| 摘要 |
A bill accepting apparatus has a pair of photo-electronic sensors disposed spaced apart from each other on an imaginary line orthogonal to a bill transport direction. The leading edge of the bill being transported is detected at times T1 and T2 by the respective sensors. A time difference between T1 and T2 is compared with a predetermined value. From a known distance between the two sensors, a known bill transport speed and the time difference, the tilt angle of the leading edge can be determined. Analog outputs hyof the sensors are individually converted at a given frequency to first and second series of digital values. A CPU interrupt signal is obtained each time when both of each of the first and second series of digital values are obtained, and this interrupt signal initiates a skewed bill detecting task in a CPU. The time difference between T1 and T2 is obtained by counting a number of the interrupt signal therebetween, and the bill is determined to be skewed if the counted number is greater than a predetermined number. The outputs of the sensors are also utilized for identifying and verifying the bill.
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