The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 19, 1996
Filed:
Feb. 28, 1995
International Business Machines Corporation, Armonk, NY (US);
Abstract
Air entrainment effects are avoided in a bi-directional, reel-to-reel tape transport in which magnetic tape can be moved in either of two opposing directions for data recording thereon. Control of tape position is implemented in a servo algorithm that uses tachometer inputs to determine parameter values for generating reel motor drive currents. A fine-line tachometer is mounted on each of two reels in the tape drive and multiplexing selects the fine-line output from the tachometer on the reel supplying tape for use in the servo algorithm. At least one of the tachometers is preferably of the type which generates an index line once each revolution of the motor to which it is mounted. This tachometer is coupled to the reel to which the tape is initially threaded and the index line is used to indicate that the motor is at a predetermined threading position for this operation.