Defective nozzle compensation
AssigneeCanon Kabushiki Kaisha
InventorsPeter Ilbery, Noribumi Koitabashi, Shoji Kanemura, James Metcalfe
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Abstract
An image recording apparatus (2000) is disclosed, which comprises forming elements (2002) for forming an image, a memory (2006) indicating relative desirability of utilising the forming elements (2002) for forming the image, and processing means (2008) for computing image recording signals using input image signals (2012) and the stored data. The use of a particular forming element is thereby biased dependent upon the relative desirability data for the other forming elements and the corresponding input image signals for the other forming elements.
Claims29
A method, in printing an image comprising a plurality of image values, of compensating for one or more defective printer nozzles in a plurality of printer nozzles, said method comprising the steps of:
- biasing, for each first image value associated with a first nozzle, at least one second image value associated with another nozzle, said biasing being dependent upon said first image value and a printing desirability factor for said first nozzle;
- halftoning said at least one biased second image value to form at least one corresponding nozzle firing value;
- and
- printing the image using said at least one nozzle firing value, thereby reducing print artefacts otherwise caused by the one or more defective nozzles.
An image recording apparatus for recording an image comprising a plurality of image values, the apparatus comprising:
- a plurality of forming elements for forming the image using image recording signals;
- memory means for storing data for said forming elements indicating the relative desirability of utilising said forming elements for forming the image;
- image processing means for computing biased image values using said image values and said data stored in said memory means, wherein use of a particular forming element is biased dependent upon the relative desirability data of other forming elements;
- and
- halftoning means for halftoning the biased image values to form corresponding said image recording signals.
An image recording apparatus for recording an image comprising a plurality of image values, the apparatus comprising:
- a plurality of forming elements for forming the image using image recording signals;
- memory means for storing data for said forming elements indicating the relative desirability of utilising said forming elements for forming the image;
- image processing means for computing biased image values using said image values and said data stored in said memory means, wherein use of a particular forming element is biased dependent upon the relative desirability data of other forming elements and the image values for the other forming elements;
- and
- halftoning means for halftoning the biased image values to form corresponding said image recording signals.
An image recording apparatus for recording an image comprising a plurality of image values, the apparatus comprising:
- a plurality of forming elements for forming the image using image recording signals;
- memory means for storing data for said forming elements indicating the relative desirability of utilising said forming elements for forming an image;
- image processing means for redistributing said image values based on said data stored in said memory means so as to form redistributed image values the use of which biases use of said forming elements;
- and
- halftoning means for halftoning the redistributed image values to form corresponding said image recording signals.
An image recording apparatus for recording an image comprising a plurality of image values, the apparatus comprising:
- a plurality of forming elements for forming the image using image recording signals;
- memory means for storing data for said forming elements indicating the relative desirability of utilising said forming elements for forming the image;
- image processing means for redistributing said image values based on said data stored in said memory means to form redistributed image values the use of which biases the use of said forming elements, wherein the use of a particular one of said forming elements is thereby biased dependent upon the relative desirability data of other forming elements and the image values for the other forming elements;
- and
- halftoning means for halftoning the redistributed image values to form corresponding said image recording signals.
Dependencies are inferred from the claim text.