Ink jet recording apparatus capable of increasing a monochrome print

Abstract

An ink jet recording apparatus capable of increasing a monochrome print speed without causing ink supply shortage to an image includes a carriage, a plurality of ink jet heads mounted on the carriage and including first, second, and successive ink jet heads for making dots in first, second, and successive colors, respectively. The ink jet recording apparatus further includes a head drive circuit for selectively driving the plurality of ink jet heads at a variable head drive frequency, a carriage drive circuit for driving the carriage at a variable carriage drive speed, a mode selecting circuit for selecting a multiple-head monochrome print mode in which a monochrome image is formed in such a way that a dot in the first color and at least one of dots in the second and successive colors are positioned in an alternating sequence, and a control circuit for controlling the head drive circuit to generate a monochrome image in the multiple-head monochrome mode and to adjust said variable head drive frequency from a first level to a different level which is equal to or lower than the first level and for controlling the carriage drive circuit to adjust said variable carriage drive speed from a first level to a different level which exceeds the first level, when the multiple-head monochrome print mode is selected by the mode selecting circuit.