Patent ID: 7926908

Claim:
An ink jet printing apparatus comprising: a printing head; and a print unit configured to scan the printing head in a forward direction and a backward direction, which is opposite to the forward direction and crosses a conveying direction of a printing medium to perform printing, wherein the printing head includes a first eject port array having a plurality of eject ports for ejecting black ink, arranged in the conveying direction of the printing medium, and a second eject port array having a plurality of eject ports for ejecting color ink, arranged in the conveying direction of the printing medium and being shorter than the first eject port array in the conveying direction of the printing medium, wherein the first eject port array has a first eject port group and a second eject port group, wherein the first eject port group is disposed in a same position as the second eject port array in the conveying direction, wherein the second eject port group is disposed in a displaced position from the second eject port array in the conveying direction, wherein the printing unit causes the printing head to eject the black ink and the color ink in both forward and backward directions, wherein in an identical printing area of the printing medium, a printing ratio of the first eject port group is lower than that of the second eject port group, and wherein the color ink contains a component that reduces dispersion stability of the black ink.