| 摘要 |
PURPOSE:To detect position of a slider accurately by providing a slider detecting means, means for counting slits in a slit board, slider position calculating means, a speed calculating means, a target position calculating means, and means for controlling the exciting current of a coil based on an output from a speed correcting means. CONSTITUTION:When a Hall sensor 12 for exciting current 3 is detecting the field of a magnet arranged on a slider SL, a constant current circuit 10 regulates the magnetic force of a coil and controls the speed of the slider SL to a predetermined level. A magnetic sensor 5a detects passage of the slider SL and a photo-encoder 5b outputs a pulse every time when the slit in a slit board is detected. A correcting speed is calculated based on the speed deviation and positional deviation of the slider SL from speed data in order to control the speed of the slider SL. By such arrangement, position of the slider SL can accurately be detected. |
