| 摘要 |
PURPOSE:To eliminate a synchronous wiring between detection circuits by arranging an output so as to be produced only when an input is received continuously more than two times with the delay of ultrasonic wave emitting intervals corresponding to the period of floor surface reflection removal gate opening, by means of the two detectors provided on a ceiling side by side. CONSTITUTION:The intervals at which the pulses are generated from a pulse generation circuit 3 are delayed by means of an interval setting circuit 1 for emitting the ultrasonic pulse p and an emission changeover switch 2 so that the output pulse is amplified with an amplifier circuit 4 to be applied to a wave transmitter 5 whereby the ultrasonic pulse p is emitted to the floor surface 14. The reflected waves F and R are received with a wave receiver 6 and amplified with an amplifier 7 and then applied to a subject detecting circuit 9 by way of the gate 8 for removing the reflected wave F on the floor surface. The detecting circuit 9 produces the output when pulses are inputted continuously more than twice. Two detectors 9 thus made are so arranged to delay the ultrasonic wave emitting intervals corresponding to the period the gate 8 opens thereby eliminating the synchronous wiring. |
