Abstract: A liquid viscosity measurement device for measuring a viscosity of a liquid includes: a substrate; a channel configured to be installed on the substrate so that the liquid flows through the channel; a heating element configured to generate a bubble in the liquid inside the channel; a sensor configured to be placed in a vicinity of the heating element so as to measure a temperature; and a deriving unit configured to derive the viscosity of the liquid by specifying a bubble disappearance time period from generation to disappearance of the bubble based on a change in temperature obtained by use of the sensor, so that the viscosity of the liquid is derived based on the bubble disappearance time period.

Abstract: A liquid discharge head includes: a substrate, where a recording element is disposed; and a discharge orifice forming member, where a discharge orifice, facing the recording element, and configured to discharge the liquid, is formed. The liquid discharge head has a pressure chamber, a first liquid channel configured to supply liquid to the pressure chamber, and a second liquid channel configured to recover liquid from the pressure chamber. The substrate has a liquid supply channel connected to the first liquid channel to supply liquid to the first liquid channel, and a liquid recovery channel connected to the second liquid channel, to recover liquid from the second liquid channel. Pressure at an inlet portion of the liquid supply channel is higher than pressure at an outlet portion of the liquid recovery channel, and a flow velocity of liquid within the pressure chamber is 3 to 140 mm/s.

Abstract: A liquid discharge head includes: a substrate, where a recording element is disposed; and a discharge orifice forming member, where a discharge orifice, facing the recording element, and configured to discharge the liquid, is formed. The liquid discharge head has a pressure chamber, a first liquid channel configured to supply liquid to the pressure chamber, and a second liquid channel configured to recover liquid from the pressure chamber. The substrate has a liquid supply channel connected to the first liquid channel to supply liquid to the first liquid channel, and a liquid recovery channel connected to the second liquid channel, to recover liquid from the second liquid channel. Pressure at an inlet portion of the liquid supply channel is higher than pressure at an outlet portion of the liquid recovery channel, and a flow velocity of liquid within the pressure chamber is 3 to 140 mm/s.

Abstract: A cleaning method of a liquid ejection head where recording element substrates having an ejection orifice forming-face having ejection orifice arrays which are aligned, and at least one array ejects a different recording liquid than another, includes wiping and preliminary ejection. In the wiping, a wiping member is caused to move along and wipe the arrays. In the preliminary ejection, before the wiping of the entire ejection orifice forming-face is completed, preliminary ejection from the wiped ejection orifices is started. The wiping and preliminary ejection are sequentially performed from a recording element substrate at one end to a recording element substrate at the other end.

Abstract: A liquid discharge head includes a liquid discharge substrate that has a discharge-orifice row, pressure generating elements, and pressure chambers. The liquid discharge head discharges a liquid in a block-by-block manner using sequential driving. The discharge-orifice row is disposed so as to incline at an angle ?=Arctan (d1/d2) relative to a direction extending orthogonal to the conveyance direction of the medium, in which d1 (?m) is a disposition spacing of the discharge orifices in the discharge-orifice row in the conveyance direction and d2 (?m) is a disposition spacing of the discharge orifices in the discharge-orifice row in the direction orthogonal to the conveyance direction. A partition wall is formed between adjacent pressure chambers so as to separate the adjacent pressure chambers from each other. The partition wall has a communicating portion that communicates the adjacent pressure chambers with each other.

Abstract: A liquid discharge head includes: a substrate, where a recording element is disposed; and a discharge orifice forming member, where a discharge orifice, facing the recording element, and configured to discharge the liquid, is formed. The liquid discharge head has a pressure chamber, a first liquid channel configured to supply liquid to the pressure chamber, and a second liquid channel configured to recover liquid from the pressure chamber. The substrate has a liquid supply channel connected to the first liquid channel to supply liquid to the first liquid channel, and a liquid recovery channel connected to the second liquid channel, to recover liquid from the second liquid channel. Pressure at an inlet portion of the liquid supply channel is higher than pressure at an outlet portion of the liquid recovery channel, and a flow velocity of liquid within the pressure chamber is 3 to 140 mm/s.

