Zarley, McKee, Thomte, Voorhees & Sease
Frustrated total internal reflection camera shutter
 An improved camera shutter system which employs the principles of frustrated total internal reflection as a means for controlling transmission of light to a camera film. The shutter is comprised of at least two prism elements, one facing the other and one movable with respect to the other, to allow a common adjoining surface to move from a closed position to an open position wherein the surfaces have a space or gap therebetween. When the surfaces are open having a space or gap in between, the gap is at least just slightly larger than a wave length of light, with the result being that light is reflected rather than transmitted from one prism to the other. When the gap is closed, light is transmitted directly through one prism into the other and from there to a film positioned behind the second prism. 
Iowa State University Research Foundation, Inc.
G G
G03B G03B
inventional inventional
Malvern K. John R.
Iles Hull