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:
Nov. 30, 1999
Filed:
May. 28, 1997
Shigeru Furuki, Fukushima-ken, JP;
Mikio Sekine, Fukushima-ken, JP;
Alps Electric Co. Ltd., Tokyo, JP;
Abstract
An index signal generating circuit for generating a precise index signal free from time shifting even under ambient temperature changes. An index signal generating circuit includes a magnet attached onto the circumference of the rotor of a spindle motor, a magnetic flux detecting device for detecting magnetic flux of the magnet when the magnet moves past the magnetic flux detecting device, a Hall effect device for switching a current in the driving coil of the spindle motor, a first waveform shaping circuit for shaping the detected output of the magnetic flux detecting device into a rectangular-wave signal, a second waveform shaping circuit for shaping the output of the Hall effect device into a rectangular-wave signal, and a logic circuit for ANDing the output rectangular-wave signals from the first and second waveform shaping circuits, wherein an index signal is generated at the timing of a transition of the AND output of the logic circuit.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile