Physical Principles, Design and Performance of the Ventarc High-Intensity Projection Lamps

The Ventarc lamps represent a new series of high-intensity carbon arc lamps for motion picture projection recently developed by the author at Zurich, Switzerland. The blown arc of the new lamp produces a distribution of brilliance which is highly advantageous for the illumination of the aperture. By using a new negative electrode the arc can be pushed up to an extremely high brilliance. The precision feed control of the Ventarc insures a perfect homogeneity and invariability of the screen illumination. The visible radiation of the arc is effectively concentrated on the projecture aperture by an entirely new optical system. Heating of the film is minimized by eliminating all invisible radiation. No surplus energy not useful at the screen has to pass through the film.