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:
Dec. 01, 1998
Filed:
Apr. 17, 1998
Richard J Ivers, West Newton, MA (US);
Cambridge Technology, Inc., Cambridge, MA (US);
Abstract
A position detector for determining the angular position of a rotatable element, the detector having a single light source for directing a uniform wide angle field of light in a direction generally along the longitudinal axis of the rotatable element, multiple sector-shaped light detectors aligned circumferentially about the rotatable element to receive light directly from the source, and a light blocker connected to the rotatable element to rotate therewith about the longitudinal axis for periodically blocking portions of the light which impinge upon the light detectors from the light source. The space between the light source and the detectors being essentially free of any object, except for the light blocker, so that the light from the light source can impinge directly upon at least those portions of the detectors which the light blocker is not blocking, without passing through any other object. A linear output of each of pairs of connected detectors being utilized to provide a reliable measurement of the angular position of the rotatable element.