Title: Optical-electricity encoder
Application Number: 200610164042 Application Date: 2006.12.06
Publication Number: 1979096 Publication Date: 2007.06.13
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: G01D5/26;G01D5/36;G01D5/38
Applicant(s) Name: Mitutoyo Corp. Address:
Inventor(s) Name: Yaku Toru;Kiriyama Tetsuro
Attorney & Agent: taofeng bei
Abstract:
    A three-grating type photoelectric encoder includes a second grating (20) formed on a scale and first and third gratings (22, 31) disposed on a side of a detector. A part of at least the first grating (22) is shifted in a direction of a measurement axis by P/(2n) (wherein P is a grating pitch, n is the order of a harmonic component to be removed) in order to remove a harmonic component of the nth order. This encoder can be improved with high accuracy by removing harmonic components without increasing manufacturing costs.
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