The American credited with the invention of teleprompter Hubert Schlafly has died at the age of 91. Hubert Schlafly Jr died last week in the US state of Connecticut after a brief illness. Schlafly was working at 20th Century Fox film studios in 1950 when he developed the teleprompter. He was asked by the company to build a device that will help actors remember their lines. The teleprompter feeds scripts to actors, politicians and newsreaders.