Patent ID: 7677379

Claim:
An optical sensing device for detecting optical features of valuable papers, comprising first and second photocouplers positioned in the vicinity of and on the opposite sides of a passageway for guiding the valuable paper; wherein the first photocoupler comprises an upper case, a first light emitting element located in the upper case for emitting a first light of a first wavelength, and a first light receiving element located in the upper case adjacent to the first light emitting element; the upper case has a partition for keeping the first light emitting element and first light receiving element in an appropriately spaced relation to each other; the second photocoupler comprises a lower case, a second light emitting element located in the lower case for emitting a second light of a second wavelength different from the first wavelength of the first light emitted from the first light emitting element, and a second light receiving element located in the lower case adjacent to the second light emitting element; the lower case has a partition for keeping the second light emitting element and second light receiving element in an appropriately spaced relation to each other; the first light receiving element receives the first light from the first light emitting element reflected on the valuable paper and the second light from the second light emitting element penetrating the valuable paper; the second light receiving element receives the second light from the second light emitting element reflected on the valuable paper and the first light from the first light emitting element penetrating the valuable paper; one of the first and second lights is an ultraviolet ray, and the other of the first and second lights has a wavelength other than a wavelength of the ultraviolet ray; and the ultraviolet ray received by the first or second light receiving element provides reference or basic light data for detecting a light amount level of light other than the ultraviolet ray.