Inventor · disambiguated record
Takefumi Oguma
Also filed as: OGUMA TAKEFUMI
18 granted patents·8 pending applications·122 citations·filing 1996–2022
92Inventor score
Top patents by PatentIndex Score
26 records- 0188US8135280B2Method and system for power stability control in wavelength division multiplexing networksZONG LEI·Filed 2008·Granted Mar 13, 2012·21 cites·18 claims
- 0286US11483067B2Optical time domain reflectometer, test method of optical transmission line, and test system of optical transmission lineNEC CORP·Filed 2019·Granted Oct 25, 2022·5 cites·12 claims
- 0374US11476930B2Optical time domain reflectometer, method of testing optical transmission line, and test system of optical transmission lineNEC CORP·Filed 2019·Granted Oct 18, 2022·3 cites·17 claims
- 0471US8095011B2Wavelength division multiplexing filter, wavelength division multiplexing system, and wavelength division multiplexing methodYANO YUTAKA·Filed 2009·Granted Jan 10, 2012·4 cites·12 claims
- 0570US7127183B2Output monitor/control apparatus and optical communication systemNEC CORP·Filed 2001·Granted Oct 24, 2006·12 cites·17 claims
- 0666US7389032B2Method and apparatus for adjusting loss caused by optical fiber curvature, and optical transmission system using the sameNEC CORP·Filed 2006·Granted Jun 17, 2008·4 cites·16 claims
- 0765US6911627B2Heating element device, heating element mounted structure, temperature control circuit, temperature control apparatus, and moduleNEC CORP·Filed 2003·Granted Jun 28, 2005·10 cites·45 claims
- 0865US2023104053A1Optical transmission apparatus and control method of optical transmission apparatusNEC CORP·Filed 2022·Application pending·0 cites
- 0961US5880874AOptical equalizer and optical amplifier and wavelength multiple optical transmission apparatus using optical equalizerNEC CORP·Filed 1997·Granted Mar 9, 1999·27 cites·45 claims
- 1060US5936768AOptical passive device for an optical fiber amplifier and the optical amplifierNEC CORP·Filed 1996·Granted Aug 10, 1999·25 cites·8 claims
- 1159US8238745B2Collection of data from an optical channel monitor without causing a malfunction of a transmission apparatusOGUMA TAKEFUMI·Filed 2008·Granted Aug 7, 2012·2 cites·9 claims
- 1259US2024055819A1Optical amplifierNEC CORP·Filed 2022·Application pending·0 cites
- 1358US8879908B2Optical channel monitorOGUMA TAKEFUMI·Filed 2012·Granted Nov 4, 2014·1 cites·7 claims
- 1447US11626937B2Optical transmission apparatus and control method of optical transmission apparatusNEC CORP·Filed 2017·Granted Apr 11, 2023·0 cites·20 claims
- 1546US2013315601A1Optical transmission deviceOGUMA TAKEFUMI·Filed 2012·Application pending·0 cites
- 1646US2013315602A1Optical transmission deviceOGUMA TAKEFUMI·Filed 2011·Application pending·0 cites
- 1744US10539741B2Optical device with optical filters and processing method of optical signalsNEC CORP·Filed 2017·Granted Jan 21, 2020·0 cites·16 claims
- 1844US7649162B2Optical feedback control unit, optical communication system, feedback control method, and recording medium for recording programOGUMA TAKEFUMI·Filed 2008·Granted Jan 19, 2010·0 cites·15 claims
- 1943US10659165B2Optical transmission deviceNEC CORP·Filed 2017·Granted May 19, 2020·0 cites·13 claims
- 2042US2023138272A1Node apparatus, wdm transmission system, and control methodNEC CORP·Filed 2021·Application pending·0 cites
- 2140US2006239684A1Optical add/drop device, optical add/drop system, and optical signal add/drop methodNEC CORP·Filed 2006·Application pending·0 cites
- 2237US8837939B2Wavelength division multiplexing transmission system, optical channel monitor and optical channel monitoring methodSUGAHARA HIROMITSU·Filed 2011·Granted Sep 16, 2014·0 cites·8 claims
- 2337US6597483B1Laser oscillation wavelength monitoring deviceNEC CORP·Filed 1999·Granted Jul 22, 2003·8 cites·20 claims
- 2436US6601401B2Temperature controller and light-waveguide with the sameNEC CORP·Filed 2001·Granted Aug 5, 2003·0 cites·12 claims
- 2536US2003127445A1Heater for heating waveguide and waveguide with heaterNEC CORP·Filed 2002·Application pending·0 cites
- 2634US2012008941A1Optical channel monitor and method of calculating signal light level of optical channel monitorOGUMA TAKEFUMI·Filed 2010·Application pending·0 cites
Join the waitlist — get patent alerts
Get an alert when Takefumi Oguma files or is granted a new patent.
We store only your email — no account needed. See our privacy policy.
Identity basis: PatentsView inventor disambiguation (2025Q4-odp release). How scoring works →