Method and circuit arrangement for the evaluation of photoelectrically obtained difference scanning signals from narrow and low-contrast structures

摘要

The invention relates to a method and a circuit arrangement for the evaluation of photoelectrically obtained difference scanning signals from narrow and low-contrast structures. According to the invention, polarity-dependent trigger signals from the difference signal are counted before and after scanning of a narrow structure, while polarity-dependent trigger signals from the difference signal inside a structure reset the counting process. As a function of the counter condition, the transmission path for the zero pulse is respectively activated or locked. <IMAGE>