Zero reference generating method and apparatus for optical encoders
AssigneeBEI Electronics, Inc.
InventorDale LaPlante
Life of this patent
Estimating the term…
Abstract
An encoder for providing positional information about a moveable member comprising code member means couplable to the moveable member for movement with the moveable member, reference means positioned to be stationary relative to the code member, an index sequence positioned on the code member, a mask sequence positioned on the reference member means, and means for detecting the degree of registration between the index sequence and the mask sequence, wherein the index sequence and the mask sequence include a plurality of building block patterns that are separated by predetermined spacings.
Claims14
An encoder for providing positional information about a moveable member comprising
- code member means couplable to the moveable member for movement with the moveable member;
- reference member means positioned to be stationary relative to the code member;
- an index sequence positioned at a single zero position on the code member means and on the reference member means comprising a plurality of index patterns, wherein each of the plurality of index patterns comprises a mask component positioned on the reference member means and a corresponding code disk component positioned on the code member means, and wherein for each of the plurality of index patterns the mask component includes a plurality of unit width indicia and the code disk component includes a different plurality of unit width indicia, and further wherein the mask components of each of the plurality of index patterns are separated from one another, and the code disk component of each of the plurality of index patterns are separated from one another, by predetermined spacings;
- and
- means for detecting the degree of registration between the mask and code disk components of the index sequence.
An encoder for providing positional information about a moveable member comprising
- code member means coupled to the moveable member for movement with the moveable member;
- reference member means positioned to be stationary relative to the code member means;
- position indicia positioned on the code member means along a position indica track;
- reference indicia positioned on the reference member means along a reference indicia track so that said reference indicia track is in registration with said position indicia track;
- means for determining the degree of registration between the reference indicia and the position indicia;
- an index sequence positoned at single a zero position on the code member means and reference member means said index sequence including a plurality of the same index pattern, wherein the index pattern comprises a mask component positioned on the reference member means and a code disk component positioned on the code member means, wherein the mask component and the code disk component each include a plurality of unit width indicia, and further wherein the mask components of each of the plurality of the same index pattern are separated from one another, and the code disk components of each of the plurality of the same index pattern, are separated from one another by predetermined spacings;
- and
- wherein said determining means further determines the degree of registration between the mask and code disk components of the index sequence.
An apparatus for indicating a reference position of a moveable member of the type used in positional encoders said positional encoders including a code member coupled for movement with the moveable member and a reference member which is stationary relative to the moveable member, the apparatus comprising
- an index sequence positioned about a single point on the code member and the reference member including a plurality of index patterns, wherein each of the plurality of index patterns comprises a mask component positioned on the reference member means and a corresponding code disk component positioned on the code member means, and wherein for each of the plurality of index patterns the mask component includes a plurality of unit width indicia and the code disk component includes a different plurality of unit width indicia, and further wherein the mask components of each of the plurality of index patterns are separated from one another, and the code disk component of each of the plurality of index patterns are separated by predetermined spacings;
- and
- detector means for determining the degree of registration between the mask and code disk components of the index sequence.
Dependencies are inferred from the claim text.