| 摘要 |
PURPOSE:To perform stable positioning with a high accuracy by providing a resolver for coupling with a DC motor for driving a shutter blade to detect the rotating amount of the motor. CONSTITUTION:An exposure is controlled by a rotary or reciprocating type shutter blade 1. In this case, a resolver 10 coupled with a DC motor 3 for driving the blade 1 to detect the rotating amount of the motor 3 is provided. The resolver 10 operates to convert the rotated angle of the shaft of the resolver 10 into a phase moving amount of an AC electric signal and to output it. Accordingly, when a phase difference between the AC electric signal of constant phase to become a reference and the output signal of the resolver 10 is detected to be converted to a DC voltage proportional to the phase difference, a DC signal proportional to the rotating amount of the shaft of the revolver 10 is obtained. Thus, a positioning servo system does not vibrate but stably controls even in the vicinity of a deviation near '0' when the blade 1 arrives at a target position. Thus, accurate positioning can be stably performed. |
