PURPOSE: To achieve a higher reliability, by a method wherein an magnified image with a fixed area on a test surface printed at a fixed density is memorized into an image memory to determine the coordinate range in which each dot pattern should exist on the image memory and then, the dot patterns are evaluated in respective coordinate ranges separately to count the total number of dot patterns judged to be defective.
CONSTITUTION: A test paper piece printed at a fixed density is set on a sample base 4 and focusing of a microscope 1 is done watching a monitor CRT 3. Then, the sample base 4 is turned so that lines of the dot patterns will parallel horizontal scan lines on the CRT 3 while a fine adjustment of the sample base 4 is done in the directions (x) and (y) so that any dot pattern images will not fall on the boundary lines between A and B. After the end of these adjustments, a start command is provided with a keyboard 7 and a CPU 5 memorizes image data into an image memory 6. The CPU 5 determines the coordinate range in which each dot pattern should exist on the memory 6 and evaluates dot patterns in respective coordinate ranges separately by a specified dot pattern evaluation algorithm and count the total number of dot patterns judged to be defective to be displayed 8 or printed out 9.
OMATSU MASAMOTO
TAJIMA HIROSHI
