Inventor · Seongnam-si, KR

Masaaki Sofue

13Patents
5h-index
17Co-inventors
63Inventor score

Filing activity: May 25, 1990 → May 22, 2015

Most-cited inventions

PatentTitleAreaCited byStatus
US5086422A Optical disk apparatus Physics 49 Expired
US5991251A Method and apparatus for changing laser beam power of an optical storage device for various types of compact disks Physics 9 Expired
US5392274A Optical pickup device Physics 7 Expired
US8928220B2 White light emitting device and display apparatus Electricity 7 Active
US6128259A Optical pickup apparatus for accurate detection of a tracking error signal Physics 6 Expired
US5668793A Disk cartridge driving apparatus Physics 5 Expired
US5875155A Optical disk unit having reduced recording and reproducing errors Physics 3 Expired
US6353583B1 Signal operational circuit for a multi-beam pick-up device Physics 3 Expired
US6147947A Optical disk apparatus for accessing optical disks with different substrate thicknesses Physics 2 Expired
US5737292A Optical data recording/reproducing device Physics 2 Expired
US5926451A Optical disk unit having reduced wobble Physics 2 Expired
US9548426B2 Semiconductor light-emitting device Electricity 1 Active
US9190583B2 White light emitting device and display apparatus Electricity 0 Active

Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.