1. Field of the Invention
The present invention relates to a film patrone (i.e. a film cartridge), and more particularly to a film patrone of the type in which a photographic film 35 mm wide contained in the form of a roll therein is delivered by rotation of a spool.
2. Related Art Statement
Various proposals have conventionally been made for a film delivery mechanism of a film patrone in which the leading end of a photographic film is contained.
An example of such proposals is the film delivery mechanism disclosed in Japanese Patent Laid-Open No. 3-180838 in which a photographic film is wound in a roll about a spool, the spool being rotatably contained in the patrone body, the photographic film is delivered to the outside of the patrone body by rotating the spool, and elastic flanges are integrally formed at both ends of the spool, the distance between the flanges being greater than the width of the film on the inner peripheral side and slightly smaller than the width of the film on the outer peripheral side. When the film is wound around the spool until it substantially reaches the outer peripheries of the flanges, the film on the outer peripheral side is elastically held in the narrow portion between the outer peripheries of the flanges. The film is delivered from the patrone body by rotating the spool in the delivery direction.
Japanese Patent Laid-Open No. 4-143749 discloses a film patrone provided with a film delivery mechanism in which a film patrone rotatably containing the film wound around a spool in the patrone body comprises a pair of flanges provided on the spool so as to prevent a slack of the film wound around the spool, and at least one of the flanges is rotated with the spool and can be inclined with respect to the spool to partially form a gap wider than the width of the film between the two flanges. Since one of the flanges is inclined with respect to the spool so that the distance between both flanges is greater than the width of the film on the film entrance side and smaller than the width of the film on the side opposite to the entrance side, the film is held in the narrow portion between the flanges, and the leading end of the film is delivered from the film entrance to the outside of the patrone body by rotating the spool.
However, since the film-delivery mechanism disclosed in Japanese Patent Laid-Open No. 3-180838 comprises the flanges having outer peripheries which are maintained at a distance smaller than the width of the film, there are the problems that, particularly, when the photographic film is rewound in the film patrone, the flanges cause resistance, and difficulties in rewinding due to the overload on the film, and that the film is sometimes wound around the outer peripheries of the flanges and cannot be exactly wound around the spool.
In the film-delivery mechanism disclosed in Japanese Patent Laid-Open No. 4-143749, since both edges of the film contact the inner surfaces of the flanges in the narrow portion between both flanges, there is the problem that, particularly, when the photographic film is rewound, the flanges cause strong resistance and thus difficulties in precise rewinding due to the overload on the film.