Magnetic head positioning and playback apparatus utilizing a split head for self-tracking and selective reproduction
US4055849A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 15, 1976 |
| Grant date | Oct 25, 1977 |
| Priority date | — |
| Expiry date | Apr 15, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B23/0007
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Magnetic head positioning and playback apparatus is provided for use with a helical scan tape recorder to accurately position a playback head with respect to a magnetic track. The playback head has a split face portion dividing the playback gap substantially in half. Reproduce signals from the corresponding portions are simultaneously processed to provide an indication of positional error and summed to provide a playback signal. In one form, by differencing the reproduce signals from the corresponding portions and by multiplying the difference and sum signals together, a usable correction signal is provided to a servo circuit for simultaneously centering the head on the track while reproducing a playback signal -- this being accomplished without the use of a separate control track. By further comparing the correction signal with a reference level, momentary disturbances in the track are detected as they occur; this information is used to determine which portion of the head provided the disturbance and to prevent that portion's signal from summing into the playback signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.