1. Field of the Invention
The present invention relates to a waterproof type photographing apparatus like a waterproof lens-fitted photo film unit, and a package for containing lens-fitted photo film unit in an airtight manner.
2. Background Arts
A lens-fitted photo film unit has a simple photographing mechanism and is pre-loaded with a film cartridge with an unexposed photo film. Owing to convenience and low price, the lens-fitted photo film unit, hereinafter referred to simply as the film unit, is widely used as a kind of simple cameras. There are various types of the film units adapted to purposes and situations in photography. For example, for the purpose of underwater photography, kinds of waterproof type lens-fitted photo film unit are sold. The water proof type lens-fitted photo film unit, hereinafter referred to simply as the waterproof film unit, is constituted by a film unit and a waterproof housing for containing the film unit in a watertight manner. The photographing mechanism is operable externally by use of a winding wheel and a shutter lever disposed through the waterproof housing.
A waterproof photographing apparatus, such as a waterproof camera with photo film or a waterproof electronic still camera, is also provided. Such apparatus is constructed for its purpose, for example, an underwater photography or a water washing. Besides, an exclusive waterproof housing for a photographing apparatus is well known. This waterproof housing makes it possible to carry out underwater photography by operating the apparatus externally.
The above mentioned photographing apparatus has a dry battery as a power supplying source. For example, the film unit has a dry battery in the flash device. Some dry battery discharges hydrogen gas gradually by using the film unit. Furthermore, the flash device has a capacitor that discharges hydrogen gas according to deterioration with time thereof.
Hydrogen gas generated in this way is accumulated in the waterproof housing of the photographing apparatus. In a photographing apparatus having a photo film, characteristics of the photo film may be deteriorated because of the reaction with hydrogen gas, which reacts as reducing gas. In a photographing apparatus without a photo film, such problem is not occurred. When an amount of hydrogen gas accumulated in the waterproof housing is increased, however, the apparatus may have a fire because of sparks generated at a contact in an electronic circuit.
In order to prevent the photo film from being deteriorated by humidity, the film unit is contained in a humidity-proof packaging bag in an airtight manner. If the film unit has a dry battery for a flash device or the like, the dry battery generates hydrogen gas which is accumulated in the packaging bag. Therefore, such hydrogen gas may cause a bad influence on the photo film.
In view of the foregoing, an object of the present invention is to provide a waterproof type photographing apparatus and a packaging bag for containing a film unit capable of removing hydrogen gas effectively so as not to accumulate hydrogen gas, which causes ignition of the apparatus or deterioration of the film.
To achieve the above objects, the waterproof type photographing apparatus of the present invention has a catalyst for accelerating a chemical reaction between hydrogen gas and oxygen gas. Hydrogen gas is generated from a dry battery loaded in the photographing apparatus, and oxygen gas is contained in a waterproof housing for keeping the photographing apparatus in a watertight manner.
The catalyst itself is not changed at all by the chemical reaction, and quite a small amount is needed for removing hydrogen gas. Accordingly, the catalyst is more effective for removing hydrogen gas than a hydrogen gas absorbent. Water is produced by this chemical reaction. Although an amount of water is small, it is preferable to provide a water absorbent (a desiccant) in order to prevent a photo film and a contact in an electronic circuit from being influenced by the water.
In the preferable embodiment of the present invention, a film unit is covered with a waterproof housing in a watertight manner. Although the film unit has a flash device with a dry battery, hydrogen gas is removed by a catalyst provided in the housing. Since hydrogen gas is accumulated upward, it is more preferable to dispose the catalyst on an upper wall of the housing.
Moreover, the present invention is also applicable to a packaging bag for containing a film unit with a flash device. In order to remove hydrogen gas, a catalyst is contained in the packaging bag. Since the packaging bag is humidity-proof, a wrapping label and a spacer sheet are sufficiently dried to be water-absorptive in order to absorb water generated by the chemical reaction. More preferably, a water absorbent may be contained in the packaging bag.