10 to be easily cracked, which causes a problem that the strength of the hinge portion 10 is extremely reduced.

It is an object of the present invention to provide a lens-fitted film unit in which the hinge portion is configured so that the corners are rounded without reducing the strength of the hinge portion.

[0007]

In order to achieve the above object, the lens-fitted photo film unit of the present invention has two hinge grooves formed in the front and back of the rear cover, the hinge parts being parallel to each other and offset in the width direction. It is composed of.

[0008]

Since the hinge portion is composed of two grooves on the front and back sides of the rear cover that are parallel to each other and are offset in the width direction, the hinge portion has two bending centers, and the corners when the hinge portion is bent are R becomes large. This makes the body line of the lens-fitted film unit smooth.

Of the two grooves forming the hinge portion, the groove formed on the front side of the rear cover has a flat bottom surface with a predetermined width, and both edges are formed by gentle curved surfaces. As a result, the corners when the hinge is bent are gentle.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 2, a lens-fitted photo film unit 20 includes a unit main body 21 having a photographing mechanism incorporated therein.
And an outer case 22 accommodating this.
The outer case 22 includes a winding knob 23 and a strobe light emitting section 2.
4. The outline is such that the shutter button 25 and the like are exposed, and holes for exposing the taking lens 26, the finder 27, the number-of-photographs display plate 28, and the like are provided.

The unit body 21 is, as shown in FIG.
A film roll chamber 31 for storing the photo film 30 wound in a roll and a cartridge storage chamber 33 for storing the cartridge 32 are provided, and a main body base 34 incorporating various photographing mechanisms, and a front surface of the main body base 34. The front cover 35 that covers the side, and the lid members 36 and 37 that cover the bottoms of the film roll chamber 31 and the cartridge storage chamber 33 are hinge parts 4.
1 and 42, and a rear cover 38 that covers the back side of the main body base 34 in a light-tight manner.

Since the hinge portions 41 and 42 have the same structure, only one of the hinge portions 41 will be described below. As shown in FIG. 1A, the hinge portion 41 is composed of grooves 46 and 47 formed on the front and back wall surfaces 44 and 45. Each of the grooves 46 and 47 has a trapezoidal sectional shape as shown in the drawing, and its center positions P and Q are displaced by a distance D in the width direction of the grooves 46 and 47. The cross-sectional shape of the front side wall surface 44 which is continuous with both ends of the groove 46 is formed so as to gently draw an arc. Further, the back side wall surface 45 has a lid member 3
The regulating groove 48 and the regulating projection 49 with the groove 47 sandwiched so that the lid member 36 and the rear cover 38 form a right angle when the 6 is closed.
And are formed.

When the lid member 36 is rotated in the closing direction of the arrow S, the groove 46 is extended and the groove 47 is conversely deformed so as to be contracted, as shown in FIG. The regulating protrusion 49 abuts on the groove 48, and the lid member 36 and the rear cover 38 form a right angle. At this time, the bending center of the one groove 46 is at the center position P, and the bending center of the other groove 47 is at the center position Q, which are offset from each other. Has a gentle roundness γR. In addition, the load of bending is thereby dispersed, and the hinge portion 41 does not break even after several tens of opening and closing operations. Although the original shape of the groove 46 is slightly left on the surface of the hinge portion 41 when the hinge portion 41 is bent,
There is no problem because it is barely noticeable.

[0014]

As described above, according to the lens-fitted photo film unit of the present invention, since the hinge portion is composed of the two grooves parallel to each other and offset in the width direction on the front and back sides of the rear cover,
Since the bending center of the hinge portion is two, the corner radius R can be increased. This makes the body line of the lens-fitted film unit smooth. Further, since the hinge portion has two bending centers, the bending load is dispersed and the durability of the hinge portion is improved. Also,
The groove on the front side of the rear cover has a flat bottom surface with a certain width, and both edges of this groove are configured with gentle curved surfaces, so the curved corner surface when the hinge is bent is a curved surface. This contributes to smoothing the body line of the lens-fitted film unit.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a structure of a hinge portion according to the present invention.

FIG. 2 is an external perspective view of a lens-fitted film unit of the present invention.

FIG. 3 is an exploded perspective view of a unit main body.

FIG. 4 is an explanatory diagram showing a conventional example of a hinge portion.

FIG. 5 is an explanatory diagram showing a conventional example of a hinge portion having a rounded corner.

[Explanation of symbols]

 20 film unit with lens 21 unit body 36, 37 lid member 38 rear cover 41, 42 hinge part 46, 47 groove

Claims (2)

[Claims] 1. A film roll chamber for accommodating a photographic film wound in a roll and a patrone accommodating chamber for accommodating a cartridge, a main body base incorporating an exposure mechanism, a film roll chamber and a cartridge accommodating chamber. In the lens-fitted film unit including a rear cover that covers each bottom portion integrally via a hinge portion, and a rear cover that covers the back side of the main body base in a light-tight manner, the hinge portion is provided on the front and back sides of the rear cover. A film unit with a lens, which is composed of two formed grooves that are parallel to each other and are offset in the width direction. 2. The groove formed on the front side of the rear cover among the two grooves forming the hinge portion has a flat bottom surface having a predetermined width, and both edges have a gentle curved surface. The lens-fitted film unit according to claim 1, which is configured.