Inventor
KAZAWA TOHRU
JP65 patents
⚠️ This page may combine multiple inventors who share the name “KAZAWA TOHRU”. Patents are grouped by organization below to help distinguish them — per-person disambiguation is on the roadmap.
HITACHI LTD
26 patentsUS7675936B2Mar 9, 2010
Passive optical network (PON) system
HITACHI LTD73 citations98
US5500756AMar 19, 1996
Optical fiber transmission system and supervision method of the same
HITACHI LTD183 citations97
US5434886AJul 18, 1995
Digital communication system
HITACHI LTD60 citations95
US5424882AJun 13, 1995
Signal processor for discriminating recording data
HITACHI LTD24 citations93
US7873277B2Jan 18, 2011
Passive optical network system and wavelength assignment method
HITACHI LTD27 citations92
US4841521AJun 20, 1989
Method and system for bidirectionally transmitting data
HITACHI LTD25 citations92
US5237590AAug 17, 1993
Timing extraction circuit and communication system utilizing the same
HITACHI LTD42 citations90
US8374504B2Feb 12, 2013
Optical communication system
HITACHI LTD8 citations84
US8036532B2Oct 11, 2011
Passive optical network system, optical line terminal, and optical network unit
HITACHI LTD9 citations84
US7889990B2Feb 15, 2011
Optical line terminal capable of active bandwidth allocation for passive optical network system
HITACHI LTD11 citations84
US7734178B2Jun 8, 2010
Passive optical network system, optical line terminal, and optical network unit
HITACHI LTD13 citations84
US7680414B2Mar 16, 2010
Passive optical network system and operating method thereof
HITACHI LTD13 citations84
US7957647B2Jun 7, 2011
Passive optical network system and ranging method
HITACHI LTD9 citations81
US8948595B2Feb 3, 2015
Passive optical network system, optical line terminal, and optical network unit
HITACHI LTD8 citations79
US8023511B2Sep 20, 2011
Communication system, optical line terminal, and congestion control method
HITACHI LTD13 citations79
US7773880B2Aug 10, 2010
Optical access system
HITACHI LTD6 citations74
US8005362B2Aug 23, 2011
Passive optical network system and optical line terminal
HITACHI LTD6 citations73
US7725031B2May 25, 2010
Passive optical network system and ranging system thereof
HITACHI LTD7 citations73
US7711268B2May 4, 2010
Passive optical network system and ranging system thereof
HITACHI LTD5 citations73
US5276709AJan 4, 1994
Correlation code transmission system
HITACHI LTD16 citations71
US5267267ANov 30, 1993
Timing extraction method and communication system
HITACHI LTD15 citations71
US5123030AJun 16, 1992
Timing extraction method and communication system
HITACHI LTD15 citations71
US7962037B2Jun 14, 2011
PON system and optical network unit
HITACHI LTD4 citations63
US6301033B1Oct 9, 2001
Optical transmission equipment and optical networks
HITACHI LTD3 citations63
US7936992B2May 3, 2011
Apparatus of adjusting optical signal transmission timing
HITACHI LTD2 citations62
US7908390B2Mar 15, 2011
Packet forwarding apparatus using token bucket algorithm and leaky bucket algorithm
HITACHI LTD5 citations62
HITACHI COMM TECH LTD
9 patentsUS7630637B2Dec 8, 2009
PON system and optical network unit
HITACHI COMM TECH LTD20 citations93
US7483506B2Jan 27, 2009
Bit synchronization circuit with phase tracking function
HITACHI COMM TECH LTD18 citations93
US7620325B2Nov 17, 2009
Transmission apparatus with function of multi-step bandwidth assignment to other communication apparatuses
HITACHI COMM TECH LTD28 citations92
US7548694B2Jun 16, 2009
Apparatus of adjusting optical signal transmission timing
HITACHI COMM TECH LTD15 citations92
US7239813B2Jul 3, 2007
Bit synchronization circuit and central terminal for PON systems
HITACHI COMM TECH LTD24 citations89
US7369768B2May 6, 2008
Optical access system
HITACHI COMM TECH LTD12 citations84
US7512341B2Mar 31, 2009
Passive optical network system and ranging system thereof
HITACHI COMM TECH LTD4 citations73
US7489869B2Feb 10, 2009
Passive optical network system and ranging system thereof
HITACHI COMM TECH LTD7 citations73
US7676127B2Mar 9, 2010
Optical communication system using WDMA and CDMA
HITACHI COMM TECH LTD3 citations63
KAZAWA TOHRU
6 patentsUS8811819B2Aug 19, 2014
Optical multiplexing terminal device, wavelength multiplexing passive optical network system and downlink wavelength transmission method
KAZAWA TOHRU16 citations83
US8260135B2Sep 4, 2012
Passive optical network system and wavelength assignment method
KAZAWA TOHRU6 citations83
US8184977B2May 22, 2012
Optical line terminal capable of active bandwidth allocation for passive optical network system
KAZAWA TOHRU6 citations83
US8477800B2Jul 2, 2013
Passive optical network system and operation method thereof
KAZAWA TOHRU5 citations72
US8724995B2May 13, 2014
Passive optical network system and operating method thereof
KAZAWA TOHRU3 citations62
US8467684B2Jun 18, 2013
Apparatus of adjusting optical signal transmission timing
KAZAWA TOHRU2 citations62
SUGAWA JUN
2 patentsNIIBE MASAO
2 patentsOHIRA MASAKI
1 patentSUGAWARA TOSHIKI
1 patentHASEGAWA MAKOTO
1 patentTSUCHIYA AKIHIKO
1 patentMIZUTANI MASAHIKO
1 patentShowing the top 50 of 65 patents by PatentIndex Score.