Abstract: A liquid discharge head includes: a substrate, where a recording element is disposed; and a discharge orifice forming member, where a discharge orifice, facing the recording element, and configured to discharge the liquid, is formed. The liquid discharge head has a pressure chamber, a first liquid channel configured to supply liquid to the pressure chamber, and a second liquid channel configured to recover liquid from the pressure chamber. The substrate has a liquid supply channel connected to the first liquid channel to supply liquid to the first liquid channel, and a liquid recovery channel connected to the second liquid channel, to recover liquid from the second liquid channel. Pressure at an inlet portion of the liquid supply channel is higher than pressure at an outlet portion of the liquid recovery channel, and a flow velocity of liquid within the pressure chamber is 3 to 140 mm/s.

Abstract: A fluid ejection apparatus executes a cleaning process and an ejection operation of ejecting fluid from ejection ports while causing the fluid to flow from a supply port to a fluid collection port of a flow channel provided in a fluid ejection head. Moreover, the fluid ejection apparatus adjusts a flow rate of the fluid flowing in the flow channel to a first flow rate during the ejection operation and adjusts the flow rate of the fluid flowing in the flow channel to a second flow rate higher than the first flow rate at least during the cleaning process.

Abstract: A cleaning method of a liquid ejection head where recording element substrates having an ejection orifice forming-face having ejection orifice arrays which are aligned, and at least one array ejects a different recording liquid than another, includes wiping and preliminary ejection. In the wiping, a wiping member is caused to move along and wipe the arrays. In the preliminary ejection, before the wiping of the entire ejection orifice forming-face is completed, preliminary ejection from the wiped ejection orifices is started. The wiping and preliminary ejection are sequentially performed from a recording element substrate at one end to a recording element substrate at the other end.

Abstract: A liquid discharge head includes: a substrate, where a recording element is disposed; and a discharge orifice forming member, where a discharge orifice, facing the recording element, and configured to discharge the liquid, is formed. The liquid discharge head has a pressure chamber, a first liquid channel configured to supply liquid to the pressure chamber, and a second liquid channel configured to recover liquid from the pressure chamber. The substrate has a liquid supply channel connected to the first liquid channel to supply liquid to the first liquid channel, and a liquid recovery channel connected to the second liquid channel, to recover liquid from the second liquid channel. Pressure at an inlet portion of the liquid supply channel is higher than pressure at an outlet portion of the liquid recovery channel, and a flow velocity of liquid within the pressure chamber is 3 to 140 mm/s.

Abstract: A liquid discharge head includes: a substrate, where a recording element is disposed; and a discharge orifice forming member, where a discharge orifice, facing the recording element, and configured to discharge the liquid, is formed. The liquid discharge head has a pressure chamber, a first liquid channel configured to supply liquid to the pressure chamber, and a second liquid channel configured to recover liquid from the pressure chamber. The substrate has a liquid supply channel connected to the first liquid channel to supply liquid to the first liquid channel, and a liquid recovery channel connected to the second liquid channel, to recover liquid from the second liquid channel. Pressure at an inlet portion of the liquid supply channel is higher than pressure at an outlet portion of the liquid recovery channel, and a flow velocity of liquid within the pressure chamber is 3 to 140 mm/s.

Abstract: A liquid ejection head includes a plurality of liquid chambers each including an energy generating element that generates energy for ejecting a liquid, an ejection opening that ejects the liquid, and a liquid supply opening that supplies the liquid, the liquid flowing in a first direction in the plurality of liquid chambers, and the plurality of liquid chambers being arranged in a second direction that intersects the first direction, and a plurality of first side walls that extend in the first direction and that form walls on both sides of the plurality of liquid chambers. In the liquid ejection head, each of the plurality of first side walls includes a fragmenting portion that fragments each of the plurality of first side walls in the first direction.

