| 摘要 |
PROBLEM TO BE SOLVED: To accurately achieve an ink residue graspably before an ink deficiency occurs and to perform such numeric measurement of the ink residue by a simple method. SOLUTION: An ink residue measuring unit 5 obtains the electrostatic capacity value Cv of an electric capacitor Cv based on the oscillation frequency of a voltage waveform detected by an electric capacity detector 4, and then obtain an ink residue value V corresponding to the value Cv. Regarding information indicating the corresponding relationship or functional relationship between the value Cv and the value V, various types of experiments or the like are previously conducted, and the corresponding relationship between the value Cv and the value V is grasped, and the value V is obtained at that time from the value Cv based on the information of the corresponding relationship. |
