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:
May. 12, 1981
Filed:
Feb. 27, 1979
Kazuhiko Kawakami, Katsuta, JP;
Noboru Sugiura, Katsuta, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A rotational angle detecting apparatus comprises a rotary disc having first protrusions for an angle signal provided along the outer periphery of the disc and second protrusion for a reference signal arranged adjacent to the first protrusions in the thickness direction of the disc. A pick-up assembly is disposed to face the second protrusion to sense the rotationl position thereof. The sensed signal including noise components due to a magnetic coupling between the pick-up assembly and the first protrusions is subject to an integration and then applied to a level detector to generate a first pulse signal which occurs only during the integration signal being greater than a predetermined threshold level. On the other hand, a second pulse signal is produced by shaping the sensed signal. The first and second pulse signals are applied to an AND logic gate from which an output pulse is obtained in synchronism with the rotation of the disc.