Abstract: An ink composition is provided which has excellent initial filling characteristics and continuous printing stability even in the case of an ink composition (for example, dissolved nitrogen is equal to or greater than 5 ppm) which is almost not deaerated or an ink composition (for example, dissolved nitrogen is equal to or greater than 7 ppm) which is not deaerated at all. The ink composition includes an alkylene oxide adduct (A) of acetylenic glycol in which a main chain has 12 or more carbon atoms, acetylenic glycol (B) in which a main chain has 10 or more carbon atoms, and polyoxyalkylene alkyl ether (C).

Abstract: An ink composition is provided which has excellent initial filling characteristics and continuous printing stability even in the case of an ink composition (for example, dissolved nitrogen is equal to or greater than 5 ppm) which is almost not deaerated or an ink composition (for example, dissolved nitrogen is equal to or greater than 7 ppm) which is not deaerated at all. The ink composition includes an alkylene oxide adduct (A) of acetylenic glycol in which a main chain has 12 or more carbon atoms, acetylenic glycol (B) in which a main chain has 10 or more carbon atoms, and polyoxyalkylene alkyl ether (C).

Abstract: An ink set according to the invention includes a yellow ink, a magenta ink, and a cyan ink, in which each of the inks contains a coloring agent which includes water and a pigment, the coloring agent of the magenta ink and the cyan ink is a first coloring agent which has a phosphorus-containing group on a surface of the pigment, the coloring agent of the yellow ink is a second coloring agent where a surface of the pigment is covered by a styrene-acryl resin, and each of the inks contains 50 mass % or more to 60 mass % or less of water with respect to the total mass of the ink.

Abstract: An ink jet ink set, at least has a cyan ink, a magenta ink, and a yellow ink, in which the cyan ink contains at least either one of C.I. Acid Blue 9 or C.I. Direct Blue 199, the magenta ink contains at least either one of C.I. Acid Red 249 or C.I. Reactive Red 141, the yellow ink contains at least either one of C.I. Direct Yellow 86 or C.I. Direct Yellow 132, and the cyan ink, the magenta ink, and the yellow ink all contain an alkylene oxide adduct of acetylene glycol having 12 or more carbon atoms in the main chain, acetylene glycol having 10 or more carbon atoms in the main chain, and polyoxy alkylene alkyl ether.

Abstract: An ink jet recording ink according to this invention is an ink jet recording ink to be contained in an ink containing vessel, in which the ink containing vessel has an ink containing chamber containing the ink and an air introduction flow path which introduces air into the ink containing chamber through the ink contained in the ink containing chamber, the ink contains a self-dispersion pigment, resin particles having a glass transition temperature of 10° C. or lower, and wax particles whose specific gravity is smaller than the specific gravity of a main solvent, and a ratio (R1/R2) of the volume average particle size (R1) of the resin particles and the volume average particle size (R2) of the wax particles is 1.0 or lower.

Abstract: A printer includes: a fluid ejecting head provided with multiple nozzles that eject ink; an ink supply tube that supplies the ink to the fluid ejecting head; and a pressure application mechanism that pressurizes the ink to swell from the nozzles by pressurizing the ink within the ink supply tube and then depressurizes the interior of the ink supply tube while the ink is swelling from the nozzles.

Abstract: There is provided an ink composition which has excellent initial filling characteristics and continuous printing stability even in a case of an ink composition (for example, dissolved nitrogen is equal to or greater than 5 ppm) which is almost not deaerated or an ink composition (for example, dissolved nitrogen is equal to or greater than 7 ppm) which is not deaerated at all. The ink composition includes an alkylene oxide adduct (A) of acetylenic glycol in which a main chain has 12 or more carbon atoms, acetylenic glycol (B) in which a main chain has 10 or more carbon atoms, and polyoxyalkylene alkyl ether (C).

Abstract: A toner includes toner base particles containing at least a binder resin, a coloring agent, and a release agent; and alumina fine particles whose phase angle (?) is |80°| or less at an alternating current frequency of 1 to 10 kHz in an alternating current impedance method.

Abstract: An ink jet ink set, at least has a cyan ink, a magenta ink, and a yellow ink, in which the cyan ink contains at least either one of C.I. Acid Blue 9 or C.I. Direct Blue 199, the magenta ink contains at least either one of C.I. Acid Red 249 or C.I. Reactive Red 141, the yellow ink contains at least either one of C.I. Direct Yellow 86 or C.I. Direct Yellow 132, and the cyan ink, the magenta ink, and the yellow ink all contain an alkylene oxide adduct of acetylene glycol having 12 or more carbon atoms in the main chain, acetylene glycol having 10 or more carbon atoms in the main chain, and polyoxy alkylene alkyl ether.

Abstract: The ink set according to the invention includes a first ink containing water, pigments, and first metal ions as counter-ions of the pigments; and a second ink containing water, specific dyes, and second metal ions as counter-ions of the dyes, in which the maximum equivalent conductivity [S·cm2/eq] of the first metal ions is greater than the maximum equivalent conductivity [S·cm2/eq] of the second metal ions.

