| 摘要 |
<p>PURPOSE:To realize a stable operation and to be hardly influenced by a noise by a constitution wherein a Z-axis position control operation is synchronized with respect to unstable elements at the time of a change of data of a comparator without a latch signal as well as the asynchronous time of a counter by utilizing pulse signals of an encoder. CONSTITUTION:An encoder A-phase signal 12 and an encoder B-phase signal 11 whose phases have been shifted by 90 deg. by using an encoder connected directly with a motor shaft are inputted. A sampling circuit 9 to which the encoder B-phase signal is input is constituted. Even when a counter reset signal is outputted early from a 16-bit comparator 4, the comparator waits until a data is stabilized by the sampling circuit 9, and a 16-bit counter 5 is reset. That is to say, the encoder B-phase signal is used as a sample pulse and a reset pulse is generated when the data has been stabilized surely by an output of the 16-bit comparator 4 and by an output of an AND circuit 9a. Thereby, the reset signal is outputted to the counter after the data has been stabilized surely.</p> |
