Patent ID: 6149263
Filing Date: 2000-11-21
Classification: B41J

Abstract:
An ink jet recording apparatus, comprising:a carriage;a plurality of ink jet heads mounted on said carriage and including first, second, and successive ink jet heads respectively using first, second, and successive color ink for making dots in first, second, and successive colors, respectively;head drive means for selectively driving said plurality of ink jet heads at a variable head drive frequency;carriage drive means for driving said carriage at a variable carriage drive speed;mode selecting means for selecting a multiple-head monochrome print mode in which a monochrome print operation is performed by alternatively driving said first ink jet head and at least one of said second and successive ink jet heads, wherein an image is formed in such a way that a dot in said first color and at least one of dots in said second and successive colors are positioned in an alternating sequence; andcontrol means for controlling said head drive means to perform a monochrome print operation in said multiple-head monochrome print mode and to adjust said variable head drive frequency from a first level to a second level which is equal to or lower than said first level and for controlling said carriage drive means to adjust said variable carriage drive speed from a first level to a second level which exceeds said first level, when said multiple-head monochrome print mode is selected by said mode selecting means,wherein said first, second, and successive color inks are black, yellow, magenta, and cyan, respectively, and during said monochrome print operation in said multiple-head monochrome print mode, said control means controls said head drive means to drive said ink jet heads to successively form dots in such a way that a black ink dot made of said black ink and at least one of a yellow ink dot made of yellow ink, a magenta ink dot made of magenta ink, and a cyan ink dot made of cyan ink, and a blended-black dot made of said yellow, magenta, and cyan ink are positioned in an alternating sequence, and said control means controlling said carriage drive means to drive said carriage at said second level of said variable carriage drive speed which is twice as fast as said first level of said variable carriage drive speed.