US 6,578,958 B2Granted

Inkjet recording method and apparatus and ink therefor

AssigneeRicoh Company, Ltd.

InventorsAkihiko Gotoh, Akiko Bannai

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Abstract

An inkjet recording apparatus including (A) a recording head including: plural nozzles discharging an ink drop to form an image on a receiving material; and plural pressure generators applying a pressure to the corresponding nozzles; (B) an ink container containing the ink, wherein the ink includes a pigment and a volatile solvent, and wherein the ink has a pigment content decreasing property such that the pigment content decreases at a meniscus portion of the ink in the nozzles when the ink is allowed to settle; and (C) a driver selectively actuating the pressure generators to discharge the ink from the corresponding nozzles, wherein the driver selectively actuates at least one of the pressure generators at a predetermined timing such that the ink at the meniscus portion is vibrated to an extent such that the ink is not discharged from the corresponding nozzle.

Claims20

Dependent claims

An inkjet recording apparatus comprising:

(A) a recording head including,
plural nozzles configured to selectively discharge a drop of an ink to form an image on a receiving material at an image forming area, and plural pressure generators configured to apply a pressure to corresponding nozzles of the plural nozzles;
(B) an ink container containing the ink, the ink including a pigment at a first pigment content, a volatile solvent and a solvent having a low volatility, and the ink having a pigment content decreasing property such that the pigment content decreases at a meniscus portion of the ink in the plural nozzles when the ink is allowed to settle;
and
(C) a driver configured to actuate at least one of the plural pressure generators by applying a first pulse to selectively discharge the ink from at least one of the plural nozzles,
wherein the driver actuates at least one of the plural pressure generators at a predetermined timing by applying a second pulse such that the ink at the meniscus portion is vibrated to an extent such that the ink is not discharged from a corresponding nozzle of the plural nozzles, and further,
wherein the ink further has a first zeta potential not less than 20 mV and a property that when due to evaporation of at least the volatile solvent a condensed ink is produced that has a second pigment content increases from 1.25 to 1.50 times the first pigment content, the condensed ink has a second zeta 5 potential, and an absolute value of the second zeta potential is less than an absolute value of the first zeta potential by at least 5 mV.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/102,890Filed 22 Mar 2002
Priority: JP 2001-08329722 Mar 2001
Published: US 2003/0076394 A124 Apr 2003
Granted: 17 Jun 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

B41J 2/04566
Control methods or devices therefor, e.g. driver circuits, control circuits: detecting humidity
B41J 2/04578
Control methods or devices therefor, e.g. driver circuits, control circuits: controlling heads based on electrostatically-actuated membranes
B41J 2/04581
Control methods or devices therefor, e.g. driver circuits, control circuits: controlling heads based on piezoelectric elements
B41J 2/04596
Control methods or devices therefor, e.g. driver circuits, control circuits: non-ejecting pulses