Moire simulator and method of using same

摘要

A moire simulator comprises a moire detecting pattern constituted by grating patterns having equal grating constants and equal grating shapes, and an angle scale. The moire detecting pattern and the angle scale are positioned on at least one transparent plate. The moire simulator is superposed on an original and rotated thereon to read a rotation angle with respect to the original, at which the extent of generation of a moire pattern is the lowest, by using the angle scale. A setting angle of a screen during screening at which the extent of generation of a moire pattern is the lowest is then calculated before a screening process is started.