Apparatus and methods of detecting relative position of RF signature on print media

摘要

The presence of a radio frequency signature ( 88 ) on a cut sheet of print media ( 28 ) is detected by a radio frequency interrogating device ( 94 ) to determine it's relative left/right position on the print media ( 28 ). Either the leading edge ( 124 ) or trailing edge ( 126 ) of the print media ( 28 ) is detected by one or more print media sensors ( 86, 90 ). A print controller ( 24 ) can note the time (t₁) when print media is detected and cause the radio frequency interrogating device ( 94 ) to detect the radio frequency signature ( 88 ) at a time (t₂) when the print media has reached a predetermined point along the print media pathway ( 110 ). The position of the radio frequency signature ( 88 ) on the print media ( 28 ) can be calculated using the time differential (t₂-t₁) and the known angular displacement of the radio frequency interrogating device ( 94 ).