Abstract: An inkjet recording apparatus efficiently recovers defective discharge while reducing the amount of waste ink, acquires position information of a defective discharge nozzle and, based on the position information, determines whether the defective discharge has been caused by a bubble or a dust particle, and selects an ink circulation mode or a wiping mode.

Abstract: An ink jet printing apparatus according to the present invention includes a dryer configured to dry ink on a print medium. The dryer includes a heating unit configured to heat air in the dryer, and an outside air adjustment mechanism configured to adjust the amount of outside air introduced into the dryer. When the outside air adjustment mechanism is controlled so that the outside air introduction amount is increased, before the control of the outside air introduction amount, the heating unit is controlled so that heated air heated by the heating unit is preheated to a second target temperature higher than a predetermined first target temperature for a normal operation. Even if the outside air introduction amount is actually increased to temporarily reduce the temperature of heated air, the temperature of the heated air can be maintained at a value required for sufficient drying.

Abstract: During a cleaning operation, the following steps are executed. The steps includes a first step of pressurizing ink in a supply path to overflow the ink from a nozzle, a second step of stopping the pressurization, a third step of executing wiping while the pressurization is stopped and a negative pressure is not applied, and a fourth step of applying a negative pressure to the ink at the nozzle to generate a meniscus.

Abstract: The present invention provides an ink jet printing apparatus that can substantially prevent possible variation in the color of an image on a print medium discharged from an ink jet printing apparatus. A drying condition is determined under which the color of the image varies until the color of the image becomes a target one having a color difference ?E of at most 3 from a stable color with substantially no temporal variation. The image is dried according to the drying condition. The print medium is then discharged from the printing apparatus. This enables variation in the color of the image on the print medium discharged from the printing apparatus to be prevented from exceeding 3 in terms of color difference ?E. As a result, a user can be prevented from perceiving variation in color.

Abstract: An active energy radiation polymerizable substance is disclosed which is represented by the following general formula (I): wherein Z is a dihydric to hexahydric polyol residue, and A, B and D are groups represented by the following formulas (II) to (IV), respectively: (II), (III), and (IV).

Abstract: To provide an active energy ray curable aqueous ink composition exhibiting excellent curing performance by including a water-soluble polymerizable substance with high reactivity and a water-soluble polymerization initiator having high initiation efficiency; and an inkjet recording method, ink cartridge, recording unit, and inkjet recording apparatus all using the active energy ray curable aqueous ink composition. The active energy ray curable aqueous ink composition includes at least water; a polymerizable substance which undergoes radical polymerization by active energy rays; and a polymerization initiator which generates radicals by active energy rays, in which the polymerizable substance is a water-soluble compound having 2 to 6 (meth)acrylic groups; and the polymerization initiator is a water-soluble acylphosphine oxide compound.

Abstract: To provide an active energy ray curable aqueous ink composition exhibiting excellent curing performance by including a water-soluble polymerizable substance with high reactivity and a water-soluble polymerization initiator having high initiation efficiency; and an inkjet recording method, ink cartridge, recording unit, and inkjet recording apparatus all using the active energy ray curable aqueous ink composition. The active energy ray curable aqueous ink composition includes at least water; a polymerizable substance which undergoes radical polymerization by active energy rays; and a polymerization initiator which generates radicals by active energy rays, in which the polymerizable substance is a water-soluble compound having 2 to 6 (meth)acrylic groups; and the polymerization initiator is a water-soluble acylphosphine oxide compound.

Abstract: If an ink for a particular color (for example, red) having an excellent color developing characteristic is used in addition to inks for three primary colors of subtractive color mixture, the high color reproducibility is to be maintained for a long period. To accomplish this, at least one (for example, a yellow ink) of the inks of two colors between which the hue angle of red, included in the three primary colors, is sandwiched is applied to an area of a printing medium to which a red ink is applied so that the inks overlap each other. Thus, the yellow ink, having a high weatherability, is applied to an area on the printing medium to which only the red ink, having a low weatherability, is otherwise applied. It is therefore possible to improve the weatherability while maintaining the color developing characteristic at a high level.

Abstract: A water-based ink that comprises a water-soluble anionic colorant, an aluminum ion and an acid ion, wherein the content of the acid ion is more than that of the aluminum ion, and the content of the water-soluble anionic colorant is 20 to 1,000 times as much as that of the acid ion by molar ratio.

Abstract: An active energy ray curable ink which is quickly polymerized by an active energy ray, high in crosslinking degree of a cured material formed, excellent in adhesive property, low in viscosity, excellent in long-term storability and also excellent in ejection stability, and an ink-jet recording process, an ink cartridge, a recording unit and an ink-jet recording apparatus using such an ink are provided. In the active energy ray curable aqueous ink comprising at least water and a polymerizable material which is radically polymerized by an active energy ray, the polymerizable material is a water-soluble polymerizable material represented by the following general formula (I).

Abstract: Disclosed herein is an image-forming method, including performing image formation on the basis of pixel data by using at least a yellow recording agent, a magenta recording agent, and a third recording agent. A color represented on a recording medium by the third recording agent on a color space of CIE-L*a*b* has lightness higher than lightness of a color reproduction region represented on the recording medium by a combination of the yellow recording agent and the magenta recording agent, and has a hue angle in the color reproduction region. A difference in hue angle on the color space between a color represented by the yellow recording agent and a color represented by the magenta recording agent is in a range of 60 to 113°.

