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:
Jun. 20, 1995
Filed:
Jun. 30, 1993
Nan-Hsiung Yeh, Foster City, CA (US);
Kuo-Nan Yang, Saratoga, CA (US);
Charles R Olson, Cupertino, CA (US);
George R Varian, Palo Alto, CA (US);
Ampex Corporation, Redwood City, CA (US);
Abstract
A transition overshoot of the record current is usual to compensate record head efficiency loss at high frequencies. Recording compatibility is achieved by decreasing the record current overshoot at the digital data signal transitions as the head gap depth decreases due to wear. Additionally, the different gap depth record heads of different head efficiencies require different optimum record current levels to provide maximum signal-to-noise ratio in the reproduced signal. The head gap depth thus is monitored by means of the optimum record current level without actually measuring the gap depth. The desired amount of overshoot is adaptively adjusted to the gap depth during the recording process by tracking the overshoot to the optimum record current level derived by adjusting the record drive level signal. Recording compatibility between different gap depth heads is achieved using the existing normal record current optimization process during recording.