| 摘要 |
Longitudinally spaced and laterally spaced sensors are used to sense longitudinally spaced and laterally spaced areas on each inserted bill. The lateral spacing of those sensors enables one of those sensors to engage and sense part of the upper half, and enables the other of those sensors to engage and sense part of the lower half, of each inserted bill - thereby making it possible to prevent the acceptance of a sheet of paper bearing just the upper half of an authentic bill and also making it possible to prevent the acceptance of a sheet of paper bearing just the lower upper half of an authentic bill. The longitudinal spacing of those sensors enables one of those sensors to engage and sense part of the leading half, and enables the other of those sensors to engage and sense part of the trailing half, of each inserted bill - thereby making it possible to prevent the acceptance of a sheet of paper bearing just the leading half of an authentic bill and also making it possible to prevent the acceptance of a sheet of paper bearing just the trailing half of an authentic bill. In addition, the longitudinal spacing of those sensors enables those sensors to provide four signals which correspond to the longitudinally spaced and laterally spaced areas on an authentic bill and which are spaced apart in time; and thus makes it possible to use two sensors to provide four time-spaced signals. The two sensors of the paper currency validator are connected in series; and the series connecting of those sensors and the time-spacing of the signals corresponding to the longitudinally spaced and laterally spaced areas on an authentic bill make it possible for one amplifier to receive and amplify the signals from both of those sensors. The paper currency validator uses phase locked loops as frequency detectors, and thereby provides very compact, relatively inexpensive, and readily adjusted frequency detectors. One of these locked loops responds to signals which are developed as an authentic U.S. 1 dollar bill is engaged and sensed by the sensors, and the other of those phase locked loops responds to signals which are developed as an authentic U.S. 5 dollar bill is engaged and sensed by the sensors; and hence the paper currency validator can test the validity of authentic U.S. 1 dollar and 5 dollar bills. Additionally, the paper currency validator can respond to signals from a dispensing machine with which it is associated to selectively reject such 1 dollar bills, such 5 dollar bills, or all such 1 dollar and 5 dollar bills. The sensors of the paper currency validator engage and sense the border on each inserted authentic bill before they engage and sense the longitudinally spaced and laterally spaced areas on the bill - thereby making it possible to reject any bill which does not have a border. The paper currency validator requires a number of specifically different events to occur within a corresponding number of specifically different time periods; and it utilizes timing circuits which include gates and a binary counter to determine the lengths of those time periods. In using timing circuits which include a binary counter and gates instead of using RC networks, the paper currency validator attains more precise control over the lengths oF the time periods, and it does so at less cost and in a smaller space. |
