Hisashi Yamada
128Patents
22h-index
170Co-inventors
93Inventor score
Filing activity: Dec 15, 1975 → May 4, 2017
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US6490683B1 | Optical disk having electronic watermark, reproducing apparatus thereof and copy protecting method using the same | Physics | 136 | Expired |
| US6301663A | Copy protection apparatus and information recording medium used in this copy protection apparatus | Physics | 119 | Expired |
| US4432610A | Liquid crystal display device | Physics | 95 | Expired |
| US4491553A | Method for producing filler-loaded thermoplastic resin composite | Chemistry; Metallurgy | 94 | Expired |
| US5903531A | Reproduction device for optical disks | Physics | 73 | Expired |
| US7137012B1 | Storage medium and contents protection method using the storage medium | Physics | 64 | Expired |
| US4830779A | Electrically conductive resin composition | Electricity | 46 | Expired |
| US4800339A | Amplifier circuit | Electricity | 41 | Expired |
| US6144743A | Information recording medium, recording apparatus, information transmission system, and decryption apparatus | Physics | 39 | Expired |
| US5930214A | Recording/reproducing optical head apparatus compatible with different optical media | Physics | 38 | Expired |
| US7065648B1 | Mutual authentication method, recording apparatus, reproducing apparatus, and recording medium | Physics | 36 | Expired |
| US5729510A | Optical head used for recording on optical recording medium having various thicknesses, warpage and the like | Physics | 35 | Expired |
| US6847950B1 | Contents managing method and contents managing apparatus | Physics | 35 | Expired |
| US6795381B2 | Multi-body multi-purpose information processing apparatus | Physics | 34 | Expired |
| US6556679B1 | Copy-guard system and information recording medium used in the same system | Electricity | 34 | Expired |
| US5774078A | Single merging bit DC-suppressed run length limited coding | Physics | 30 | Expired |
| US5325242A | Magnetic recording/reproducing apparatus for decreasing an error rate in recording/reproducing a digital signal | Physics | 28 | Expired |
| US6159572A | Information recording medium and method of manufacturing resinous substrate for use in the recording medium | Emerging Cross-Sectional Technologies | 27 | Expired |
| US6438692B1 | Copy protection apparatus and information recording medium used in this copy protection apparatus | Physics | 24 | Expired |
| US4023053A | Variable capacity diode device | Electricity | 23 | Expired |
| US5987066A | Digital data transmitting method | Electricity | 22 | Expired |
| US5475210A | Noise reduction system for optical record and reproduction apparatus using auto-power controlled semiconductor laser device | Electricity | 22 | Expired |
| US5677801A | Magnetic recording/reproducing apparatus for automatically adjusting a recording current in accordance with the wear of a read head | Physics | 22 | Expired |
| US4542370A | Cascade-comparator A/D converter | Electricity | 21 | Expired |
| US7181008B1 | Contents management method, content management apparatus, and recording medium | Physics | 21 | Expired |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.