Phonofilm - DeForest's Use of Case Patents

DeForest's Use of Case Patents

Case's falling out with DeForest was due to DeForest taking full credit for the work of Case and Earl I. Sponable (1895–1977) at the Case Research Lab in Auburn, New York. To record film, DeForest tried using a standard light bulb to expose amplified sound onto film. These bulbs quickly burned out, and, even while functioning, never produced a clear recording. To reproduce his nearly inaudible soundtracks, DeForest used a vacuum tube that could not react quickly enough to the varying light coming to it as the soundtrack passed through the sound gate, causing an incomplete reproduction of sound from an essentially inaudible recording—a dual failure. DeForest's attempts to record and reproduce sound failed at every turn until he used inventions provided by Case.

Having failed to create a workable system of recording sound onto film by 1921, DeForest contacted Case to inquire about using the Case Research Lab's invention of the Thallofide (thallium oxysulfide) Cell, for use in reproducing his recorded sound. Case provided DeForest with that invention from his lab, and later provided DeForest with the AEO Light, another Case Research Lab invention, used for reading the soundtrack of a finished film. Due to DeForest's continuing misuse of these inventions, the Case Research Lab proceeded to build its own camera. That camera was used by Case and Sponable to record President Coolidge on 11 August 1924, which was one of the films shown by DeForest and claimed by him to be the product of "his" inventions.

Seeing that DeForest was more concerned with his own fame and recognition than he was with actually creating a workable system of sound film, and because of DeForest's continuing attempts to downplay the contributions of the Case Research Lab in the creation of Phonofilm, Case severed his ties with DeForest in the fall of 1925. On 23 July 1926, William Fox of Fox Film Corporation bought Case's patents. Sponable and others in the Western Electric/Electrical Research Products Inc. (ERPI) consortium set the projection standard for sound film at 24 frames per second, making it impossible for Phonofilms to be projected on new sound projectors. (See the Fleischer cartoon Finding His Voice (1929) credited to Mr. W. E. Erpi.) The Library of Congress and other film archives have printed new copies of Phonofilms, allowing them to be projected on modern projectors.