METHOD AND DEVICE FOR GENERATING ARBITRARY FUNCTION AND DIGITAL CONVERGENCE CORRECTING DEVICE USING THEM

摘要

PROBLEM TO BE SOLVED: To perform an interpolation operation on the convergence correcting value corresponding to an arbitrary scanning position at a high speed. ;SOLUTION: A manual adjusting means 11 which sets a manual adjusting value D_ij to an adjusting point A_ij and an arbitrary function generating device 20 which performs a interpolation operation on convergence correction data D based on a plurality of sets of adjusting data (A_ij and D_ij) are provided. The device 20 is provided with a storing means 21 which stores the adjusting data (A_ij and D_ij), a first arithmetic means 22 which decides an interpolation expression composed of quadratic expression by using the Newton's forward interpolation method, a second arithmetic means 23 which develops the interpolation expression by using the Runge-Kutta quadratic equation, and a storing means 24 and outputs the convergence correction value D synchronously to a scanning position P(x, y).;COPYRIGHT: (C)1998,JPO