| 摘要 |
PURPOSE:To enable detection with high accuracy, without mis-detection such as detour of a ultrasonic wave, by locating ultrasonic wave transmitter/receiver obliquely against an object to be detected and detecting the presence of the object. CONSTITUTION:Ultrasonic wave transmitter and receiver 101 and 103 are located opposingly with each other, and obliquely against a moving direction of an object to be detected 105 such as copied paper carried with a roller pair 106 and the pesence of the object 105 is detected with ultrasonic waves. The ultrasonic waves from the transmitter 101 are totally reflected by the oblique location to prevent reflection and detour from other objects, and to make detection of object with high accuracy without mis-detection. |
