Method for compensating a failing nozzle

摘要

A method is provided for compensating a failing nozzle in a printhead comprising a series of print elements with nozzles for operation in an inkjet printing process in which a colorant is applied for locally changing an optical density, thereby printing an image. The method comprises at least two compensation mechanisms, each providing a different amount of additional optical density in the environment of a missing dot in the printed image. A nozzle is recorded as a failing nozzle if the associated print element does not apply an ink dot within predetermined specifications. An environment density is determined in an environment of a missing dot associated with said failing nozzle. The environment density is compared with a predetermined threshold, and an appropriate compensation mechanism is selected from the at least two compensation mechanisms. The method is applied in an inkjet printing system for balancing under- and overcompensated optical density.

主权项

1. A method for compensating a failing nozzle in a printhead comprising a series of print elements with nozzles for operation in an inkjet printing process in which a colorant is applied to a receiving medium for locally changing an optical density, thereby printing an image, a nozzle being recorded in a list as a failing nozzle if an associated print element is unable to eject an ink drop within predetermined specifications, the method comprising at least two compensation mechanisms, each providing additional optical density in an environment of a missing dot in the printed image associated with a failing nozzle and comprising the steps of:
a) selecting a failing nozzle from the list of failing nozzles; b) determining an environment density and a density deficit in an environment of a missing dot associated with said failing nozzle; c) comparing the environment density with a predetermined threshold, and d) selecting a compensation mechanism from the at least two compensation mechanisms, based on the result of the comparison, each compensation mechanism adding an amount of colorant to compensate the density deficit, wherein said at least two compensation mechanisms comprise a first mechanism for transferring a density deficit compensation to a neighbouring print element of a failing nozzle and a second mechanism for transferring a density deficit compensation to corresponding nozzle of a different colorant.