Abstract: An ink jet recording ink according to this invention is an ink jet recording ink to be contained in an ink containing vessel, in which the ink containing vessel has an ink containing chamber containing the ink and an air introduction flow path which introduces air into the ink containing chamber through the ink contained in the ink containing chamber, the ink contains a self-dispersion pigment, resin particles having a glass transition temperature of 10° C. or lower, and wax particles whose specific gravity is smaller than the specific gravity of a main solvent, and a ratio (R1/R2) of the volume average particle size (R1) of the resin particles and the volume average particle size (R2) of the wax particles is 1.0 or lower.

Abstract: A liquid ejecting apparatus includes a recording head that ejects an ink from a plurality of nozzles, a liquid supply passage and a reservoir that supply the ink from an upstream side toward a downstream side, a maintenance pump that is able to suck and discharge the ink from and to the liquid supply passage, a filter that clarify the ink in the reservoir, and a control unit that performs a recovery process of the nozzles by controlling an operation of the pump, wherein the control unit causes the maintenance pump to perform a sucking operation to suck the ink, and then causes the pump to perform a discharging operation to discharge the ink, thereby supplying the ink clarified by the filter to the nozzle side.

Abstract: A printer includes: a fluid ejecting head provided with multiple nozzles that eject ink; an ink supply tube that supplies the ink to the fluid ejecting head; and a pressure application mechanism that pressurizes the ink to swell from the nozzles by pressurizing the ink within the ink supply tube and then depressurizes the interior of the ink supply tube while the ink is swelling from the nozzles.

Abstract: The liquid ejecting apparatus includes nozzles which eject ink, an ink flow path which supplies ink from the upstream side toward the downstream side, a maintenance pump capable of suctioning and discharging ink from the ink flow path, a one-way valve which is opened in accordance with decompression on the downstream side, thereby allowing passage of ink from the upstream side to the downstream side, and a control unit which controls the driving of the maintenance pump, thereby performing a cleaning process, wherein the control unit makes the maintenance pump suction ink from a pressure-changing position in the ink flow path by performing the suction driving of the maintenance pump after making the maintenance pump discharge ink from the pressure-changing position in the ink flow path into the ink flow path by performing the discharge driving of the maintenance pump.

Abstract: A developing device includes a toner particle-bearing roller that bears toner particles on its surface and develops a latent image borne by an image-bearing member with those toner particles, the toner particle-bearing roller has a projection portion disposed on its surface, the projection portion having a top surface having a flat portion, and a width of the top surface being equal to or more than a volume average particle diameter of the toner particles.

Abstract: A liquid droplet discharge apparatus includes a head member. The head member is provided with a nozzle surface, a plurality of nozzle arrays including a first nozzle array and a second nozzle array is arranged on the nozzle surface, the nozzle array includes a plurality of nozzle holes which are arranged in a predetermined pattern, the first nozzle array discharges a pigment ink which contains water and a pigment, the second nozzle array discharges a dye ink which contains water and a dye, and the relationship between the conductivity [E1 (mS/cm)] of the pigment ink and the conductivity [E2 (mS/cm)] of the dye ink is expressed by the formula 0<(E2?E1)?3.

Abstract: The ink set according to the invention includes a first ink containing water, pigments, and first metal ions as counter-ions of the pigments; and a second ink containing water, specific dyes, and second metal ions as counter-ions of the dyes, in which the maximum equivalent conductivity [S·cm2/eq] of the first metal ions is greater than the maximum equivalent conductivity [S·cm2/eq] of the second metal ions.

Abstract: A developing apparatus includes: a housing which contains toner; a toner supporting roller; and a regulating blade, wherein bias voltage is applied to the regulating blade, the toner includes, an insulating external additive and an electrically-conductive external additive, satisfies any of the following first to third conditions, the first condition: a volume average grain diameter of the electrically-conductive external additive is larger than a volume average grain diameter of the insulating external additive, the second condition: a volume average grain diameter of the electrically-conductive external additive is larger than a volume average grain diameter of the insulating external additive in which coverage in the toner is higher than that of the electrically-conductive external additive, and the third condition: coverage of the electrically-conductive external additive in the toner is higher than coverage of the insulating external additive that is larger in volume average grain diameter than the elect

Abstract: A developing device includes a toner particle-bearing roller that bears toner particles on its surface and develops a latent image borne by an image-bearing member with those toner particles, the toner particle-bearing roller has a projection portion disposed on its surface, the projection portion having a top surface having a flat portion, and a width of the top surface being equal to or more than a volume average particle diameter of the toner particles.

Abstract: An image forming apparatus includes an image carrier that carries an electrostatic latent image on a surface thereof, a toner carrying roller that is disposed to face the image carrier and rotates in a predetermined rotation direction with charged toner carried on a surface thereof so as to transport the toner in an opposing position for facing the image carrier, and a bias applying unit that develops the electrostatic latent image with the toner by applying an AC voltage as a developing bias to the toner carrying roller. In addition, periodical concavo-convexes that are formed of a plurality of convex portions arranged at a constant pitch in a circumferential direction and concave portions that surround the plurality of convex portions are formed on the surface of the toner carrying roller.