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:
Jan. 05, 1999
Filed:
Oct. 02, 1997
Applicant:
Inventor:
Bruce A Horwitz, Newton Centre, MA (US);
Assignee:
MicroE, Inc., Natick, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01B / ;
U.S. Cl.
CPC ...
356356 ; 25023117 ;
Abstract
An index structure and method are disclosed which employ, in addition to a main diffractive grating track of an encoder, a short diffractive grating track (the vernier or index track) having a different frequency than that of the main track. The phase of the index track is used to provide windows for the main track in a manner so that a preselected phase condition of the main track occurs in only one of the windows provided by the index track.