JPH09127653A - Film unit equipped with lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of scratches due to foreign matter and pressure fogging and to facilitate working a metallic die by forming plural recessed parts on at least a part with which the photographic picture on a film comes in contact, on a pressure plate surface. SOLUTION: Plural recessed parts are formed on the pressure plate surface 4a. That is, by forming plural recessed parts on the pressure plate surface 4a with which the film F comes into contact, the foreign matter gets into the recessed parts in accordance with film feeding even in the case the foreign matter such as dust enters, and an abutting distance with the film F extremely becomes shorter, so that the film F is prevented from being successively scratched. And also, the part coming into contact with the film F is always formed on a prescribed surface of the pressure plate 4a, so that the uniform surface is obtained, different from the case where the projection part is formed so that it may come into contact with the film F in the conventional technology. Besides, it is allowed to have various kinds of pattern for plural recessed parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for preventing a film from being scratched in a film unit with a lens.

[0002]

2. Description of the Related Art A film unit with a lens holds a film at a predetermined position in the optical axis direction by a rail surface of a main body and a pressure plate surface of a rear cover at the time of shooting, and connects a light beam from a shooting lens to the film with an appropriate focus. It is configured to image.

If the pressure plate surface of the cover is thereafter formed to be a smooth surface, foreign matter such as dust may enter between the rail surface and the pressure plate surface, or the film surface may be scratched by minute protrusions on the pressure plate surface. Occurs. Therefore, as shown in FIG. 1, a plurality of ribs or a plurality of small protrusions are provided on the pressure plate surface in the film feeding direction.

[0004]

However, when a plurality of ribs are provided on the pressure plate surface in the film feeding direction, the invading dust first adheres to the side surface of the rib and eventually moves to the apex of the rib. May cause scratches on the film. Also, if the contact area between the rib and film is reduced,
Although such a problem is reduced, there is a problem that the contact pressure on the film is increased and the pressure fogging is likely to occur on the film.

On the other hand, when a plurality of protrusions are provided on the surface of the pressure plate, the contact pressure on the film also increases, and there is a problem that pressure fogging easily occurs on the film.

Further, since these ribs and protrusions contact the film, it is necessary to make the surface roughness extremely fine.
Therefore, it is necessary to polish portions corresponding to the ribs and the protrusions of the die, which is extremely troublesome to process.

In view of the above problems, the present invention provides a lens-fitted film unit having a pressure plate surface which does not cause scratches even when foreign matter such as dust enters and does not cause pressure fog and is easy to process a die. It is a proposal.

[0008]

According to the present invention, there is provided a lens-equipped film unit for holding a film at a predetermined position in the optical axis direction by a rail surface of a main body and a pressure plate surface of a rear cover in the present invention. The lens-equipped film unit is characterized in that a plurality of concave portions are provided at least in a portion of the film where the photographing screen abuts.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail with reference to FIGS.

First, the lens-fitted film unit used in the present invention will be described with reference to FIGS. 2 is an exploded perspective view of the film unit with lens, FIG. 3 is a cross-sectional view of the film unit with lens, and FIG. 4 is a vertical cross-sectional view of the film unit with lens.

The lens-equipped film unit 1 is a simple camera unit that is put on the market with an unexposed film loaded, and the film is loaded in the assembly process.
The user does not need to load or rewind the film.

The lens-fitted film unit 1 includes a main body 2
In addition, the front cover 3 and the rear cover 4 are assembled from the front and back. A shooting frame 5 is provided in the center of the main body 2, a cartridge chamber 6 is provided on one of the left and right sides of the shooting frame 5, and a scroll chamber 7 is provided on the other side. A patrone 8 is accommodated in the patrone chamber 6 and a scroll chamber 7
The film F is wound on the spool 9 in advance.

The hoisting mechanism 10 is composed of a hoisting knob 11 and the like, is arranged from above the cartridge chamber 6 to above the photographing frame 5, and a photographing lens 12 is provided in front of the photographing frame 5. A finder 13 is arranged above the photographing frame 5.

The strobe unit 14 is assembled from the front of the main body 2, and the power supply battery 15 is assembled from below.

When the film F is wound up in the lens-fitted film unit 1 thus constructed,
When the winding knob 11 shown in FIG. 2 is rotated counterclockwise, the film F is fed by the winding mechanism 10 from the scroll chamber 7 to the cartridge 8 in the cartridge chamber 6 by the length of one frame. At this time, the film F passes through a so-called tunnel, which is a gap between the rail surface 2a provided in the center of the main body 2 and the pressure plate surface 4a provided on the rear cover 4, and after the film is wound up, the focusing by the taking lens 12 is performed in this tunnel. Is guaranteed.

Here, with respect to the pressure plate surface of the rear cover, conventionally, a problem was caused by providing a plurality of ribs or convex portions as described above. Next, the pressure plate surface of the present invention will be described.

The gist of the present invention is to provide a plurality of recesses in the pressure plate surface 4a, as shown in FIGS.
By providing a plurality of recesses on the pressure plate surface 4a that comes into contact with the film F, even if foreign matter such as dust enters, the distance that the foreign matter will enter the recesses as the film F is fed and will come into contact with the film F Is extremely short, so that the film F is not continuously scratched. In addition, since the portion of the pressure plate surface 4a that comes into contact with the film F can always be formed into a predetermined surface, a uniform surface can be obtained, unlike the case where a protrusion is provided and brought into contact with the film F as in the prior art.

