US 9,810,554 B2
Position measuring instrument
Johann Oberhauser, Vachendorf (DE); and Heinz Tovar, Siegsdorf (DE)
Assigned to DR. JOHANNES HEIDENHAIN GMBH, Traunreut (DE)
Filed by Dr. Johannes Heidenhain GmbH, Traunreut (DE)
Filed on Jun. 4, 2013, as Appl. No. 13/909,603.
Claims priority of application No. 12171783 (EP), filed on Jun. 13, 2012.
Prior Publication US 2013/0334409 A1, Dec. 19, 2013
Int. Cl. G01D 5/347 (2006.01)
CPC G01D 5/3473 (2013.01) [G01D 5/34792 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A position measuring instrument, comprising:
a code carrier comprising:
a first code track comprising a first series of consecutive and uninterrupted code elements, wherein each of said consecutive and uninterrupted code elements of said first series of code elements consists essentially of two subregions with associated complementary properties, which are disposed in succession in a measuring direction; and
a second code track extending parallel to said first code track and comprising a second series of code elements that is identical to said first series of consecutive and uninterrupted code elements, wherein said first series of consecutive and uninterrupted code elements and said second series of code elements each define identical code information, wherein said second series of code elements of said second code track is displaced, relative to said first series of consecutive and uninterrupted code elements of said first code track, in said measuring direction on said code carrier in such a way that said consecutive and uninterrupted code elements of said first code track and said code elements of said second code track that form a code word overlap one another at least partially, and wherein said second series of code elements of said second code track are displaced by an amount V=N/2+K/2 code elements relative to said first series of consecutive and uninterrupted code elements of said first code track;
a scanning unit comprising a plurality of detectors for scanning code elements of said first code track and said second code track, wherein said plurality of detectors form a corresponding scanning signal from each of said two subregions of said scanned code elements; and
an evaluation unit comprising a structure for generating one item of code information in the form of a Bit from said corresponding scanning signal formed from each of said two subregions of each of said scanned code elements, and for forming said code word from said Bits which defines an absolute position in said measuring direction, wherein said code word is composed of N Bits from successive code elements of said first code track and K Bits from successive code elements of said second code track, with N and K being greater than 1.