Motion-Picture Film Printer

a device for printing the picture and sound track on motion-picture film.

According to the printing method, a distinction is made between contact printers, in which the films are pressed tightly together during exposure, and optical printers, in which the image to be copied is projected through an optical system onto the light-sensitive layer of the film. The optical printers, in addition to printing on a 1:1 scale, also make it possible to convert the image from one format to another—for example, from 35-mm to 16- and 8-mm and from 16-mm to 35-mm—and to make combined images, printing titles in the frame. The image may be printed intermittently, at the moment when the films are in a strictly fixed position in the aperture, or continuously, during the process of moving the films past a slot through which they are illuminated. The sound track is always printed while the film is in continuous motion. The number of possible exposures in most printers is 20.

The exposure may be used in various combinations. With intermittent movement the exposures are changed when the light flux is blocked by the shutter; in continuous-motion printing, on the area of a single frame. In the printing process the exposure is regulated mechanically, by mounting diaphragms, gray light filters, on other devices in the path of the light flux that illuminates the aperture or slot, or electrically, by changing the filament incandescence of the printing lamp. Many printers are equipped with shutoff devices for stopping the printer at the end of the picture being copied, breakage of the film, or overheating of the printing lamp, as well as a dust catcher, footage counters, and other auxiliary equipment.

Printers are among the precision equipment of the film studios and printing plants, and they are regularly inspected for frame steadiness, image sharpness, and absence of film damage. The printers differ greatly in productivity, ranging from two frames per second to several thousand meters per hour.