Edge method of detection and being the edge

摘要

PPROBLEM TO BE SOLVED: To provide a method and device capable of detecting the edge position with high detection accuracy fit to the resolution of a line sensor. PSOLUTION: Each correlation between a normalized light quantity distribution acquired by normalizing an output from the line sensor and an approximate expression acquired by approximating a light quantity distribution pattern by Fresnel diffraction is calculated, respectively, by differentiating a reference position in the approximate expression, and a position where a correlation value is peaked is detected as the edge position of a detection object. Especially, the sum total of the absolute value of the difference of the light quantity between the normalized output from the line sensor and the approximate expression of the Fresnel diffraction pattern is calculated as the correlation value. PCOPYRIGHT: (C)2007,JPO&INPIT