SCANNING OPTICAL SYSTEM MEASURING/EVALUATING METHOD AND SCANNING OPTICAL SYSTEM MEASURING/EVALUATING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a scanning optical system measuring/evaluating method and a scanning optical system measuring/evaluating device precisely measuring and evaluating the linearity and a scanning line deflection quantity of the scanning optical system unit of an image forming device. SOLUTION: In this scanning optical system measuring/evaluating device 1, the laser light source 51 of the scanning optical system unit 50 under evaluation is driven and controlled based on a prescribed evaluation pattern, and the light beam emitted from the laser light source 51 forms an image in the scanning direction on a linear line as a spot on a position detecting element 2 arranged at a photoreceptor image position R via the scanning optical system unit 50. The position detection signal outputted from the position detecting element 2 is converted into digital position detection data synchronously with the occurrence timing of the evaluation pattern, and the position detection data are signal-processed for the measurement and evaluation of the scanning optical system unit 50. The position detection signal of the whole of one line can be performed in one scan, and the evaluation of a scanning optical system can be performed with high precision.