公开(公告)号：JPH046408A

公开(公告)日：1992-01-10

申请号：JP10912790

申请日：1990-04-25

Applicant: NAT AEROSPACE LAB

Inventor： YAMANE KOUSABUROU ,  SOTOZAKI TOKUO

IPC: G01B21/28 ,  G06G7/48

Abstract: PURPOSE:To compute the cross-sectional area of each groove by the simple method by detecting the difference between the output of the shape of the groove from a groove-size input part before movement and the output from a half-pitch moving part after the shape of the groove is moved by a half pitch. CONSTITUTION:A groove-size input part 1 receives the shapes of a plurality of grooves which are arranged in a comb pattern. A half-pitch moving part 2 moves the shape of each groove outputted from the input part 1 by a half pitch in the horizontal direction. Then a difference detecting part 3 detects the absolute value of the difference between the output from the input part 1 before the horizontal movement and the output from the moving part after the horizontal movement. A threshold-value setting part 4 sets the threshold value having the required size with respect to the output of the detecting part 3 so as to prevent the adverse effects which are caused when the heights of the crests on both sides are different and when the upper part of the crest is not flat. Integration is performed in an integrating part 5 only when the output of the detecting part 3 is higher than the threshold value which is set by the setting part 4. The integrated value is obtained as the cross-sectional area of the shape of the groove.