| 摘要 |
PROBLEM TO BE SOLVED: To adequately perform perfecting printing by a method wherein a discrimination mark for a paper orientation is formed on a first face of a recording paper when printing on the first face and the discrimination mark is detected when printing on the second face, thereby determining the orientation of the set recording paper. SOLUTION: A discrimination mark for a paper orientation is recorded on a recording paper 32 when printing on a first face of the paper. The discrimination mark is read by means of mark sensors 40, 41 when printing on the second face. The mark pattern is recognized by a pattern recognizing section 61 based on a discrimination mark detecting signal. The orientation of the recording paper 32 is determined by a paper orientation determining section 62 based on the mark pattern and the position of the mark. When the orientation of the set paper is adequate, the printing on the second face is performed. When it is inadequate, the printing on the second face is not performed and an alarm is generated. As a result, it is possible to avoid perfecting printing on the recording paper in the erroneous orientation. |
