Patent ID: 7963629
Filing Date: 2011-06-21
Classification: B41J

Abstract:
1. An ejection status determining method of determining an ink ejection status of an inkjet printing head including a heating element generating thermal energy as the energy utilized for ejecting ink and a temperature detecting element detecting a temperature change accompanying driving the heating element, the method comprising the steps of: extracting, as extracted data, temperature information at a plurality of points in a predetermined section including a timing at which appears an inflection point arising from the ink being ejected normally by the driving of the heating element, in a descending process of the temperature detected by the temperature detecting element after the driving of the heating element; computing a summation of absolute values of differences between each of curvatures of the temperature change curve at the plurality of points and a first threshold value determined based on a curvature of a temperature change curve in the case of an ejection-failure occurring; and determining an ejection status of the ink, based on the computed summation and a second threshold value with respect to the summation determined in advance.