Nippon Telegraph and Telephone Public Corporation
518Patents
0Active
518Granted
46Portfolio score
Filing activity: Jun 7, 1973 → May 17, 2004
Most-cited patents
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US4491386A | Optical fiber cable and process for production thereof | Physics | 245 | Expired |
| US4644458A | Electric power supply circuit capable of reducing a loss of electric power | Electricity | 219 | Expired |
| US4320191A | Pattern-forming process | Electricity | 204 | Expired |
| US4742558A | Image information retrieval/display apparatus | Electricity | 192 | Expired |
| US4538176A | Buffer memory dispersion type video/audio transmission system | Electricity | 183 | Expired |
| US4401054A | Plasma deposition apparatus | Emerging Cross-Sectional Technologies | 166 | Expired |
| US4518989A | Buffer memory dispersion type video/audio transmission system with spatially and timewise divided inter-office junction lines | Emerging Cross-Sectional Technologies | 154 | Expired |
| US4244045A | Optical multiplexer and demultiplexer | Electricity | 149 | Expired |
| US4146902A | Irreversible semiconductor switching element and semiconductor memory device utilizing the same | Electricity | 147 | Expired |
| US4047221A | Interframe coding apparatus | Electricity | 124 | Expired |
| US4503807A | Chemical vapor deposition apparatus | Emerging Cross-Sectional Technologies | 123 | Expired |
| US4547811A | Method and apparatus for gray level signal processing | Electricity | 122 | Expired |
| US4180798A | Character recognition and communication system | Physics | 119 | Expired |
| US4251691A | Picture/audio signal transmission system | Electricity | 118 | Expired |
| US4625076A | Signed document transmission system | Electricity | 115 | Expired |
| US4679244A | Method of transmitting terminating call signals within a restricted duration and a base station and a portable unit for use in the same | Emerging Cross-Sectional Technologies | 110 | Expired |
| US4142155A | Diversity system | Electricity | 105 | Expired |
| US4492620A | Plasma deposition method and apparatus | Electricity | 103 | Expired |
| US4557036A | Semiconductor device and process for manufacturing the same | Emerging Cross-Sectional Technologies | 103 | Expired |
| US4328579A | Voice band multiplex transmission system | Electricity | 98 | Expired |
| US4426247A | Method for forming micropattern | Emerging Cross-Sectional Technologies | 95 | Expired |
| US4633510A | Electronic circuit capable of stably keeping a frequency during presence of a burst | Electricity | 89 | Expired |
| US4369511A | Semiconductor memory test equipment | Physics | 89 | Expired |
| US4536887A | Microphone-array apparatus and method for extracting desired signal | Electricity | 87 | Expired |
| US4207556A | Programmable logic array arrangement | Electricity | 84 | Expired |
Source: USPTO / EPO open patent data. Counts and citation impact are objective bibliographic measures.