Development Of Paper Currency Identification System In Money-counting Machine

In 2010 the State Administration of Quality Supervision, Inspection and Quarantine announced “condition of RMB instrument for verifying the general technology” clearly put forward that money counter should have 10 kinds of identifiable means and 2 kinds of recognizable means, magnetic and multispectral images identification is listed from that. By comparing the original function which belongs to mainstream money counter, magnetic and multispectral is added, it can improve accuracy of the banknotes identification, and at the same time it can better deal with the difficulty that high-tech counterfeiting bring about.According to requirements for identification ability promotion of RMB paper currency magnetic property from PBC published “Introduction to the fifth series RMB in 2005”: magnetic property can be detected by instrument and adopt holographic and magnetic windowing security line taking the place of micro lettering security line. In order to meet the PBC’s requirement for RMB paper currency magnetic characteristics identification, the system mainly to achieve RMB’s edge magnetic, middle magnetic qualitative analysis and holographic magnetic windowing security line magnetic quantitative analysis. Five sets of Indium Antimonide magnetic head are designed, and build five electronic circuits for magnetic signal acquisition, amplifying, voltage comparing and switching, finally TMS320DM642 DSP obtains the digital signal and finish the magnetic detection. Because of most advanced imprint technology and high requirement, it is nearly impossible for security line forging. Experimental result demonstrated that the system can obtain the fifth set RMB’s signal from edge magnetic, middle magnetic, security line, and the signal can be processed by the follow-up software.The system has infrared light, ultraviolet light image acquisition function. In order to meet the mainstream money counter’s speed of 20 frames per second, and give DSP a full play to process data at the same time, a method of CIS+DSP+CPLD is proposed. Timing and clock of infrared and ultraviolet image acquisition system is created by CPLD, to ensure the rapid image acquisition of the entire system. Image acquisition system includes paper currency position detecting unit, paper currency image acquisition and storage unit, the data transfer and display unit. Experiments show that the system is capable for continuously infrared and ultraviolet two-sided image acquisition using the time of 38.88 ms.