An ejection surface extends in a first direction as a scanning direction and a second direction orthogonal to the first direction and is externally exposed. A plurality of nozzles opens at the ejection surface. A plurality of partial channels is located inside the ejection surface, and at bottom surfaces on a side of the ejection surface, the nozzles open. The plurality of nozzles is arranged in a direction intersecting with the first direction in plural rows to constitute a plurality of nozzle rows. The number of the nozzles arranged in each row is greater than the number of the plural rows. Between the nozzles in each nozzle row, the nozzles in other nozzle rows appear as seen in the first direction. A position of openings in the bottom surfaces of the partial channels differs across at least some of the nozzles in each nozzle row.

In a printing chip overlapping area being an area in which a first printing chip and a second printing chip overlap with each other when viewed from a second direction, ink is discharged so that a first overlapping area and a second overlapping area at least partially do not overlap with each other when viewed from the second direction. In the first overlapping area, a nozzle usage ratio of a first nozzle row and a nozzle usage ratio of a third nozzle row are neither 0% nor 100%. In the second overlapping area, a nozzle usage ratio of a second nozzle row and a nozzle usage ratio of a fourth nozzle row are neither 0% nor 100%.

In a printing chip overlapping area being an area in which a first printing chip and a second printing chip overlap with each other when viewed from a second direction, ink is discharged so that a first overlapping area and a second overlapping area at least partially do not overlap with each other when viewed from the second direction. In the first overlapping area, a nozzle usage ratio of a first nozzle row and a nozzle usage ratio of a third nozzle row are neither 0% nor 100%. In the second overlapping area, a nozzle usage ratio of a second nozzle row and a nozzle usage ratio of a fourth nozzle row are neither 0% nor 100%.

A method of printing a pattern from at least two rows of fluid ejection nozzles, said nozzles ejecting a first fluid in a multi-pass printing mode, the method comprising: dividing the pattern to be printed between the rows of fluid ejection nozzles; applying masks to the rows of fluid ejection nozzles for printing with selected nozzles of each of the rows of fluid ejection nozzles during each pass; wherein a first mask for printing from a first row of fluid ejection nozzles during an n-th pass is different from a second mask for printing from a second row of fluid ejection nozzles during said n-th pass.

A liquid discharge head includes a nozzle to discharge a liquid, an individual chamber communicating with the nozzle, a supply channel communicating with the individual chamber to supply the liquid to the individual chamber, and a discharge channel communicating with the individual chamber to discharge the liquid in the individual chamber. A fluid resistance of the supply channel is greater than a fluid resistance of the discharge channel.

A liquid discharge head includes a nozzle to discharge a liquid, an individual chamber communicating with the nozzle, a supply channel communicating with the individual chamber to supply the liquid to the individual chamber, and a discharge channel communicating with the individual chamber to discharge the liquid in the individual chamber. A fluid resistance of the supply channel is greater than a fluid resistance of the discharge channel.

The width by which the first, second heads overlap each other cross-sectionally along the first direction is greater than the width by which the fifth, sixth heads overlap each other cross-sectionally along the first direction.

A liquid ejecting head includes an ejection surface including head chips, and a first-positioning-portion and a second-positioning-portion disposed in a second-direction orthogonal to a first-direction with respect to the ejection surface and positioning a holding member, the liquid ejecting head has a first-edge and a second-edge separated from each other in the first-direction and extending along a third-direction parallel to the ejection surface and inclined with respect to the first-direction and the second-direction, and one end portion and the other end portion forming both end portions in the second-direction, and the first-positioning-portion does not overlap a virtual parallelogram having a first-virtual side contacting the first-edge and extending along the third-direction, a second-virtual side contacting the second-edge and extending along the third-direction, a third-virtual side contacting the one end portion and extending along the first-direction, and a fourth-virtual side contacting the other end portion and extending along the first-direction.

A wafer structure including a chip substrate and plural inkjet chips is disclosed. The chip substrate is a silicon substrate fabricated by a semiconductor process on a wafer of at least 12 inches. The inkjet chips are formed on the chip substrate by the semiconductor process and diced into the first inkjet chip and the second inkjet chip. Each of the first inkjet chip and the second inkjet chip includes plural ink-drop generators. Each of the ink-drop generators includes a nozzle. A diameter of the nozzle is in a range between 0.5 micrometers and 10 micrometers. A volume of an inkjet drop discharged from the nozzle is in a range between 1 femtoliter and 3 picoliters. The ink-drop generators form plural longitudinal axis array groups having a pitch and form plural horizontal axis array groups having a central stepped pitch equal to 1/600 inches or less.

A wafer structure including a chip substrate and plural inkjet chips is disclosed. The chip substrate is a silicon substrate fabricated by a semiconductor process on a wafer of at least 12 inches. The inkjet chips are formed on the chip substrate by the semiconductor process and diced into the first inkjet chip and the second inkjet chip. Each of the first inkjet chip and the second inkjet chip includes plural ink-drop generators. Each of the ink-drop generators includes a nozzle. A diameter of the nozzle is in a range between 0.5 micrometers and 10 micrometers. A volume of an inkjet drop discharged from the nozzle is in a range between 1 femtoliter and 3 picoliters. The ink-drop generators form plural longitudinal axis array groups having a pitch and form plural horizontal axis array groups having a central stepped pitch equal to 1/600 inches or less.