Masaaki Sofue

Person

Tokyo, JP

People

Patents Grantslast 30 patents

Information Patent Grant
Signal operational circuit for a multi-beam pick-up device
- Patent number 6,353,583
- Issue date Mar 5, 2002
- Ricoh Company, Ltd.
- Ryuuji Kudoh
- G11 - INFORMATION STORAGE
Information Patent Grant
Optical disk apparatus for accessing optical disks with different s...
- Patent number 6,147,947
- Issue date Nov 14, 2000
- Ricoh Co., Ltd.
- Masaaki Sofue
- G11 - INFORMATION STORAGE
Information Patent Grant
Optical pickup apparatus for accurate detection of a tracking error...
- Patent number 6,128,259
- Issue date Oct 3, 2000
- Ricoh Co., Ltd.
- Masaaki Sofue
- G11 - INFORMATION STORAGE
Information Patent Grant
Method and apparatus for changing laser beam power of an optical st...
- Patent number 5,991,251
- Issue date Nov 23, 1999
- Ricoh Company, Ltd.
- Tatsuaki Sakurai
- G11 - INFORMATION STORAGE
Information Patent Grant
Optical disk unit having reduced wobble
- Patent number 5,926,451
- Issue date Jul 20, 1999
- Ricoh Co., Ltd.
- Masaaki Sofue
- G11 - INFORMATION STORAGE
Information Patent Grant
Optical disk unit having reduced recording and reproducing errors
- Patent number 5,875,155
- Issue date Feb 23, 1999
- Ricoh Company, Ltd.
- Masaaki Sofue
- G11 - INFORMATION STORAGE
Information Patent Grant
Optical data recording/reproducing device
- Patent number 5,737,292
- Issue date Apr 7, 1998
- Ricoh Company, Ltd.
- Syuichi Honda
- G11 - INFORMATION STORAGE
Information Patent Grant
Disk cartridge driving apparatus
- Patent number 5,668,793
- Issue date Sep 16, 1997
- Ricoh Company, Ltd.
- Takashi Ogawa
- G11 - INFORMATION STORAGE
Information Patent Grant
Optical pickup device
- Patent number 5,392,274
- Issue date Feb 21, 1995
- Ricoh Company, Ltd.
- Masaaki Sofue
- G11 - INFORMATION STORAGE
Information Patent Grant
Optical disk apparatus
- Patent number 5,086,422
- Issue date Feb 4, 1992
- Ricoh Company, Ltd.
- Toshimichi Hagiya
- G11 - INFORMATION STORAGE

Masaaki Sofue

Person

Patents Grantslast 30 patents

Signal operational circuit for a multi-beam pick-up device

Optical disk apparatus for accessing optical disks with different s...

Optical pickup apparatus for accurate detection of a tracking error...

Method and apparatus for changing laser beam power of an optical st...

Optical disk unit having reduced wobble

Optical disk unit having reduced recording and reproducing errors

Optical data recording/reproducing device

Disk cartridge driving apparatus

Optical pickup device

Optical disk apparatus