AO

Akihiko Oka

Fujitsu Limited: 10 patents #3,161 of 24,456Top 15%
HI Hitachi: 3 patents #10,712 of 28,497Top 40%
Overall (All Time): #388,296 of 4,157,543Top 10%
13
Patents All Time

Issued Patents All Time

Showing 1–13 of 13 patents

Patent #TitleCo-InventorsDate
7020395 Optical transmission apparatus monitoring optical performance Dai Hagimura, Junichi Ishiwatari 2006-03-28
6657953 Signal loopback device Masanori Hiramoto, Hidetaka Kawahara, Keiichiro Tsukamoto 2003-12-02
6192437 Transmission apparatus with control circuit/relay within each card providing connection to related card output depending on related slot ID/ redundancy/non-redundancy, working/protection signals Keiichiro Tsukamoto 2001-02-20
6188701 Apparatus and method for interfacing between communication networks Keiichiro Tsukamoto 2001-02-13
5790520 Path protection switch ring system for line saving even though line setting operation was not carried out Koji Iwamoto 1998-08-04
5757774 Network traffic protection system 1998-05-26
5754545 Add-drop multiplexer with enhancement of accessibility to signals in different hierarchical levels and flexibility in various services and circuit setting operations Masahiro Shinbashi, Kazuo Takatsu, Hideaki Mochizuki, Junichi Ishiwatari, Koji Iwamoto 1998-05-19
5719747 Interface unit for communication device with parts positioned on a printed-wiring board for achieving desirable operating characteristics Kazuaki Kashiwada, Kenji Joukou 1998-02-17
5640140 Alarm processing apparatus Kanta Yamamoto 1997-06-17
5557437 Optical terminal system having self-monitoring function Toshiharu Sakai, Yoshinori Nakamura, Takashi Umegaki, Nobuo Iguchi, Miki Hagino +4 more 1996-09-17
5177758 Semiconductor laser device with plural active layers and changing optical properties Shinji Sakano, Naoki Chinone, Tsukuru Ohtoshi, Kazuhisa Uomi, Tomonobu Tsuchiya +1 more 1993-01-05
5173909 Wavelength tunable laser diode Shinji Sakano, Katutoshi Saito, Naoki Chinone 1992-12-22
5119393 Semiconductor laser device capable of controlling wavelength shift Shinji Sakano, Naoki Chinone, Tsukuru Ohtoshi, Kazuhisa Uomi, Tomonobu Tsuchiya +1 more 1992-06-02