| 摘要 |
PURPOSE:To enhance an image quality, by a method wherein a recording signal having a pulse width coincident with a printing pattern is selected for printing. CONSTITUTION:Input image information is successively inputted to a shift register 251 in synchronism with an image clock. A relation between a pixel and a plurality of pixels adjacent thereto in the image information in the shift register 251 is judged by an isolated black pixel judgement circuit 252 and an isolated white pixel judgement circuit 253. A black pixel among a white pixel group is judged by the isolated black pixel judgement circuit 252, and a white pixel among a black pixel group is judged by the isolated white pixel judgement circuit 253. For a black pixel among a white pixel group, the pulse width of a recording signal is set large by a recording signal pulse width set circuit 254. For a white pixel among a black pixel group, the pulse width of a recording signal is set small by the recording signal pulse width set circuit 254. A pattern change-over signal 261 is inputted to a recording signal change- over circuit 260 to change-over a character printing and a graphic printing. |
