On March 01, 2016 , the USPTO issued U.S. Patent Number 9,274,065 to RAPISCAN SYSTEMS, INC., which was successfully prosecuted by Novel IP.
The '065 patent is directed towards a high speed scanning system for scanning cargo carried by rail. The system uses a two-dimensional X-ray sensor array with, in one embodiment, a cone-beam X-ray geometry. The pulse rate of X-ray source is modulated based on the speed of the moving cargo to allow a distance travelled by the cargo between X-ray pulses to be equal to the width of the detector, for a single energy source, and to half the width of the detector for a dual energy source. This ensures precise timing between the X-ray exposure and the speed of the passing object, and thus accurate scanning of cargo even at high speeds.
Independent Claim 1 describes " An X-ray system for scanning moving cargo, the system comprising: an X-ray source for generating a cone-beam of X-rays to irradiate the moving cargo, wherein the moving cargo travels along a linear trajectory perpendicular to the plane of the cone-beam of X-rays and wherein the X-ray source is a dual energy source configured to generate a high energy beam and a low energy beam; at least one two-dimensional detector array, comprising a plurality of pixels, to receive the cone-beam of X-rays transmitted through the moving cargo, wherein said X-ray source and said at least one detector array are placed on opposite sides of the moving cargo; a sensor to measure a speed of the moving cargo; and a control system for receiving data indicative of said speed from the sensor and modulating a pulse rate of the cone-beam of X-rays based upon the speed of the moving cargo and a dimension of said detector array, wherein the control system modulates the pulse rate such that a distance travelled by the moving cargo between a first X-ray pulse and a second X-ray pulse is substantially equal to a width of the detector array and each of said plurality of pixels in the detector array is irradiated once with the high energy beam and once with the low energy beam and wherein the control system acquires data generated from the first pulse and data generated from the second pulse and processes half of said data from the first pulse in combination with half of said data from the second pulse to form a materials separation image. "