Ricoh Company, Ltd.

Kaoru Tadokoro

Michihiko Namba

Masayuki Shoshi

Tomoyuki Shimada

Chiaki Tanaka

Hiroshi Gotou

Takashi Watanabe

Tomohiro Inoue

Mio Kumai

Taku Hatakeyama

Sho Oyamatsu

Masaomi Sasaki

Yasuo Suzuki

Eiji Kurimoto

Masayuki Koyano

Takaaki Ikegami

Katsuichi Ohta

Megumi Kawahara

Takashi Rokutanzono

An ink set comprises black ink having a static surface tension A and yellow ink having a static surface tension B, wherein the static surface tension A is 28.7 mN/m or more and greater than the static surface tension B, wherein the ink set is used in an image forming device including an inkjet head including a nozzle plate including a first nozzle array and a second nozzle array disposed adjacent to the first nozzle array, the first nozzle array including multiple first nozzles configured to discharge the black ink and a second nozzle array including multiple second nozzles configured to discharge the yellow ink wherein each nozzle of the multiple first nozzles and the multiple second nozzles has a cylindrical portion having a length of 25 &#x3bc;m or longer along an axial direction with an opening on an ink discharging side of the nozzle plate.

Ink set and image forming device

A liquid discharge apparatus includes a conveyance path, a liquid discharge head, and a drying device. A medium is to be conveyed on the conveyance path. The liquid discharge head discharges liquid onto the medium conveyed on the conveyance path. The conveyance path includes a switchback path and an ejection path. The switchback path switches back a conveyance direction of the medium onto which the liquid has been discharged. The ejection path conveys the medium onto which the liquid has been discharged to an ejection port. The drying device dries the medium both on the switchback path and on the ejection path.

Liquid discharge apparatus

A liquid discharge apparatus includes a conveyance path, a liquid discharge head, an ejection tray, and a drying device. A medium is conveyed in the conveyance path. The liquid discharge head discharges liquid onto the medium conveyed in the conveyance path. The medium is ejected to the ejection tray. The drying device dries the medium. The conveyance path includes a first bending portion to bend the medium, with a liquid-applied surface of the medium facing inward. The ejection tray includes a second bending portion to bend the medium, with the liquid-applied surface of the medium facing inward. A curvature of the medium bent by the first bending portion is greater than a curvature of the medium bent by the second bending portion. The drying device dries the medium conveyed in the first bending portion.

An ink set comprises black ink having a static surface tension A and yellow ink having a static surface tension B, wherein the static surface tension A is by 0.6 mN/m or more greater than the static surface tension B, wherein the ink set is used in an image forming device including an inkjet head including a nozzle plate including a first nozzle array and a second nozzle array disposed adjacent to the first nozzle array, the first nozzle array including multiple first nozzles configured to discharge the black ink and a second nozzle array including multiple second nozzles configured to discharge the yellow ink, wherein each nozzle of the multiple first nozzles and the multiple second nozzles has a cylindrical portion having a length of 25 &#x3bc;m or longer along an axial direction with an opening on an ink discharging side of the nozzle plate.

REACTION PRODUCT, PROCESS FOR THE PRODUCTION THEREOF, ELECTROPHOTOGRAPHIC PHOTOCONDUCTOR USING THE REACTION PRODUCT, ELECTROPHOTOGRAPHIC APPARATUS USING THE PHOTOCONDUCTOR, AND PROCESS CARTRIDGE FOR ELECTROPHOTOGRAPHIC APPARATUS

Mixture of titanyltetraazaporphyrin compounds and electrophotographic photoconductor using the same

A reaction product useful as an organic photoconductive material for electrophotographic photoconductors is provided, obtainable by reacting (i) a nitrile derivative, (ii) a phthalonitrile derivative or a 1,3-diiminoisoindoline derivative and, if necessary, (iii) a metal or a metal-containing compound.

REACTION PRODUCT, PROCESS OF PRODUCING SAME, ELECTROPHOTOGRAPHIC PHOTOCONDUCTOR USING SAME, ELECTROPHOTOGRAPHIC APPARATUS HAVING THE PHOTOCONDUCTOR, AND PROCESS CARTRIDGE FOR ELECTROPHOTOGRAPHIC APPARATUS

A mixture is made of a plurality of different titanyltetraazaporphyrin compounds, each of which is represented by formula (1):

A pigment includes a compound with a tetraazaporphyrin skeleton represented by formula (I): ##STR1## wherein M is a hydrogen atom, or an atom or compound capable of bonding to tetraazaporphyrin through a covalent bond or a coordinate bond; and R.sup.1 to R.sup.8 are each independently a hydrogen atom, a lower alkyl group which may have a substituent, or an aryl group which may have a substituent. In addition, the above-mentioned pigment is used as a charge generation material in an electrophotographic photoconductor comprising an electroconductive support and a photoconductive layer formed thereon.

Tetraazaporphyrin pigment for use in electrophotographic photoconductor

An electrophotographic photoconductor has an electroconductive support, and a photoconductive layer formed thereon which contains as a charge generation material a pigment including a compound with a tetraazaporphyrin skeleton represented by formula (I): ##STR1## wherein M is a hydrogen atom, or an atom or compound capable of bonding to tetraazaporphyrin through a covalent bond or a coordinate bond; and R.sup.1 to R.sup.4 are each independently a hydrogen atom, a lower alkyl group which may have a substituent, or an aryl group which may have a substituent.

Electrophotographic photoconductor

An electrophotographic photoconductor has an electroconductive support and a photoconductive layer provided thereon, containing at least one phenol compound of formula (1): ##STR1## wherein R.sup.1 to R.sup.4 and R.sup.11 to R.sup.14 are each independently a hydrogen atom, an alkyl group which may have a substituent, an alkoxyl group which may have a substituent, an alkoxycarbonyl group which may have a substituent, an aryl group which may have a substituent, nitro group, cyano group or a halogen atom; and Y is ##STR2## in which R is a hydrogen atom, an alkyl group which may have a substituent, an alkoxyl group which may have a substituent, an alkoxycarbonyl group which may have a substituent, an aryl group which may have a substituent, nitro group, cyano group, hydroxyl group or a halogen atom, and n is an integer of 0 to 5, or --(CH.dbd.CH).sub.x --, in which x is an integer of 0 to 5.

An electrophotographic photoconductor includes an electroconductive support and a single-layered photoconductive layer formed thereon, containing a charge transporting material, a binder resin, and a simultaneously pulverized mixture including at least one disazo pigment of formula (1) and at least one trisazo pigment of formula (2), which is obtained by simultaneously pulverizing those azo pigments: ##STR1## wherein R.sup.1 and R.sup.2 each is hydrogen, a halogen atom, trifluoromethyl group, nitro group or cyano group; R.sup.3 is hydrogen, chlorine, fluorine, iodine, bromine, nitro group or cyano group; and Ar.sup.1, Ar.sup.2 and Ar.sup.3 each is a coupler radical, which may be the same or different.

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Kanagawa, Japan

Kaoru Tadokoro