Combined black and color ink jet printing

Abstract

The present invention provides an ink jet printer which has a mechanism for receiving and incrementing paper or other ink-receiving medium vertically and a print head and a mechanism for moving the print head horizontally across the paper. The print head has a plurality of orifices and associated operating devices to eject ink drops from each orifice. In particular, the orifices are configured such that there is a plurality of black ink orifices to print black ink, which is generated by a single black color from an orifice or orifices, and a plurality of color ink orifices to print color ink, whereby the color is generated by three different color inks, with each color ink being ejected from a separate orifice or orifices. The orifices are arranged in a pattern in which the orifices are spaced vertically and horizontally with respect to each other. In this pattern, there is at least one color ink orifice interposed or interspersed between two black ink orifices in the vertically spaced direction. The vertical spacing of the orifices is typically one dot distance. With this configuration, the full height of all of the orifices combined can be utilize for printing during a single swath for printing black lines or characters.