Apparatus and a method for checking an object to be checked for authenticity

摘要

A large number of magnetic pieces are distributed at random in a scanning region of an object to be checked. A magnetic sensor of a processing apparatus for checking the object for authenticity comprises first and second detecting element pairs. Each of these detecting element pairs include a pair of MR elements arranged in a scanning direction. The MR elements of the second detecting element pair are deviated from those of the first detecting element pair in parallel relation. The apparatus registers data associated with the detection signal obtained by means of the first detecting element pair in a code indicator section of the object when the object is manufactured or issued. The apparatus is provided with a circuit which collates all the detection signals obtained by means of the detecting element pairs with the data registered in the code indicator section, in checking the object for authenticity, and concludes that the object is real if any of the detection signals corresponds to the data in the code indicator section.