SCOTT KIRKWOOD GORDON
Pilots at Chieftan Trl, Tucson, AZ

4023036, May 10, 1977

Jun 16, 1975

5/587352

Harrison H. Barrett - Tucson AZ
Scott Gordon - Tucson AZ

University Patents, Inc. - Stamford CT

H01J 3912, G01N 2304

250237R

An apparatus and method for generating a two-dimensional back-projected image of a slice of an object. In accordance with the invention there is provided a carrier means having a plurality of substantially parallel elongated projections thereon, each projection having an optical characteristic (transmissivity or reflectivity) representing the density characteristic of said slice of the object as measured at a particular relative rotational angle. Means are provided for imaging successive sinusoidal patterns on the carrier means, the successive sinusoidal patterns being imaged at a predetermined rate. Photodetector means are responsive to the imaged sinusoidal patterns. Finally, a display or recording means, synchronized at the predetermined rate, is responsive to the output of the photodetector for displaying the back-projected image. In a preferred embodiment of the invention the carrier means is a cylindrical film having projections thereon with transmissivities that represent the density characteristic of the slice of the object under consideration. In this embodiment, means are provided for uniformly illuminating the projections and optical mask means are provided in spaced relation to the cylindrical film and operative to image portions of the projections on the cylindrical film.