Akira Usui
58Patents
18h-index
85Co-inventors
87Inventor score
Filing activity: Jun 30, 1981 → Feb 26, 2015
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US6252261A | GaN crystal film, a group III element nitride semiconductor wafer and a manufacturing process therefor | Electricity | 203 | Expired |
| US6348096B1 | Method for manufacturing group III-V compound semiconductors | Emerging Cross-Sectional Technologies | 138 | Expired |
| US5469806A | Method for epitaxial growth of semiconductor crystal by using halogenide | Chemistry; Metallurgy | 105 | Expired |
| US4409776A | Method and apparatus for packing articles with composite stretched films | Performing Operations; Transporting | 91 | Expired |
| US6924159B2 | Semiconductor substrate made of group III nitride, and process for manufacture thereof | Electricity | 56 | Expired |
| US6555845B2 | Method for manufacturing group III-V compound semiconductors | Emerging Cross-Sectional Technologies | 44 | Expired |
| US5014349A | Television tuner for common use in BS/UV | Electricity | 30 | Expired |
| US6183677A | Method of manufacturing abrasive sheet with thin resin film | Emerging Cross-Sectional Technologies | 28 | Expired |
| US4680602A | Light emitting diode | Electricity | 27 | Expired |
| US5355532A | Television tuner unit having shield housing | Electricity | 27 | Expired |
| US5179729A | Tuner station selecting apparatus | Electricity | 25 | Expired |
| US5902393A | Method for growing p-type gallium nitride based compound semiconductors by vapor phase epitaxy | Electricity | 24 | Expired |
| US4694293A | Data transmission system | Electricity | 23 | Expired |
| US7196399B2 | Epitaxially grown nitride-based compound semiconductor crystal substrate structure with low dislocation density | Electricity | 21 | Expired |
| US8345883B2 | Audio playback method and apparatus using line array speaker unit | Electricity | 19 | Active |
| US4861941A | Shielding device | Emerging Cross-Sectional Technologies | 18 | Expired |
| US5553042A | Optical disk recording device | Physics | 18 | Expired |
| US4817195A | Channel selection apparatus having automatic frequency compensation for transmission frequency error | Electricity | 18 | Expired |
| US7082094B2 | Optical recording apparatus with drawing capability of visible image on disk face | Physics | 17 | Expired |
| US5598447A | Integrated circuit device having internal fast clock source | Electricity | 17 | Expired |
| US6345388B1 | Method and apparatus for transmitting and receiving television signal | Electricity | 17 | Expired |
| US6812051B2 | Method of forming an epitaxially grown nitride-based compound semiconductor crystal substrate structure and the same substrate structure | Electricity | 16 | Expired |
| US5526333A | Optical disk recording device | Physics | 14 | Expired |
| US4677692A | Frequency conversion apparatus | Electricity | 13 | Expired |
| US7189588B2 | Group III nitride semiconductor substrate and its manufacturing method | Electricity | 13 | Expired |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.