| 摘要 |
PROBLEM TO BE SOLVED: To provide an object detection method and an object detection device capable of reducing a time for waiting convergence, enlarging the amplitude of reverberant vibration, and fixing the magnitude of the amplitude. SOLUTION: A vibration element 2 is allowed to abut on a diaphragm 1, and a square-wave signal is oscillated from a fundamental oscillation circuit 21, and a projecting-wave generation circuit 22 shortens the pulse width of the square wave, and generates a pulsing projecting wave and imparts it to the vibration element 2 to oscillate it. The vibration element 2 is reverberantly vibrated corresponding to the projecting wave, and when powder adheres to the diaphragm 1, the level of a reverberant vibration component becomes low, and the reverberant vibration component is compared with a reference value determined beforehand by a vibration discrimination circuit 30, to thereby discriminate existence of the powder. COPYRIGHT: (C)2003,JPO |
