Keiji Tomooka

Person

Yokohama-shi, JP

People

Patents Grantslast 30 patents

Information Patent Grant
Optical transmission system constructing method and system
- Patent number 7,292,785
- Issue date Nov 6, 2007
- Hitachi, Ltd.
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Optical transmission system constructing method and system
- Patent number 7,167,652
- Issue date Jan 23, 2007
- Hitachi, Ltd.
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Optical transmission system constructing method and system
- Patent number 6,728,489
- Issue date Apr 27, 2004
- Hitachi, Ltd.
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Optical transmission equipment which transmits an amplified optical...
- Patent number 6,266,169
- Issue date Jul 24, 2001
- Hitachi, Ltd.
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Optical transmission equipment which transmits an amplified optical...
- Patent number 6,018,405
- Issue date Jan 25, 2000
- Hitachi, Ltd.
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Optical wavelength multiplexing system
- Patent number 6,005,699
- Issue date Dec 21, 1999
- Hitachi, Ltd.
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Optical repeater and optical transmitter
- Patent number 5,875,046
- Issue date Feb 23, 1999
- Hitachi, Ltd.
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Optical multiplex transmission equipment and method
- Patent number 5,861,972
- Issue date Jan 19, 1999
- Hitachi, Ltd.
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Optical repeater and optical transmitter
- Patent number 5,812,289
- Issue date Sep 22, 1998
- Hitachi, Ltd.
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Optical transmission system constructing method and system
- Patent number 5,739,932
- Issue date Apr 14, 1998
- Hitachi, Ltd.
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Optical multiplex transmission equipment and method
- Patent number 5,671,074
- Issue date Sep 23, 1997
- Hitachi, Ltd.
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Add-drop multiplexer
- Patent number 5,586,115
- Issue date Dec 17, 1996
- Hitachi, Ltd.
- Yukio Nakano
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Optical transmission system constructing method and system
- Patent number 5,555,477
- Issue date Sep 10, 1996
- Hitachi, Ltd.
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Timing signal extracting circuit
- Patent number 4,658,217
- Issue date Apr 14, 1987
- Hitachi, Ltd.
- Hiroshi Takatori
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Clock signal extracting circuit
- Patent number 4,435,825
- Issue date Mar 6, 1984
- Hitachi, Ltd.
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Grant
Power supply system
- Patent number 4,425,512
- Issue date Jan 10, 1984
- Hitachi, Ltd.
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE

Patents Applicationslast 30 patents

Information Patent Application
Optical transmission system constructing method and system
- Publication number 20070053687
- Publication date Mar 8, 2007
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Application
Optical transmission system constructing method and system
- Publication number 20040161189
- Publication date Aug 19, 2004
- Hitachi, Ltd.
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE
Information Patent Application
Optical transmission system constructing method and system
- Publication number 20020024699
- Publication date Feb 28, 2002
- Hitachi, Ltd
- Keiji Tomooka
- H04 - ELECTRIC COMMUNICATION TECHNIQUE

Keiji Tomooka

Person

Patents Grantslast 30 patents

Optical transmission system constructing method and system

Optical transmission system constructing method and system

Optical transmission system constructing method and system

Optical transmission equipment which transmits an amplified optical...

Optical transmission equipment which transmits an amplified optical...

Optical wavelength multiplexing system

Optical repeater and optical transmitter

Optical multiplex transmission equipment and method

Optical repeater and optical transmitter

Optical transmission system constructing method and system

Optical multiplex transmission equipment and method

Add-drop multiplexer

Optical transmission system constructing method and system

Timing signal extracting circuit

Clock signal extracting circuit

Power supply system

Patents Applicationslast 30 patents

Optical transmission system constructing method and system

Optical transmission system constructing method and system

Optical transmission system constructing method and system