| US 7,508,193 B2 | ||
| Encoder | ||
| Kenichi Yarimizu, Fukushima (Japan); Shinji Nagasawa, Fukushima (Japan); Yoshiaki Ono, Fukushima (Japan); and Naoto Kobayashi, Fukushima (Japan) | ||
| Assigned to NOK Corporation, Tokyo (Japan) | ||
| Appl. No. 11/597,660 PCT Filed Apr. 14, 2005, PCT No. PCT/JP2005/007206 § 371(c)(1), (2), (4) Date Nov. 24, 2006, PCT Pub. No. WO2005/116588, PCT Pub. Date Dec. 08, 2005. |
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| Claims priority of application No. 2004-157027 (JP), filed on May 27, 2004. | ||
| Prior Publication US 2007/0182406 A1, Aug. 09, 2007 | ||
| Int. Cl. G01P 3/48 (2006.01); G01P 3/54 (2006.01); H02K 11/00 (2006.01); H02K 23/66 (2006.01); H02K 21/12 (2006.01) | ||
| U.S. Cl. 324—174 [310/68 B; 310/156.45] | 1 Claim |
| 1. An encoder comprising
a body having N poles and S poles of magnets arranged alternately in a circumferential direction at an equal pitch and an
unequal pitch portion in a part on a circumference,
said unequal pitch portion being formed by arranging said N poles and said S poles at an equal pitch all over the circumference
and forming a shielding body shielding a magnetism portion in the part on the circumference, and
said shielding body being formed in one of a U-shaped and J-shaped cross section, and being attached to the circumference
of said body by being pressure inserted and having a magnetizing portion formed by a combination of said N poles and said
S poles, thereby covering the part on the circumference of said magnetizing portion.
|