Photographic slide audio visual device - two hemispherical canopies protect screen from exterior rays

摘要

Audio-visual device of the type used for projecting slides on a screen with or without sound accompaniment, has a frame consisting of two hemispherical canopies, hinged to each other along a horizontal diameter and whose respective dimensions are complementary. One of the canopies forming the fixed lower part of the housing, the other forming the cover, can because of the hinge, pivot from a closed position frame in form of sphere, to open position in which the interior screen is visible from the outside. On the hinged axis are means of locking the cover in any intermediate angular position between its open and closed position.