Patent ID: 8000645

Claim:
A productivity module for increasing duplex throughput of a first print engine, comprising: a second print engine; a controller configured to receive one or more timing signals from the first print engine and synchronize timing of the second print engine with the first print engine based at least in part on the timing signals received from the first print engine; and an inverter comprising: a) an input paper path having an entrance configured to accept one or more receiver sheets from the first print engine; b) an output paper path having an exit configured to supply the one or more receiver sheets to the second print engine; c) an inversion paper path having: i) an entrance coupled to an exit of the input paper path; and ii) an exit coupled to an entrance of the output paper path; and d) a diverter operable to selectively couple the exit of the input paper path to either the entrance of the inversion paper path or a bypass entrance of the output paper path; wherein a first path comprises a receiver sheet travel path through the input paper path, the inversion paper path, and the output paper path when the diverter is in an inversion position; a second path comprises a receiver sheet travel path through the input paper path and the output paper path when the diverter is in a non-inversion position; and the controller is further configured to adjust a difference of a travel time of a receiver sheet in the first path as compared to a travel time of a receiver sheet in the second path to be an integral multiple of a period between the receiver sheets.