Kenichi Utsumi
51Patents
16h-index
69Co-inventors
87Inventor score
Filing activity: Apr 18, 1988 → Sep 14, 2007
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US5357431A | Character string retrieval system using index and unit for making the index | Emerging Cross-Sectional Technologies | 273 | Expired |
| US5857021A | Security system for protecting information stored in portable storage media | Physics | 150 | Expired |
| US5418852A | Unauthorized use prevention method for optical disks, optical disk having unauthorized use prevention function, and optical disk apparatus | Physics | 121 | Expired |
| US5537636A | File management system for a partially rewritable storage medium where file management information is created in a rewritable zone based on medium management information in a read only zone | Physics | 67 | Expired |
| US5623548A | Transformation pattern generating device and encryption function device | Electricity | 65 | Expired |
| US5982886A | Unauthorized use preventing method for optical disks, optical disk having unauthorized use prevention function, and optical disk apparatus | Physics | 52 | Expired |
| US5886979A | Information recording medium and method for recording and reproducing information to a medium to prevent unauthorized copying | Physics | 51 | Expired |
| US5327411A | Write control method and apparatus for writing optical disk data | Physics | 50 | Expired |
| US5875247A | System for decrypting encrypted software | Physics | 37 | Expired |
| US6425723B1 | Loading device | Physics | 34 | Expired |
| US5617393A | Optical disk having an erased-state indicator and optical disk apparatus for reducing frequency of disk erasing operation | Physics | 27 | Expired |
| US5684785A | Optical disk and method of preventing fraudulent use of optical disk rotation synchronous control system | Physics | 23 | Expired |
| US5708650A | Multiple format interchangeable optical recording medium and method of controlling same | Physics | 23 | Expired |
| US6999947B2 | License devolution apparatus | Electricity | 23 | Expired |
| US4889746A | Process for manufacturing an optical recording medium | Physics | 22 | Expired |
| US4947372A | Optical information memory medium for recording and erasing information | Emerging Cross-Sectional Technologies | 17 | Expired |
| US5940243A | Cartridge direct entry/exit station for library apparatus | Physics | 16 | Expired |
| US5752009A | Recording medium for electronic publications including multiple format emulation | Physics | 16 | Expired |
| US6278984A | Software processing apparatus writing software to a medium only if identification information in the software corresponds to identification information in the medium | Physics | 14 | Expired |
| US5872751A | Library apparatus and a method for assembly thereof | Physics | 14 | Expired |
| US5967339A | Positional correction relative-flag structure of cartridge storage rack in library apparatus, and library apparatus | Physics | 14 | Expired |
| US5422871A | Method and apparatus for producing an optical disk having a read-only area and a rewritable area | Physics | 13 | Expired |
| US6088189A | Cartridge entry/exit station for a library apparatus | Physics | 13 | Expired |
| US6189014A | File management method for interchangeable storage media | Physics | 12 | Expired |
| US5963514A | Accessor position alignment in a library apparatus | Physics | 11 | Expired |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.