Inventor · Tokyo, JP

Seiji Oka

59Patents
15h-index
94Co-inventors
87Inventor score

Filing activity: Feb 29, 1984 → Mar 21, 2023

Most-cited inventions

PatentTitleAreaCited byStatus
US5109254A Developing apparatus Emerging Cross-Sectional Technologies 69 Expired
US5805965A Developing device for an image forming apparatus having developer distribution features Physics 58 Expired
US5659860A Developing device for an image forming apparatus and toner cartridge Physics 56 Expired
US5416568A Developing unit for an image forming apparatus Physics 54 Expired
US5771426A Developing device using a toner and carrier mixture Physics 45 Expired
US5983059A Recyclable toner container for an image forming apparatus Physics 42 Expired
US5235384A Image forming apparatus with replaceable process units Physics 39 Expired
US5822664A Developing machine which uses a developing agent including a toner and magnetic particles Physics 38 Expired
US4650070A Toner cartridge Emerging Cross-Sectional Technologies 38 Expired
US5758241A Developing device for an image forming apparatus Physics 32 Expired
US5771429A Developing device capable of automatic toner content control Physics 25 Expired
US4800411A Magnetic brush development device for electrostatic latent images Physics 24 Expired
US4799608A Toner cartridge Emerging Cross-Sectional Technologies 22 Expired
US5255059A Image forming apparatus Physics 21 Expired
US4969557A Toner cartridge Emerging Cross-Sectional Technologies 17 Expired
US5077584A Toner supply device for electrophotographic equipment Emerging Cross-Sectional Technologies 11 Expired
US8436459B2 Power semiconductor module Electricity 10 Active
US6664127B2 Method of manufacturing multi-layer printed wiring board Emerging Cross-Sectional Technologies 9 Expired
US6108511A Toner collecting and reusing device for use in an image forming apparatus and a method thereof Physics 8 Expired
US8299601B2 Power semiconductor module and manufacturing method thereof Electricity 8 Active
US5555469A Image forming apparatus having toner recycling device with electrostatic conveyor Physics 8 Expired
US8502385B2 Power semiconductor device Electricity 8 Active
US6807072B2 Electric power conversion device with push-pull circuitry Electricity 7 Expired
US4591623A Thermosetting resin composition Chemistry; Metallurgy 6 Expired
US6451710B1 Method of manufacturing multi-layer printed wiring board Emerging Cross-Sectional Technologies 5 Expired

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