Patent ID: 6224183
Filing Date: 2001-05-01
Classification: B41J

Abstract:
An ink-jet printing apparatus employing an ink-jet head having a plurality of ejection openings to perform printing by ejecting ink toward a printing medium, comprising:a detecting unit having a light emitting element and a photosensing element, said photosensing element outputting a signal in accordance with an interrupted state of a light path formed between said light emitting element and said photosensing element caused by the ejected ink;moving means for causing relative movement between the ink-jet head and said detecting unit within a moving range;ejection control means for controlling the ink-jet head to eject the ink while controlling said moving means to cause the relative movement between said detecting unit and the ink-jet head;detecting range determining means for determining a detecting range in a predetermined range within the moving range, based on a variation of the output signal from said detecting unit upon ejection of the ink from the ink-jet head controlled by said ejection control means, the predetermined range being wider than the detecting range; andejection condition detecting means for detecting an ejection condition of the ink-jet head based on the output signal from said detecting unit upon ejection of the ink, in the detecting range determined by said detecting range determining means, from the ink-jet head controlled by said ejection control means.