Abstract: A liquid ejection head including first and second recording element substrates adjacent in a direction intersecting a relative movement direction include ejection opening rows that include ejection openings arranged in the intersecting direction. A straight line connecting the ejection openings in end portions on a second recording element substrate side in the first recording element substrate and a straight line connecting the ejection openings in end portions on a first recording element substrate side in the second recording element substrate are inclined towards a middle area side of the first recording element substrate, and arrangement intervals of the ejection openings in an end portion area on the second recording element substrate side of a first ejection opening row is larger than arrangement intervals of the ejection openings in an end portion area on the first recording element substrate side of a second ejection opening row.

Abstract: A liquid discharge head includes a recording element configured to generate thermal energy and a discharge orifice disposed at a position facing the recording element. A bubble is generated in liquid by the thermal energy, liquid between the bubble and the discharge orifice is discharged from the discharge orifice by the pressure of the generated bubble, and the bubble communicates with the atmosphere on the outside of the discharge orifice.

Abstract: A print element substrate and a liquid ejection head capable of suppressing degradation of a print quality caused by a white stripe/black stripe etc., is actualized without using a high degree of microfabrication technology. As a result of asymmetric deformation by swelling in a direction of relative movement to a print medium, print elements having different liquid droplet ejection directions are made to coexist and arrayed for that purpose.

Abstract: A liquid ejection head includes a plurality of liquid chambers each including an energy generating element that generates energy for ejecting a liquid, an ejection opening that ejects the liquid, and a liquid supply opening that supplies the liquid, the liquid flowing in a first direction in the plurality of liquid chambers, and the plurality of liquid chambers being arranged in a second direction that intersects the first direction, and a plurality of first side walls that extend in the first direction and that form walls on both sides of the plurality of liquid chambers. In the liquid ejection head, each of the plurality of first side walls includes a fragmenting portion that fragments each of the plurality of first side walls in the first direction.

Abstract: A liquid discharging head includes a discharge port that discharges a liquid, a pressure chamber that communicates with the discharge port, and an energy generating element that is disposed in the pressure chamber. In the liquid discharging head, the discharge port is provided with a plurality of projections that project towards a central portion of the discharge port from an inner peripheral edge of the discharge port, and an interval between the projections at a location where the projections are closest to each other is 5 ?m or less.

Abstract: A liquid ejection head including first and second recording element substrates adjacent in a direction intersecting a relative movement direction include ejection opening rows that include ejection openings arranged in the intersecting direction. A straight line connecting the ejection openings in end portions on a second recording element substrate side in the first recording element substrate and a straight line connecting the ejection openings in end portions on a first recording element substrate side in the second recording element substrate are inclined towards a middle area side of the first recording element substrate, and arrangement intervals of the ejection openings in an end portion area on the second recording element substrate side of a first ejection opening row is larger than arrangement intervals of the ejection openings in an end portion area on the first recording element substrate side of a second ejection opening row.

Abstract: A liquid ejection head includes a plurality of liquid chambers each including an energy generating element that generates energy for ejecting a liquid, an ejection opening that ejects the liquid, and a liquid supply opening that supplies the liquid, the liquid flowing in a first direction in the plurality of liquid chambers, and the plurality of liquid chambers being arranged in a second direction that intersects the first direction, and a plurality of first side walls that extend in the first direction and that form walls on both sides of the plurality of liquid chambers. In the liquid ejection head, each of the plurality of first side walls includes a fragmenting portion that fragments each of the plurality of first side walls in the first direction.

Abstract: A printing element substrate includes a substrate, an energy generating element, and an ejection-port formed member. The energy generating element is disposed on one surface of the substrate and configured to generate energy for use in ejecting liquid. The ejection-port formed member includes ejection ports that eject the liquid. A protrusion protruding toward inside of each of the ejection ports is provided on an inner surface of the ejection port. In a surface of the ejection-port formed member remote from the substrate, a tip portion of the protrusion is positioned closer to the substrate than an outer periphery of the ejection port.