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. 10, 1996
Filed:
Dec. 20, 1994
Yoshiji Kitamura, Tokyo, JP;
Hirofumi Takiue, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In order to bring and keep a slave phase of rotation of a slave spindle into and in synchronism with a master phase, the master phase is represented in a predetermined time duration by zeroth through (N-1)-th master region data with an N-th master region datum added, where N represents a predetermined integer which is not less than two. The slave phase is represented, during one rotation of the slave spindle, by zeroth through (N-1)-th slave region data with an N-th slave region datum additionally used to provide a guard time. The zeroth through the (N-1)-th slave and master region data are compared to render a phase difference between the master and the slave phases either to zero or to a predetermined value. Alternatively, the master phase is represented in the predetermined time duration by a sequence of composite pulses which comprise N master clock pulses with at least one of the clock pulses omitted to indicate a start point of the sequence. The slave phase is represented, during one rotation of the slave spindle, by a combination of N slave clock pulses and a slave index signal. As a further alternative, the master phase is represented by a combination of the N master clock pulses without omission and a master index signal produced once in the predetermined time duration.