Abstract: An apparatus and method for monitoring operation of an ink jet printhead. An ink jet printer is controlled to eject a periodic sequence of ink jet curtains through an illuminated gap. Variations in the intensity of the illumination caused by the ink jet curtains are detected to generate a signal representative of the opaqueness of the curtains. The signal is compared to a reference and if insufficient opaqueness is detected a poor print quality signal is generated. In one embodiment a feedback loop is established during a calibration mode to adjust the nominal level of illumination.

Abstract: A postage printing system, comprising an ink jet printer including a print head for printing a postal indicia on a mailpiece and a control system. The control system is in operative communication with the print head and performs the following: monitoring an initial temperature of the print head; causing the print head to print a test print; monitoring a subsequent temperature of the print head after completion of the test print; comparing an actual temperature change, from the initial temperature to the subsequent temperature, within an expected temperature change; and continuing normal operation of the postage printing system if the actual temperature change is with an acceptable range of the expected temperature change.

Abstract: A mail handling system includes a printhead for printing a postage indicium on a mailpiece; a transport mechanism that moves the mailpiece past the printhead during printing of the postage indicium; a postage meter including means for accounting for a value of postage associated with the postage indicium; an image generator in operative communication with the postage meter, the image generator producing a synchronous image data stream for use by the printhead in printing the postage indicium; a buffer which receives and stores the synchronous image data stream from the image generator; apparatus for switching the image generator between an ON status whereby the image generator produces the synchronous image data stream and an OFF status whereby the image generator does not produce the synchronous image data stream based upon the occurrence of a predetermined condition; structure for transferring the stored synchronous image data stream to the printhead in an asynchronous manner; and wherein the switching appa