Patent attributes
An exposing device including means which has a plurality of pixels and modulates, per pixel, an optical beam irradiated from a light source, for exposing a plotted image on an exposure surface by modulating, per pixel, the plurality of pixels of the modulating means based on image data, the multi beam exposing device comprising: beam position detecting means for detecting exposure point positional information pertaining to an optical beam irradiated on the exposure surface from predetermined pixels to be measured of the modulating means; and positional deviation calculating means for calculating a relative positional deviation between positional information pertaining to the pixels to be measured of the modulating means and exposure point positional information pertaining to each of the optical beams projected at the exposure surface from each of the pixels to be measured detected by the use of the beam position detecting means, based on the two positional informations.