Fluid ejection apparatus

A fluid ejection apparatus, comprising:

• a first head chip extending from a first end in a first direction towards a second end in the first direction, wherein the first head chip comprises:
• a nozzle row A comprising nozzles A arranged along the first direction;
• a nozzle row B comprising nozzles B arranged along the first direction;
• and
• a nozzle row C comprising nozzles C arranged along the first direction;
• a second head chip extending from a third end in the first direction towards a fourth end in the first direction, wherein the second head chip comprises:
• a nozzle row D comprising a plurality of nozzles D arranged along the first direction;
• a nozzle row E comprising nozzles E arranged along the first direction;
• and
• a nozzle row F comprising nozzles F arranged along the first direction,
• a controller configured to control the first head chip and the second head chip to eject fluid from the first head chip and the second head chip,
• wherein the nozzle row B is positioned between the nozzle row A and the nozzle row D in a second direction orthogonal to the first direction,
• wherein the nozzle row D is positioned between the nozzle row B and the nozzle row E in the second direction,
• wherein the nozzles A of the nozzle row A are arranged into a nozzle group A1 and a nozzle group A2,
• wherein the nozzle group A1 comprises some of the nozzles A,
• wherein the nozzle group A2 comprises others of the nozzles A,
• wherein the nozzle group A1 is positioned between the nozzle group A2 and the center of the first head chip in the first direction,
• wherein the nozzles B of the nozzle row B are arranged into a nozzle group B1,
• wherein the nozzle group B1 comprises some of the nozzles B,
• wherein the nozzle group A1 and the nozzle group B1 are aligned along the second direction,
• wherein the nozzles C of the nozzle row C are arranged into a nozzle group C,
• wherein the nozzle group C comprises some of the nozzles C,
• wherein the nozzle group A1 and a portion of the nozzle group C are aligned along the second direction,
• wherein the nozzles D of the nozzle row D are arranged into a nozzle group D2,
• wherein the nozzle group D2 of the nozzle row D comprises some of the nozzles D,
• wherein the nozzle group A2 and the nozzle group D2 are aligned along the second direction,
• wherein the nozzles E of the nozzle row E are arranged into a nozzle group E1 and a nozzle group E2,
• wherein the nozzle group E1 comprises some of the nozzles E,
• wherein the nozzle group E2 comprises others of the nozzles E,
• wherein the nozzle group A1 and the nozzle group E1 are aligned along the second direction,
• wherein the nozzle group A2 and the nozzle group E2 are aligned along the second direction,
• wherein the nozzles F of the nozzle row F are arranged into a nozzle group F,
• wherein the nozzle group F comprises some of the nozzles F,
• wherein the nozzle group A1 and a portion of the nozzle group F are aligned along the second direction,
• wherein the nozzle group C and the nozzle group F are aligned along the second direction,
• wherein the controller is configured to control:
• the nozzle group A1 to eject fluid at an average usage rate A1 that is an average of usage rates of the some of nozzles A comprising the nozzle group A1;
• the nozzle group A2 to eject fluid at an average usage rate A2 that is an average of usage rates of the others of nozzles A comprising the nozzle group A2;
• the nozzle group B1 to eject fluid at an average usage rate B1 that is an average of usage rates of the some of nozzles B comprising the nozzle group B1;
• the nozzle group C to eject fluid at an average usage rate C that is an average of usage rates of the some of nozzles C comprising the nozzle group C;
• the nozzle group D2 to eject fluid at an average usage rate D2 that is an average of usage rates of the some of nozzles D comprising the nozzle group D2;
• the nozzle group E1 to eject fluid at an average usage rate E1 that is an average of usage rates of the some of nozzles E comprising the nozzle group E1;
• the nozzle group E2 to eject fluid at an average usage rate E2 that is an average of usage rates of the others of nozzles E comprising the nozzle group E2;
• and
• the nozzle group F to eject fluid at an average usage rate F that is an average of usage rates of the some of the nozzles F comprising the nozzle group F,
• wherein the average usage rate A2 is smaller than the average usage rate A1,
• wherein the average usage rate B1 is smaller than the average usage rate A1,
• wherein the average usage rate C is smaller than the average usage rate A1,
• wherein the average usage rate D2 is smaller than the average usage rate E2,
• wherein the average usage rate E1 is smaller than the average usage rate E2, and
• wherein the average usage rate F is smaller than the average usage rate E2.