Apparatus and method for automatic write current calibration in a streaming tape drive
US5172280A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 26, 1989 |
| Grant date | Dec 15, 1992 |
| Priority date | — |
| Expiry date | Oct 26, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/09
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus and a method for calibrating the write current applied to a write head (110, 114) in a tape drive (100) finds the peak value of the write current applied to the tape head (110, 114) (i.e., the write current value providing the maximum read voltage amplitude on a tape (104)) by indirectly measuring the voltage sensed by a read head (112, 115). The apparatus includes a digital write current control circuit (170, 160) that applies a write current having a magnitude responsive to a digital write current value. An amplifier (190) in a read circuit (180, 182, 184, 190, 196) has a gain responsive to a digital read gain value. The method includes the steps of sampling the output of a pattern detector (146) (e.g., a gap detector) as the digital read gain value is adjusted for each of a number of digital write current data values applied to the write current control circuit (170, 160). The digital read gain value is adjusted to provide a predetermined range of the number of samples wherein the pattern corresponds to a predetermined pattern. The digital read gain value for each digital write current value is inversely related to the amplitude of the signal recorded on the tape (1…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.