| 摘要 |
PURPOSE:To prevent deterioration of the printing density when an image is enlarged by providing a standard printing mode whereby a paper is fed at normal speeds to print printing data and an extended printing mode whereby said paper is fed at speeds higher than by said standard printing mode, so that the same printing data is overlapped on the adjacent two lines according to said extended printing mode. CONSTITUTION:In a standard paper-feed mode, first, fourth, seventh,... timing pulses SP are used to rewrite the content of a line memory 2 and print on line. On the other hand, in an extended paper-feed mode, first, fifth, ninth,... timing pulses SP are used to rewrite the content of the line memory to print the one line. It is so controlled according to the extended paper-feed mode that every content of the line memory 2 is read two times. Therefore, the paper is fed at higher speeds for one line. When an image screen '3:4' is converted to an image screen '1:1', since the adjacent lines are printed by the same printing data at the part of the image screen where a circle with some density exists, the gradation of this part is never reduced. |
