Masafumi Ohta
63Patents
18h-index
44Co-inventors
84Inventor score
Filing activity: Dec 10, 1975 → Jun 15, 2012
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US5492784A | Positively-chargeable single-layered type electrophotographic photoconductor | Physics | 64 | Expired |
| US5420288A | Electroluminescent device comprising oxadiazole compounds luminescent material, oxadiazole compounds for the device, and method of producing oxadiazole compounds | Electricity | 62 | Expired |
| US5656401A | Electroluminescent device comprising oxadiazole compounds luminescent material, oxadiazole compounds for the device, and method of producing oxadiazole compounds | Electricity | 58 | Expired |
| US5597925A | Method of producing oxadiazole compounds | Electricity | 55 | Expired |
| US5610309A | Electroluminescent device comprising oxadiazole compounds luminescent material, oxadiazole compounds for the device, and method of producing oxadiazole compounds | Electricity | 53 | Expired |
| US5153073A | Electroluminescent device | Emerging Cross-Sectional Technologies | 52 | Expired |
| US4245021A | Electrophotographic element having charge transport layer | Emerging Cross-Sectional Technologies | 51 | Expired |
| US5747204A | Electrophotographic photoconductor and aromatic polycarbonate resin for use in the same | Physics | 36 | Expired |
| US6027846A | Electrophotographic photoconductor and aromatic polycarbonate resin for use therein | Physics | 31 | Expired |
| US4264695A | Electrophotographic photosensitive material with electron donors and electron acceptors | Emerging Cross-Sectional Technologies | 27 | Expired |
| US4596754A | Electrophotographic printing original plate and electrophotographic plate making process using the printing original plate | Physics | 25 | Expired |
| US4279981A | Electrophotographic elements containing trisazo compounds | Chemistry; Metallurgy | 24 | Expired |
| US4272598A | Electrophotographic material containing disazo compounds | Chemistry; Metallurgy | 23 | Expired |
| US5118986A | Electroluminescent device | Electricity | 23 | Expired |
| US4251614A | Novel disazo compounds, process for the preparation of same and application of said disazo compounds and analogues thereof to electrophotographic sensitive materials | Physics | 20 | Expired |
| US4260672A | Electrophotographic sensitive element having a photoconductive disazo pigment | Emerging Cross-Sectional Technologies | 19 | Expired |
| US6316577A | Electrophotographic photoconductor and aromatic polycarbonate resin for use therein | Physics | 19 | Expired |
| US4251613A | Disazo compounds, process for preparation of same and application of said disazo compounds and analogues thereof to electrophotographic sensitive materials | Chemistry; Metallurgy | 18 | Expired |
| US4299896A | Electrophotographic sensitive materials containing a disazo pigment | Physics | 18 | Expired |
| US4582771A | Disazo compound, method for preparing the same, and electrophotographic element containing the same for use in electrophotography | Chemistry; Metallurgy | 16 | Expired |
| US5604065A | Electrophotographic photoconductor and triphenylamine compound for use therein | Physics | 16 | Expired |
| US4507471A | "Trisazo compounds prepared from 4,4',4""-triaminotriphenylamine and 2-hydroxy-3-phenylcarbamoylbenzo[a]carbazole derivatives" | Physics | 16 | Expired |
| US4314015A | Electrophotographic sensitive materials containing disazo compounds | Physics | 15 | Expired |
| US5830980A | Electrophotographic photoconductor, aromatic polycarbonate resin for use in the same, and method of producing the aromatic polycarbonate resin | Physics | 15 | Expired |
| US4567124A | Electrophotographic element with trisazo photoconductor and an amine substituted charge transfer material | Physics | 15 | Expired |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.