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:
Oct. 23, 2001
Filed:
May. 12, 2000
Alex Chliwnyj, Tucson, AZ (US);
Colleen Renee Stouffer, Tucson, AZ (US);
Steven Carter Wills, Tucson, AZ (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Servo errors can be avoided in a bi-directional reel-to-reel tape transport in which magnetic tape is moved in either of two opposite directions for data recording by providing a fine-line tachometer for each reel and a directly coupled tension sensor. Control of tape speed is implemented in a servo algorithm that uses tachometer inputs to determine parameter values for generating reel motor drive currents. If the linear velocity of both reels is the same then the tension output must be within a tolerable range. The directly coupled tension output provided an is indication of the actual current of the tension sensor. The difference between the linear velocities of the tape from each reel is calculated and monitored together with the tape tension. A trip level is set when an error occurs to stop tape motion and permit recovery without damaging the tape. The status of each outputs indicates the status of the tape velocity and whether the tape is slack or stretched on one reel which could cause a servo error which must be detected in order to prevent chopped blocks of data or data slivers. Motor problems may also be detected using the invention.