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(11) | EP 0 854 039 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Method and apparatus for measuring the amount of discharged ink, printing apparatus, and method of measuring the amount of ink discharged in the printing apparatus |
| (57) A method of instantly measuring the amount of ink discharged from a nozzle. The method
of measuring the amount of discharged ink includes: a line pattern forming step of
forming a line pattern by discharging ink from an ink-jet printhead; a first image-sensing
step of sensing the line pattern by an image sensing device; a second image-sensing
step of sensing a portion other than the line pattern by the image sensing device;
a density calculating step of calculating density of each pixel of the line pattern
by dividing the luminance value of the portion sensed in said second image-sensing
step by the luminance value of the line pattern sensed in said first image-sensing
step and calculating a common logarithm; an integrating step of integrating the density
of each pixel of the entire line pattern calculated in said density calculating step;
and an ink-discharge-amount determining step of obtaining the amount of discharged
ink on the basis of the integrated density calculated in said integrating step. |