Detection arrangements for X-ray security systems

摘要

The present invention provides an improvement to a digital system for reading out image information of items passing on a conveyor belt through an X-ray fan-beam. The improvement involves an oscillating screen or mask moving between the items and detector elements with the mask having openings in registration with at most one half of each of several detector elements. The mask oscillates over the detector elements to expose alternate portions of the radiation detecting surface of each of the detector elements to the incident X-rays.