摘要 |
Identification tags (22) are secured to objects (20) moving upon a transport band (16). The identification tags (22) each contain a transponder circuit (32) in electrical communication with transponder antennae (30, 31). The transponder circuit (32) contains a unique digital code containing data relating to the object (20). When the identification tag (22) is located beneath the object (20), at least one reader antenna (25) is positioned beneath the transport band (16) and in alignment with a selected aperture (34) extending through a support plate (12). One or more apertures (34) in alignment with the reader antenna (25) provide capacitive coupling between the transponder antennae (30, 31) and the reader antenna (25). The reader circuit (28) generates a signal in the presence of an identification tag (22), which is transmitted to the transponder antenna (30) located on the identification tag (22). The signal energizes the transponder circuit (32), which sends a transponder signal via the transponder antenna (30) back to the reader antenna (25). The reader circuit (28) demodulates the transponder signal to identify the data.
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