Apparatus for detecting an abnormality in paperlike material

An apparatus for examining a piece of paper having a pattern printed thereon, comprising:

• means for transferring said piece of paper;
• means for irradiating X-rays on said piece of paper transferred by said transferring means;
• detecting means for detecting fluorescent X-rays scattered from said printed pattern on said paper;
• subdividing means for subdividing said paper and the pattern located thereon into a plurality of areas;
• a plurality of discriminator means each connected to said detecting means and said subdividing means for discriminating scattering characteristics of specific elements and for outputting pulses indicative of the presence of specific elements;
• a plurality of rectifying circuit means corresponding to said plurality of discriminator means and each connected to said corresponding discriminator means for rectifying said output pulses from each of said discriminator means;
• a plurality of Schmitt trigger circuit means corresponding to said plurality of rectifying circuit means, each connected to said rectifying circuit means for detecting output pulses;
• Schmitt trigger level circuit fixer means, connected to the output of said corresponding Schmitt trigger circuit means for comparing the output of said Schmitt trigger circuit means with a presset value and for outputting a pulse when the output of said Schmitt trigger circuit means exceedes said preset level in said Schmitt level fixer means;
• shift register means connected to said plurality of said Schmitt trigger level fixer means for storing the output of said plurality of Schmitt trigger level fixer means;
• means for generating a predetermined reference signal indicative of an authentic document;
• comparison judgement means connected to said shift register means for comparing the stored pattern contained within said shift level register means with said predetermined reference signal.