Apparatus for discriminating paper-like sheets and method for discriminating same

1 . A method for discriminating paper-like sheets, comprising:

an authenticity judgment step;

the authenticity judgment step includes:

a pattern detection step for irradiating infrared light on predetermined irradiation lines extending in a paper-like sheet along the direction corresponding to that to be inserted with a predetermined interval to detect amounts of a pattern of transmitted light on the predetermined irradiation lines;

an arithmetic processing step for comparing amounts of the pattern of transmitted light through the paper-like sheet obtained by the pattern detection step with amounts of a pattern of transmitted light through a genuine paper-like sheet which has been previously obtained by means of the pattern detection step to standardize data thereby obtaining standard values at the respective irradiation points of the paper-like sheet inserted; and

a judgment step for comparing the standard values with the maximum standard value of the genuine paper-like sheet which has been previously obtained thereby to judge the paper-like sheet as a counterfeit note in the case when the number of the standard values each of which is larger than the maximum standard value reaches a predetermined number.

2 . The method for discriminating paper-like sheets as defined in claim 1 , wherein:

the paper-like sheet inserted and the genuine paper-like sheet are the same kind of paper moneys wherein watermark areas and the other design areas are arranged.

3 . The method for discriminating paper-like sheets as defined in claim 1 , wherein:

the genuine paper-like sheet is two or more pieces.

4 . The method for discriminating paper-like sheets as defined in claim 1 , wherein:

the standard values are calculated through a division of differences between an average value of amounts of transmitted lights at the respective irradiation points on the predetermined irradiation lines in a genuine paper-like sheet which have been previously obtained and amounts of transmitted light at irradiation points corresponding to respective irradiation points on the predetermined irradiation lines of the paper-like sheet inserted by standard deviations of the amounts of transmitted light at the respective irradiation points in the genuine paper-like sheet.

5 . The method for discriminating paper-like sheets as defined in claim 1 , wherein:

the maximum standard value is the maximum numerical value among values calculated through a division of differences between an average value of amounts of transmitted lights on respective irradiation points on the predetermined irradiation lines in the genuine paper-like sheet which have been previously obtained and amounts of transmitted lights on respective irradiation points of respective genuine paper-like sheets by standard deviations of amounts of transmitted light at the respective irradiation points.

6 . The method for discriminating paper-like sheets as defined in claim 1 , wherein:

the pattern detection step detects the pattern of amounts of transmitted light through the inserted paper-like sheet and the genuine paper-like sheet, each having watermark areas and the other design areas.

7 . The method for discriminating paper-like sheets as defined in claim 1 , wherein:

an instruction for adding the standard value calculated in a paper-like sheet inserted to a standard value at the following irradiation point is issued for a further comparison, when the standard value calculated is judged that it is larger than the maximum standard value in the genuine paper-like sheet.

8 . An apparatus for discriminating paper-like sheets, comprising:

an authenticity judgment part;

the authenticity judgment part includes:

a pattern detection means for irradiating infrared light on predetermined irradiation lines extending in a paper-like sheet along the direction corresponding to that to be inserted with a predetermined interval to detect amounts of a pattern of transmitted light on the predetermined irradiation lines;

an arithmetic processing means for comparing amounts of the pattern of transmitted light through the paper-like sheet obtained by the pattern detection means with amounts of a pattern of transmitted light through a genuine paper-like sheet which has been previously obtained by means of the pattern detection means to standardize data thereby obtaining standard values at the respective irradiation points of the paper-like sheet inserted; and

a judgment means for comparing the standard values with the maximum standard value of the genuine paper-like sheet which has been previously obtained thereby to judge the paper-like sheet as a counterfeit note in the case when the number of the standard values each of which is larger than the maximum standard value reaches a predetermined number.

9 . The apparatus for discriminating paper-like sheets as defined in claim 8 , wherein:

the pattern detection means contains a plurality of light projection areas and a plurality of light reception areas arranged in parallel corresponding to a plurality of irradiation lines, respectively.

10 . The apparatus for discriminating paper-like sheets as defined in claim 8 , wherein:

the pattern detection means irradiates infrared light based on a pattern of the irradiation points stored in a memory.

11 . The apparatus for discriminating paper-like sheets as defined in claim 8 , wherein:

the authenticity judgment part is composed of the pattern detection means, arithmetic processing means, and the judgment means.

12 . The apparatus for discriminating paper-like sheets as defined in claim 8 , wherein:

the discrimination sensor is a reflection type sensor in which infrared light is projected and received on the same side.

13 . The apparatus for discriminating paper-like sheets as defined in claim 8 , wherein:

the discrimination sensor is constituted in such that infrared light is irradiated at a given input angle, and a light reception area is disposed through reflection.