Various patterns can be considered for such a plurality of recesses, and representative examples thereof are shown in FIGS.

5 to 7 are views of the rear cover 4 viewed from the inner surface, in which a plurality of recesses are provided only on the pressure plate surface 4a. FIG.
The round portions are holes as concave portions, FIG. 6 is the mesh-shaped solid line portions, and FIG. 7 is the irregularly arranged grain pattern, and the solid line portions are the concave portions.

Further, in FIG. 3, when the film F is wound around the scroll chamber 7 in the process, it has the maximum winding diameter, and the spool 9 can freely rotate if the winding shaft of the winding machine is removed. , There is a possibility that it will be a bull roll. Also, when the spool 9 is not used, it is similarly wound into a bull. Therefore, the rear cover 4 facing the scroll chamber 7
It may also come into contact with the scroll portion 4b. Therefore, it is more preferable to provide the scroll portion 4b with a plurality of recesses. 8 to 10 are views in which the same concave portions as those in FIGS. 5 to 7 are provided in the scroll portion 4b.

In the above-mentioned pattern of each recess,
The area occupied by the recesses is preferably 10 to 40%, particularly 15
-30% is desirable. The depth of the groove is preferably 0.1 mm or more.

In addition, in FIG. 5 to FIG. 10, a plurality of recesses are provided on all of the pressure plate surface 4a.
The problem with the scratches on the inside of the shooting screen is. Therefore, at least, a plurality of concave portions may be provided only in the portion of the vertical dimension L corresponding to the photographing screen of the pressure plate surface 4a shown in FIG. However, since a portion of the film F outside the photographing screen passes through the tunnel between the rail surface 2a and the pressure plate surface 4a, the friction at the time of feeding the film F is reduced, and even outside the screen, for example. From the point that scratches are not desirable as a product, the pressure plate surface 4a
In addition to the vertical dimension L, it is desirable to provide a plurality of recesses.

When a plurality of protrusions are provided on the pressure plate surface 4a and a plurality of small protrusions are provided outside the photographing screen as in the conventional case, the perforation of the film F may be caught by the protrusions. Therefore, since it is not possible to provide a plurality of small protrusions, it is not possible to reduce the friction during the feeding of the film F.

Further, if necessary, a plurality of recesses may be provided in all the portions such as the inner wall of the scroll chamber 7 in the main body 2 where the film F may come into contact.

Further, the processing of forming a plurality of recesses on the pressure plate surface 4a or the like involves processing of a convex shape on the molding die, but etching processing can be more easily processed than cutting processing, and moreover, it can be processed in the height direction. Can be formed to have a uniform size, and the surface roughness can be easily made very fine.

[0026]

According to the film unit with lens of the first aspect, even if foreign matter such as dust enters, it does not enter into the recess and contact the film, so that the film is scratched. Never. Further, since the portion of the pressure plate surface that comes into contact with the film can always be formed into a predetermined surface, a uniform surface can be obtained, unlike the case where the projection is provided and brought into contact with the film F as in the prior art.

According to the film unit with lens of the second aspect, by providing a plurality of recesses also on the pressure plate surface in the tunnel, it is possible to reduce the friction at the time of feeding the film and reduce the rotating torque of the winding knob. it can.

According to the lens-equipped film unit of the third aspect, even if the film in the scroll chamber is wound in a roll, the rear cover does not scratch the film during feeding.

[Brief description of the drawings]

FIG. 1 is a diagram in which a plurality of ribs are provided on a pressure plate surface in a film feeding direction.

FIG. 2 is an exploded perspective view of a film unit with a lens.

FIG. 3 is a cross-sectional view of a film unit with a lens.

FIG. 4 is a vertical cross-sectional view of a film unit with a lens.

FIG. 5 is a view of the rear cover as viewed from the inside, in which a plurality of recesses are provided only on the pressure plate surface.

FIG. 6 is a view of the rear cover as viewed from the inner surface in which a plurality of recesses are provided only on the pressure plate surface.

FIG. 7 is a diagram of the rear cover as viewed from the inner surface in which a plurality of recesses are provided only on the pressure plate surface.

FIG. 8 is a view of the rear cover, which is provided with a plurality of recesses on the pressure plate surface and the scroll portion, as viewed from the inside.

FIG. 9 is a view of the rear cover, which is provided with a plurality of recesses on the pressure plate surface and the scroll portion, as viewed from the inside.

FIG. 10 is a view of the rear cover provided with a plurality of recesses on the pressure plate surface and the scroll portion as viewed from the inside.

[Explanation of symbols]

 F film 1 film unit with lens 2 main body 2a rail surface 3 front cover 4 rear cover 4a pressure plate surface 4b scroll part 6 patrone chamber 7 scroll chamber

Claims (3)

[Claims] 1. A lens-equipped film unit for holding a film at a predetermined position in the optical axis direction by a rail surface of a main body and a pressure plate surface of a rear cover at the time of photographing, in a portion of the pressure plate surface where at least a photographing screen on the film abuts. A film unit with a lens, characterized in that a plurality of recesses are provided in the. 2. The film unit with a lens according to claim 1, wherein a plurality of recesses are provided in the entire area of the pressure plate surface. 3. The scroll section of the back cover, which faces the scroll chamber of the main body in which the unexposed film is wound up in advance, is provided with a plurality of recesses. Film unit with lens.