Abstract: The present invention provides an ink set, an ink jet recording apparatus, an ink jet recording method, a recording unit, and an ink cartridge, which can produce ink jet color images in which the color balance does not easily become unstable even if the image is stored for a long time, and in which the color images have greater durability so that degradation of the visual appearance is not easily recognizable even if the image is stored for a long time. The ink set includes a first aqueous ink and a second aqueous ink having the same color tone, the second ink having a lower coloring material content than that of the first ink, and the degree of fading of an image produced with the second ink is the same as or lower than that of an image produced with the first ink.

Abstract: An ink-jet ink comprises water, a water-soluble coloring material having a molecular weight of 600 or less as a free acid form, at least two kinds of water-soluble organic solvents, and urea or a derivative thereof. The vapor pressures at 25° C. of the at least two kinds of water-soluble organic solvents are lower than that of water. The water-soluble organic solvents include a water-soluble organic solvent A and a water-soluble organic solvent B. The solubility of the water-soluble coloring material in the water-soluble organic solvent A is higher than its solubility in water, while its solubility in the water-soluble organic solvent B is equal to or lower than its solubility in water. The difference between the solubilities of the water-soluble coloring material in the water-soluble organic solvent A and in the water-soluble organic solvent B is 10% or more.

Abstract: To provide an active energy ray curable aqueous ink composition exhibiting excellent curing performance by including a water-soluble polymerizable substance with high reactivity and a water-soluble polymerization initiator having high initiation efficiency; and an inkjet recording method, ink cartridge, recording unit, and inkjet recording apparatus all using the active energy ray curable aqueous ink composition. The active energy ray curable aqueous ink composition includes at least water; a polymerizable substance which undergoes radical polymerization by active energy rays; and a polymerization initiator which generates radicals by active energy rays, in which the polymerizable substance is a water-soluble compound having 2 to 6 (meth)acrylic groups; and the polymerization initiator is a water-soluble acylphosphine oxide compound.

Abstract: An active energy ray curable ink which is quickly polymerized by an active energy ray, high in crosslinking degree of a cured material formed, excellent in adhesive property, low in viscosity, excellent in long-term storability and also excellent in ejection stability, and an ink-jet recording process, an ink cartridge, a recording unit and an ink-jet recording apparatus using such an ink are provided. In the active energy ray curable aqueous ink comprising at least water and a polymerizable material which is radically polymerized by an active energy ray, the polymerizable material is a water-soluble polymerizable material represented by the following general formula (I). An ink-jet recording process, an ink cartridge, a recording unit and an ink-jet recording apparatus using such an ink.

Abstract: An ink-jet ink comprises water, a water-soluble coloring material having a molecular weight of 600 or less as a free acid form, at least two kinds of water-soluble organic solvents, and urea or a derivative thereof. The vapor pressures at 25° C. of the at least two kinds of water-soluble organic solvents are lower than that of water. The water-soluble organic solvents include a water-soluble organic solvent A and a water-soluble organic solvent B. The solubility of the water-soluble coloring material in the water-soluble organic solvent A is higher than its solubility in water, while its solubility in the water-soluble organic solvent B is equal to or lower than its solubility in water. The difference between the solubilities of the water-soluble coloring material in the water-soluble organic solvent A and in the water-soluble organic solvent B is 10% or more.

Abstract: Disclosed herein is an image-forming method, comprising performing image formation on the basis of pixel data by using at least a yellow recording agent, a magenta recording agent, and a third recording agent. A color represented on a recording medium by the third recording agent on a color space of CIE-L*a*b* has lightness higher than lightness of a color reproduction region represented on the recording medium by a combination of the yellow recording agent and the magenta recording agent, and has a hue angle in the color reproduction region. A difference in hue angle on the color space between a color represented by the yellow recording agent and a color represented by the magenta recording agent is in a range of 60 to 113°.

Abstract: An ink set includes inks each containing a colorant and an aqueous medium, wherein in a fading test under conditions that cause fading corresponding to pseudo-indoor sunlight fading through a window for 3 years or more, the difference between respective images' ?E, the images being produced with the respective inks, is 10 or less in a CIELAB color space display system, and each of the images has a residual ratio of reflection density of 70% or more. By using the ink set including the color inks with which images having substantially the same fading ?E after long-term storage are produced, the color balance of a recorded image can be maintained after long-term storage.

Abstract: If an ink for a particular color (for example, red) having an excellent color developing characteristic is used in addition to inks for three primary colors of subtractive color mixture, the high color reproducibility is to be maintained for a long period. To accomplish this, at least one (for example, a yellow ink) of the inks of two colors between which the hue angle of red, included in the three primary colors, is sandwiched is applied to an area of a printing medium to which a red ink is applied so that the inks overlap each other. Thus, the yellow ink, having a high weatherability, is applied to an area on the printing medium to which only the red ink, having a low weatherability, is otherwise applied. It is therefore possible to improve the weatherability while maintaining the color developing characteristic at a high level.

Abstract: Magenta ink exhibiting excellent coloration on various recording materials is provided according to the present invention. The magenta ink can realize high image densities and can produce images having superior light resistance.