John O. Ryan
77Patents
26h-index
24Co-inventors
88Inventor score
Filing activity: Mar 23, 1979 → Oct 2, 2018
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US5513260A | Method and apparatus for copy protection for various recording media | Electricity | 258 | Expired |
| US5574787A | Apparatus and method for comprehensive copy protection for video platforms and unprotected source material | Electricity | 250 | Expired |
| US5315448A | Copy protection for hybrid digital video tape recording and unprotected source material | Electricity | 246 | Expired |
| US5524051A | Method and system for audio information dissemination using various modes of transmission | Electricity | 203 | Expired |
| US5406626A | Radio receiver for information dissemenation using subcarrier | Physics | 195 | Expired |
| US6374036B1 | Method and apparatus for copy-once watermark for video recording | Electricity | 184 | Expired |
| US5751806A | Audio information dissemination using various transmission modes | Electricity | 174 | Expired |
| US5659613A | Method and apparatus for copy protection for various recording media using a video finger print | Electricity | 158 | Expired |
| US5590195A | Information dissemination using various transmission modes | Electricity | 136 | Expired |
| US4631603A | Method and apparatus for processing a video signal so as to prohibit the making of acceptable video tape recordings thereof | Electricity | 110 | Expired |
| US5754649A | Video media security and tracking system | Physics | 103 | Expired |
| US5754648A | Video media security and tracking system | Physics | 90 | Expired |
| US4695901A | Method and apparatus for removing pseudo-sync and/or agc pulses from a video signal | Electricity | 65 | Expired |
| US4819098A | Method and apparatus for clustering modifications made to a video signal to inhibit the making of acceptable videotape recordings | Electricity | 57 | Expired |
| US6330334A | Method and system for information dissemination using television signals | Electricity | 55 | Expired |
| US6381367B1 | Method and apparatus for compression compatible video fingerprinting | Physics | 53 | Expired |
| US4577216A | Method and apparatus for modifying the color burst to prohibit videotape recording | Electricity | 47 | Expired |
| US4937679A | Dual deck video recording apparatus having enhanced copy protection and method for providing enhanced copy protection to such a recording apparatus | Electricity | 44 | Expired |
| US4907093A | Method and apparatus for preventing the copying of a video program | Electricity | 43 | Expired |
| US6590979B1 | Method and apparatus for compression compatible video scrambling | Electricity | 43 | Expired |
| US5784523A | Method and apparatus for defeating effects of color burst modifications to a video signal | Electricity | 43 | Expired |
| US6091822A | Method and apparatus for recording scrambled video audio signals and playing back said video signal, descrambled, within a secure environment | Electricity | 38 | Expired |
| US5583936A | Video copy protection process enhancement to introduce horizontal and vertical picture distortions | Electricity | 33 | Expired |
| US4354243A | Two dimensional interpolation circuit for spatial and shading error corrector systems | Electricity | 28 | Expired |
| US5130810A | Method and apparatus for processing a video signal so as to prohibit the making of acceptable videotape recordings | Electricity | 27 | Expired |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.