| US 7,602,086 B2 | ||
| Driving device, exposure apparatus using the same, and device manufacturing method | ||
| Yoshiyuki Okada, Sakura (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Jul. 13, 2006, as Appl. No. 11/485,360. | ||
| Claims priority of application No. 2005-206126 (JP), filed on Jul. 14, 2005. | ||
| Prior Publication US 2007/0013895 A1, Jan. 18, 2007 | ||
| Int. Cl. H02K 41/00 (2006.01) | ||
| U.S. Cl. 310—12 [310/13] | 8 Claims |
| 1. A driving device comprising:
(a) an electromagnetic actuator including a first coil and a second coil which detects a change in magnetic flux generated
by said first coil; and
(b) an electromagnetic actuator controller which feedback-controls said electromagnetic actuator, wherein said electromagnetic
actuator controller comprises:
(i) a modulator which gives a modulated signal, which is generated based on a target value in the feedback control, to said
first coil, wherein the target value is a target thrust of said electromagnetic actuator; and
(ii) a demodulator which demodulates an output signal from said second coil, and
said electromagnetic actuator controller includes a scale converter which performs a square-root arithmetic operation for
the target value to feedback-control said electromagnetic actuator, based on an output signal from said scale converter and
a signal demodulated by said demodulator.
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