An image forming apparatus 101 capable of performing printing with a high image quality, and a control method of the image forming apparatus 101 are provided. For this purpose, a threshold value Dt is preliminarily set that allows printing without occurrence of blur, for each of preliminarily set monitoring areas A. In the case where a print duty for each of the monitoring areas A has exceeded the threshold value Dt, an ejection frequency of ink and conveying speed of a print medium are reduced in association therebetween.

A liquid ejection head includes an ejection opening; a passage in which an energy generation element is disposed; an ejection opening portion that allows communication between the ejection opening and the passage; a supply passage for allowing the liquid to flow into the passage; and an outflow passage for allowing the liquid to flow out to the outside. An expression of H.sup.0.34P.sup.0.66W>1.7 is satisfied when a height of the passage is set to H, a length of the ejection opening portion is set to P, and a length of the ejection opening portion is set to W.

A fluid ejection die may include a number of fluid ejection chambers laid to correlate with a number of dividers formed in a fluid channel layer such that adjacent fluid ejection chambers are alternatively arranged on a relatively higher-temperature side of the fluid ejection die and a relatively lower-temperature side of the fluid ejection die.

A fluid ejection unit may include a fluid supply passage, a fluid circulation loop having a first segment extending from the fluid supply passage, a second segment extending from the fluid supply passage and a bend connecting the first segment and the second segment, a fluid ejector along the second segment, the fluid ejector comprising a fluid ejection orifice and a fluid actuator and a fluid bypass spaced from the fluid actuator and in parallel with the bend to connect the first segment and the second segment.

A liquid discharge head includes a nozzle plate including a plurality of nozzles to discharge liquid, a plurality of individual chambers communicating with the plurality of nozzles, respectively, a supply-side channel communicating with the plurality of individual chambers, and a collection-side channel communicating with the plurality of individual chambers. The collection-side channel includes a first channel arranged in a first direction along a surface of the nozzle plate, a second channel communicating with the first channel, the second channel arranged in a second direction across the surface of the nozzle plate, and a branch channel branched from the first channel and connected to the second channel, the branch channel arranged in a third direction across the surface of the nozzle plate.

A first flow path is provided between the first layer and the second layer, a second flow path is provided between the second layer and the third layer, a filter chamber is provided inside the third layer, and the second layer is thinner than each of the first layer and the third layer.

A fluid ejection device includes a fluid slot, three laterally adjacent fluid ejection chambers each having a drop ejecting element therein, a fluid circulation path communicated with each of the three laterally adjacent fluid ejection chambers, and a fluid circulating element within the fluid circulation path, with at least two laterally adjacent fluid ejection chambers of the three laterally adjacent fluid ejection chambers to substantially simultaneously eject drops of fluid therefrom such that the drops of fluid are to coalesce during flight.

A metal member includes a first layer and a second layer. The second layer has an average crystal grain size different from an average crystal grain size of the first layer. An intermediate layer having an average crystal grain size smaller than the average crystal grain sizes of the first layer and the second layer is interposed between the first layer and the second layer.

An ink jet recording apparatus is provided with a conveying unit, a drive roller controller and a discharge timing controller. The drive roller controller controls a rotation speed of a drive roller based on pulse signals output by an encoder and corresponding to an angular velocity of a driven roller and an actual outer diameter of the driven roller. The discharge timing controller controls an ink discharge timing based on signals obtained by attenuating multiple frequency components of a target frequency corresponding to a pulse number of the pulse signals output from the encoder during one turn of the driven roller in the pulse signals and an actual outer diameter of the driven roller.

There is provided a liquid discharge head including a channel unit. The channel unit includes: first and second individual channel groups including a plurality of first and second individual channels; two supply manifolds and two return manifolds; and bypass channels communicating with the two supply manifolds or with the two return manifolds. A relationship of |P1|>|P2| is satisfied, wherein P1 is a first pressure of the supply manifold provided commonly for the first individual channel group, P2 is a second pressure of the supply manifold provided commonly for the second individual channel group, P1 is a third pressure of the return manifold provided commonly for the first individual channel group, and P2 is a fourth pressure of the return manifold provided commonly for the second individual channel group.