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:
Apr. 10, 2001
Filed:
Nov. 28, 1997
Keitaro Yamashita, Kanagawa, JP;
Kanzo Okada, Chiba, JP;
Shunji Okada, Kanagawa, JP;
Masayuki Nakayama, Tokyo, JP;
Minoru Watanabe, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
In a recording/reproduction apparatus, when a rotational-speed-mode setting instruction is received from an I/F unit, a CPU reads out a control procedure from a storage device, controlling other components in accordance with the procedure. As a result, a node switch driving circuit controls field windings of a pulse motor to a switching sequence, driving the pulse motor to rotation at a predetermined rotational speed. Since the control is feedback control, the pulse motor rotates at the predetermined rotational speed specified by an instruction setting a rotational-speed mode with a high degree of reliability. Data can thus be recorded into and reproduced from a magnetic disk at a variable speed.