摘要 |
A thermal imaging system including a biassed elongate detector element of photoconductive material, over which an image of a thermal scene is scanned at a velocity that is matched to the drift velocity of photocarriers generated in the element. In order to improve responsivity and detectivity the length of the detector element or the magnitudes of bias and scan velocity are selected so that the time taken to scan the detector element from one end to a read-out region of the detector element is greater than the lifetime of the photocarriers generated in the element. In order to avoid loss of resolution by photocarrier diffusion the photocarrier lifetime of the detector material is of relatively low value. The system may include one detector element only, or it may include several detector elements arranged in parallel. Furthermore, one or more additional read-out regions, each formed by a pair of conductors, may be included in the detector element between the bias contact at one end of the element and the read-out region already mentioned.
|