ABSOLUTE LOCATION DETECTING APPARATUS AND MEASURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an optical absolute location encoder having a relatively small reading head size and/or a relatively narrow scale width. SOLUTION: The optical absolute location encoder 100 includes a scale 110. The scale 110 includes a integrated scale track 300 extended along the directions 112 of a measuring axis. An integrated scale track 300' includes a plurality of aperiodic parts 330 and a plurality of alternately arranged periodic parts 310. Each periodic part 310 includes a plurality of periodically arranged scale elements. Each aperiodic part 330 includes code elements which indicate absolute measurement values. The code elements have a narrower length than the length of the scale elements along the directions 112 of the measuring axis. The offset of periodic elements to a reading head 126 is coupled with absolute measurement values for determining absolute values. COPYRIGHT: (C)2004,JPO