A device for recognising and examining bank-notes or the like

Claim 1

1 . A device for recognising and examining bank-notes or similar objects, comprising guiding means with driving means for transporting a bank-note to be examined, a light source producing a light beam across the transport path of the bank-note, a row of light-sensitive cells at the other side of said path, the length of said row being at least equal to the largest occurring width of bank-notes, means for processing the output signals of said light-sensitive cells and comparing said signals with reference values stored in a memory, means for determining at least one dimension of the bank-note and of its colour, characterised in that the processing means comprises a matrix buffer memory (30) having as many rows as there are light-sensitive cells (10), the number of columns corresponding to the number of times that the transverse dimension; of said cells (10) is comprised in the length of the largest area of a bank-note (21) to be examined; each memory cell (31) being adapted to contain a plurality of digital values corresponding to different light intensities measured by the light-sensitive cells (10), this in such a manner that the buffer memory (30) will form a digital picture of the transmission pattern of the bank-note (21), said memory contents, irrespective of the orientation of the bank-note (21), then being compared in a comparator (37) with the corresponding contents of partial memories (36) each comprising a standard pattern for a specific bank-note value, said comparator (37) being connected to a circuit (44) adapted to perform a statistical correlation operation, said circuits being, moreover, connected to comparator circuits (41, 45) for measuring the colour and/or ultraviolet reflection over a larger area, said correlation circuit (44) being adapted to emit an acceptance signal at a sufficient correspondence of both patterns.

Claim 5

The device of any one of claims 1-.3, characterised in that the partial memories (36) each contain standard values relating to measuring points distributed substantial arbitrarily over at least a part of the bank-note, the comparison taking place solely in these points.

Claim 6

The device of any one of claims 1..4, characterised in that the correlation operation comprises a correlation operation on the ratios of individual measurement values.

Claim 7

The device of any one of claims 1..5, characterised in that the comparison operation of the comparator (37) relates to a portion, and in particular one half, of the bank-note, and is repeated with a different threshold for another portion if the first-mentioned operation is not sufficiently decisive.

Claim 8

The device of any one of claims 1..6, characterised in that the comparison operation is performed only if the dimensions, colour, ultraviolet reflection or the like of a bank-note comply with the standards.

Claim 9

The device of any one of claims 1..7, characterised in that the colour measuring means (12..15) are adapted to perform an integration over a substantial part of the width of a bank-note to be examined.

Claim 10

The device of any one of claims 1..8, characterised in that the colour measuring (14,15, 40..42) are adapted to calibrate the light intensity measurements on the basis of an intensity measurement of the light source (6) before the arrival of the bank- note (21).