Patent ID: 7414759
Filing Date: 2008-08-19
Classification: H04N

Abstract:
1. A method for measuring linear spot velocity or spot position variations in a scanning system comprising: a) providing at least two radiation detectors that can move in tandem across a scan line, the two radiation detectors being spaced apart by a distance d; b) positioning the at least two radiation detectors at a first point on the scan line; c) scanning the at least two radiation detectors with scanning radiation and recording the position of the two detectors along the scan line and the time taken for the scanning radiation to scan from a first of the at least two radiation detectors to a second of the at least two radiation detectors while the at least two radiation detectors are positioned at the first point; d) moving the at least two radiation detectors to a second point on the scan line maintaining the distance d between the at least two radiation detectors; and e) again scanning the at least two radiation detectors with scanning radiation and recording the position of the two detectors along the scan line and the time taken for the scanning radiation to scan from a first of the at least two radiation detectors to a second of the at least two radiation detectors while the at least two radiation detectors are positioned at the second point.