Photography – Underwater – waterproof – or water-resistant camera
Reexamination Certificate
2000-12-28
2002-04-23
Gray, David M. (Department: 2851)
Photography
Underwater, waterproof, or water-resistant camera
C396S029000, C396S543000
Reexamination Certificate
active
06377751
ABSTRACT:
FIELD OF THE ART
The present invention relates to a waterproof lens-fitted photo film unit that contains a body of the lens-fitted photo film unit in a watertight waterproof case to permit photographing in the water, and relates also to an assembling method therefor. More specifically, the present invention relates to a waterproof lens-fitted photo film unit that is superior in waterproof properties and handing properties, saves manufacturing cost, prevents mishandling thereof and prevents defective joints in the waterproof case, and also relates to an assembling method therefor.
BACKGROUND ARTS
Lens-fitted photo film units, which are preloaded with a photo filmstrip and provided with simple photographic mechanisms, are widely used in the world because of its handiness. There are a variety of lens-fitted photo film units for use in different photographic purposes and applications. For example, there are a flash type that allows photography even in the night, and a non-flash type which is simplified by minimizing functions to essential ones. There is also a waterproof lens-fitted photo film unit that permits photography in the water as a body of the lens-fitted photo film unit, hereinafter referred to as the film unit body, is contained in a waterproof case that has a watertight structure.
Of the waterproof lens-fitted photo film unit, operation members are provided on the waterproof case, such that actuation members may be operated from outside the waterproof case, wherein the actuation members are provided in the film unit body for actuating a flash device, a shutter mechanism or the like. These operation members of the waterproof type are made comparatively larger than actuation members, such as a shutter button, of other types of lens-fitted photo film units, or they are protruded from external surfaces of the waterproof case, so that the operation members may be operated without fail even in the water or when the photographer wares thick gloves.
An example of these operation members is an operation button made of rubber, as disclosed in Japanese Patent Application No. 9-347754. This operation button is attached to the waterproof case by force-fitting a portion of the button into a hole that is formed in the waterproof case, from outside the waterproof case, and can be pressed for operation because of its resiliency. In this way, waterproof property is obtained. Because being supported by the external surface of the waterproof case, this operation button is proof against the pressing operation from outside to inside, pressures from water and the like.
As the operation button is formed as an integral part from rubber, it is superior in water-tightness, and also reduces the number of parts and the cost for manufacturing and assembling the waterproof case. However, since the operation button is mounted from the outside, it is easy to remove, so the case is likely to loose its water-tightness. Where the operation button is protruded outward from the waterproof case, it can be pressed unexpectedly while the lens-fitted photo film unit is carried in a bag, or in other situations like that.
The lens-fitted photo film unit contains a photo film cartridge with its unexposed photo filmstrip previously pulled out from a cartridge shell and coiled into a roll. A winding knob that is coupled to a spool of the cartridge shell is rotated after each exposure, to wind up the photo filmstrip by each exposed frame into the cartridge shell. A shutter mechanism is designed to be charged in cooperation with the winding knob being rotated for winding up one frame. For this purpose, the film unit body is provided with a stop-winding mechanism for locking the winding knob from rotating when one frame of the photo filmstrip has been wound up into the cartridge shell. The stop-winding mechanism cooperates with the movement of the photo filmstrip, and includes a stop lever. The stop lever is brought into engagement with teeth that are formed around an external periphery of the winding knob when the winding knob is rotated in a winding direction by an amount corresponding to one frame. Besides, an anti-reverse claw is provided on the film unit body. The anti-reverse claw is engaged with the teeth around the winding knob, for preventing the winding knob from being rotated in reverse to the winding direction.
In the waterproof lens-fitted photo film unit, a winding dial is provided on the waterproof case, and is engaged with the winding knob of the film unit body. The winding dial is made larger in diameter than the winding knob, thereby to obtain a larger rotational torque, and thus improve handling properties thereof, as it is operated in the water or with gloved hands. For this reason, the anti-reverse claw provided for the winding knob is too weak to securely prevent reverse rotation of the winding dial.
Japanese Laid-open Patent Application No. 5-248448 discloses a teaching to provide a torque limiter between the winding knob of the film unit body and the winding dial on the waterproof case, such that the torque limiter does not transmit rotational force from the winding dial to the winding knob if the winding dial is rotated while a load is applied to the winding knob or while the winding knob is locked. Because of this torque limiter, if the winding dial is rotated in the winding direction or in the reverse direction while the winding knob is locked, the winding dial idles, and the winding knob does not rotate.
However, because the torque limiter as above allows the winding dial to rotate endlessly, if the user does not know much about this type of waterproof lens-fitted photo film unit, the user might not notice that the winding knob is being rotated reversely, and could not take photographs.
The film unit body is generally constituted of a body base portion in which the photo filmstrip is loaded and the photographic mechanisms, including the shutter mechanism, are incorporated, and front and rear covers that covers front and rear sides of the body basic portion. These parts are modified according to the type of the lens-fitted photo film unit. For instance, the body base portion for the flash type is provided with a mounting portion for a flash unit that is constituted of a capacitor, a battery, a circuit board and so forth. The front cover for the flash type is provided with a flash opening for exposing a flash projector. On the other hand, in the non-flash type, the flash unit mounting portion and the opening for the flash projector are not provided, thereby to eliminate useless spaces and useless parts.
In order to use specific parts for the respective types of lens-fitted photo film unit, metal molds are needed for forming the specific parts of the respective types. This has been one of causes of raising manufacturing cost of the lens-fitted photo film unit. As for the waterproof lens-fitted photo film unit, not only the film unit body but also the waterproof case need to be modified depending upon whether it is with flash or without flash, so the increase in the manufacturing cost is more remarkable.
When assembling the waterproof lens-fitted photo film unit, it is conventional to mount the operation members to the waterproof case water-tightly before inserting the film unit body in the waterproof case and joining a pair of members that constitute the waterproof case to each other in a watertight fashion.
However, when the pair of case members are water-tightly joined to each other after the operation members are mounted water-tightly, air cannot get out of the waterproof case, and is confined in the waterproof case in a compressed condition, so the air pressure inside the waterproof case gets higher. As a result, a load is applied to joints between the case members, and sometimes breaks or loosens the joints, so the case looses its water-tightness. For the same reason, defective products with incompletely joined case members are likely to be manufactured.
The present invention is made to solve the above problems, and has an object to provide a waterproof camera or a waterproof lens-fitted
Fuji Photo Film Co. , Ltd.
Gray David M.
Young & Thompson
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