| 摘要 |
<p>The invention relates to an X-ray inspection system for security screening applications of the type which are employed at aircraft terminals to determine if dangerous items are being carried in passenger luggage. The system in accordance with the invention includes a detector station having a linear array of phototransistors, covered with a fluorescent screen, disposed on one side of the conveyor belt which carries the luggage past the detector station. On the other side of the belt, and disposed in parallel arrangement with the array, is an X-ray head, and objects passing between the array and the source will alter the density of the rays emitted by the source so that an X-ray picture can be obtained, as well known in the art. The inventive system uses such an array to eliminate the requirement for optical systems of present screening apparatus. The disclosure also teaches a mode for operating the array which eliminates difficulties due to wide ranging differences in the characteristics of the individual phototransistors, and it also teaches a mode of operating each of the phototransistors to increase the outputs thereof.</p> |
