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

摘要

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.