Abstract: A folding slide viewer has a rear projection screen which swings into a ft position for storage. In a second, operating position, the projection screen it is provided with a lightproof bellows. The optical axis of the lens system is inclined at an angle with respect to the horizontal base of the housing. A reflector is along the optical axis of the lens system, when the screen is in its operating position, to reflect an image onto the screen. An image trap is swingable between a first position perpendicular to a longitudinal axis of the slide magazine and a second position perpendicular to the optical axis of the lens system.

Abstract: A mounting for a supply reel and a take-up reel in a camera, projector or other recording or reproducing apparatus comprises two coaxially juxtaposed mandrels of substantially the same diameter cantilevered for independent rotation on a common support. The outer mandrel carries one or more radially retractable detents whose withdrawal from a projecting position enables the take-up reel to be fitted onto the inner mandrel and which thereafter form a stop for the supply reel, thereby preventing the two reels from contacting each other. The withdrawal of the detents, or the removal of an abutment blocking such withdrawal, may be carried out as a separate operation; alternatively, withdrawal may be blocked automatically upon the emplacement of a reel on the inner mandrel.