| 摘要 |
PURPOSE:To make the operation stable against temperature or power supply voltage fluctuation and to attain highly accurate error detection by using a digital circuit means to measure a time signal and allowing an analog circuit means to detect and interpolate a quantized error produced in the measurement. CONSTITUTION:When an original time signal VEL1 obtained from the rotation of a motor 1 is given to a timing information detector 20, the signal is given to an FF31, where it is synchronized with a clock signal CLK and a synchronized time signal VEL2 is counted by a counter 33. The count value is converted into an analog voltage signal VOUTO by a D/A converting circuit 35 via a latch circuit 34 and then given to an adder circuit 52. On the other hand, a leading error time signal ERRH is given from an AND circuit for an error time TH to a constant current circuit 43 in a quantized error detection circuit 40 to charge a capacitor C. Then a trailing error time signal ERRL is given similarly to a constant current circuit 44 to discharge the capacitor C. Then a voltage Vc across the capacitor is subject to sample and hold, and the result is given to the circuit 52. The circuit 52 adds the signal Vc to a signal VOUTO to output an interpolated signal. |
