Inventor
Ryoji Takeyari
Inventor
Koganei, JP
Overview
Patents· 30 as inventor
Public. Assignee & technology derived from the patent record. Each patent links to its LexDana page.
H04Bprimary
H04BTransmission33%
H04JMultiplex communication28%
H04QSelecting25%
H04LTransmission of digital information, e.g. telegraphic communication7%
H01SDevices using the process of light amplification by stimulated emission of radiation [laser] to amplify or generate light3%
H03FAmplifiers2%
H03GControl of amplification2%
PatentTitleYear
7,292,785'Optical transmission system constructing method and system'20077,167,652'Optical transmission system constructing method and system'20077,127,170'Optical frequency division multiplexing network'20067,099,596'Optical transmitter'20066,931,039'Optical transmitter equipment and semiconductor laser device'20056,850,713'Optical single sideband transmitter'20056,728,489'Optical transmission system constructing method and system'20046,658,217'Optical receiver'20036,619,865'Optical frequency division multiplexing network'20036,587,260'Band-expanding method for optical amplifiers and optical transmission apparatus'20036,304,357'Optical receiver'20016,266,169'Optical transmission equipment which transmits an amplified optical data signal and an optical surveillance signal'20016,018,405'Optical transmission equipment which transmits an amplified optical data signal and an optical surveillance signal'20006,005,699'Optical wavelength multiplexing system'19995,875,046'Optical repeater and optical transmitter'19995,861,972'Optical multiplex transmission equipment and method'19995,844,445'Feedback type pre-amplifier'19985,838,475'Optical regenerator and an optical transmission system'19985,812,289'Optical repeater and optical transmitter'19985,801,864'Optical frequency division multiplexing network'19985,739,932'Optical transmission system constructing method and system'19985,612,959'Multicast communications method'19975,576,876'Optical regenerator and an optical transmission system'19965,555,477'Optical transmission system constructing method and system'19965,510,921'Optical frequency division multiplexing network'19965,506,711'Star type multi-stage network'19965,438,444'Optical routing system'19955,323,258'Homodyne optical receiver equipment'19945,321,540'Optical frequency division multiplexing network'19945,142,402'Polarization diversity optical receiving apparatus and method'1992Career & activity timeline
Assembled from patent assignee/location history and declaration credentials.
1992–2007Patents assigned to HITACHI LTD (30)· patent assignee history
1992–2006Based in Kokubunji, JP· patent location history
1995–2007Based in Koganei, JP· patent location history
1996–1998Patents assigned to NIPPON TELEGRAPH & TELEPHONE (2)· patent assignee history
2001–2003Patents assigned to HITACHI DEVICE ENG (2)· patent assignee history
Inventor activity
Assignee and location history derived from the patent record.
Assignees
| Assignee | Patents | Span |
|---|---|---|
| HITACHI LTD | 30 | 1992–2007 |
| HITACHI DEVICE ENG | 2 | 2001–2003 |
| NIPPON TELEGRAPH & TELEPHONE | 2 | 1996–1998 |
Locations
| Location | Patents | Span |
|---|---|---|
| Koganei, JP | 22 | 1995–2007 |
| Kokubunji, JP | 8 | 1992–2006 |