Inventor

Masafumi Ohta

Inventor

Susono, JP

Overview

1977–2014

Patent span

Physics

Primary field (CPC G)

Patents· 63 as inventor

Public. Assignee & technology derived from the patent record. Each patent links to its LexDana page.

G03Gprimary

G03GElectrography41%

C09BOrganic dyes or closely-related compounds for producing dyes, e.g. pigments17%

C07DHeterocyclic compounds8%

H05BElectric heating5%

H10KOrganic electric solid-state devices5%

C09KMaterials for miscellaneous applications, not provided for elsewhere5%

Y10STechnical subjects covered by former uspc cross-reference art collections [xracs] and digests4%

B43KImplements for writing or drawing3%

C08GMacromolecular compounds obtained otherwise than by reactions only involving unsaturated carbon-to-carbon bonds3%

C07CAcyclic or carbocyclic compounds2%

PatentTitleYear

8,767,748'Signal distribution circuit and stuffing control unit'2014 8,557,489'Gallium phthalocyanine compound, gallium phthalocyanine composite pigment, method for preparing gallium phthalocyanine composite pigment, and electrophotographic photoconductor'2013 8,541,557'Azo compound and method of preparing the azo compound'2013 8,530,124'Hydroxygallium phthalocyanine composite pigment, electrophotographic photoconductor containing the same, and image forming device and process cartridge for image forming device using the same'2013 8,383,304'Gallium phthalocyanine compound, and image bearing member, image forming method, image forming apparatus, and process cartridge using the gallium phthalocyanine compound'2013 8,380,109'Image forming apparatus and process cartridge'2013 8,232,031'Naphthalenetetracarboxylic acid diimide derivative and electrophotographic photoconductor having the same'2012 8,232,376'Azo compound and method of preparing the azo compound'2012 8,207,312'Method of preparing complex-AZO pigment and complex-AZO pigment thereof'2012 8,206,880'Electrophotographic photoreceptor, and image forming apparatus and process cartridge therefor using the photoreceptor'2012 7,858,278'Electrophotographic photoreceptor, and image forming apparatus and process cartridge using the electrophotographic photoreceptor'2010 6,316,577'Electrophotographic photoconductor and aromatic polycarbonate resin for use therein'2001 6,090,508'Optically anisotropic recording medium and method of recording and erasing information using the same'2000 6,027,846'Electrophotographic photoconductor and aromatic polycarbonate resin for use therein'2000 5,830,980'Electrophotographic photoconductor, aromatic polycarbonate resin for use in the same, and method of producing the aromatic polycarbonate resin'1998 5,747,204'Electrophotographic photoconductor and aromatic polycarbonate resin for use in the same'1998 5,672,756'Triphenylamine compound for use in electrophotographic photoconductors'1997 5,656,401'Electroluminescent device comprising oxadiazole compounds luminescent material, oxadiazole compounds for the device, and method of producing oxadiazole compounds'1997 5,631,404'Diamine compounds for use in electrophotographic photoconductors'1997 5,610,309'Electroluminescent device comprising oxadiazole compounds luminescent material, oxadiazole compounds for the device, and method of producing oxadiazole compounds'1997 5,604,065'Electrophotographic photoconductor and triphenylamine compound for use therein'1997 5,597,925'Method of producing oxadiazole compounds'1997 5,492,784'Positively-chargeable single-layered type electrophotographic photoconductor'1996 5,489,495'Electrophotographic photoconductor and diamine compounds for use in the same'1996 5,420,288'Electroluminescent device comprising oxadiazole compounds luminescent material, oxadiazole compounds for the device, and method of producing oxadiazole compounds'1995 5,153,073'Electroluminescent device'1992 5,118,986'Electroluminescent device'1992 5,093,210'Electroluminescent device'1992 4,992,109'Photoelectric conversion element'1991 4,830,942'Electrophotographic photoconductor'1989 4,663,442'Disazo triphenylamine compounds'1987 4,596,754'Electrophotographic printing original plate and electrophotographic plate making process using the printing original plate'1986 4,582,771'Disazo compound, method for preparing the same, and electrophotographic element containing the same for use in electrophotography'1986 4,567,124'Electrophotographic element with trisazo photoconductor and an amine substituted charge transfer material'1986 4,529,678'Electrophotographic photoconductor comprising a dithiol derivative'1985 4,507,471'Trisazo compounds prepared from 4,4\',4\"-triaminotriphenylamine and 2-hydroxy-3-phenylcarbamoylbenzo[a]carbazole derivatives'1985 4,454,212'Electrophotographic photoconductor'1984 4,439,506'Multilayer electrophotographic element containing a trisazo charge carrier generating substance and an anthracene or divinyl benzene charge carrier transfer substance'1984 4,436,800'Multilayer electrophotographic element containing a trisazo charge carrier generating substance and a hydrazone charge carrier transfer substance'1984 4,426,327'3,6-Disazo-9-ethyl carbazole compounds'1984 4,365,014'Electrophotographic photoconductor'1982 4,327,020'Bis-azo compounds'1982 4,314,016'Electrophotographic element having a bisazo photoconductor'1982 4,314,015'Electrophotographic sensitive materials containing disazo compounds'1982 4,299,896'Electrophotographic sensitive materials containing a disazo pigment'1981 4,293,492'Disazo compounds derived from 3,6-bis(styryl)-9-ethylcarbazole'1981 4,293,628'Electrophotographic elements containing disazo compounds'1981 4,279,981'Electrophotographic elements containing trisazo compounds'1981 4,272,598'Electrophotographic material containing disazo compounds'1981 4,264,695'Electrophotographic photosensitive material with electron donors and electron acceptors'1981 4,260,672'Electrophotographic sensitive element having a photoconductive disazo pigment'1981 4,251,614'Novel disazo compounds, process for the preparation of same and application of said disazo compounds and analogues thereof to electrophotographic sensitive materials'1981 4,251,613'Disazo compounds, process for preparation of same and application of said disazo compounds and analogues thereof to electrophotographic sensitive materials'1981 4,247,614'Electrophotographic element containing a disazo pigment'1981 4,245,021'Electrophotographic element having charge transport layer'1981 4,242,260'2-Hydroxy-3-carbonylanilinonaphth-1-yl disazo derivatives and 1-phenyl-3-methyl-5-hydroxypyrazol-4-yl disazo derivatives of 1,4-bis(4-aminostyryl) benzene'1980 4,209,327'Electrophotographic sensitive element with benzylamino carbazole charge transfer material'1980 4,148,638'Photoconductive sensitive material with a trinitro-11-indeno[1,2-b]quinoxaline-11-one'1979 4,137,413'1,3,7-Trinitrophenazine-5-oxide'1979 4,135,928'Electrophotographic light-sensitive member'1979 4,108,656'Photoconductive member having a charge generating pigment and 2,4,7-trinitrothioxanthone as charge transport material'1978 4,082,750'Trinitro-11H-indeno[1,2-b]quinoxaline-11-one and process for preparing same'1978 4,055,421'Sensitizer for photoconductive sensitive material'1977

