Mark O'Brien
9Patents
6h-index
9Co-inventors
56Inventor score
Filing activity: Aug 18, 1982 → Jun 5, 2007
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US6351464B1 | Virtual second line hybrid network communication system | Emerging Cross-Sectional Technologies | 125 | Expired |
| US6697474B1 | Systems and methods for receiving telephone calls via instant messaging | Electricity | 109 | Expired |
| US6393017B1 | Virtual PBX system | Electricity | 67 | Expired |
| US6775272B2 | Virtual PBX system | Electricity | 18 | Expired |
| US4452461A | Boomerang | Human Necessities | 13 | Expired |
| US7274778B2 | Systems and methods for receiving telephone calls via instant messaging | Electricity | 6 | Expired |
| US7496091B2 | Virtual PBX system | Electricity | 5 | Active |
| US6724754B2 | Virtual PBX system | General | 0 | Revoked |
| US8553857B2 | Systems and methods for receiving telephone calls via instant messaging | Electricity | 0 | Active |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.