Apparatus which detects the thickness of a sheet of paper such as a bank note

Abstract

A thickness detecting apparatus comprises a printed board in a part of which a coil is patterned, a detection roller which is disposed near the coil, which detects thickness of a sheet P of paper as a displacement amount, and a thickness detection circuit mounted on the surface of the printed board, which supplies a high frequency signal to the coil via a wiring pattern formed on the surface of the printed board and detects the amplitude of the high frequency signal which changes according to the displacement amount of the detection roller as a thickness of the sheet P of paper.

1 . A thickness detecting apparatus comprising: 
 a print-circuit board including a pattern of a coil and a detection circuit which detects a signal representing thickness of an object detected, the coil being embedded in the printed-circuit board and having a plurality of layers embedded within the printed-circuit board such that, in each of the layers, the coil is embedded in a spiral shape and that the coil in second one of the layers is embedded on the coil in first one of the layers and that the coil in the third one of the layers is embedded on the coil in the second one of the layers;    a detecting unit which detects thickness of the object by displacement of a roller; and    a thickness-representing unit disposed near the coil whose displacement amount represents the thickness of the object detected by the detecting unit, wherein    the detection circuit supplies a high-frequency signal to the coil via a wiring connected to the coil and detects the thickness of the object based on the signal representing the thickness of the object which varies according to the displacement amount of the thickness-representing unit, the coil is disposed adjacent to the detection circuit on the printed-circuit board, and the coil is disposed at a position where the thickness-representing unit approaches.    
   
   
       2 . The thickness detecting apparatus according to  claim 1 , wherein the thickness-representing unit includes: 
 a moving unit disposed near the coil; and    a linking unit which links the detecting unit and said moving unit and displaces the moving unit in a direction opposite to a direction in which the detecting unit is displaced.    
   
   
       3 . The thickness detecting apparatus according to  claim 2 , further comprising a displacement amount amplifying unit which amplifies a displacement amount of the moving unit proportionally with respect to a displacement amount of the detecting unit connected to the linking unit.  
   
   
       4 . A thickness detecting apparatus comprising: 
 a print-circuit board including a pattern of a coil and a detection circuit which detects a signal representing thickness of an object detected, the coil being embedded in the printed-circuit board and having a plurality of layers embedded within the printed-circuit board such that, in each of the layers, the coil is embedded in a spiral shape and that the coil in second one of the layers is embedded on the coil in first one of the layers and that the coil in the third one of the layers is embedded on the coil in the second one of the layers; and    a detecting unit which detects thickness of the object by displacement of a roller, wherein    the roller is a conductor, and the detection circuit supplies a high-frequency signal to the coil via a wiring connected to the coil and detects the thickness of the object based on the signal which varies according to the displacement amount of the roller, the coil is disposed adjacent to the detection circuit on the printed-circuit board, and the coil is disposed adjacent to the detection circuit on the printed-circuit board, and the coil is disposed at a position where the roller approaches.