Career & activity timeline

Assembled from patent assignee/location history and declaration credentials.

1977–2000Patents assigned to RICOH KK (51)· patent assignee history

1977–1982Based in Tokyo, JP· patent location history

1979–1984Based in Yokohama, JP· patent location history

1981–2012Based in Numazu, JP· patent location history

1984–2013Based in Susono, JP· patent location history

1996–2001Patents assigned to HODOGAYA CHEMICAL CO LTD (8)· patent assignee history

2010–2013Patents assigned to RICOH CO LTD (10)· patent assignee history

2012–2014Patents assigned to OHTA MASAFUMI (10)· patent assignee history

2012–2013Patents assigned to YANAGAWA YOSHIKI (5)· patent assignee history

2013Based in Shizuoka, JP· patent location history

Inventor activity

Assignee and location history derived from the patent record.

Assignees

Assignee	Patents	Span
RICOH KK	51	1977–2000
OHTA MASAFUMIself	10	2012–2014
RICOH CO LTD	10	2010–2013
HODOGAYA CHEMICAL CO LTD	8	1996–2001
YANAGAWA YOSHIKI	5	2012–2013

Locations

Location	Patents	Span
Susono, JP	31	1984–2013
Yokohama, JP	14	1979–1984
Tokyo, JP	7	1977–1982
Numazu, JP	5	1981–2012
Shizuoka, JP	3	2013