Abstract: A liquid discharge apparatus has a liquid discharge head having a recording element board that includes a plurality of discharge orifices configured to discharge liquid, a plurality of pressure chambers internally provided with a recording element configured to generate energy used to discharge liquid, the plurality of pressure chambers each communicating with the plurality of discharge orifices via discharge channels, a liquid supply channel configured to supply liquid to the plurality of pressure chambers, and a liquid recovery channel configured to recover liquid from the plurality of pressure chambers, and a tank configured to store liquid supplied to the liquid discharge head. The plurality of pressure chambers communicate between the liquid supply channel and the liquid recovery channel so that liquid flows through the plurality of pressure chambers, and the specific permittivity ?r of the liquid stored in the tank satisfies the relationship of ?r?65.

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 discharge device to perform recording by use of a liquid discharge head including discharge ports to discharge a liquid, pressure generation elements to generate energy to be used to discharge the liquid, and pressure chambers communicating with the discharge ports. The liquid discharge device includes: a control unit to control a temperature of the liquid discharge head by applying heat with heating elements arranged in divided areas of a region of the liquid discharge head where the discharge ports are arranged. When there is recording data for the discharge port in a certain one of the divided areas, the control unit causes the heating element in the divided area to generate heat, and when there is no recording data for the discharge port in the certain divided area, the control unit keeps the heating element in the certain divided area from generating heat.

Abstract: A liquid ejection head substrate includes a heating resistor array including a plurality of heating resistors and a protective film covering at least one of the heating resistors. The liquid ejection head substrate further includes a supply opening array and an electrode. The supply opening array is disposed on a side of a surface of the liquid ejection head substrate on which the protective film is provided. The supply opening array includes a plurality of supply openings through which a liquid is supplied arranged in a direction along the heating resistor array. The electrode is disposed on the side of the surface in a space between the supply openings adjacent to each other in a direction along the supply opening array. The electrode is configured such that a voltage is applied between the electrode and the protective film.

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: In order that the interior of a cap member, in a case where the cap member abuts to a cover member, is allowed to have improved airtightness so that the cap member can sufficiently function, a sealing member is used to seal between the cover member and first and second flow path members for retaining the cover member.

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.

Abstract: A liquid ejecting apparatus has a liquid ejecting unit and a negative pressure regulating unit provided between passages connecting the tank to the liquid ejecting unit, regulates fluid pressure of liquid flowing into the liquid ejecting unit. The negative pressure regulating unit includes a negative pressure chamber whose internal pressure is regulated within a predetermined range, and a discharging passage for discharging liquid stored in the negative pressure chamber from the negative pressure regulating unit. The discharging passage has an outlet disposed in an upper portion of the negative pressure chamber in a direction of gravity, a bubble accumulation portion connected to the outlet and having a space above the outlet in the direction of gravity, and a passage guiding liquid flowing from the outlet to a discharging port opened in a bottom of the negative pressure regulating unit.

Abstract: A liquid ejection head includes a support member extending in a first direction, a print element board having an ejection port through which liquid is ejected, and first and second members arranged in the support member adjacent to each other along the first direction, each having a supply path extending in the first direction. The print element board element generates energy used for ejection of the supply paths supplied liquid. The first member includes an outlet port through which the supplied liquid flows out. The second member includes an inlet port through which the liquid from the outlet port flows. The outlet port is provided near a first member supply path end portion on the support member side on which the second member is provided. The inlet port is provided near a second member supply path end portion on the support member side on which the first member is provided.

Abstract: A recording element substrate includes: a substrate on which a plurality of energy generating elements that generate energy used for ejecting liquid are arranged side by side, an ejection port forming member in which ejection ports are formed at positions corresponding to the plurality of energy generating elements, a plurality of supply passages which are channels extending in a thickness direction of the substrate and through which liquid is supplied to the energy generating elements, and a support member that is formed between the substrate and the ejection port forming member and supports the ejection port forming member, in which supply ports that are apertures of the plurality of supply passages are linearly arranged side by side on the substrate, and a plurality of support members are provided side by side between adjacent supply ports on the substrate in a direction in which the supply ports are aligned.

Abstract: In order to keep possible local temperature differences in a liquid ejection head small to allow stable liquid ejection performance to be achieved, temperatures in a plurality of heating areas in a liquid ejection head are discretely controlled using heating elements and temperature detection elements.

