| 摘要 |
PROBLEM TO BE SOLVED: To specify malfunctioning nozzles accurately by a simple constitution. SOLUTION: Odd number nozzles for a black ink are driven to record a check line 45a for the odd number nozzles. Then, after a recording paper 17 is sent, even number nozzles for the black ink are driven to record a check line 45b for even number nozzles. In the same manner, check lines 45c-45h for yellow, magenta and cyan colors are recorded. A line sensor 46 having light-receiving elements 46a arranged to positions corresponding to the lines 45a-45h is set. The line sensor 46 is moved parallel to a horizontal scanning direction M by a scanning mechanism 67. A density of recording pixels P of each of lines 45a-45h is read by each light-receiving element 46a synchronously with the parallel movement. The nozzle which records a pixel P2 having the density not reaching a predetermined value is specified as the malfunctioning nozzle. Since a gap is formed between the recording pixels P, the malfunctioning nozzle can be specified surely.
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