METHOD FOR MEASUREMENT OF HIGH-SPEED SCAN ERROR OF RASTER SCANNER

摘要

PROBLEM TO BE SOLVED: To provide a measurement system for the high-speed scan errors of a raster output scanner(ROS) in order to determine whether a laser beam position existing in a high-speed scan direction exists within the permissible operation threshold or not. ;SOLUTION: Images are successively captured in multiplex from the respective facets of the ROS during the operation of the apparatus by using, for example, a line scan type or area array type camera as a detector 40. The positions (central loci) of a beam spot 28 at a scan line terminal are measured for the respective rotating facets and the central loci are collected by as much as a sufficient number. These central loci are subjected to Fourier transform, by which the exact space frequency spectra measured in a cycle/millimeter unit are obtd. These spectra may be easily compared and contrasted with the specification threshold of the high-speed scan errors of products.;COPYRIGHT: (C)1999,JPO