摘要 |
The present invention overcomes disadvantages including the occurrence of uneven printing, the need to provide a large-sized power supply, high cost and the deterioration of energy conversion efficiency resulting from the application of high current to the common resistance of a line head in a thermal printer for printing an image by the line head. Specifically, a gradation generating means (14) for generating gradation data; a selection means (15) for alternatively selecting each image data the number of which corresponds to the number of head elements of a head, and data of value 0 for the respective image data, and for switching selection as to which data is to be selected, the image data or the data of value 0, every time a value of the gradation data changes; and a comparison means (16) for feeding signals each indicating a comparison result of comparing the data selected by the selection means (15) with the gradation data, are provided at a line head controller (7) of a thermal printer.
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