Reel servo control system
US4065074A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1976 |
| Grant date | Dec 27, 1977 |
| Priority date | — |
| Expiry date | Jun 2, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B15/58
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A tape reel servo control system for use with a tape transport system wherein tape loop position within vacuum loop boxes is maintained by digital techniques as opposed to analog techniques. In normal operation when the tape loop deviates from an equilibrium position in one direction within a loop box, its associated reel is accelerated to move it back to its equilibrium position by means of a series of motor drive pulses whose pulse lengths are determined by the count registered in a counter wherein the count is varied in accordance with the difference between actual and required acceleration of the reel. When the tape loop deviates from the equilibrium position in the other direction, the reel drive motor is braked by electronically shorting its terminals until the tape loop moves back to its equilibrium position. When the direction of tape movement is changed, means are provided which override the normal control of the system and prevents tape damage by overrun into or removal of the tape from its associated loop box by applying a combination of motor braking and plugging current to the motor drive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.