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:
Mar. 20, 2007
Filed:
Jul. 07, 2003
Donald K. Mitchell, Wayland, MA (US);
Donald K. Mitchell, Wayland, MA (US);
GSI Group Corporation, Billerica, MA (US);
Abstract
An optical encoder includes a sensor head, an encoder scale, and an optical wavefront dividing element. The sensor head includes a substrate, a light source, a first optical detector, and a second optical detector. The light source, the first optical detector, and the second optical detector are disposed on the substrate. The scale includes a first track and a second track. The optical wavefront dividing element is disposed between the sensor head and the scale. A light beam emitted by the light source is divided into a first beam and a second beam by the wavefront dividing element. The first beam is incident on the first track and the second beam is incident on the second track. Light from the first beam diffracted by the first track is incident on the first optical detector. Light from the second beam diffracted by the second track is incident on the second optical detector.