| 摘要 |
PROBLEM TO BE SOLVED: To ensure cost reductions by simplifying the structure of a pulse width modulation circuit for modulating driving pulse width data to a driving pulse signal in a printer. SOLUTION: The halftoning section has a threshold value matrix (42) having a plurality of threshold values corresponding to a plurality of pixels and a conversion circuit (47) which compares (46) a plurality of threshold values output from the threshold value matrix with image data and generates driving pulse width data in accordance with the result of comparison. Random noise is superposed on the threshold values or the image data and compared, whereby a tone jump is suppressed from occurring. Furthermore, the halftoning section has a pulse position determination means to determine the driving pulse position of pixels in course of processing in accordance with the driving pulse width data of pixels adjacent to the pixels in course of processing and a pulse width modulator to generate a driving pulse signal following driving pulse width data in the determined driving pulse position. COPYRIGHT: (C)2007,JPO&INPIT
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