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:
Jan. 27, 1976
Filed:
Apr. 29, 1974
Frederik Ate de Jonge, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A device for recording and playing back information in a spiral-like track or a track consisting of concentric circles present on a disk-shaped recording medium, in which the storage and playback element consists of a sheet of magnetizable material which contains a single-wall magnetic domain. The polarity of a radially directed magnetic field can be inverted according to a frequency modulated with a signal to be recorded so as to record information together with the stray field of the domain. A detector is present to detect position variations of the domain upon playing back and means are present to correct the position of the domain in the sheet by way of fine control upon playing back.