Patent ID: 7762645
Filing Date: 2010-07-27
Classification: B41J,G01J

Abstract:
1. A method of evaluating a performance of an optical sensor of an ink jet printing apparatus including a printing head for ejecting a plurality of ink colors on a basis of printing data and the optical sensor having a plurality of light-emitting elements whose light-emitting wavelengths are mutually different, said method comprising the steps of: counting a cumulative number of ejections, which is obtained by accumulating a number of times the printing head makes an ejection, for each ink color; obtaining an influence degree at which each of the plurality of light-emitting elements is affected by use of an influence coefficient indicating how much each of the ink colors affects each of the plurality of light-emitting elements as well as the cumulative number of ejections for each ink color; and evaluating the performance of the optical sensor by comparing the influence degree with a predetermined threshold value.