US 20020093557A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2002/0093557 A1 Takuhara et al. (43) Pub. Date: Jul. 18, 2002 (54) INK SET, INK JET RECORDING METHOD, (30) Foreign Application Priority Data RECORDING UNIT, INK CARTRIDGE, INK JET RECORDING APPARATUS, Sep. 4, 2000 (JP) . . . . . . . . . . . . .. 2000-267800 BLEED_ALLEVIATING METHOD, AND Feb. 7, 2001 (JP) .................................... .. 2001-031439 METHOD FOR IMPROVING FIXABILITY OF Publication Classi?cation BLACK IMAGE (51) Int. Cl? ................................................... .. G01D 11/00 (52) Us. 01. ............................................................ ..347/100 (76) Inventors: Hiroyuki Takuhara, Tokyo (JP); Yoshihisa Takizawa, Tokyo (JP); (57) ABSTRACT Kumiko Mafune, KanagaWa (JP); An ink set Which comprises a black ink containing an Hisashi Teraoka, ShiZuoka (JP); Yoichi aqueous medium and a pigment dispersed in the aqueous Takada, KanagaWa (JP); Noriyasu medium by an action of an ionic group, and at least tWo color Asaki, KanagaWa (JP); Yuko Takada, inks each containing a coloring material and an aqueous KanagaWa (JP); Tsuyoshi Kanke, medium, Wherein respective images formed With the KanagaWa (JP) respective color inks have the same AE or have the differ ence in AB that is 10 or less in a CIELAB color space display system in a fading test under conditions that cause fading Correspondence Address: corresponding to pseudo-indoor sunlight fading through a FITZPATRICK CELLA HARPER & SCINTO WindoW for 3 years or more, and (ii) at least one of the color 30 ROCKEFELLER PLAZA inks contains at least one of a coloring material and an NEW YORK, NY 10112 (US) additive that destabilize dispersion stability of the pigment in the black ink. The ink set can provide a high quality (21) Appl. No.: 09/942,579 multicolor image keeping color balance after long preser vation and shoWing less bleeding betWeen black and color (22) Filed: Aug. 31, 2001 regions. Patent Application Publication Jul. 18, 2002 Sheet 1 0f 14 US 2002/0093557 A1 Patent Application Publication Jul. 18, 2002 Sheet 2 0f 14 US 2002/0093557 A1 Patent Application Publication Jul. 18, 2002 Sheet 3 0f 14 US 2002/0093557 A1 45 / l | | I ‘ ‘_l\ / > t . X y 1 4‘2 ) > 40 44 Patent Application Publication Jul. 18, 2002 Sheet 4 0f 14 US 2002/0093557 A1 Patent Application Publication Jul. 18, 2002 Sheet 5 0f 14 US 2002/0093557 A1 :wwww _ a Patent Application Publication Jul. 18, 2002 Sheet 6 0f 14 US 2002/0093557 A1 Patent Application Publication Jul. 18, 2002 Sheet 7 0f 14 US 2002/0093557 A1 FIG. 10 Patent Application Publication Jul. 18, 2002 Sheet 8 0f 14 US 2002/0093557 A1 FIG. 12 C FIG. 13 1338 N2 1337 936 Patent Application Publication Jul. 18, 2002 Sheet 9 0f 14 US 2002/0093557 A1 FIG. 15 AFTER 1 #8 1a 1141a