Patent ID: 6988842

Claim:
A postage meter printing apparatus for use in a continuous high velocity mail piece processing system, the printing apparatus comprising: a transport path conveying a series of mail pieces at a print velocity; an upstream ink jet print head fixedly positioned contiguous with the transport to print postage indicia on mail pieces transported thereon; a downstream ink jet print head, fixedly positioned downstream of the upstream print head, and contiguous with the transport to print postage indicia on mail pieces transported thereon; a controller controlling a first one of the upstream or downstream print heads to print postage indicia on transported mail pieces traveling at a print velocity, the controller further switching to a second of the upstream or downstream print heads when the first one undergoes a periodic ink jet maintenance operation; at predetermined intervals wherein the controller periodically takes the print head that is in use out of service to perform maintenance operations; whereby the maintenance operations are a print head wipe or a print head purge and whereby subsequent to a maintenance operation the first print head is in a condition to return to service.