![]() | Fig. 3 of US Patent No. 2,883,902, "Prompting Apparatus." [3] |
US President Barack Obama using a teleprompter during a speech (Fixing No Child Left Behind, March 14, 2011). (Still image from a White House video, modified).
Why would the author of a blog that publishes articles about graphene, thermodynamics and quantum mechanics be interested in something as mundane as the teleprompter? The partially-silvered mirror is one of the most useful optical components. I worked on a team that developed a unique sensor that fired a light beam into free space and looked at the scattered light from the same direction. The optical circuit was exactly the same as the teleprompter, with a light-emitting diode replacing the projector, and a phototransistor replacing the camera. What's past is prologue.