| 摘要 |
PURPOSE:To reduce the influence such as the temperature characteristic of a circuit and the fluctuation in a supply voltage by measuring a voltage immediately before a signal rises and a voltage after it rises and obtaining the amplitude value of the output signal of a sensor. CONSTITUTION:A signal to an A/D converter 58 generates an offset fluctuation according to the fluctuation of the supply voltage and the temperature characteristic of a circuit element. Both the voltage value immediately before the rise and the voltage value after the rise are A/D converted, the difference therebetween is taken by a CSU 59, thereby, a correct detected value can be obtained even when the offset fluctuation of the circuit is produced. The value obtained in such a way is compared with the data of a natural vertical landing position in the CPU 59 and a correct feedback can be applied according to the output thereof.
|
