Ted Case and Lee de Forest’s relationship began as one between colleagues, but as Case became essential to Phonofilm’s existence, de Forest erased Case and the Research Laboratory’s contributions to the system. While Case and de Forest still worked together, a very clear dynamic of frustration was created between the two until their final break in 1925. Have a quick refresher of the two men’s viewpoints below.
Case vs. de Forest, Part I
Case vs. de Forest, Part I
Case vs. de Forest, Part I
Case vs. de Forest, Part I
Case vs. de Forest, Part I
Case vs. de Forest, Part I
The defining feature of the race to bring sound film to the world was the sheer chaos of competing patents and the inflated egos of the personalities involved.
Ted Case

By the early 1920s, Case had already established himself on the national scientific front through his work during World War I and the development of the Thalofide Cell. It was this cell that caught Lee de Forest’s attention in the first place, and its sensitivity to infrared light made it a much more effective tool for imprinting sound onto a film strip. Case, Earl Sponable, and his fellows in the Case Research Laboratory were methodical in their approach to sound film, constantly suggesting improvements to de Forest’s Phonofilm system. De Forest’s immovability and insistence on treating the Laboratory as a subsidiary rather than an equal partner would finally lead Case to break ties and open up the legal battles that would determine their relationship for the remainder of Case’s time in the film industry.
Lee de Forest

De Forest’s loose patents on a gas discharge apparatus and his suggestions for customizing the Thalofide Cell led him to believe early on that the AEO Light and later developments of the Case Research Laboratory were due to his own efforts. De Forest was impatient, and more interested in courting financing and press attention than creating a more effective sound film apparatus. This distinct disinterest in the scientific process became a primary breaking point between de Forest and Case, but while Case was essential to the engineering process and behind the scenes work such as financing and building business relationships, de Forest was more beloved by the press due to his confident assertions and ability to simply describe his technology (which he often did not understand himself based on observations from Case Research Lab workers). De Forest’s pride would prove to be his downfall in later legal battles, but it remains a defining feature in his biography and the decades of assertion that he was the sole father of sound on film technology.
Now it’s time to test out your Case and de Forest knowledge! If you get all ten questions right in the quiz below, you have earned bragging rights and are welcome to share your expertise with your tour guide when you visit the Case Research Laboratory
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Crediting for Images on this Page
Header: De Forest Phonofilm Co. Inc. in White House grounds. , 1924. Photograph. https://www.loc.gov/item/2016838214/
Image: Phonofilm still, Egyptian Dancer, 1923
Image: Theodore Case c. 1920
Image: Bain News Service, Publisher. Lee De Forest. , ca. 1920. [Between and Ca. 1925] Photograph. https://www.loc.gov/item/2014715931/.
Image: Case resting at Auburn Exposition of Progress, c. 1925