IMAGING APPARATUS AND METHOD

摘要

Apparatus for inspecting an article comprising: a controller configured to generate a drive signal having a periodic amplitude variation; a source, the source being operable by the controller to emit a source beam thereby to irradiate an article, the source beam comprising a beam of electromagnetic radiation having a periodic amplitude variation corresponding to that of the drive signal; and a detector, the detector being configured to detect a portion of the source beam that has been transmitted through at least a portion of the article, and to generate a detector signal having an amplitude variation corresponding to the amplitude variation of said portion of the source beam, the controller being further configured to generate a difference value corresponding to a difference between the amplitude of the detector signal and the amplitude of a reference signal.

主权项

1. Apparatus for imaging an object concealed in an article comprising:
a controller configured to generate a drive signal having a periodic amplitude variation; a source, the source being operable by the controller to emit a source beam thereby to irradiate an article, the source beam comprising a beam of non-ionising electromagnetic radiation having a periodic amplitude variation corresponding to that of the drive signal; and a detector, the detector being configured to detect a portion of the source beam that has been transmitted through at least a portion of the article, and to generate a detector signal having an amplitude variation corresponding to the periodic amplitude variation of said portion of the source beam, the controller being further configured to perform an autocorrelation or other lock-in detector function between a reference signal related to the drive signal and the detector signal to generate a value corresponding to an amplitude of the portion of the source beam that has been transmitted through at least the portion of the article to image the object concealed in the article in the path of the source beam solely from the amplitudes of the detector signals.