Asymmetric distribution of the scanned field of a rotating reflective polygon

A rigorous vector analysis is performed to investigate the structure of the scan field produced by a rotating polygon, and it is shown that the scan field is asymmetric to the ray reflected by the polygon at a neutral scan position. Some fundamental aspects of the polygon scanning systems are addressed, such as the scan duty cycle, the locus of the scan center, the depth of the scan field, and the off-axis defocus in convergent beam scanning.