The Research Of Anti-counterfeiting Detection Technical Of Invisible Magnetic Code

Invisible magnetic code is a new high-tech anti-counterfeiting product.As it is invisible,tiny magnetic,coding of several features,as well as lowcost,invisible anti-counterfeiting magnetic code has a wide prospect.Recently it is widely used in the advanced anti-counterfeit and auto-identify fields.Thus, a machine-readable detection equipment to detect and recognize such anti-counterfeit features with high efficiency and accuracy is badly needed.Since the traditional detection system has many disadvantages and drawbacks, this paper introduces our research on the detection system which is based on MCU and DSP.The work has been done as follows:1. Studied the detection method of invisible magnetic code. Chose the giant magneto resistance sensor as the detector.By discussing and comparing the transmittance curves of different invisible magnetic code, we approved the feasibility of the detection method.We applied correlation coefficient to identify invisible magnetic code of different type.2. According to the design requirement we completed the hardware design of the detection system.Designed the software part of the system to finish the target.The software design is composed of MCU software part , DSP software part and the software run on PC.3. Used the invisible magnetic code detection system to do experiments and get the signals and output . And analyzed the results and experimental curves of invisible magnetic code of different types.Computed the correlation coefficient of invisible magnetic code's curve,and derived the threshold to discriminate the counterfeit is 0.8.We also made preparatory experiments on the magnetic ink characters printed on checks, and compared the experimental waveforms and the standard waveforms of the characters.Analyzed the detecting results.