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:
Aug. 15, 2000
Filed:
Nov. 28, 1997
Hiroya Abe, Hiratsuka, JP;
Hideo Nishijima, Katsuta, JP;
Kouji Kaniwa, Yokohama, JP;
Kouji Minabe, Katsuta, JP;
Yoshio Narita, Katsuta, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A tracking apparatus for a helical scan magnetic recording/reproducing system includes a rotation speed controller for controlling the rotation speed of a capstan motor which transports a magnetic tape, a speed deviation generator for applying a deviation to the rotation speed, an envelope level detector for detecting the envelope level of a reproduced signal, a memory for storing the value of detection by the envelope level detector, and an envelope level comparator for comparing envelope levels before and after the deviation is applied to the rotation speed, whereby the rotation of the capstan motor is controlled so that the envelope level becomes a value in the vicinity of a maximum value. The tracking apparatus further includes a steady speed deviation detector for detecting a steady speed deviation between a recording apparatus and a reproducing apparatus, and a steady speed deviation corrector for correcting the detected speed deviation.