Abstract: A main body of a lens-fitted photographic film unit is provided with a film wind-up mechanism, a taking lens and a shutter mechanism. The main body with an unexposed film incorporated is covered by a front cover and a rear cover, which are directly attached to each other by arresting claws in holes formed thereon. The main body is positioned by being held fixedly between the two covers in order to prevent the main body from being damaged when the two covers are removed. In a preferred embodiment, the main body is provided with an electronic flash device, which is operated in synchronism with a shutter blade by use of an X contact. A pair of terminals of metal plates extend toward, and are in contact with, a printed circuit board which is removably supported on the main body by cooperation of supporting members and a supporting plate, both of which are formed outside a light-shielding tube of the main body.

Abstract: An L-shaped rear cover is removably attached to a main body so as to close the rear and bottom sides of the main body. The rear cover is formed with at least one engaging hole or engaging claw engaging with the main body. Near the engaging member, there is a groove for providing a thin wall portion in the rear cover. When detaching the rear cover from the main body for film reloading, the rear cover is deformed or broken along the groove. After the main body is loaded with a new film, a new rear cover is attached to the main body thereby to produce a new film package with a reused main body. In order to reuse the rear cover, the rear cover has an L-shaped engaging claw engaging with an engaging hole in the main body, the L-shaped engaging claw being deformable within that engaging hole.

Abstract: An L-shaped rear cover is removably attached to a main body so as to close the rear and bottom sides of the main body. The rear cover is formed with at least one engaging hole or engaging claw engaging with the main body. Near the engaging member, there is a groove for providing a thin wall portion in the rear cover. When detaching the rear cover from the main body for film reloading, the rear cover is deformed or broken along the groove. After the main body is loaded with a new film, a new rear cover is attached to the main body thereby to produce a new film package with a reused main body. In order to reuse the rear cover, the rear cover has an L-shaped engaging claw engaging with an engaging hole in the main body, the L-shaped engaging claw being deformable within that engaging hole.

Abstract: A defrosting system for a heat exchanger includes a temperature detector arranged adjacent to the exchanger, a temperature memory for storing temperature data detected by the detector, and a central processing unit, wherein when a second temperature which is detected by the temperature detector after normal operation requested by a user has restarted and after a predetermined minimum defrosting prohibitive time has passed, drops by a predetermined difference in temperature from a first temperature which is detected by the temperature detector after the normal operation has restarted and after a predetermined defrosting prohibitive time has passed, and the second temperature is a predetermined temperature or below; the central processing unit carries out the defrosting operation.