| 摘要 |
<p>PURPOSE:To obtain a person detector capable of surely eliminating error signal due to dielectric breakdown and the like between electrodes. CONSTITUTION:If a reference signal for a detection space between a pair of electrodes of a sensor Cx is supplied to a charging circuit including this, a signal delayed for the reference signal is formed in accordance with the change in the electrostatic capacity of the sensor Cx. This delay time is compared with a first threshold value in a first comparison means M1, the comparison result according to the delay time is output to a judgment means M3 and the existence of man is judged. Simultaneously, the delay signal is compared with the level of a second threshold value in a second comparison means M2 and the comparison result is output to an elimination means M4. By this, if the delay signal does not reach the second threshold value, the comparison result of the first comparison means M1 is eliminated from the judgment of existence of man at the judgment means M3.</p> |
