Patent ID: 9511589
Filing Date: 2016-12-06
CPC Classification: B41J

Claim Text:
1. An ink jet printer comprising: an ink jet head in which a row of nozzles for discharging ink droplets toward a print medium is formed; a light emitting section that emits light at an angle greater than 0° and less than 90° with respect to the row of nozzles for detecting the ink droplets that are flying and were discharged from the nozzles; a light receiving section that receives the light emitted by the light emitting section; a print executor that executes printing by the ink jet head based on print data; an ink droplet detector that detects the ink droplets in a case where an amount of the light received by the light receiving section among the light emitted by the light emitting section is equal to or less than a predetermined amount; and a defective nozzle detector that detects a defective nozzle, wherein the defective nozzle detector determines a nozzle as being defective, in a case where an ink droplet discharged from the nozzle based on the print data in printing executed by the print executor is not detected by the ink droplet detector at a scheduled timing of passing through a detection region to be detected by the ink droplet detector, wherein determining the nozzle as being defective by the defective nozzle detector takes place during the ink jet head executing the printing based on the print data.