Patent ID: 7246870
Filing Date: 2007-07-24
Classification: B41J

Abstract:
1. A method of determining abnormality of a nozzle of an ejection head including an ejection unit to eject liquid droplets, the method comprising: imaging a peripheral portion of the nozzle; comparing a shape of the nozzle with a shape of a normal nozzle; determining the abnormality of the imaged nozzle; and determining the abnormality of the nozzle as a first abnormality in which the nozzle can be recovered by a recovery operation or a second abnormality in which the nozzle cannot be recovered by the recovery operation, wherein the second abnormality is based on whether or not a diameter of the nozzle is enlarged, whether or not an outline of the nozzle is defective, or whether or not a film used to coat a nozzle plate in which the nozzle is formed is present or removed in the vicinity of the nozzle.