Mabel Frederick, US1449663A
Projection apparatus.
Image credit: Frederick, M. (1920)
On March 27, 1923, Mabel Frederick, of Pueblo, Colorado, was awarded a patent for developing a projector that could permit an image to be projected in a stable position for a considerable amount of time and automatically move to the next animation without the aid of an operator.
Date of Application: 28 October 1920
Date of Issuance: 27 March 1923
For more information, please refer to the following webpage:
Francesca Chiaradia
PhD Student in Economics
My research interests include law and economics, economics of innovation, and information economics.