| US 7,602,088 B2 | ||
| Linear motor and exposure apparatus having the same | ||
| Aya Niwatsukino, Tokyo (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Aug. 10, 2007, as Appl. No. 11/836,939. | ||
| Application 11/836939 is a division of application No. 11/212652, filed on Aug. 29, 2005, granted, now 7,271,510. | ||
| Claims priority of application No. 2004-250390 (JP), filed on Aug. 30, 2004. | ||
| Prior Publication US 2007/0279614 A1, Dec. 06, 2007 | ||
| Int. Cl. H02K 41/00 (2006.01) | ||
| U.S. Cl. 310—12 | 6 Claims |
| 1. A driving device for driving an object using an N-phase excitation sinusoidal wave drive type linear motor, where N≧2,
wherein:
a stator of the linear motor is movable in a direction opposite to or approximately opposite to a driving direction of the
object;
said driving device includes stator moving means configured to position the stator so that an electrical phase angle of the
linear motor when the object is accelerated or decelerated is brought into a predetermined state; and
the predetermined state is such that the electrical phase angle at a moment where a driving electric power of the linear motor
becomes largest is equal to or close to 90(deg.)/N.
|