Apparatus for measuring amount of positional deviation of a recording sheet.

摘要

Apparatus for measuring amount of positional deviation of a recording sheet (11), in which the equation for obtaining the sum of square of the differences between the border coordinate data of the patterns obtained from the video image and the approximate straight line approximating the borders of the patterns is solved with respect to the constants of the approximate straight line, so that a straight line is obtained which represents the borders best, and the positions of the patterns are each determined with at least two approximate straight lines. And a cubic curve is set up which passes through the positions of at least two patterns, and the equation representing the sum of squares of the differences between the cubic curve and the positions of the two patterns with the edge of the recording sheet (11) as a reference position is solved with respect to the variables of the approximate straight line, to obtain a cubic curve equation. The cubic curve equation is utilized to detect the amount of positional deviation of the recording sheet (11) in the direction of conveyance. <IMAGE>