Keiji Koga
41Patents
9h-index
41Co-inventors
75Inventor score
Filing activity: Aug 14, 1986 → Feb 24, 2009
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US5419938A | Magnetic recording medium comprising two magnetic layers of hexagonal ferrite magnetic particles and binder wherein the easy axes of the particle is specified | Emerging Cross-Sectional Technologies | 111 | Expired |
| US5589297A | Lithium secondary cell | Emerging Cross-Sectional Technologies | 47 | Expired |
| US5565284A | Lithium secondary cell | Emerging Cross-Sectional Technologies | 41 | Expired |
| US4794042A | Magnetic recording medium | Emerging Cross-Sectional Technologies | 35 | Expired |
| US5160761A | Method for making a magnetic disk | Emerging Cross-Sectional Technologies | 24 | Expired |
| US4772522A | Magnetic recording medium | Emerging Cross-Sectional Technologies | 21 | Expired |
| US5530609A | Magnetic recording/reproducing method using a thin film magnetic | Physics | 16 | Expired |
| US6930911B2 | Magnetic memory device, method for writing on the same and method for reading from the same | Physics | 14 | Expired |
| US5219708A | Optical disk | Emerging Cross-Sectional Technologies | 11 | Expired |
| US5340698A | Optical disk | Emerging Cross-Sectional Technologies | 9 | Expired |
| US4780366A | Magnetic recording medium for image recording | Emerging Cross-Sectional Technologies | 9 | Expired |
| US7209380B2 | Magnetic memory device and method of reading the same | Electricity | 8 | Expired |
| US5140486A | Magnetic recording and reproduction | Physics | 8 | Expired |
| US7825658B2 | Magnetic device and frequency detector | Electricity | 7 | Active |
| US6996001B2 | Magnetic memory device, write current drive circuit, and write current drive method | Physics | 7 | Expired |
| US4741977A | Magnetic sheet | Emerging Cross-Sectional Technologies | 7 | Expired |
| US4834213A | Noise silencer for use in joint gap in highway | Fixed Constructions | 7 | Expired |
| US7991377B2 | Mixer and frequency converting apparatus | Electricity | 6 | Active |
| US7808229B2 | Magnetic device and frequency analyzer | Electricity | 5 | Active |
| US7277320B2 | Magnetic memory device, sense amplifier circuit and method of reading from magnetic memory device | Electricity | 5 | Expired |
| US7295460B2 | Magnetic memory cell, magnetic memory device, and method of manufacturing magnetic memory device | Electricity | 4 | Expired |
| US7227771B2 | Magnetoresistive effect element and magnetic memory device | Physics | 4 | Expired |
| US5393584A | Magnetic disc | Emerging Cross-Sectional Technologies | 4 | Expired |
| US7342822B2 | Magnetic memory device, write current driver circuit and write current driving method | Physics | 4 | Expired |
| US7100675B2 | Air conditioner for vehicle | Performing Operations; Transporting | 4 | Expired |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.