Print position correction device

Abstract

Abstract PURPOSE:To print the printing information of a 2nd color without shifting the position, by changing the recording paper transfer timing, printing information carrying frequency, and scanning speed of a scanning means in accordance with an aberration in the print starting position of recording paper calculated from a measured pattern distance and the degree of expansion and contraction of the recording paper. CONSTITUTION:Patterns PTN1 and PTN3 for calculating the shifting of printing position and patterns PTN2 and PTN4 for calculating the degree of expansion and contraction, which are printed in the printing inhibited area of recording paper just before an optical sensor is brought to a fixing device, are detected by the optical sensor and counters 9a and 9b respectively count clock signals 10c and send count signals 9c and 9d, which correspond to the pre-fixing pattern distances, to a main control section 3. The driving timing of a paper refeeding roller is controlled in accordance with the signal 9c. Moreover, the degree of expansion and contraction of the recording paper is calculated by comparing the signal 9d with the pre-fixing pattern distance stored in the internal memory of the main control section 3 and the frequency of a frequency signal 12a supplied to a readout control section 6 and parallel-serial converter 7 and the revolving frequency of a motor for scanning are changed.

Inventors

• 👤 Shigeru Ueda
• 👤 茂 上田

Bibliographic Details