Abstract: A liquid ejection head substrate includes a heating resistor array including a plurality of heating resistors and a protective film covering at least one of the heating resistors. The liquid ejection head substrate further includes a supply opening array and an electrode. The supply opening array is disposed on a side of a surface of the liquid ejection head substrate on which the protective film is provided. The supply opening array includes a plurality of supply openings through which a liquid is supplied arranged in a direction along the heating resistor array. The electrode is disposed on the side of the surface in a space between the supply openings adjacent to each other in a direction along the supply opening array. The electrode is configured such that a voltage is applied between the electrode and the protective film.

Abstract: Provided is a liquid ejection head including: a plurality of recording element substrates including energy generating elements that generate ejection energy for ejecting liquid from ejection orifices; a first support member that supports the plurality of recording element substrates such that the recording element substrates are arranged in one or more lines on a main surface of the first support member; and a second support member that supports the first support member on a surface opposite to the main surface. A first thermal resistance concerning an in-plane direction parallel to the main surface, of a region between the recording element substrates in the first support member is higher than a second thermal resistance concerning a thickness direction of the second support member, of a projection region that overlaps with each recording element substrate in the second support member.

Abstract: The liquid ejection apparatus includes a circulation unit configured to circulate a liquid along a circulation passage extending from a liquid supply source to the liquid supply source through a liquid ejection head. Further, the liquid ejection apparatus includes a deaeration unit configured to perform a deaeration operation of decreasing a dissolved gas amount of the liquid, a recovery unit configured to recover ejection performance of an ejection opening, and a control unit configured to control an operation of driving the circulation unit and the deaeration unit. The control unit starts the deaeration operation and circulates the liquid having been deaerated by the deaeration operation inside a circulation path after the recovery operation and before an initial printing operation after the recovery operation.

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 discharge orifices, recording elements that generate energy, supply channels that supply liquid to the recording elements, a common supply channel communicating with the supply channels, recovery channels that recover liquid supplied to the recording elements, a common recovery channel that recovers liquid from the recovery channels, a first inlet port that supplies liquid to the common supply channel, a first recovery port that recovers liquid from the first common supply channel, a second inlet port that supplies liquid to the common recovery channel, and a second recovery port that recovers liquid from the second common recovery channel. The first inlet port and the first recovery port communicate without going through channel portions where recording elements are disposed, and the second inlet port and the second recovery port communicate without going through channel portions where recording elements are disposed.

Abstract: A liquid ejection apparatus of the invention is a liquid ejection apparatus including a liquid storage container that stores liquid, a circulation mechanism that circulates liquid in a circulation path, and a liquid ejection head fluidly-connected to the liquid storage container, the liquid ejection head having a plurality of ejection openings, wherein the liquid ejection head includes at least a pair of common passages and a plurality of individual passages that connect one of the pair of common passages to the other one of the pair of common passages and communicate with the plurality of ejection openings, respectively, and at least a pair of pressure adjustment mechanisms whose pressures are set to different control pressures is connected to respective upstream sides or downstream sides of the pair of common passages.

Abstract: A liquid discharge apparatus has a liquid discharge head having a recording element board that includes a plurality of discharge orifices configured to discharge liquid, a plurality of pressure chambers internally provided with a recording element configured to generate energy used to discharge liquid, the plurality of pressure chambers each communicating with the plurality of discharge orifices via discharge channels, a liquid supply channel configured to supply liquid to the plurality of pressure chambers, and a liquid recovery channel configured to recover liquid from the plurality of pressure chambers, and a tank configured to store liquid supplied to the liquid discharge head. The plurality of pressure chambers communicate between the liquid supply channel and the liquid recovery channel so that liquid flows through the plurality of pressure chambers, and the specific permittivity ?r of the liquid stored in the tank satisfies the relationship of ?r?65.

Abstract: A recording element board includes a discharge orifice configured to discharge liquid, a pressure chamber communicating with the discharge orifice, a recording element configured to generate thermal energy to cause bubbling of the liquid, the recording element being disposed in the pressure chamber facing the discharge orifice, and a substrate on which the recording element is formed. When the recording element is driven and the liquid of within the pressure chamber is discharged, a generated bubble communicates with the atmosphere. A discharge orifice projection region where the discharge orifice has been projected on the substrate includes a region includes a region extending beyond a heat-generating region projection region where the heat-generating region of the recording element has been projected on the substrate, the outline of the discharge orifice projection region is circumscribed by the outline of the heat-generating region projection region.

Abstract: A liquid ejection head capable of suppressing a change in pressure of a pressure chamber, a liquid ejection apparatus, and a manufacturing method are provided. For that reason, a lid member is formed on a wafer-shaped element board and the element board is cut into chips to manufacture a print element board.