音響を利用したシートの枚数検出法

抄録

This paper deals with the development of a new detecting method of a number of sheets without contact. For example, in a cash dispenser paper sheets are transferred one by one and counted synchronously. So it is necessary to detect one or a plural number of sheets to avoid mistransferring. Hitherto, the contact measuring method has been used for detecting the transference of sheets. This noncontact sensor utilizes the variations of frequency response of the whole acoustic system of the sensor with sheets which are set near the sensor. The impedance of sheets varies with its number. The number of sheets has shown good correspondence with the resonant frequency and frequency response of the acoustic system. An electrical analogy is adopted for theoretical analysis of the acoustic system. The results of the calculation and experiments coincide significantly. It is possible to detect the number of sheets within a very short time period by means of variations of the frequency response.