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. 03, 2009
Filed:
Apr. 11, 2002
Iain Robert Gordon-ingram, Marshfield, GB;
Iain Robert Gordon-Ingram, Marshfield, GB;
Renishaw PLC, Gloucestershire, GB;
Abstract
An absolute measurement scale has an incremental scale with light reflecting lines alternating with non-light reflecting lines in which absolute data, in the form of discrete codewords, is embedded in the incremental scale by removing light reflecting lines. The codewords are arranged such that the scale is palindromic and cyclic. A look-up table is used to determine a coarse absolute position by comparing absolute position data extracted from the scale with absolute codewords in the look-up table. The absolute position is determined by combining the coarse absolute position with the position of the start of the first codeword in the data extracted. The absolute position may be determined to within a scale pitch by combining the absolute position with the incremental position.