Document Type and Number:
Japanese Patent JPH0341846
Kind Code:
B2
Abstract:
PURPOSE:To improve the coordinate correction accuracy by moving the correction line signal and the correction hole signal to the closest intersecting point of total surface virtual grids for normalization through a normalizing means after the rotary correction, overall correction and local correction are carried out successively. CONSTITUTION:A rotary error detection means 102 produces a rotary error signal (l) to the total surface virtual grids of line and hole signals (d) and (k). A circuit error correction means 105 corrects the signal (d) so as to reduce the sloping angle of said signal according to the signal (l) and delivers a correction line signal (h). An overall error detection means 103 calculates a frequency distribution to obtain a position shift of the maximum frequency and delivers an overall error signal (f). An overall error correction means 106 delivers a correction line signal (i) based on the signal (f). A local error detection means 104 delivers a local error signal (g), and a local error correction means 107 delivers a correction line signal (j) and a correction hole signal (n) according to the signals (g) and (i). These detection means carry out the rotary, overall and local corrections successively. Then signals (i) and (n) are normalized by a normalizing means. Thus the correction accuracy is improved.
Application Number:
JP11264084A
Publication Date:
June 25, 1991
Filing Date:
June 01, 1984
Export Citation:
International Classes:
G06F3/041; G06F3/03; G06F3/048; G06F3/0488; G06K11/06
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