MO

Masafumi Ohta

Ricoh Company: 54 patents #183 of 9,818Top 2%
HC Hodogaya Chemical Co.: 8 patents #37 of 359Top 15%
Fujitsu Limited: 1 patents #14,843 of 24,456Top 65%
RC Richo Company: 1 patents #3 of 57Top 6%
Overall (All Time): #43,380 of 4,157,543Top 2%
57
Patents All Time

Issued Patents All Time

Showing 26–50 of 57 patents

Patent #TitleCo-InventorsDate
5153073 Electroluminescent device Teruyuki Ohnuma, Tomoyuki Shimada, Fumio Kawamura, Yohta Sakon, Toshihiko Takahashi 1992-10-06
5118986 Electroluminescent device Teruyuki Ohnuma, Fumio Kawamura, Yohta Sakon, Toshihiko Takahashi, Mitsuru Hashimoto 1992-06-02
5093210 Electroluminescent device Teruyuki Ohnuma, Fumio Kawamura, Yohta Sakon, Toshihiko Takahashi 1992-03-03
4992109 Photoelectric conversion element Masao Yoshikawa, Tetsuro Suzuki, Akio Kojima, Masayuki Shoshi 1991-02-12
4830942 Electrophotographic photoconductor Toshio Fukagai, Michio Kimura, Mitsuru Hashimoto 1989-05-16
4663442 Disazo triphenylamine compounds 1987-05-05
4596754 Electrophotographic printing original plate and electrophotographic plate making process using the printing original plate Kyoji Tsutsui, Mitsuru Hashimoto, Masaomi Sasaki 1986-06-24
4582771 Disazo compound, method for preparing the same, and electrophotographic element containing the same for use in electrophotography 1986-04-15
4567124 Electrophotographic element with trisazo photoconductor and an amine substituted charge transfer material Masaomi Sasaki, Masayuki Shoshi 1986-01-28
4529678 Electrophotographic photoconductor comprising a dithiol derivative 1985-07-16
4507471 "Trisazo compounds prepared from 4,4',4""-triaminotriphenylamine and 2-hydroxy-3-phenylcarbamoylbenzo[a]carbazole derivatives" 1985-03-26
4454212 Electrophotographic photoconductor Kiyoshi Sakai, Mitsuru Hashimoto, Masaomi Sasaki 1984-06-12
4439506 Multilayer electrophotographic element containing a trisazo charge carrier generating substance and an anthracene or divinyl benzene charge carrier transfer substance Masaomi Sasaki 1984-03-27
4436800 Multilayer electrophotographic element containing a trisazo charge carrier generating substance and a hydrazone charge carrier transfer substance Kiyoshi Sakai 1984-03-13
4426327 3,6-Disazo-9-ethyl carbazole compounds Mitsuru Hashimoto, Akio Kozima, Kiyoshi Sakai, Masaomi Sasaki 1984-01-17
4365014 Electrophotographic photoconductor Kiyoshi Sakai, Mitsuru Hashimoto, Masaomi Sasaki 1982-12-21
4327020 Bis-azo compounds Masaomi Sasaki, Kyoji Tsutsui 1982-04-27
4314016 Electrophotographic element having a bisazo photoconductor Mitsuru Hashimoto, Kyoji Tsutsui 1982-02-02
4314015 Electrophotographic sensitive materials containing disazo compounds Mitsuru Hashimoto, Kiyoshi Sakai, Akio Kozima, Masaomi Sasaki, Kyoji Tsutsui 1982-02-02
4299896 Electrophotographic sensitive materials containing a disazo pigment Mitsuru Hashimoto, Kiyoshi Sakai, Akio Kozima, Masaomi Sasaki, Kyoji Tsutsui 1981-11-10
4293628 Electrophotographic elements containing disazo compounds Mitsuru Hashimoto, Akio Kozima, Kiyoshi Sakai, Masaomi Sasaki 1981-10-06
4293492 Disazo compounds derived from 3,6-bis(styryl)-9-ethylcarbazole Masaomi Sasaki, Kiyoshi Sakai, Mitsuru Hashimoto, Kyoji Tsutsui 1981-10-06
4279981 Electrophotographic elements containing trisazo compounds Kiyoshi Sakai, Mitsuru Hashimoto, Akio Kozima, Masaomi Sasaki 1981-07-21
4272598 Electrophotographic material containing disazo compounds Masaomi Sasaki, Kiyoshi Sakai, Mitsuru Hashimoto, Akio Kozima 1981-06-09
4264695 Electrophotographic photosensitive material with electron donors and electron acceptors Akio Kozima, Mitsuru Hashimoto, Masaomi Sasaki, Zenjiro Okuno 1981-04-28