Apparatus for detecting the condition of a sheet
AssigneeDe La Rue Systems Limited
InventorGraham H. Hilton
Life of this patent
Estimating the term…
Abstract
Apparatus is disclosed for determining the degree of stiffness of a sheet, for example a banknote, the stiffness being indicative of the condition of the banknote. The banknote (4) is drawn around a bobbin-shaped drum (1) by means of a pair of belts (2, 3) which grip a central portion of the banknote. The inner belt (2) drives or is driven by the central portion of the drum (1). The concave shape of the drum (1) imparts a curvature to the banknote in an axial plane, while the banknote is simultaneously curved in an orthogonal plane as it is wrapped around the drum. As the banknote passes around the drum it emits an audible noise which is picked up by a microphone (5). The amplitude of the microphone signal (7) is proportional to the crispness of the banknote and is indicative of the age of the banknote.
Claims8
Apparatus for determining the stiffness of a note or document comprising means (1, 2) for conveying the note (4) along a flow path, bending means (3) at a given location in the flow path for continuously bending the note (4) during its movement past that location, a microphone (5) arranged to respond to noise produced by the note while it is being bent, and means (20-25) responsive to a noise signal from the microphone to indicate the degree of stiffness of the note.
Dependencies are inferred from the claim text.