Abstract: In a thermal transfer type color printer, an ink film on which plural color inks are sequentially painted in its longitudinal direction is sequentially transported forward between an ink film supply roll and winding roll, while a printing paper is repeatedly transported forward and backward in order to print out a color image by overlapping plural color inks. In color printing, the printing paper and ink film are partially overlapped and wound around a platen roller, and a thermal head is pressed against the platen roller by sandwiching the ink film and printing paper therebetween so that the thermal head transfers the color inks on the printing paper. In order to prevent wrinkles from being formed on the ink film, tension applying means applies tension force to the ink film by temporarily controlling or stopping revolution of the ink film supply roll.

Abstract: The image data including a grid pattern to be printed by a thermal printer line by line is stored for three lines of dots in a plural line buffer, and the image data is scanned by a window frame of an inverted T-shape which covers the three lines. When a dot arrangement extracted by the window frame including an object dot and its surrounding dots coincides with a predetermined window frame pattern defined in an intermediate table, an address representing the dot arrangement is convertred into an intermediate code by the intermediate table. The intermediate code indicates the amount of heating energy to be supplied to a heating element corresponding to the object dot in order to preheat when the area of the object dot is a non-printing area, or to heat additionally when this area is a printing area, thereby to prevent a thin or broken portion from appearing in the printed pattern line.

Abstract: A method of thermally printing a multicolor image on a print paper is disclosed. With this method, a lengthy multicolor image can be printed on a paper over a plurality of pages of a length determined by a length of each ink zone of an ink ribbon. First, the ink ribbon is set over a platen roller with the paper being interposed therebetween, the ink ribbon having plural groups of ink zones, the ink zones of each group carrying a plurality of heat-dissolving inks of different colors, respectively. One of the ink zones is positioned at a printing position where a thermal head contacts with the platen roller through the ink ribbon and paper. The thermal head is then activated in accordance with image data stored in a memory, and the ink ribbon and paper are advanced to effect transfer of ink so that one of color component images of the image is printed on the paper. The ink ribbon and paper are then advanced by a predetermined distance to separate the paper from the ink ribbon.