| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem of useless consumption of ink caused by frequently performing negative pressure recovery operation due to air being mixed into a sub-tank. SOLUTION: The frequency of air detection for detecting that the amount of air in the sub-tank 35 supplying ink to a recording head 34 is a predetermined amount or more, is stored, and an elapsed time from a predetermined starting time is computed. Whether the frequency of air detection exceeds the predetermined frequency when the elapsed time exceeds the predetermined time, is discriminated, and when the frequency of air detection exceeds the predetermined frequency, an error is diagnosed. COPYRIGHT: (C)2009,JPO&INPIT |
