Accession Number : ADD002533

Title :   Precision Light Exposure Timing and Shutter Mechanism for a Wide Range of Exposure Durations.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON D C

Personal Author(s) : Borehard,David C ; Chan,Robert E ; Ratzel,Neil F

Report Date : 27 Apr 1976

Pagination or Media Count : 5

Abstract : The patent describes a mechanism which can be used to drive a rotating sector disc type light shutter with a high degree of precision, so as to control light exposures that are made through a stationary aperture. Unlike the prior art, this inventive mechanism can be used to extend the exposure duration range almost indefinitely. In essence, this is accomplished with the inventive mechanism by stopping the motion of the sector disc shutter, with the open portion of the sector disc aligned with the stationary aperture, and then, after a preset elapsed interval, restarting the disc to close the aperture and terminate the exposure. Also unlike the prior art, this inventive mechanism obviates the need for critical timing.

Descriptors :   *Shutters(Optics), *Patents, Timing devices, Light

Subject Categories : Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE