Patent ID: 6893106
Filing Date: 2005-05-17
Classification: B41J

Abstract:
1. A printing apparatus which performs printing by discharging ink onto a print medium by using a printhead, based on an ink-jet method, having a plurality of nozzles arrayed in a predetermined arrayed direction, said apparatus comprising: scan means for scanning said printhead; print means for performing a print operation by using said printhead; a photo-sensor, provided between a home position of said printhead at one end of a scanning path of said printhead by said scan means, and a position outside of an effective printing area for said printhead, and having a light emission device for emitting a light beam and a photoreception device for receiving the light beam, wherein the light emission device and the photoreception device are provided such that a light axis of the light beam intersects the predetermined arrayed direction of the plurality of nozzles of said printhead at a predetermined angle, for outputting an output signal in accordance with a status of blocking the light axis; test discharge means for controlling operation of said printhead to select at least a part of said plurality of nozzles and perform test ink discharge at a photo-sensor position while said scan means scans said printhead; and control means for controlling detection of an ink-discharge status of each nozzle which has discharged ink by said test discharge means, based on the output signal from said photo-sensor at each of plural positions of said printhead with respect to a scanning direction by said scan means when discharging ink from said printhead by said test discharge means, wherein said test discharge means uses different nozzles to be test-discharged between a scanning and a subsequent scanning at plural scannings of said printhead.