Abstract: A large number of characters are formed on a sheet such as microfiche. The characters are further divided into classes such as a class of Roman alphabet characters, a class of Japanese hiragana characters, a class of Japanese katakana characters and a plurality of classes of Chinese characters arranged phonetically according to their leading syllables. Each class contains a predetermined number of characters. The characters are arranged in an alternating arrangement on the microfiche which is movable relative to a mask formed with apertures in such a manner that at each position of the microfiche all of the characters of a corresponding class are displayed through the respective apertures of the mask. Class selection means comprising one or more switches control drive means to move the microfiche so that the desired class of characters is displayed.

Abstract: An electrophotographic process and a system for preparing microfilm is provided in which use is made of a roll film including a photosensitive layer a thin film of organic photoconductive material on a film of polyester. A portion of the film is taken out of the roll and is conveyed to and stationarily held in a processing position where the film plane is vertical. A movable unit including a charger, an exposure window and a vessel of developing solution is moved parallel to the photosensitive surface which is thus held in place, in a direction which traverses the optical axis of a taking lens as well as in a direction parallel to the optical axis of the lens to effect an electrophotographic processing of the photosensitive surface while mainintaing the film plane vertical.