Hitachi Computer Peripherals Co., Ltd.
71Patents
39Active
71Granted
47Portfolio score
Filing activity: Apr 20, 1987 → Feb 23, 2012 · 32 expiring within 5 years
Most-cited patents
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US6795322B2 | Power supply with uninterruptible function | Electricity | 303 | Expired |
| US4872009A | Method and apparatus for data compression and restoration | Electricity | 115 | Expired |
| US6959359B1 | Software prefetch system and method for concurrently overriding data prefetched into multiple levels of cache | Physics | 45 | Expired |
| US7106904B2 | Form identification method | Physics | 43 | Expired |
| US7694092B2 | Storage subsystem and back-up/recovery method | Physics | 39 | Active |
| US7053502B2 | Power supply with uninterruptible function | Electricity | 34 | Expired |
| US7495415B2 | DC backup power supply system | Emerging Cross-Sectional Technologies | 27 | Expired |
| US7157810B2 | Backup power supply | Electricity | 27 | Expired |
| US5777952A | Thin bias magnet unit for magneto-optical recording device | Physics | 25 | Expired |
| US6507507B2 | DC power supply device | Emerging Cross-Sectional Technologies | 24 | Expired |
| US5159503A | Phase and period synchronization for a slave disk drive | Physics | 23 | Expired |
| US4803572A | Recording/reproducing method and apparatus of magnetic disk unit in which playback commences before the magnetic head is completely centered on the track | Physics | 22 | Expired |
| US5689481A | Method of accessing multifile storage medium and library system | Physics | 20 | Expired |
| US6977448B2 | Backup power supply | Electricity | 20 | Expired |
| US5623607A | Data transfer control method for controlling transfer of data through a buffer without causing the buffer to become empty or overflow | Physics | 18 | Expired |
| US5657176A | Method and apparatus for optimizing the recording and reproducing of information from magnetic disks | Physics | 17 | Expired |
| US7848118B2 | Bi-directional DC-DC converter and method for controlling the same | Emerging Cross-Sectional Technologies | 17 | Active |
| US7840840B2 | DC backup power supply system, a disk array and a DC backup power supply | Electricity | 16 | Active |
| US7589436B2 | Data processing unit and DC backup power supply | Physics | 15 | Expired |
| US5530830A | Disk array system | Physics | 15 | Expired |
| US7245469B2 | DC backup power supply device and method for diagnosing the same | Electricity | 15 | Expired |
| US6643152B2 | DC power supply device | Emerging Cross-Sectional Technologies | 14 | Expired |
| US7406623B2 | DC backup power supply system and disk array using same | Electricity | 12 | Expired |
| US7812575B2 | Bidirectional DC-DC converter and power supply apparatus with the same | Emerging Cross-Sectional Technologies | 12 | Active |
| US5860087A | Data search method wherein the court-key-data (CKD) storage subsystem disconnects from the central processing unit when searching | Physics | 12 | Expired |
Source: USPTO / EPO open patent data. Counts and citation impact are objective bibliographic measures.