Encad, Inc.

Warren Free

David A Neese

Loan M Hoang

James J Haflinger

David Allen Purcell

David M Dull

A method and system for compensating for nonfunctional ink jets in an ink jet printer. The ink-jet printer includes a printhead having a plurality of ink jets, each ink jet being assigned to print respective dots on a respective raster line of a recording medium in accordance with a print mask, wherein when an ink jet is detected as being defective, at least a portion of said print mask is replaced with a replacement mask such that one or more of the remaining ink jets of the plurality of ink jets compensates for the defective ink jet. The method includes: detecting when an ink jet is nonfunctional; and when an ink jet is determined to be nonfunctional, replacing at least a portion of the print mask with a replacement mask such that one or more of the remaining ink jets of the plurality of ink jets compensates for the nonfunctional ink jet.

Open jet compensation during multi-pass printing

A droplet deposition analysis system for an ink jet printer including a flexible transparent substrate. The printer may include a light source on one side of the substrate, and an optical detector on the other side of the substrate.

Ink droplet analysis apparatus

A method and system for detecting a nonfunctional element in an ink jet printhead is disclosed. The ink jet printer system includes: a switching power supply, coupled to the inkjet printhead, for supplying power to the printhead; an output capacitor, coupled to an output of the switching power supply, for storing a dc voltage therein; a bleed resistor, coupled in parallel to the output capacitor, for discharging current from the output capacitor; an output shifting circuit, coupled to the switching power supply, for shifting the dc voltage level across the output capacitor between a low state and a high state; and a sensor, coupled to the output of the switching power supply, for detecting when the switching power supply is switching, wherein an element of the printhead is tested by measuring a test current discharging from the output capacitor when the element is activated and comparing the measured test current with a reference current which discharges from the output capacitor through the bleed resistor. The method includes: supplying regulated power to the printhead; storing the regulated power in a capacitor so as to provide a dc voltage across the capacitor; shifting the dc voltage level stored in the capacitor between a low state and a high state; measuring a test current discharging from the capacitor when an element of the printhead is activated; measuring a reference current discharging from the capacitor through a bleed resistor, when no elements of the printhead are activated; and comparing the measured test current with the reference current.

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Anaheim, CA, United States of America

Warren Free