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:
Sep. 12, 1995
Filed:
Jul. 01, 1993
Sony Corporation, Tokyo, JP;
Abstract
Magneto-optically recorded data can be recorded at high density, such that the data can be overwritten by a simple arrangement and with a small energy. Also, data of high recording density can be accurately recorded and reproduced by a simple arrangement. An alternating field having the same frequency as that of a recording fundamental clock generated by a PLL circuit (8) is generated by a coil (5) that is part of a tank circuit (7) and then applied to a magneto-optical disc (1). A phase of the recording fundamental clock is modulated by a phase modulating circuit (12) in association with recording data and a pulse synchronized with leading edge and trailing edge of such clock is generated by a pulse generating circuit (13). An optical pickup device (4) irradiates the magneto-optical disc (1) with a laser light in synchronism with the pulse. Therefore, a high density recording method in which the edge position of pit is shifted stepwise in association with data to be recorded can be applied to a magneto-optical recording medium.