Encoder unit using magnetoresistance effect element
AssigneeCanon Denshi Kabushiki Kaisha
InventorsShuzo Abiko, Hirokazu Goto, Masakazu Kuhara, Hideto Sano, Hisanori Hayashi, Takeshi Osato
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Abstract
An encoder unit comprising an object to be detected having a track having a first region with a magnetization pattern at a predetermined pitch and a second region having no periodic magnetization pattern, and a detector having a magnetoresistance effect element arranged in the direction which intersects the direction of the magnetic flux of the magnetization pattern and in opposed relationship with the object to be detected. The encoder unit is simple in construction yet capable of detecting the position of the object to be detected with a higher degree of accuracy than conventional encoders.
Claims6
An encoder unit comprising:
- an object to be detected which has a plurality of tracks each alternately having a first region having a periodic magnetization pattern and a second region having no magnetization pattern, the length of said second region being greater than the period of said periodic magnetization pattern of said first region;
- and
- a detector for detecting said object to be detected having a plurality of sensors disposed in opposed relationship with said object to be detected and oriented in the direction which intersects the direction of the magnetic flux of the magnetized pattern of said first region, each of said plurality of sensors having a plurality of unit magnetoresistance effect elements which are equidistantly spaced apart from each other and which are connected in series, the spacing between adjacent elements of said sensors being less than the length of the period of said magnetization pattern.
Dependencies are inferred from the claim text.