Method and device for selective recording head maintenance for an ink recording apparatus

An ink recording apparatus for recording a color image on a receiving medium, comprising:

• an ink recording head having a plurality of color inks and a plurality of ink ejectors for each color ink that eject ink drops on a receiving medium in response to color image data;
• a purge ink receiver periodically cooperated with the ink recording head;
• and
• a maintenance controller, in communication with the ink recording head, for directing the ink recording head to perform a purge ink procedure, including an ejection of purge ink drops to the purge ink receiver from the plurality of ink ejectors, as a function of the color image data and at least one property of each of the plurality of color inks, wherein the maintenance controller comprises:
• a maintenance timing reset signal generator that generates a maintenance timing reset signal,
• a timer that determines a current image recording time, which defines a time elapsed during image recording since an occurrence of one of a last purge ink procedure and said maintenance timing reset signal,
• a color image data monitor to monitor a number of print drop commands received by each of the plurality of ink ejectors during the current image recording time,
• a set-up memory that stores the value of the maximum current image recording time T, and a plurality of target numbers of print drop commands, one target number N.sub.i of print drop commands corresponding to each of the plurality of color inks, and
• control means that, after the current image recording time exceeds said maximum current recording time T, compares the number of print drop commands received by each color ink ejector to the corresponding one of the plurality of target numbers of print drop commands N, for a corresponding color ink, and generating a maintenance timing reset signal if all of the ink ejectors have received the corresponding target number of eject print drop commands, and interrupting image recording and directs a purge ink procedure if at least one of the plurality of color ink ejectors has failed to receive the corresponding target number of print drop commands.

A method of maintaining proper operation of an ink recording apparatus having an ink recording head with a plurality of ink ejectors for ejecting ink drops on a recording medium in response to print drop commands based on image data and a plurality of performance modes, the method comprising the steps of:

• determining whether the ejection of purge ink drops from the plurality of ink ejectors is appropriate;
• interrupting image recording when ejection of purge ink drops is appropriate;
• and
• purging ink from the nozzles as a function of the image data and one of a plurality of pre-selected performance modes to maintain a proper operation of the ink recording head, wherein said determining step further comprises:
• measuring a current image recording time, which defines a time elapsed during image recording since an occurrence of one of a last purge ink procedure and a maintenance timing reset signal,
• monitoring a number of print drop commands received by each of the plurality of ink ejectors,
• storing a value of a maximum current recording time T, and a target number of print drop commands N, based on a pre-selected performance mode,
• detecting when the current image recording time exceeds said maximum current recording time T,
• comparing the number of print drop commands received by each of the plurality of ink ejectors to N at said maximum current recording time T, and
• generating a maintenance timing reset signal,
• wherein said determining step determines that a purge drop procedure is appropriate if at least one of the plurality of drop ejectors has failed to receive N print drop commands at said maximum current recording time T.