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US 6,172,745 B2Granted
Sensing device
AssigneeMars, Incorporated
InventorsChristian Voser, Didier Rossel, Bernard Bouchet
Life of this patent
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AssigneeMars, Incorporated
InventorsChristian Voser, Didier Rossel, Bernard Bouchet
Estimating the term…
An optical head (4) for sensing banknotes using six different groups of light sources, namely LEDs generating light at six different wavelengths both in the visible range of the spectrum and in the infra-red range of the spectrum. Unitary light guides (16,18) define the path between linear arrays (8,10) of the LEDs and the surface of a banknote (2). Diffusely reflected light is separately collected by a pin diode detector array (12). Both the LEDs and the detectors are commonly mounted on a single printed circuit board (14). The light sources (8,10) are arranged to shine directly into the light-receiving end of each light guide, which are unitary and allow the light to mix and spread within in order to provide a homogeneous illumination. The detectors (12) are optically isolated and detect discrete areas on the banknote transport path.
A device for sensing the optical characteristics of a document moving relative to the device in a transport path, said device comprising:
A device for use in sensing the optical characteristics of a banknote moving relative to the device of a transport path, said device comprising a plurality of light sources, a unitary light guide optically coupling said light sources to one side of said transport path, and a plurality of detectors optically coupled to the same side of the transport path externally of said light guide to receive light from said light sources when reflected from a document travelling along said transport path.
A sensing device comprising:
An optical banknote sensing device comprising a light guide attached to a substrate by means allowing unmatched thermal expansion between said light guide and said substrate.
An optical device comprising light transducing means and light guide means optically coupling said light transducing means to a transport path along which a document is transportable, wherein said light guide means comprises at least one metallised surface.
An optical device for a sensing a document comprising light transducing means and light guide means optically coupled to said light transducing means at a coupling end, said coupling end having portions following a generally convex profile in cross section, for an increased focusing effect, said portions comprising a groove to accommodate the light transducing means.
Dependencies are inferred from the claim text.