| 摘要 |
PROBLEM TO BE SOLVED: To take large the amplitude of a detection voltage for detecting the position and the speed, and to reduce noise superimposition, by preventing generation of an exciting current to be supplied to a power source of a circuit for detecting the position and the speed and to a magnetostrictive drive coil for generating an ultrasonic wave from being synchronized with a clock signal used in the circuit, in a position detector for detecting the position and the speed of a slider moving linearly by using the ultrasonic wave. SOLUTION: This position detector is equipped with a position speed detection means for calculating the position and the speed of the slider moving linearly by the propagation state of the ultrasonic wave. In the position speed detection means, when the clock signal rises, the power source of a circuit is charged to a first capacitor relative to a coil current driving circuit for generating a current for generating the ultrasonic wave, and a voltage charged into the first capacitor is charged to a second capacitor for driving the magnetostrictive drive coil for generating the ultrasonic wave, and the voltage charged into the second capacitor is supplied to the magnetostrictive drive coil when a delay clock slower in time than the clock signal rises. COPYRIGHT: (C)2004,JPO&NCIPI
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