Keiji Nagayama
12Patents
5h-index
24Co-inventors
66Inventor score
Filing activity: Oct 14, 1976 → Dec 20, 2007
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US6226449A | Apparatus for recording and reproducing digital image and speech | Electricity | 71 | Expired |
| US6876612B2 | Information recording apparatus and method | Physics | 14 | Expired |
| US4085034A | Method for the thermal cracking of heavy hydrocarbon | Chemistry; Metallurgy | 9 | Expired |
| US6445654B1 | Recording/reproducing method and device with supplementary data storage and output | Electricity | 8 | Expired |
| US7106954B2 | Digital camcorder | Electricity | 5 | Expired |
| US8270816B2 | Information recording and/or playback apparatus | Electricity | 3 | Active |
| US4147753A | Apparatus for the thermal cracking of heavy hydrocarbon | Chemistry; Metallurgy | 1 | Expired |
| US7885515B2 | Recording/reproducing device and recording/reproduction method | Electricity | 0 | Expired |
| US4077258A | Method of determining liquid level in a petroleum cracking reactor | Physics | 0 | Expired |
| US8009536B2 | Recording and reproducing apparatus | Electricity | 0 | Active |
| US7193946B2 | Information recording apparatus and method | Physics | 0 | Expired |
| US8224151B2 | Apparatus for recording and reproducing digital image and speech | Electricity | 0 | Active |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.